NC0020559_Historical_2000

02/15/2002 16:39 2524923324
Al t
T5, CA�Cv
TO:
FROM:
HENDERSON WWTP
CITY OF IgENDE.ROON
NUTBUSH CREEK WWTP
NORTH CARO,LINA
FAX NO. 1-252-492-3324
DATE:
PAGE 01
NUMEBER OF SLEETS TRANSNHTTED _
(INCLUDING TRANSMITTAL SHEET)
If you do not receive the correct number of sheets tr Please call me aasmitfed or have any questions
WWTP FAX nuumbberer ow _ shown above, 6 _ ,
or use the City of Henderson Nutbush Creek
commxl .' / e l

02/15/2002 16:38 2524923324 HENDERSDN WWTP PAGE 02
CITY OF HENDERSON
Post Office Box 1434
180 Beckford Drive
Henderson, North Carolina 27536-1434
Phone! [phone] FAX! [phone]
February 15,2002
Mr. Ken Schuster,
Raleigh Regional Supervisor
NC DENR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
RE: City of Henderson Nutbush Creek WWTP
NPDES #NC0020559
SOC EMC WQ#96-05
Dear Mr. Schuster,
I am sending this letter as required by our SOC in reference to the Nutbush
Interceptor/Redbud Creek Upgrade Project.
NUTBUSH CREEL( WASTEWATER
TREATMENT PLANT
The City has not been able to meet the complete construction date of January 31, 2002
contained in the Order.
The City awarded contracts for the project in January, 2001 but has not been able to give
the contractors notice to proceed because additional Environmental Assessment work had
to be done and approval was delayed by the State because a previous Environmental
Assessment in the Ruin Creek Basin never went through the clearing house process.
I have just talked to Benny Goetz of the DWQ who is reviewing the plans and
specification for the project.
He said he had approved the project contingent upon several small items being addressed.
The City requests that a schedule for completion of the project be included in the new
Collection Permit soon to be issued and that no penalty be assessed for violation of the
Consent Order because of delay of State approval of the Environmental Assessment, the
elimination of all bypasses at Redbud Pump Station with a portable pump since February,
2000 and the installation of Activated Carbon at the WWTP in July, 2000 that brought
the effluent in compliance with chronic toxicity.

02:15 2002 15:3e 2524923324 HENDERSON WWTP PAGE 03
The City will discuss the project with our engineer, McKim and Creed, and submit a
schedule to you for your review in the near future.
1 want to thank you and your staff for your assistance with this project and the rapid State
review of the plans and specifications.
The City looks forward to bringing this project to completion.
If you need additional information, please contact me at 252-431-6081.
Sincerely,
Thomas M. Spain J
WWTP Director
C: Eric Williams, City Manager
Mark Warren, Assistant City Manager
Frank Frazier, Engineer
Bryce Mendenhall, Director Water & Sewer
Linda Leyen, Chief Operator
Tim Baldwin, McKim and Creed
Files

City of Henderson Office of
P. O. Box 1434 City Manager
180 Beckford Drive Eric M. Williams
Henderson, NC 27536
[e-mail] o
Phone:[phone] Fax:[phone]
December 8.1_000
Mr. Kirk Stafford
Raleigh Regional Office
DENR-DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: Revision Requested to Special Order by Consent
City of Henderson — Vance County
Nutbush Creek WWTP
NPDES # NCOO2O559
EMC SOC WQ 96-005
Dear Mr. Stafford:
In reference to our meeting on 11-17-00 with you, Mr. Ken Schuster and other members of the Division of Water Quality staff,
the City of Henderson is requesting the following revisions to Henderson's Special Order by Consent:
Section 2. (c) 10) of the SOC requires construction to start on the Phase II project by February
1, 2001
Revision proposed: The Phase II project contains inflow/infiltration repairs that can be accomplished with the City
staff. Presently, there is an I&I Division that is supervised by our Utility Operations Director, Bryce Mendenhall who is
the ORC for the Wastewater Collection System. The City requests that beginning these repairs by February 1, 2001 be
considered to satisfy the requirement to start construction of the Phase II project.
The City proposes to award contracts and Notice to Proceed to contractors on the Redbud Pump Station and line
upgrades by April 1, 2001 provided the financing which includes the issuance of revenue bonds remain on schedule and
provided approval is given by the Local Government Commission. The revised schedule will still meet the final dates to
complete construction and eliminate overflows contained in Section 2. (c) 11) and 12) of the SOC
The City did not receive notification in writing from the DWQ that the Redbud project would not be funded, but Mr. Bobby Blowe
informed us verbally during a meeting on May 16, 2000 with City representatives that all of the loan funds had been allocated to other
projects for the 2000 and 2001 budget year
The City was and is facing multiple funding issues in general services and utilities during the period that a funding source was
developed for the Redbud project. Listed below is a summary of events that the City has undertaken thus far to secure financing for this
project:
\\ADM]N\PGLOVERS\Leners\Kirk Stafford SOC Extension Ittr Revision Dec 12, OO.doc Page 1 of 2

• Dave Dresbach was hired as a Financial Advisor and completed a general fund debt study for Henderson in
March, 2000.
■ Requests for Proposals were prepared in June and July, 2000 to complete a Feasibility and Water and Sewer
Rate Study.
• The firm of SVBK Consulting Group was hired on August 16, 2000 to begin this work.
■ The City then hired Gundars Aperans with Robinson, Bradshaw and Hinson, PA to begin the process of
assisting the City to issue revenue bonds.
■ The City then sent our Requests for Proposals and selected Robinson -Humphrey as the City's bond
underwriter.
The time frame from May 16, 2000 when the City realized that no state funding was available for the Redbud project to March 2,
2001 when the Local Government Commission should approve issuing the bonds is considered reasonable by the City because of the
complexity involved in this process.
If you have any questions, please contact Thomas M. Spain at [phone] or Mark R. Warren, Assistant
City Manager, at [phone].
Sincerely,
CITY OF HENDERSON
City Manager
C: Thomas M. Spain, WWTP Manager
Bryce Mendenhall, W&S Director
Frank Frazier, Engineering Director
Tim Baldwin, McKim & Creed
Mark Warren, Asst. City Manager
Linda Leyen, Chief Operator
Jennifer Anderson, Pretreatment Coordinator
Ken Schuster, DWQ, Raleigh Regional Supervisor
\WDMIN\PCLOVERS\Leuers\Kakk Stafford SOC Extension Ittr Revision Dec 12, 00.doc Page 2 of 2

L 1 rY OF HENDERSG,
Post Office Box 1434
180 Beckford Drive
Henderson, North Carolina 27536-1434
Phone: [phone] FAX: [phone]
II AW 11 aeon
DEHNR RNLEIGH REGIONAL OFFICE
Mr. Ken Schuster
Raleigh Regional Supervisor
NC DENR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: City of Henderson Nutbush Creek W WTP
NPDES #NC0020559
SOC-EMC WQ No. 96-05
August Quarterly THE Report
Dear Mr. Schuster,
NUTBUSH CREEK WASTEWATER
TREATMENT PLANT
August 11, 2000
I am forwarding our August Quarterly Toxicity Reduction Evaluation (TRE) report as
required by our SOC.
If you have any questions, please contract me at [phone].
Sincerely,
7(7k-✓rVj//tr M W�
VS_
Thomas M. Spam
WWTP Director
C: Eric Williams, City Manager
Mark Warren, ACM
Reggie Hicks, Lab Supervisor
Judy Garrett, DWQ-RRO
Kirk Stafford, DWQ-RRO
Matt Matthews, DWQ-ATU
Kevin Bowden, DWQ-ATU
Tom Poe, DWQ Pretreatment
Dana Folley, DWQ Pretreatment
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin, McKim and Creed
Files

Progress Report
for the Toxicity Reduction Evaluation
at the City of Henderson's Nutbush Creek Wastewater Treatment Plant
NPDES No. NCO020559
May 16 through August 15, 2000
Submitted In Consideration of the Reporting Requirement
Given in the Special Order by Consent
EMC WQ No. 96-05
Prepared for
Department of Environment and Natural Resources
3800 Barrett Drive, Suite 100
Raleigh, North Carolina 27609
Prepared by:
City of Henderson
P.O. Box 1434
Henderson, NC
With Assistance by:
Aquatic Sciences Consulting
15751 Bushy Park Rd
Woodbine, Maryland 21797

City of Henderson THE Progress Report Page 2
NPDES No. 0020559 August 10, 2000
Introduction
This quarterly progress report is prepared and submitted to meet the August 151h date specified
by Section 2(b)2 of the City of Henderson's draft Special Order by Consent (SOC EMC WQ No.
96-05). It should be noted that the SOC condition regarding toxicity compliance expired
September 30, 1999; however, the city continues to inform the Department of Environment and
Natural Resources (DENR) of progress achieved in the Toxicity Reduction Evaluation (TRE).
This report describes the progress made in the last quarter (May 16 through August 15, 2000),
the plans for the next quarter, and any significant issues that may delay progress in completing
the TRE.
Progress in the Preceding Quarter
1. Results of WWTP Effluent Toxicity Monitoring
A total of three toxicity compliance tests were successfully completed in the preceding quarter.
Monthly effluent monitoring was performed, as required by the SOC. Results are summarized
in Table 1 and Appendix A.
Table 1. Summary of Monthly Compliance Test Results
Sample Collection Dates Test Initiation Date Chronic Value (ChV, %)
Jun 11-12 and Jun 14-15*
Jun 13
55.1
Jun 11-12 and Jun 14-15*
Jun 14
77.9
Jul 25-26 and Jul 27-28
Jul 26
>100
* Split sample analysis performed by TriTest (Raleigh) and Research & Analytical (Kernersville).
A split sample analysis was performed in June. Both tests indicated noncompliance with the
toxicity limit (i.e., ChVs of 55.1 and 77.9%). Each test met the criteria specified in DENR's
Phase II procedures, including startup within 72 hours of sample collection; therefore, the city
believes that, together, the tests constitute a single failure.
When effluent toxicity was observed in June, the city quickly installed activated carbon
treatment (see Item 5 below) and a follow-up test in July was a "pass" at >100% effluent. As
stated in DENR's new permit condition language, compliance will be determined by
arithmetically averaging the ChV results for the second and third months (i.e., July and August)
of the quarter. The city is in the process of conducting a test in August and, if the test passes at
>80%, the city will be in compliance for the quarter.

City of Henderson THE 1-rugress Report Page 3
NPDES No. 0020559 August 10, 2000
2. Pretreatment Program
Progress achieved in the preceding quarter includes:
• Monitoring the progress of the THE recently completed by Harriet & Henderson at its south
cotton mill (see Sections 3)
• Confirming toxicity reduction at Americal Corporation's textile processing facility (see
Section 3).
• Continuing to monitor the toxicity of other industrial user discharges (see Section 3).
Receiving weekly chemical usage reports that list quantities of chemicals used.
• Continuing inspections of major industrial users.
• Continuing frequent communication with the industries regarding pretreatment activities and
their relationship to toxicity.
The city reviewed data provided by car wash operators to identify potential chemicals of
concern. The city considers cleaners to be problematic, if known toxic compounds, including
nonyl phenols, quaternary amines or sulfonated compounds, are present. In one case, a car wash
operator volunteered to substitute a cleaner containing nonyl phenols with one that does not
contain nonyl phenols. However, most of the MSDS on cleaners did not provide sufficient
information (constituents listed as proprietary and no toxicity data provided). Therefore, the city
recently sent another letter to car wash operators requesting additional data within thirty days.
3. Sewer and Industrial User Monitoring
The City continues to conduct intensive sewer and industry monitoring. Weekly samples
collected from several locations in the sewer system were tested using Microtox. RTA tests were
also performed to monitor previously identified sources of toxicity. In addition, quarterly
monitoring of significant industrial users was performed.
3.1 Microtox Monitoring
Although Microtox is not a direct surrogate for Ceriodaphnia dubia, the city has observed a good
correlation in Microtox and chronic C. dubia test results. The city continued the intensive sewer
monitoring initiated the beginning of this year.
In general, the Microtox results show a decrease in toxicity in the Sandy Creek sewershed that
coincides with the abatement of effluent toxicity at the city's W WTP. Coincidentally, toxicity
has also decreased at the previous sources of toxicity in the sewershed (i.e., Americal and Harriet
& Henderson's south mill).

City of Henderson THE 1.,,bress Report Page 4
NPDES No. 0020559 August 10, 2000
In contrast, relatively high toxicity has been consistently observed in the North Nutbush
sewershed. Refractory toxicity in the North Nutbush sewershed was confirmed by RTA testing
as described below in Item 3.3. This sewershed is also the largest contributor of surfactant
(MBAS) loadings to the Nutbush Creek WWTP. The city is in the process of evaluating
potential sources of toxicity and MBAS in the sewershed by testing the main tributary sewers.
3.2_ Quarterly Industry Monitoring
Quarterly toxicity tests were performed on the discharges of each permitted industrial user in
May, June and July. The May, June and July tests were performed for the first, second and third
quarters of 2000, respectively. Please note that the February tests reported in the last quarterly
report are repeat tests for invalid tests conducted in the fourth quarter of 1999 (December). Also,
note that the J.P. Taylor was not tested in May because an earlier test was completed in April
(result provided in the last quarterly report).
The results, summarized in Table 2, show that Americal had unacceptable toxicity in May. The
failure was caused in part by low reproduction in one replicate in the 6.4% test concentration
(see AT-1 form in Appendix B). Nonetheless, a follow-up RTA test and chronic toxicity test
were performed later in the month and in June, respectively. The results showed no evidence of
toxicity (see also Section 3.3). Another chronic toxicity test was scheduled for July 24a';
however, Americal was temporarily shutdown; therefore, the test was rescheduled for August.
LAMS' test was invalid because of no reproduction in the control. A copy of test report is
provided in Appendix B. Ball Foster, IAMB, J.P. Taylor and Kennametal complied with the
industrial user permit (IUP) toxicity requirement for the first through third quarters of 2000.
Harriet & Henderson's south mill also passed the test performed in July.
Results of RTA tests performed on discharges from Harriet & Henderson's south mill and
Americal and the proposed groundwater discharge from the old Burkart Carolina site (owned by
Larsdale, Inc) are described in Item 3.3.
3.3 Refractory Toxicity Assessment
Only preliminary results for April's RTA were available for the previous quarterly report. Upon
further review, the final results indicated no contribution of toxicity from the Sandy Creek or
Redbud sewersheds. Tests of Americal, Harriet & Henderson's south mill and J.P. Taylor also
showed no contribution of refractory toxicity from point discharges in the Sandy Creek
sewershed. These results are consistent with the abatement of effluent toxicity at the city's
W WTP.

City of Henderson THE F,vtress Report Page 5
NPDES No. 0020559 August 10, 2000
Table 2. Quarterly Monitoring Results for Major Permitted Industries
Industry Test Pass/Fail
Concentration' Result
Samples Collected May 8 —9
Americal
6.4%
Fail
Ball Foster
1.0%
Pass
IAMB
5.6%
Invalid"
Kennametal
0.8%
Pass
Sample Collected June 11-12
Americal
6.4%
Pass
IAMs
5.6%
Pass
Samples Collected June 18-19
Ball Foster
1.0%
Pass
IAMs
5.6%
Pass
J.P. Taylor
1.6%
Pass
Kennametal
0.8%
Pass
Samples Collected July 24-25
Ball Foster
1.0%
Pass
IAMs
5.6%
Pass
J.P. Taylor
1.6%
Pass
Kennametal
0.8%
Pass
Harriet & Henderson's South Mill
3.0%
Pass
Equivalent to flow contribution to the City's treatment plant.
" Quality Control Requirements not Met. See Appendix B for results
In May, the city performed RTA tests to evaluate the toxicity contribution from the Sandy Creek
sewershed, including discharges from Harriet & Henderson's south cotton mill and Americal. In
addition, the RTA incorporated tests of the North Nutbush sewer line and the Redbud sewershed,
including a requested groundwater discharge from the old Burkart Carolina property. Refractory
toxicity in the sewer/industry/groundwater samples was assessed by spiking the samples into
surrogate wastewater treatment plant (W WTP) influent, treating the samples in a bench -scale
simulation of the W WTP, and comparing the resulting toxicity to a control (consisting of treated
surrogate influent alone).
As shown by inhibition concentration (IC25) values (Table 3), the North Nutbush line sample
was significantly more toxic than the control. No other sources of toxicity were indicated. The
lack of toxicity in the W WTP filtered effluent and final effluent [i.e., chronic value (ChV) >90%]
suggests that the toxicity contribution from the North Nutbush line is not significant. However,
data show that relatively high concentrations of surfactants are discharged from the North
Nutbush line and surfactants may accumulate in the W WTP activated sludge over time and could

CITY OF HENDERSON
Post Office Box 1434
180 Beckford Drive
Henderson, North Carolina 27536-1434
Phone: [phone] FAX: [phone]
lS � iS_ II ±J l5 Z
AIG 1 52O 1 �I
1 DEHNR RALEIGH REGIONAL UFFICEi
Mr. Ken Schuster
Raleigh Regional Supervisor
NC DENR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: City of Henderson Nutbush Creek WWTP
NPDES #NC0020559
SOC-EMC WQ No. 96-05
August Quarterly THE Report
Dear Mr. Schuster,
NUTBUSH CREEK WASTEWATER
TREATMENT PLANT
August 11, 2000
I am forwarding our August Quarterly Toxicity Reduction Evaluation (TRE) report as
required by our SOC.
If you have any questions, please contract me at [phone].
Sincerely,
r
Thomas M. Spain
WWTP Director
C: Eric Williams, City Manager
Mark Warren, ACM
Reggie Hicks, Lab Supervisor
Judy Garrett, DWQ-RRO
Kirk Stafford, DWQ-RRO
Matt Matthews, DWQ-ATU
Kevin Bowden, DWQ-ATU
Tom Poe, DWQ Pretreatment
Dana Folley, DWQ Pretreatment
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin, McKim and Creed
Files

Progress Report
for the Toxicity Reduction Evaluation
at the City of Henderson's Nutbush Creek Wastewater Treatment Plant
NPDES No. NC0020559
May 16 through August 15, 2000
Submitted In Consideration of the Reporting Requirement
Given in the Special Order by Consent
EMC WQ No. 96-05
Prepared for �HNR Rq�f� I
Department of Environment and Natural Resourcesk RFC�OIyq( OffIO f
3800 Barrett Drive, Suite 100
Raleigh, North Carolina 27609
Prepared by:
City of Henderson
P.O. Box 1434
Henderson, NC
With Assistance by:
Aquatic Sciences Consulting
15751 Bushy Park Rd
Woodbine, Maryland 21797

City of Henderson THE Progress Report Page 2
NPDES No. 0020559 August 10, 2000
Introduction
This quarterly progress report is prepared and submitted to meet the August 15`h date specified
by Section 2(b)2 of the City of Henderson's draft Special Order by Consent (SOC EMC WQ No.
96-05). It should be noted that the SOC condition regarding toxicity compliance expired
September 30, 1999; however, the city continues to inform the Department of Environment and
Natural Resources (DENR) of progress achieved in the Toxicity Reduction Evaluation (TRE).
This report describes the progress made in the last quarter (May 16 through August 15, 2000),
the plans for the next quarter, and any significant issues that may delay progress in completing
the TRE.
Progress in the Preceding Quarter
1. Results of WWTP Effluent Toxicity Monitoring
A total of three toxicity compliance tests were successfully completed in the preceding quarter.
Monthly effluent monitoring was performed, as required by the SOC. Results are summarized
in Table 1 and Appendix A.
Table 1. Summary of Monthly Compliance Test Results
Sample Collection Dates Test Initiation Date
Chronic Value (ChV, %)
Jun 11-12 and Jun 14-15*
Jun 13
55.1
Jun 11-12 and Jun 14-15*
Jun 14
77.9
Jul 25-26 and Jul 27-28
Jul 26
>100
* Split sample analysis performed by TriTest (Raleigh) and Research & Analytical (Kernersville).
A split sample analysis was performed in June. Both tests indicated noncompliance with the
toxicity limit (i.e., ChVs of 55.1 and 77.9%). Each test met the criteria specified in DENR's
Phase 11 procedures, including startup within 72 hours of sample collection; therefore, the city
believes that, together, the tests constitute a single failure.
When effluent toxicity was observed in June, the city quickly installed activated carbon
treatment (see Item 5 below) and a follow-up test in July was a "pass" at >100% effluent. As
stated in DENR's new permit condition language, compliance will be determined by
arithmetically averaging the ChV results for the second and third months (i.e., July and August)
of the quarter. The city is in the process of conducting a test in August and, if the test passes at
>80%, the city will be in compliance for the quarter.

City of Henderson THE Progress Report Page 3
NPDES No. 0020559 August 10, 2000
2. Pretreatment Program
Progress achieved in the preceding quarter includes:
• Monitoring the progress of the THE recently completed by Harriet & Henderson at its south
cotton mill (see Sections 3)
• Confirming toxicity reduction at Americal Corporation's textile processing facility (see
Section 3).
• Continuing to monitor the toxicity of other industrial user discharges (see Section 3).
• Receiving weekly chemical usage reports that list quantities of chemicals used.
• Continuing inspections of major industrial users.
• Continuing frequent communication with the industries regarding pretreatment activities and
their relationship to toxicity.
The city reviewed data provided by car wash operators to identify potential chemicals of
concern. The city considers cleaners to be problematic, if known toxic compounds, including
nonyl phenols, quaternary amines or sulfonated compounds, are present. In one case, a car wash
operator volunteered to substitute a cleaner containing nonyl phenols with one that does not
contain nonyl phenols. However, most of the MSDS on cleaners did not provide sufficient
information (constituents listed as proprietary and no toxicity data provided). Therefore, the city
recently sent another letter to car wash operators requesting additional data within thirty days.
3. Sewer and Industrial User Monitoring
The City continues to conduct intensive sewer and industry monitoring. Weekly samples
collected from several locations in the sewer system were tested using Microtox. RTA tests were
also performed to monitor previously identified sources of toxicity. In addition, quarterly
monitoring of significant industrial users was performed.
3.1 Microtox Monitorine
Although Microtox is not a direct surrogate for Ceriodaphnia dubia, the city has observed a good
correlation in Microtox and chronic C. dubia test results. The city continued the intensive sewer
monitoring initiated the beginning of this year.
In general, the Microtox results show a decrease in toxicity in the Sandy Creek sewershed that
coincides with the abatement of effluent toxicity at the city's W WTP. Coincidentally, toxicity
has also decreased at the previous sources of toxicity in the sewershed (i.e., Americal and Harriet
& Henderson's south mill).

City of Henderson THE Progress Report Page 4
NPDES No. 0020559 August 10, 2000
In contrast, relatively high toxicity has been consistently observed in the North Nutbush
sewershed. Refractory toxicity in the North Nutbush sewershed was confirmed by RTA testing
as described below in Item 3.3. This sewershed is also the largest contributor of surfactant
(MBAS) loadings to the Nutbush Creek W WTP. The city is in the process of evaluating
potential sources of toxicity and MBAS in the sewershed by testing the main tributary sewers.
3.2 Quarterly Industry Monitoring
Quarterly toxicity tests were performed on the discharges of each permitted industrial user in
May, June and July. The May, June and July tests were performed for the first, second and third
quarters of 2000, respectively. Please note that the February tests reported in the last quarterly
report are repeat tests for invalid tests conducted in the fourth quarter of 1999 (December). Also,
note that the J.P. Taylor was not tested in May because an earlier test was completed in April
(result provided in the last quarterly report).
The results, summarized in Table 2, show that Americal had unacceptable toxicity in May. The
failure was caused in part by low reproduction in one replicate in the 6.4% test concentration
(see AT -I form in Appendix B). Nonetheless, a follow-up RTA test and chronic toxicity test
were performed later in the month and in June, respectively. The results showed no evidence of
toxicity (see also Section 3.3). Another chronic toxicity test was scheduled for July 24`s;
however, Americal was temporarily shutdown; therefore, the test was rescheduled for August.
IAMB' test was invalid because of no reproduction in the control. A copy of test report is
provided in Appendix B. Ball Foster, IAMs, J.P. Taylor and Kennametal complied with the
industrial user permit (IUP) toxicity requirement for the first through third quarters of 2000.
Harriet & Henderson's south mill also passed the test performed in July.
Results of RTA tests performed on discharges from Harriet & Henderson's south mill and
Americal and the proposed groundwater discharge from the old Burkart Carolina site (owned by
Larsdale, Inc) are described in Item 3.3.
3.3 Refractory Toxicity Assessment
Only preliminary results for April's RTA were available for the previous quarterly report. Upon
further review, the final results indicated no contribution of toxicity from the Sandy Creek or
Redbud sewersheds. Tests of Americal, Harriet & Henderson's south mill and J.P. Taylor also
showed no contribution of refractory toxicity from point discharges in the Sandy Creek
sewershed. These results are consistent with the abatement of effluent toxicity at the city's
W WTP.

City of Henderson THE Progress Report
NPDES No. 0020559
Page 5
August 10, 2000
Table 2. Quarterly Monitoring Results for Major Permitted Industries
Industry Test Pass/Fail
Concentration* Result
Samples Collected May 8 —9
Americal
6.4%
Fail
Ball Foster
1.0%
Pass
IAMB
5.6%
Invalid**
Kennametal
0.8%
Pass
Sample Collected June 11-12
Americal
6.4%
Pass
IAMs
5.6%
Pass
Samples Collected June 18-19
Ball Foster
1.0%
Pass
IAMs
5.6%
Pass
J.P. Taylor
1.6%
Pass
Kennametal
0.8%
Pass
Samples Collected July 24-25
Ball Foster
1.0%
Pass
IAMs
5.6%
Pass
J.P. Taylor
1.6%
Pass
Kennametal
0.8%
Pass
Harriet & Henderson's South Mill
3.0%
Pass
Equivalent to flow contribution to the City's treatment plant.
*` Quality Control Requirements not Met. See Appendix B for results
In May, the city performed RTA tests to evaluate the toxicity contribution from the Sandy Creek
sewershed, including discharges from Harriet & Henderson's south cotton mill and Americal. hi
addition, the RTA incorporated tests of the North Nutbush sewer line and the Redbud sewershed,
including a requested groundwater discharge from the old Burkart Carolina property. Refractory
toxicity in the sewer/industry/groundwater samples was assessed by spiking the samples into
surrogate wastewater treatment plant (W WTP) influent, treating the samples in a bench -scale
simulation of the W WTP, and comparing the resulting toxicity to a control (consisting of treated
surrogate influent alone).
As shown by inhibition concentration (IC25) values (Table 3), the North Nutbush line sample
was significantly more toxic than the control. No other sources of toxicity were indicated. The
lack of toxicity in the W WTP filtered effluent and final effluent [i.e., chronic value (ChV) >90%]
suggests that the toxicity contribution from the North Nutbush line is not significant. However,
data show that relatively high concentrations of surfactants are discharged from the North
Nutbush line and surfactants may accumulate in the WWTP activated sludge over time and could

City of Henderson THE Progress Report Page 6
NPDES No. 0020559 August 10, 2000
Table 3. Summary of Refractory Toxicity Assessment Results
Sample Location Limited-scaleC. dubia Chronic Endpoints
NOEC LOEC ChV IC25
(IC25 C.Q'
Sandy Creek Main Line
90.0
> 90.0
> 90.0
> 90.0
NC+
Sandy Creek Pump Station
45.0
67.5
55.1
55.6
52.3 - 60.5
South Henderson Cotton Mill
45.0
67.5
55.1
62.2
46.6 - 73.1
Americal (6.4%)
67.5
90.0
77.9
77.3
73.6 - 80.6
Redbud Main Line
67.5
90.0
77.9
77.4
NC
Old Burkart Site Groundwater
67.5
90.0
77.9
80.4
74.6 - 84.3
North Nutbush Line
30.0
45.0
36.7
35.5
32.3 - 37.3
AT[
90.0
> 90.0
> 90.0
> 90.0
NC
Control (Sagefield Pump station)
45.0
67.5
55.1
64.3
51.8 - 72.6
WWTP Filtered Effluent (before W2)
90.0
> 90.0
> 90.0
44.4
NC
WWTP Final Effluent
90.0
> 90.0
> 90.0
> 90.0
NC
" 95% confidence intervals
+ not calculable
eventually cause toxicity. Therefore, the North Nutbush line should be considered a potential
source of long-term toxicity.
The results also show that Harriet & Henderson's south mill did not contribute refractory
toxicity. This result represents the second consecutive month of compliance. According to the
industrial user permit (IUP), Harriet & Henderson must pass two consecutive monthly RTA tests
to confirm that their THE has been completed. The city submitted a draft lUP for Harriet &
Henderson to DENR on April 24, 2000. The city subsequently received a completed permit
application from Harriet & Henderson on August 3, 2000. This application will be forwarded to
DENR.
Attorneys for Larsdale, Inc, owners of the former Burkart Carolina property, have requested to
discharge groundwater to the city's WWTP. The city required Larsdale's representatives to
perform a study on the groundwater to determine its potential effect on the WWTP. A test was
performed on a groundwater sample as part of the above RTA testing. The RTA results showed
no refractory toxicity in the groundwater sample and no potential to inhibit the activated sludge
treatment process. The city also reviewed information on the groundwater constituents and
performed a headworks analysis to determine how the constituent loadings would impact the
WWTP. The results of the city's review are documented in a letter submitted by the city to
DENR on July 31't.
3.4 Summary
The City's sewer/industry monitoring effort has yielded the following conclusions:
• The decrease in refractory toxicity in the Sandy Creek sewershed, including the reduction
of toxicity at Harriet & Henderson's south mill and Americal, is consistent with the
abatement of effluent toxicity at the city's WWTP.

City of Henderson THE Progress Report Page 7
NPDES No. 0020559 August 10, 2000
• The reoccurrence of effluent toxicity in June may be related to toxicity observed in the
North Nutbush sewershed.
4. Activated Carbon Treatment
Studies show that effluent toxicity at the City's W WTP can be removed by activated carbon. The
city and its consultants have identified several options for carbon treatment, including (1) adding
PAC to the activated sludge aeration basin and (2) replacing some or all of the tertiary filter
media with granular activated carbon (GAC), and (3) adding a dedicated GAC contactor after the
multi -media filters. GAC treatment is preferred because it is generally more cost-effective and
requires less operating effort than PAC treatment. For these reasons, the city set up and operated
a pilot -scale GAC unit to evaluate the feasibility of GAC treatment of toxicity.
Biweekly toxicity tests (limited -scale C. dubia and Microtox) were performed on the GAC unit
influent and column effluents. The results showed that toxicity was effectively eliminated by 12
inches of GAC (first column depth) for a period of three months (March 24`s - June 28`s).
When effluent toxicity reoccurred in June, the city quickly decided to proceed with installing
GAC on the existing filters based on the success of the pilot unit. The city's consultants provided
specifications for the type and amount of GAC to add to the filters and provided technical
assistance during the installation. The installation required removal of the existing anthracite and
replacement with a GAC that has the same operating characteristics, including solids removal
efficiency and backwash properties. A follow-up compliance test in July demonstrated that the
GAC was eliminating toxicity (i.e., ChV >100%). Another compliance test will be performed in
August to confirm compliance in the quarter.
Although GAC was recently installed on the WWTP filters, the pilot unit continues to be
operated to provide information on the operating life of the GAC. The pilot results will be used
to estimate the date when the GAC on the filters should be replaced (i.e., before toxicity
breakthrough occurs).

Appendix A
Historical Ceriodaphnia dubia Chronic Toxicity Data
for the Nutbush Creek WWTP Effluent

V1
N
W p m O NOi �WV�JO N A t0 N
O
p
Q(�T
�O� C�p jDOOQO
O�O�
JQJJ
Q
N
V V V V A V A V V V V V V
a
ffpp ((�� ttpp ffpp ((JJ�� fp �p tp �p
r 0 m OVo
OVo 0
V V V V V V V V V V V V V
de
f00 tW0000 � � NO(�li N fW00 (�T N J tWO �tVl�O W �f�0 V <0�� A N tN.� O N000) 0000 �O
�
A p �p Z Z c Z Z Z m Z Z W—WN m (oT Z W V t W N O m O N Z O Z Z A Z Z Z Z w Z
Ci
�tJv 00 n�Ci0000n W m W V C7 O)CT V ONIV fo Oo?O)0 00 nC)C)Oi O
3
m
s
pp ppN
C
a
Z Z Z Z'RZ
OZZVZ W ZZ� W Z Z Wg>9Zs OVoO WV rn'V0OV ZEZ Z
N V O
CiV 006)0
ni 7nnn7{VW��
mWG00O WNf7
3
s
f/I
C
O
O
D
n
m
OO UtO OmA00)W W mm OJNN W fTN
<
m
0
03

Table A-1. Results of Cedodaphnia dubia Chronic Toxicity Tests Performed on the City of Henderson's
Nutbush Creek W WTP Effluent (Continued).
ChV IC25 90%Test Conc. (IWC)
Year Sample Date (%Effluent) %Effluent 1-mer Limit Upper Limit Surv. Adults Young/Female
1998 28-Jan
78
25
10.9
66.9
2
7
11-Feb
>
90
>
90
4-Mar
>
90
>
90
23-Jun
77.9
>
90
NC
NC
2
20
17-Jul
55.1
52
49.5
52.8
0
1
21-Aug
>
90
>
90
5
21
25 Sep - invalid 27-Oct
77.9
78
NC
NC
8
20
16-Nov
>
90
>
90
e-Dec - invalid 28-Dec
>
90
>
90
1999 11-Jan
>
90
>
90
15-Feb
55.1
22-Mar
>
90
14-Apr
36.6
10-May
36.7
7-Jun
<
15
5-Jul
>
90
16-Aug
21.2
&-Sep
77.9
25-Oct
21.2
1-Nov
77.9
6-Dec
77.9
2000 31-Jan
77.9
28-Feb
>
90
13-Mar
>
90
3-Apr
>
90
2-May
>
90
12-Jun
55.1
12-Jun
77.9
25-Jul
>
100

120
100
yr
r
U e0
m w
m s0
'e W
o
U 40
L
01
U
za
Ceriodaphnia dubia Chronic Values (ChVs) for City of Henderson
Nutbush Creek W WTP Effluent
in n
m m
N
7 S
n
m
S
m
m
7
in
m
d
N
�n
m
-
m
�l
m
m
A
S
�
'd
S
m
m
m
m
d
(If
m
m
-
r
m
N
7
n
m
'T
S
r
m
A
S
r
m
-
r
m
b
111
r
m
'
m
m
N
m
m
T
S
m
m
`4
S
m
m
7
m
m
4
N
m
m
?
m
m
N
7
m
m
'5
S
m
m
'a
S
m
m
j
m
m
b
N
m
m
?
o0
N
0
o
0
0
T
0
0
Date

Appendix B
First Quarter Test Results for IAMB

Fee
Report norm - Chronic Pau/Fail and Aerate LCSC Date: 05/17/00
HENDERSON--IAMB NPD880: NC Pipes: County:
Porforming Test: WATER TECH AND CONTROLS INC
'omments: All test animals dead 9
68 hre. No C.O.C. at WTAC, Inc.
� ��w.o�vc iav�awry supervisor
Work order. $nvironmental Sciences Branch
MAIL ORIGINAL TO: Div, of Hater Quality
N.C. DEAR
1621 Mail Sorvlca Center
Raleigh„ North Carolina 27599-1621
Chronic Peaa/Fail Reproduction Toxicity Teat
'ONTROL ORGANISMS 1 2 3 4 5 6 7 8 9 10 11 12
s Young Produced 10 0 10 10 0 10 10 0 10 In 0 0
Adult (L) ive Mead L L L L L L L L L L L L
affluent 4: 5.6%
fREATABNT 2 OROANISNB 1 2 3 4 5 6 1 8 9 10 11 12
8 Young Produced 10 IO IO 10 ID IO IO IO IO 10 IO
Adult (Wive (D)ead OD ID 1D ID ID ID ID ID ID ID ID
let sample
lot sample
end sample
Cc
pR
Control
7,95
8.06
Test 8ta=
Colloctic
Treatment 2
7.e1
7.83
Sample 1:
sample T1
e
t e
•
t e
a
t e
In
d
a n
e n
ample 1
I
t
let ample
r d
t
let sample
r d
t
2nd sample
ample 2
D.C.
Control
9,19
8.03
Treatment 2
17.7517.721
Chronic Toot Reeults
Calculated t a
Tabular t =
e Reduction = n/a
a Mortality Avg.Reprod.
0,00
0.DO
Coacrol
Control
100.00
0.00
Treatment 2
Treatment 2
Control CV
0.0004
PASS FAIL
4 control Producing or
rd
brood
Check One
N/M
mpleto This For Eicher Test
t Data; 05/10/00
n (Start) Date
/ / Sample 2: /
pe/Duration
i
Drab comp. Duration D
lot
I
S
hre L
U
hre T
A
M
P
Hardness(mg/l)
46
1,14 j(e
Spec. Cond,(pmhoo)
181
1060
Chlorina(mg/1)
<0.1
LC50/Acute Toxicity Test Sample tamp, at receipt(°C) 0(;gj„,� 3.2
(Mortality expressed as 4, combining replicates)
4 e h a 4 a 4 4 4 Note: Please
4 ConCantrmtion Complete This
4 a 4 e 4 4 4 a 4 4 Mortality Section Also
start/end etdrt/and
LU50 s 4 Method of Determination Control
95a Co nos imits loving Average Prebit
4 - 4 Bpearman Karbor — Other — High
Co—,
PH D.O.
Organism Teetedt Ceriodsphnia dubia Duration(hro):
CopcQd from DWO form AT-1 (3/57) rev. 11/96 (DUSIA vor. 4.41)
2nd
P/F
5
A
M
P

Appendix A
Historical Ceriodaphnia dubia Chronic Toxicity Data
for the Nutbush Creek WWTP Effluent

CA
m�� W O�O�Y'��P' WcmgDoo mg
000, aM =c vo v j m j o O _j v a3i Q
v v v v n v n v v v v v v
V W Ncp �O V V N<Omm W cpNmmW W 01 {{pp EC M E mW mm W m W mm W m
m V �00mmm0�m V O� NNmm�Omm--+6 -+ -m"UtN--�OOOmN
v v v v v
v v v v v v v v
tmp tWDOOO SUN O Umi W tWpOOmi N �1 tWp tApNOOmo� tND JtAO W � W NtN.� O N OOO� OOOOOO
j W m A m W W W m m m W m m N A A m m
A 0 2 Z m Z 0 2 2 m m Z Z m N.IO) V t Z W m V t W O O W[ O O N Z O Z Z a Z Z Z Z W Z
W y n n jp n jp n n 6 m W m W V o m fT V m CU IV (J OJ 1 o N o o N o o o o� o
V A N V W V Am nm V mm NOmW V
NVOfWnWO mWmm
4gzz V ZZTZ
Wp7nOn nnmOWZVm'tJw O.076
m N 0 0 ONE A N O v tD � O ��� m O m m N O m m O m O W O W N W W ONo ON1 O V N N W N N
N
m
13
54
m
(i
O

Table A-1. Results of Ceriodaphnia dubia Chronic Toxicity Tests Performed on the City of Henderson's
Nutbush Creek WWTP Effluent (Continued).
ChV
IC25
90% Test Conic. (IWC)
Year Sample Date (%ERluent)
%EHluent
Lower Limit
Upper Limit
Surv. Adults
Young/Female
1998 28-Jan 78
25
10.9
66.9
2
7
11-Feb > 90 >
90
4-Mar > 90 >
90
23-Jun 77.9 >
90
NC
NC
2
20
17-Jul 55.1
52
49.5
52.8
0
1
21-Aug > 90 >
90
5
21
25 Sep - invalid 27-Oct 77.9
78
NC
NC
8
20
16-Nov > 90 >
90
9-1)ec - invalid 28-Dec > 90 >
90
1999 11-Jan > 90 >
90
15-Feb 55.1
22-Mar > 90
14-Apr 36.6
10-May 36.7
7-Jun < 15
5-Jul > 90
16-Aug 21.2
6-Sep 77.9
25-Oct 21.2
1-Nov 77.9
6-Dec 77.9
2000 31-Jan 77.9
28-Feb > 90
13-Mar > 90
3-Apr > 90
2-May > 90
12-Jun 55.1
12-Jun 77.9
25-Jul > ion
t

I
I
p
IA
p
n
Ceriodaphnia dubia ChVs
(% Effluent)
Jan-95
Aar-95
Aay-95
Jul-95
6ep-95
JoV-95
I
Jan-96
�
Aar-96
gay-96
Jul-96
iep-96
IOV-96
Jan-97
I
JIar-97
I
Aay-97
Jul-97
1
iep-97
IoV-97
Jan-98
I
Aar-98
lay 98
I
I
I
Jul-98
I
Sep-98
I
IoV-98
411
Ian-99
Aar•99
gay-99
1
Jul•99
lep-99
j
oV•99
I
lan•00
I
Tar-00
lay-00
Jul-00
W,
(D
Q
N
a
N'
Q
C
z°
C E3
93.

Appendix B
First Quarter Test Results for IAMB

i NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
NCDENRDIVISION OF WATER QUALITY
MAR - c 400
JAMES B. HUNT JR.
CERTIFIED MAIL
GOVERNOR
RETURN RECEIPT REQUESTED
Mr. Eric Williams, City Manager
BILL MOLMAN
City of Henderson
SECRETARY
P.O. Box 1434
Henderson, NC 27536
i
KERR T STEVENS
Subject: Special Order by Consent
�
DIRECTOR
EMC WQ 96-005
City of Henderson
NPDES Permit NCO020559
Vance County
Dear Mr. Williams:
The subject Special Order by Consent (SOC) was issued by the Director on March 11, 1999 and
is in full effect. The City of Henderson has requested an extension of the subject order to extend
the modified toxicity limit for one year. The present SOC promulgated a deadline of September
30, 1999 to achieve compliance with final permitted effluent limitation and conditions. The
order also required the City to reduce inflow and infiltration and to upgrade the Redbud pump
station to eliminate future overflows at this location. The City is progressing to Phase H of the
pump station upgradelexpansion and construction of a new conveyance to the W WTP.
The City had been operating under a JOC since 1988 before entering into the current SOC.
While the City has made progress toward solving the toxicity issues at the subject facility, the
Water Quality Section believes that ample time has been allowed in the initial JOC and in the
current SOC and will not recommend approval if a formal request for an SOC amendment is
made. Please be advised the City of Henderson is subject to enforcement action for violations of
any permit limit.
If you have any questions or comments please feel free to contact Ken Schuster [phone].
E_'
Coleen u i
Water Quality Section Chief
Cc: Raleigh Regional Office, Kirk Stafford
NPDES Compliance Unit, Marcia Lieber
Central Files
1617 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27699-1617
website: h2o.enr.state.nc.us PHONE [phone] FAX [phone]
AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/10% POST -CONSUMER PAPER

�7 NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
NCDENRDIVISION OF WATER QUALITY
RALEIGH REGIONAL OFFICE
DIVISION OF WATER QUALITY
February 28, 2000
JAMES 8. HUNT JR.
GOVERNOR CERTIFIED MAIL
RETURN RECEIPT REQUESTED
BILL HOLMAN Mr. Eric Williams, City Manager
SECRETARY City of Henderson
P.O. Box 1434
Henderson, NC 27536
KERB T. STEVENS
DIRECTOR Subject: November 1999 Quarterly THE Report
Special Order by Consent
EMC WQ96-005
City of Henderson
NPDES Permit NCO020559
Vance County
Dear Mr. Williams:
The Division received the subject report on November 10, 1999. Please send a
written response to the following questions and comments within 10 working days of
receipt of this correspondence.
1) Harriet and Henderson South Cotton Mill was identified as a new source of toxicity.
The facility is authorized to discharge domestic waste only but evidence of nondomestic
discharges was obtained. What evidence did the City obtain? Did the City investigate for
cross connections during subsequent visits? Why has the City not investigated this
facility before now considering its size and potential for toxic discharges? Did the City
issue a Notice of Violation (NOV) or assess civil penalties and if not why?
2) Omega Cleaning Products was identified as cleaning product containers in a local
carwash when an onsite septic tank system for treating wastewater was to be utilized.
Did the City issue an NOV or assess civil penalties and if not what was the reason?
r` 3) In August 1999 Americal Corporation replaced VircoSoft 348 with SparLube LB50.
f Did the City require Americal to test the new product prior to use?
4) Mr. Tom Spain informed Ms. Judy Garret, of the Raleigh Regional Office (RRO), that
a portable pump had been installed at the Redbud Pump Station and that the pump
combination will now be able to handle all received flow. Mr. Spain also stated that the
constriction in the downstream sewer line had been repaired three years ago and that
there have been no overflow problems since. What was the reason for not installing, , ,
this pump sooner since it would have eliminated a number of overflows at this
station? In addition, Mr. Spain has stated that any additional pump capacity at t
1628 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27699-1628
PHONE 919-S71-4700 FAX [phone]
AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - SO% RECYCLED/10% POST -CONSUMER PAPER

i
Henderson
Page Two
station would result in overflows downstream. Ms. Garrett also informed Mr. Spain to pump and
haul if necessary in the future to prevent overflows. Please comment on why the City has not
done this in the past to prevent overflows.
If you have any questions or comments please feel free to contact me at 919-571-4700.
Sincerely,
Kenneth Schuster, P.E.
Regional Supervisor
cc: Kirk Stafford-RRO
Shannon Langly-NPDES Compliance

4
Progress Report
for the Toxicity Reduction Evaluation
at the City of Henderson's Nutbush Creek Wastewater Treatment Plant
NPDES No. NC0020559
November 15,1999 through February 15, 2000
Submitted In Fulfillment of the Special Order by Consent
EMC WQ No. 96-05 --
,J
9
Prepared for
FF /
Department of Environment, Health and Natural Resources
3800 Barrett Drive, Suite 100
Raleigh, North Carolina 27609
Prepared by:
City of Henderson
P.O. Box 1434
Henderson, NC
With Assistance by:
Aquatic Sciences Consulting
15751 Bushy Park Rd
Woodbine, Maryland 21797

City of Henderson THE Progress Report
NPDES No. 0020559
Introduction
Page 2
February 11, 2000
This quarterly progress report is prepared and submitted to meet the February 15`11 date specified
by Section 2(b)2 of the City of Henderson's draft Special Order by Consent (SOC EMC WQ No.
96-05). This report describes the progress made in the last quarter (November 16, 1999 through
February 15, 2000), the plans for the next quarter, and any significant issues that may delay
progress in completing the TRE.
Progress in the Preceding Quarter
1. Results of WWTP Effluent Toxicity Monitoring
A total of three toxicity compliance tests were performed in the preceding quarter. Monthly
effluent monitoring was performed, as required by the SOC. Results are summarized in Table 1
and Appendix A.
Table 1. Summary of Monthly Compliance Test Results
Sample Collection Dates Test Initiation Date ChV (%)
Nov 1-2 and Nov 4-5 Nov 3 77.9
Dec 6-7 and Dec 9-10 Dec 8 77.9
Jan 31 — Feb1 and Feb 3-4 Feb 2 77.9
2. Pretreatment Program Initiatives
Progress achieved in the preceding quarter includes:
• Confirming a source of toxicity, the Harriet & Henderson south cotton mill (see Section 3)
Reviewing Americal Corporation's progress in identifying and controlling source(s) of
toxicity at its textile processing facility.
Receiving weekly chemical usage reports that list daily quantities of chemicals used.
• Continuing to monitor the toxicity of industrial user discharges (see Section 5).
• Continuing quarterly inspections of major industrial users (i.e., all major industries have been
and will continue to be inspected each quarter).
Reviewing industrial user survey reports to identify relatively small users of concern..

City of Henderson THE Progress Report Page 3
NPDES No. 0020559 February 11, 2000
• Continuing frequent communication with the industries regarding pretreatment activities and
their relationship to toxicity.
Although no toxic dischargers were identified in the city's industrial waste survey, the city plans
to use the survey data to indicate possible sources of cleaners, biocides and chemicals containing
surfactants. These types of chemicals have been indicated as causes of effluent toxicity. The
city plans to update its chemical use data base for industrial users and will focus on the
chemicals of concern.
In December, the City met with IAMB to review their plans for upgrade of their pretreatment
facility. The plans were approved by the city and notice to ?roceed with construction was given
on December 15`h. The city inspected IAMB on January 12` .
In January, the city investigated the source(s) of high methyl blue active substances (MBAS)
observed in the North Nutbush sewer line. The source was isolated to a sewer line serving a
laundry mat, hotels and a car wash. Although MBAS has not been directly correlated to toxicity,
the city is concerned about toxic surfactants like those distributed by Omega Cleaning Products,
a distributor of industrial -strength cleaners. Omega no longer rinses its drums at the car wash on
the North Nutbush line; however, Omega reportedly supplies the car wash with cleaners. The
city plans to contact all car washes in the city to obtain cleaner information and, if necessary,
require the removal of toxic cleaners.
3. Sewer and Industrial User Monitoring
The City conducted intensive sewer and industry monitoring in the previous quarter. RTA tests
were performed in December to evaluate the toxicity contribution from the Sandy Creek
sewershed and the Redbud main line. Samples collected from several locations in the sewer
system were also tested using Microtox.
3.1 December RTA
The RTA is designed to evaluate the toxicity of a discharge after it had undergone treatment in a
bench -scale simulation of the city's wastewater treatment plant (WWTP). This approach allows
the city to determine if the discharge is contributing toxicity that would be expected to pass
through the WWTP and cause effluent toxicity. A discharge is considered to be a source of
toxicity if the effluent of a RTA reactor treating the discharge sample and WWTP influent (or
surrogate) is more toxic than a control consisting of the WWTP influent (or surrogate) alone.

City of Henderson THE Progress Report
NPDES No. 0020559
Page 4
February 11, 2000
In December, tests were performed to evaluate the contribution of toxicity in the Sandy Creek
sewershed and the Redbud main line. The toxicity tracking was performed to evaluate the
primary sources of toxicity in the Sandy Creek sewershed (i.e., Americal and the Harriet &
Henderson cotton mills). Americal's RTA test was performed by Americal as required under
their industrial user permit.
RTA results are summarized in Table 2 and Figure 1 (full report is included in Appendix B).
Once again, the Sandy Creek pump station was found to be discharging refractory toxicity. As
shown by the inhibition concentration (IC25) results, the Sandy Creek pump station flow was
more toxic than the control effluent (i.e., 36.9 vs. 48.2%). The 95% confidence intervals for the
IC25 values do not overlap; therefore, the pump station sample contained significant refractory
toxicity. Significant refractory toxicity has been repeatedly observed at the Sandy Creek pump
station (most recently in July).
Of the three discharges evaluated in the Sandy Creek sewershed, the Harriet & Henderson south
cotton mill appeared to be contributing to the observed toxicity at the Sandy Creek pump station.
The effluent of the south mill reactor was more toxic than the control (IC25s of 34.7 vs. 48.2%,
respectively). The toxicity is significant given that the confidence intervals for the IC25 values
do not overlap. These results confirm the results of RTA tests performed in September, which
indicated the south cotton mill to be a source of refractory toxicity. Harriet & Henderson's north
cotton mill was not found to be a source of toxicity.
Table 2. Summary of Refractory Toxicity Assessment Results
Sample Location
Limited -scale C. dubia Chronic
NOEC LOEC
Sandy Creek P.S.
30.0
45.0
36.7
37.6
35.0
- 40.0
North Cotton Mill
45.0
67.5
55.1
51.3
49.2
- 52.0
South Cotton Mill
30.0
45.0
36.7
33.1
24.8
- 36.0
Americal (6.4% flow)
45.0
67.5
55.1
75.1
72.3
- 76.5
America[ (8.0% flow)
45.0
67.5
55.1
69.1
46.0
- 73.0
America[ (6.4% w/ carbon)
30.0
45.0
36.7
50.3
47.4
- 51.8
Americal (8.0% w/ carbon)
45.0
67.5
55.1
55.0
39.9
- 62.2
ATI
30.0
45.0
36.7
37.0
34.7
- 39.1
ATI (w/ carbon)
67.5
90.0
77.9
27.0
NC+
Control
30.0
45.0
36.7
50.0
48.0
- 51.3
WWTP Final Effluent
90.0
> 90.0
> 90.0
> 90
NC+
Results were calculated by first pooling the control data.
" 95% confidence intervals
+ not calculable

City of Henderson THE Progress Report
NPDES No. 0020559
04
N
U
0
0
Ul
C
D
u
X
O
F
2
a
v
'c
L
a
0
0
m
U
Page 5
February 11, 2000
Sandy North South Americal Americal Americal Americal AT] An(w/ Control WWTP
Creek Cotton Cotton (6.4% (8.0% (6.4%w/ (8.0%w/ carbon) Final
P.S. MII MII flow) flow) carbon) carbon) Effluent
Sampling Location
Figure 1. Comparison of Chronic Toxic Unit (TUc) Values for December RTA Tests
Americal's discharge did not appear to contain refractory toxicity when tested at both 6.4% and
8.0% in the RTA. The addition of Americal's discharge samples to the mock WWTP influent
actually decreased toxicity relative to the mock influent alone (i.e., 73.9 and 69.7% vs. 48.2%,
respectively). These results show that Americal was not contributing refractory toxicity on
December 6`s - 8`h.
The RTA control test, which is designed to simulate the city's WWTP, continues to treat toxicity
less effectively than the W WTP. A relatively high level of refractory toxicity was observed in
the control test (IC25 = 48.2%) as compared to the W NTP effluent (IC25 >90%). It is unclear
why this difference was observed, particularly after the steps taken to minimize toxicity
interferences in the RTA. In the December RTA, a "nontoxic" activated sludge was developed to
use in lieu of the WWTP activated sludge, which has been shown to harbor toxicity. Possible
reasons for poor toxicity treatment are that (1) the bioreactor used to develop the nontoxic
biomass was not operated long enough to purge toxicity and (2) the "domestic" influent (North
Nutbush line) sample used in the RTA was toxic. The city is in the process of evaluating another
nontoxic domestic wastewater for use in developing nontoxic biomass and for use in the RTA as
the domestic influent.

J
City of Henderson THE Progress Report
NPDES No. 0020559
3.2 Microtox Monitoring
Page 6
February 11, 2000
Although Microtox is not a direct surrogate for Ceriodaphnia dubia, the city has observed a good
correlation in Microtox and chronic C. dubia test results. In January, the city initiated intensive
sewer monitoring using Microtox. In general, the results show that the Sandy Creek sewershed
is an area of concern. The results further suggest that Americal and Harriet & Henderson's south
cotton mill are sources of toxicity in the sewershed. These results support the RTA results,
which have indicated these dischargers to be sources of toxicity.
3.3 Quarterly Industry Monitoring
As noted in the previous quarterly progress report, the city proposed to retest Ball Foster's
discharge because of the indication of toxicity observed in the last test. The results of the
November retest showed no chronic toxicity at Ball Foster's flow contribution (0.8%). These
results show that it is not necessary to conduct a RTA on Ball Foster's discharge.
In late December, composite samples were collected from each of the major industries, including
Americal, Ball Foster, IAMs, J.P. Taylor, and Kennametal. However, toxicity tests could not be
performed on the samples due to laboratory problems. A second set of samples are scheduled to
be collected for testing this quarter (February 14`h - 151h). Test results will be included in the
next quarterly progress report.
3.4 Summary
The City's sewer/industry monitoring effort has yielded the following conclusions:
Harriet & Henderson's south mill has been identified as an intermittent source of toxicity.
Information on the THE requirement issued by the city and the progress to date is given
below in Section 4.
• Americal appears to have reduced its discharge of toxicity; however, the city will continue
to monitor the discharge. Information on activated carbon studies performed by Americal
is provided below in Section 5.
4. Harriet and Henderson's THE
Harriet & Henderson initiated an internal THE as a result of the September 1999 RTA test
failure. Tasks performed in the THE included providing information on chemical usage,
submitting PT- 101 forms on biocides, completing THE date logs and investigating potential
cooling water discharges to the sanitary sewer. Harriet & Henderson submitted all of the noted
information and provided a letter report on the cooling water discharge investigation (see
Appendix Q. The letter noted no evidence of cross connection of cooling water lines to the
city's sanitary sewers. Harriet & Henderson concluded that biocides were not causing toxicity
and requested a follow-up RTA test to confirm the September RTA result.

City of Henderson THE Progress Report
NPDES No. 0020559
Page 7
February 11, 2000
A follow-up refractory toxicity assessment (RTA) test was performed on Harriet & Henderson's
cotton mill discharges to confirm the results indicating refractory toxicity in the south mill
discharges. As described in Section 3, the results indicated refractory toxicity in discharges from
Harriet & Henderson's south mill. These results confirm the results of the September RTA test,
which indicated the south cotton mill to be a source of refractory toxicity. Harriett &
Henderson's north cotton mill was not found to be a source of toxicity in the September and
December RTAs.
In February, the city submitted a letter formally requiring Harriet & Henderson to implement a
THE at its south mill. As part of the TRE, the city requested Harriet & Henderson to perform the
following tasks:
• Seal wash pits used for cleaning tow motors and provide a plan for ensuring that
wastewater from future cleaning does not enter the City's sanitary sewers
• Inspect all discharges to the City's sanitary sewers to ensure that all flows are metered
• Inspect all discharges to ensure no nondomestic sources are connected to the cotton mill's
sanitary sewers
• Confirm that the Zorrella Yarn Conditioner is not being operated now or in the future. If it
is being operated, determine the characteristics and ultimate disposal method of wastewater
from the Zorrella Yarn Conditioner
The city and Harriet & Henderson plan to meet in February to discuss the THE requirement,
schedule and the approach for conducting the TRE. The city intends to set a short timeframe for
the THE given the need to resolve the city's THE as soon as possible.
5. Americal Corporation's THE
Progress in Americal's THE included (1) performing a follow-up RTA to confirm the reduction
in discharge toxicity observed in July and (2) conducting tests to evaluate the use of activated
carbon for enhanced toxicity reduction. The full reports of these studies are provided in
Appendix C.
5.1 December RTA
As noted in the previous quarterly progress report, the RTA test performed in September was
technically a "pass"; however, the results suggested a potential for toxicity. Americal agreed to
perform another RTA. As noted in Section 3, the RTA results showed that Americal was not
contributing refractory toxicity on December 61h _ 8th
5.2 Activated Carbon Adsorption
A carbon isotherm was performed on a discharge sample collected November 9`h - 101h. Results
showed that a carbon dose of 120 mg/L is sufficient to achieve an IC25 of 9.0%, which is well
above the current and projected flow contribution for the facility. The correlation of carbon dose

City of Henderson THE Progress Report
NPDES No. 0020559
Page 8
February 11, 2000
versus IC25 for the isotherm (Freundlich) was not strong (rz = 0.56); therefore, a 50% safety
factor was recommended, which results in a dose of 180 mg/L.
Americal further evaluated the potential for carbon treatment as part of the December RTA. As
shown in Table 2 (Section 3), pretreatment of the Americal discharge samples with powdered
activated carbon actually increased the refractory toxicity (i.e., 75.1 vs. 50.3% for the untreated
and carbon treated sample tested at the 6.4% flow rate and 69.1 vs. 55.0% for the untreated and
carbon treated sample tested at 8.0% flow rate). It is important to note that carbon oxidizes
materials in addition to being a sorbent. The city has observed increases in toxicity as a result of
pure oxygen -activated sludge treatment, which may be due to the formation of a toxic byproduct.
It follows that the increase in toxicity observed in carbon/pure oxygen -activated sludge treatment
of Americal's samples in the RTA may be due to a toxic byproduct. These results cast doubt on
the potential for carbon treatment at Americal.
Further evidence for the formation of toxic byproducts was provided by the tests of the city's
aeration tank influent (ATI) samples (see Table 2). Although C. dubia mortality was reduced by
addition of 60 mg/L of activated carbon to one of the ATI reactors, reproduction remained low
(i.e., mean young of 31.2 in the control compared to 22.0 mean young in the 30% test
concentration). The low reproduction is reflected in the lower IC25 value for the carbon -treated
ATI sample (27.2%) compared to the untreated ATI sample (34.1%).
The city plans to discuss alternatives to activated carbon treatment with Americal. The city will
also be requesting product stewartship data on chemicals that Americal has substituted for
potentially toxic softeners and wetting agents. In addition, the city plans to continue to monitor
Americal's discharge using Microtox, chronic C. dubia and RTA tests.
6. Biological Treatability Testing
The city is in the process of considering plans for an upgraded W WTP, which will include a new
biological treatment system. The general design of the biological treatment process will be a
multi -stage process that includes both organic carbon removal and at least some biological
nutrient removal. The current design allows for a hydraulic retention time of 16 hours in aerobic
treatment, which may oxidize toxicants.
Although the new process will consist of several stages, the stage that is likely to achieve the
greatest toxicity reduction is the aerobic stage. The city is in the process of testing the aerobic
process in a simple bench -scale, "fill and draw" study. The testing involves treating the W WTP
influent with the current activated sludge for a sufficient period of time to establish a biomass
that is similar to the activated sludge of the new aerobic stage (at least two sludge ages).
Results of a test performed in January show that the effluent of one of the bioreactors was toxic
(ChV = 55.1%). These results confirm tests performed in September, shortly after the
bioreactors were started. Overall, the results indicate that the new process is not capable of
reducing toxicity to the discharge permit limit for toxicity.

City of Henderson THE Progress Report Page 9
NPDES No. 0020559 February 11, 2000
The city is in the process of evaluating the addition of activated carbon to the bioreactors to
remove toxicity that is not treated biologically. The results of initial PAC tests are described in
Section 7.
The city is also investigating the use of fill and draw bioreactors as a tool for tracking sources of
toxicity. The fill and draw bioreactors offer the potential for evaluating the effect of long-term
treatment of selected discharges on effluent toxicity. The fill and draw bioreactors can be
operated indefinitely using multiple samples as opposed to the RTA reactors, which evaluate
toxicity in single samples over a relatively short two-day period. The fill and draw bioreactors
will consist of a bioreactor treating "nontoxic" domestic wastewater and another bioreactor
treating nontoxic domestic wastewater spiked with an industrial user's discharge. Results of
preliminary tests performed in January were inconclusive because the domestic wastewater
(Harris St pump station) used for testing appeared to be toxic.
The city is in the process of setting up a new nontoxic domestic bioreactor using domestic
wastewater from another source (e.g., Country Club pump station inlet or Daniel St). This
bioreactor will be operated for three weeks (two sludge ages) and the effluent will be tested to
determine if it is nontoxic. Once a nontoxic domestic wastewater has been identified, the city
will start up other bioreactors treating nontoxic domestic wastewater spiked with wastewater
from dischargers of concern. After three weeks of operation, these bioreactors will be monitored
to evaluate the effect of the discharges on the city's effluent toxicity. If a discharge is indicated
to be a source of toxicity, the city will impose THE requirements as necessary to control the toxic
discharger.
7. Activated Carbon Treatment
Studies show that effluent toxicity at the City's WWTP is caused by a nonpolar organic
toxicant(s). Nonpolar organic toxicants generally have a high affinity to activated carbon;
therefore, the city initiated tests to evaluate the toxicity reduction capability of carbon. Results
of two carbon isotherms show that effluent toxicity at the city's W WTP can be effectively
removed by carbon (see Appendix B for full report). The results further suggest that the
appropriate dosage of carbon vanes depending on the toxicity of effluent. The appropriate
carbon dosage may be as low as 10.5 to 15 mg/L when the effluent has relatively low toxicity
(i.e., ChV = 78%). When the effluent is relatively toxic (i.e., ChV = 37%), the estimated carbon
dosage is as much as 55.1 to 60 mg/L.
The city must consider a carbon dose that will effectively remove toxicity even during periods of
high toxicity (e.g., ChV <15% observed in June 1999). Therefore, the optimum carbon dose
identified in the isotherm tests (60 mg/L) was selected for further testing. As shown in Table 2,
treatment of the city's ATI with 60 mg/L in a RTA reactor did not eliminate chronic toxicity
(ChV of 77.9% in carbon -treated RTA effluent vs. ChV of 36.7% in non -carbon treated RTA
effluent). However, a follow-up test performed on a fill and draw bioreactor (treating WWTP
influent) showed that 60 mg/L of carbon eliminated toxicity (i.e., ChV >90 for carbon -treated
bioreactor effluent vs. ChV of 55.1 % for non -carbon -treated bioreactor effluent).

City of Henderson THE Progress Report
NPDES No. 0020559
Page 10
February 11, 2000
Although carbon does appear to be effective for toxicity reduction, information on the most
appropriate carbon dose and mode of treatment is inconclusive. The city plans to conduct
additional fill and draw bioreactor tests to better define the operating conditions for carbon
treatment.
Plans for the Next Quarter
The City plans to conduct the following work in the next quarter (February 15 though May 15,
2000):
1. Chronic C. dubia compliance tests will be performed each month.
2. The City will review Harriet & Henderson's progress in their TRE.
3. The city will update its chemical use data base on industrial users. The city will focus on
obtaining additional product stewartship data, including toxicity data, on cleaners, biocides
and other chemicals that contain surfactants.
4. The City will continue to monitor for potential sources of toxicity in the Sandy Creek
sewershed and the Redbud main line. The tools for evaluating potential sources will include
Microtox, RTA tests and fill and draw bioreactors. The bioreactor tests will help to define
the toxic effect of long-term treatment of discharges of concern.
5. The City will inspect all major industrial users in the next quarter. During the inspections,
the City will focus again on activities that can be performed to help minimize the discharge
of toxicity.
6. The City will conduct another Phase II TIE test on a toxic effluent sample. This test will
involve passing a very large volume of effluent sample through the C18 column to
concentrate the toxicants as much as possible. Concentrating the sample may allow detection
of the toxicants when they are fractionated on the HPLC column.
7. The City will continue to evaluate the toxicity reduction capability of activated carbon
treatment.

Appendix A
Historical Ceriodaphnia dubia Chronic Toxicity Data
for the Nutbush Creek WWTP Effluent

a
N � S
�D✓'�rnrnNrOpN W �Nd O) V +V y>+�fNO Y'0+ J W g W� v W 10m O d P01P 01 �,n � V v(ONp�mOrn W W O W �iA'tO Nttl �
v` m o O➢ L
A< U 10 C j 0 d Q 7
V n v v v v v V v v v V V A V A v V v v v v
V V V N V N W W V W V + +
J V V V m^ 1 b W O b O V O W V O W V V W N (D ( V V W o W W W o N W W W W W t0 W N W N W W W W W W W W N t0 t0 t0 t0 Ip W W
J0 � 0 0 0 0� 0+� O O W W V O O W W W + WIm N N W W+ O W W+ W+ + N+ W N O O W O O O O W N
v v v v v v v v v v v v
v v v v v v v v
O O O JW O N O O O W (O tW0 O O O+ W N O (WT � (Wp O fWT N V (w0 d IV1� O OW + fW0 r m W+ A N W O N O O W 0 0 0 O O O
Z �Z 8+A8Z2 W ZeApZZNUwiZ Z W Ni WW N ZfWif W W W N0 WW tNOONZ OZZAZZZ Zy Z
O NO ip+w V OOio Opo00rn W 00 rvrnu V Om W V O1 W Nw W A W O�OOio0000m0
W W V A" V W J A W V A T W W V W W W 9 J W
Z N Z rn N V O Z Z W Z W Z Z w Z Z w (O A W Z w W W W J W N OlP W Z W Z Z V Z Z Z Z A Z
O um0 iub�ioio00�OmOOLinn Oio id in W w0'V in'rn W.
into i�i V O W 00 j�0000m0
W W Ow N 0 0 0 8 � O 8 N O O 8 0 0 .... 8 ...
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D

Ceriodaphnia dubia
Chronic Values (ChVs) for City of Henderson
Nutbush Creek WWTP Effluent
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100
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60
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40
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Appendix B
City of Henderson THE Reports

Aquatic Sciences Consulting 15751 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
December 1, 1999
Mr. Thomas Spain
Director, Wastewater Treatment
Nutbush Wastewater Treatment Plant
1646 W. Andrews Avenue
Henderson, NC 27536
Re: Results of Activated Carbon Testing>
Dear Tom:
Aquatic Sciences Consulting (ASC) is pleased to present this letter report that describes the
results of tests performed to confirm that activated carbon can remove effluent toxicity at the
City's wastewater treatment plant (WWTP). These tests were used to estimate the dose for
reducing toxicity to the compliance limit. Recommendations for evaluating the feasibility of
activated carbon treatment are included.
Summary
Studies show that effluent toxicity at the City's WWTP is caused by a nonpolar organic
toxicant(s). Nonpolar organic toxicants generally have a high affinity to activated carbon.
Several municipalities have evaluated the use of activated carbon, both in powdered and granular
form, as a toxicity reduction technique for nonpolar organic toxicants. Two primary questions
must be answered before activated carbon can be considered for treatment:
• Will the toxicant(s) be removed at reasonable carbon doses and practical contact times?
• Can the WWTP be practically retrofitted to add carbon treatment?
As described in this report, results of two carbon isotherms show that effluent toxicity can be
effectively removed by carbon. The results further suggest that the appropriate dosage of carbon
varies depending on the toxicity of effluent. The appropriate carbon dosage may be as low as
10.5 to 15 mg/L when the effluent has relatively low toxicity (i.e., ChV = 78%). When the
effluent is relatively toxic (i.e., ChV = 37%), the estimated carbon dosage is as much as 55.1 to
60 mg/L.

Thomas Spain Page 2
City of Henderson I December 1999
The city should consider a carbon dose that will effectively remove toxicity even during periods
of high toxicity (e.g., ChV <15% observed in June 1999). Therefore, the optimum carbon dose
may be 60 mg/L. If the city elects to add pulverized carbon to the aeration tank, the
recommended approach is to start with 10 mg/L of carbon (as a final concentration in the mixed
liquor) and monitor the final effluent toxicity over time using both Microtox and the limited -
scale C. dubia chronic test. If necessary, additional carbon can be added until toxicity is
consistently eliminated.
ASC recommends that the city utilize the services of an engineer. who is experienced in the
desien of carbon systems, to assess the feasibility of carbon treatment at the WWTP. This
assessment is necessary to ensure that carbon is compatible with the existing processes at the
Nutbush Creek WWTP. Major issues of concern include (1) the corrosivity of carbon, which has
the potential to damage equipment at the WWTP, and potential changes in sludge characteristics
that may affect whether or not the sludge can continue to be land applied.
ASC understands that the decision to consider carbon treatment at the city WWTP will depend
on the outcome of the ongoing carbon study being performed by Americal Corporation. The city
should be prepared to evaluate carbon treatment if Americal's efforts do not eliminate effluent
toxicity at the city's WWTP and ongoing trackdown studies fail to identify the source(s) of
toxicity.
Technical Approach
Although the powdered activated carbon (PAC)/activated sludge process is the principal method
to be evaluated, clarified effluent from the activated sludge process was tested instead of the
aeration basin mixed liquor. This approach is generally used in carbon isotherm tests because
the average pollutant concentrations (i.e., BOD, COD, TOC) in the activated sludge aeration
basin are essentially the same as the clarified effluent. Also, the presence of activated sludge
biomass generally does not affect the adsorption of toxicants on the carbon, except possibly the
rate of adsorption.
Two isotherms were performed: one on an effluent sample collected on September 7' - 8' and
another on a composite of effluent samples collected on October 28' and the other on November
5". The October and November samples were composited in equal volumes. The October and
November samples were selected based on Microtox results, which showed relatively high
toxicity in the samples.
CAMy Documents\Word DocsVoWs Work\Jobs\nenderson\Tmambility\Carbon Isotherm (Sep, Oct & Nov 99 Samples).doc
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Thomas Spain Page
City of Henderson 1 December 1999
Pulverized (powdered) activated carbon (Nuchar SA) was obtained from Westvaco Corporation.
The carbon was weighed and added to 1-L teflon-sealed glass bottles to achieve a final
concentration series of 0, 60 and 120 mg/L for the first isotherm and 0, 15, 30 and 60 mg/L for
the second isotherm. Aliquots (1-L) of the effluent sample were added to each bottle, the bottles
were sealed and the contents were stirred on a magnetic stir table. The purpose of this isotherm
is to determine if toxicity could be removed, regardless of the contact time. Therefore, the
sample aliquots were stirred overnight (12 to 18 hours). The isotherm tests were conducted at
room temperature. Following carbon treatment, the aliquots were filtered through glass fiber
filters (1.6 µm pore size) to remove carbon fines. Recent tests show that filtration does not
remove toxicity; therefore, the toxicity reduction observed in the isotherm test should be related
to carbon treatment.
The filtered sample aliquots were tested for chronic toxicity using limited -scale Ceriodaphnia
dubia procedures. Test concentrations were the same as for the City's compliance test (i.e., 15,
30, 45, 67.5 and 90%). Each sample aliquot was used for test initiation and renewal on day 5 of
the test.
Isotherm plots were drawn using chronic inhibition concentration (IC25) values and carbon
doses. Three types of plots were considered: the Langmuir and Freundlich isotherms and a
simple linear regression. The isotherm that exhibited the best fit for the data was used to
estimate the optimum dosage of carbon for toxicity treatment.
Results
In considering an appropriate carbon dosage for treatment, it is necessary to identify a
conservative, yet realistic, target for effluent toxicity. The city essentially must discharge no
chronic toxicity; therefore, the target for effluent toxicity must be to consistently meet the ChV
limit of 2:90%. Given the relatively high toxicity observed in some effluent samples and the
inherent variability in operating a carbon treatment process, it will be necessary to maintain the
highest carbon dose that will be needed to ensure consistent toxicity reduction.
The September effluent sample was relatively toxic (i.e., ChV = 37%) compared to the
October/November effluent sample (i.e., ChV = 78%). Therefore, an appropriate carbon dose
for toxicity treatment was estimated by interpreting data from both the September and
October/November tests. A summary of the isotherm results for both carbon tests is presented
below.
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Thomas Spain
City of Henderson
October/November 1999 Carbon Isotherm
Page 4
1 December 1999
Toxicity test results are summarized in Table 1. The 15 mg/L carbon dose removed all of the
effluent toxicity. This dose appeared to remove toxicity above the ChV target; therefore, the
optimum dose for treatment of the sample may be somewhat below 15 mg/L. As shown in
Figures 1 through 3, the carbon data were plotted together with the toxicity results to help
identify an appropriate treatment dosage. IC25 values were used for these plots (Note: IC25
values generally approximate the NOEC values). Neither the Langmuir (Figure 1) nor
Freundlich isotherms (Figure 2) provides a reasonable fit of the data. However, it is possible to
estimate a target dosage using a linear plot. Figure 3 shows that the preferred dosage range is
10.5 to 15 mg/L.
Table 1. Results of Carbon Isotherm for October/November Sample
Dose (ma/L) NOEC LOEC ChV IC25
0
67.5
90
78
74.9 (72.9 - 782)
15
100
> 100
> 100.0
> 100 NC
30
100
> 100
> 100.0
> 100 NC
60
100
> 100
> 100.0
> 100 NC
95 percent confidence intervals. NC = not calculable.
As noted, the October/November effluent sample was relatively nontoxic. Therefore, it is
necessary to estimate a carbon dose for periods of relatively greater toxicity.
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Thomas Spain
City of Henderson
200.0
180.0
160.0
140.0
120.0
_ 100.0
" 80.0
60.0
40.0
20.0
0.0
Page 5
1 December 1999
------------------ -- I- --- -----------------
f- TUc Goal of 1.1
♦--- -----------
--------------- ---------
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
C (TUc)
Figure 1. Langmuir Isotherm of Carbon Treatment of October/November Effluent Sample
0.00 0.02 0.04 0.06 0.08 0.10
Log (C)
Figure 2. Freundlich Isotherm of Carbon Treatment of October/November Effluent Sample
CAMy Documents\Word DocsUohn's WorkUobs\Hendemn\Treatability\Carbon Isotherm (Sep, Oct & Nov 99 Sa nples).doc
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Thomas Spain
City of Henderson
2.0 ---------- -----
1.8 ------ - -----
1.2
x
1.0
0
0.8
Regression of TUC vs.
0 and 15 mg/L Carbon
Page 6
1 December 1999
- - - - Preferred dosage range - -
- - - - TUC Goal oft.1 - 10.5 to 15 mg/L
�- ,----- —------------- (� -------,
-----------i-------------*--------,-------------------
0.4 4--------- ------------------------- ------------;-------------------
0.2 4---------- ---------- L ----------------- ---------,-------,---------
0 10 20 30 40 50 60 70
Carbon Dose (mg/L)
Figure 3. Linear Isotherm of Carbon Treatment of October/November Effluent Sample
September 1999 Carbon Isotherm
As noted, the September carbon isotherm was performed on a relatively toxic effluent sample.
Toxicity test results are summarized in Table 2. The 60 mg/L carbon dose appeared to remove
toxicity above the ChV target; therefore, the optimum dose for treatment of the sample may be
somewhat below 60 mg/L. Isotherm plots were prepared to help identify an appropriate
treatment dosage. However, neither the Langmuir nor Freundlich isotherms provides a
reasonable fit of the data.
It was possible to estimate a target dosage using a linear plot. Figure 4 shows that the preferred
dosage range is 55.1 to 60 mg/L. However, it is important to note that this plot assumes that the
relationship between carbon dose and toxicity is linear, which is usually not the case. Therefore,
it is possible that the appropriate carbon dose for this sample is less than 55.1 mg/L.
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Thomas Spain
City of Henderson
Page 7
1 December 1999
Table 2. Results of Carbon Isotherm for September Effluent Sample
Dose (mg/L) NOEC LOEC ChV IC25 (C.I.)-
0
30
45
36.7
45.2
(38.0 - 51.4)
60
100
> 100
> 100.0
> 100.0
NC
120
100
> 100
> 100.0
> 100.0
NC
2.4 - — • - , - --•
2.2 - Regression of TUc vs.
0 and 60 mg/L carbon
2.0 --- ---
1.8 -
Preferred dosage ran
ge
1. 55.1 to 60 mg/L
TUc Goal of 1.1
x 1.2 --
1.0 ----.----;---- 4 ---- ------------- --�
u •
0 0.tf -i -f -
L
0.6-----------------------------------------
0.4--- - -- - -- --- --- --- -
0.2 -- -- -- - - ------ -. - - -- - ----
0.0 . .
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Carbon Dose (mg/L)
Figure 4. Linear Isotherm of Activated Carbon Treatment of September Effluent Sample
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Thomas Spain Page S
City of Henderson I December 1999
Summary
Results of two carbon isotherms suggest that the appropriate dosage of carbon varies depending
on the toxicity of effluent. The appropriate carbon dosage may be as low as 10.5 to 15 mg/L
when the effluent has relatively low toxicity (i.e., ChV = 78%). When the effluent is relatively
toxic (i.e., ChV = 37%), the estimated carbon dosage is as much as 55.1 to 60 mg/L.
Obviously, the city must consider a carbon dose that will effectively remove toxicity even during
periods of high toxicity (e.g., ChV <15% observed in June 1999). Therefore, the optimum
carbon dose may be 60 mg/L. If the city elects to add pulverized carbon to the aeration tank, the
recommended approach is to start with 10 mg/L of carbon (as a final concentration in the mixed
liquor) and monitor the final effluent toxicity over time using both N icrotox and the limited -
scale C. dubia chronic test. If necessary, additional carbon can be added until toxicity is
consistently eliminated.
Recommendations
As described in the 1999/2000 THE Agreement (letter dated October 13, 1999), the next step in
the carbon evaluation is an engineering assessment of the feasibility of adding carbon treatment
at the City's WWTP. This assessment is necessary to ensure that carbon is compatible with the
existing processes at the Nutbush Creek WWTP Major issues of concern include (1) the
corrosivity of carbon which has the potential to damage equipment at the WWTP and potential
changes in sludge characteristics that may affect whether or not the sludge can continue to he
TIM I M, grewall
ASC recommends that the city utilize the services of an engineer who is experienced in the
design and implementation of carbon systems. As described in the 1999/2000 THE Agreement,
ASC highly recommends retaining the assistance of William Komegay, PhD, an Associate of
Aquatic Sciences Consulting. Dr. Komegay worked for many years with Westvaco's Carbon
Services Division (Covington, VA) and has conducted many carbon studies. He has prepared
design specifications for many types of treatment facilities and has assessed the feasibility of
retrofitting WWTPs for GAC, PAC, and PACT treatment.
As described in the 1999/2000 THE Agreement, Dr. Komegay recommends two initial steps in
the engineering assessment: (1) a review of the WWTP's design plans and specifications and
operations and performance data and (2) a one -day visit to review first-hand the operation and
performance of the WWTP and discuss treatment options with city officials. The scope of work
and costs of this proposed engineering assessment are presented in the 1999/2000 THE
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Thomas Spain
City of Henderson
Agreement.
Proposed Schedule
Page S
December 1999
ASC understands that the decision to consider carbon treatment at the city WWTP will depend
on the outcome of the ongoing carbon study being performed by Americal Corporation. The city
should be prepared to evaluate carbon treatment if Americal's efforts or the city's ongoing
trackdown studies fail to eliminate the source(s) of toxicity.
Given the above considerations, ASC proposes the following tentative schedule for the
recommended engineering assessment (if needed):
Americal implements carbon treatment
City performs two compliance tests
City provides data to ASC for engineering
assessment (if a compliance test fails)
ASC submits summary review of data
Site visit
Report
February 1, 2000
by March 31 (February & March tests)
April 7
April 21
April 28 (week of)
May 12
Please call me at [phone], if you have questions or comments about this report.
Sincerely,
John A. Botts
Principal Scientist
c.c.: Reginald Hicks (Laboratory Manager/ Pretreatment Coordinator)
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Aquatic Sciences Consulting 15751 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
December 28, 1999
Mr. Thomas Spain
Director, Wastewater Treatment
City of Henderson
Nutbush Wastewater Treatment Plant
P.O. Box 1434
Henderson NC 27536
Re: Toxicity Tracking in December
Dear Mr. Spain:
In December, a Refractory Toxicity Assessment (RTA) was performed to evaluate the toxicity
contribution from the Sandy Creek sewershed and the potential for treatment of toxicity with
activated carbon. At the same time, a RTA test of Americal's discharge was performed to meet
the permit requirement for consecutive monthly RTA tests. The results of this testing are
described as follows.
Summary
In December, tests were performed to evaluate the contribution of toxicity in the Sandy Creek
sewershed and the potential for treatment of toxicity with activated carbon. The toxicity tracking
was performed to confirm monitoring results that have shown the primary sources of toxicity in
the Sandy Creek sewershed to be Americal and the Harriet & Henderson cotton mills. The
Americal RTA test was performed by Americal as required under their industrial user permit.
Americal's results are presented herein and are also submitted as part of their THE monthly
progress report.
Once again, the Sandy Creek pump station was found to be discharging refractory toxicity.
Significant refractory toxicity has been repeatedly observed at the Sandy Creek pump station
(most recently in July).
Of the three discharges evaluated in the Sandy Creek sewershed, the Harriet & Henderson south
cotton mill appears to be contributing to the observed toxicity at the Sandy Creek pump station.
These results confirm the results of RTA tests performed in September, which indicated the
south cotton mill to be a source of refractory toxicity.
Americal's discharge did not appear to contain refractory toxicity when tested at both 6.4% and
8.0% in the RTA. These results show that Americal was not discharging refractory toxicity from

Thomas Spain
City of Henderson
December 6' - 8`b.
Page 2
December 28, 1999
Pretreatment of the Americal discharge samples with activated carbon actually increased the
refractory toxicity. It is important to note that carbon oxidizes materials in addition to being a
sorbent. The city has observed increases in toxicity as a result of pure oxygen -activated sludge
treatment, which may be due to the formation of a toxic byproduct. Therefore, the increase in
toxicity observed in carbon/pure oxygen -activated sludge treatment of Americal's samples in the
RTA may be due to a toxic byproduct. These results cast doubt on the potential for carbon
treatment at Americal.
Further evidence for the formation of toxic byproducts was provided by the tests of the ATI
samples. Although C. dubia mortality was reduced by addition of 60 mg/L of activated carbon
to one of the ATI reactors, reproduction remained low (i.e., mean young of 31.2 in the control
compared to 22.0 mean young in the 30% test concentration). The low reproduction is reflected
in the lower IC25 value for carbon -treated ATI sample (27.0%) compared to the untreated ATI
sample (37.0%).
Based on the RTA results, the following recommendations should be considered:
1. Additional tests should be performed to confirm that addition of activated carbon at Americal
or the city's aeration basin is not an appropriate method for toxicity control.
2. Although addition of powdered activated carbon to the city's aeration basin may not be
appropriate, post -aeration basin treatment with granular activated carbon may successfully
eliminate toxicity. This possibility is supported by the carbon isotherm tests performed in
September and November, which showed that toxicity could be eliminated when the city's
final effluent was treated with carbon. To test this possibility, the city should perform
follow-up bench -scale column tests on effluent samples using granular activated carbon
(GAC).
3. Americal should investigate alternative methods for toxicity removal. As noted in reports
submitted by Americal this year, the toxicant in their discharge is more than likely a
surfactant. Filtration is sometimes effective in removing toxic surfactants. An engineering
assessment and additional bench -scale tests are recommended to evaluate filtration and other
potential treatment options.
4. The December RTA is the second consecutive test showing Harriet & Henderson's south
cotton mill to be a source of toxicity. In the November 10' meeting at Harriet & Henderson,
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Thomas Spain Page 3
City of Henderson December 28, 1999
the city agreed that, although the September RTA test showed toxicity in the south mill's
discharge, additional testing was needed to confirm that the mill is a source of toxicity.
Given that toxicity was again observed this month, Harriet & Henderson should be notified
as soon as possible of the RTA results and the city's decision regarding a THE requirement.
According to the city's pretreatment permit language, a THE must be initiated within thirty
(30) days of reporting the RTA results. Given the evidence of a non -domestic discharge, the
city should also decide whether or not to issue a pretreatment permit for the south mill.
Technical Approach
Sampling
Twenty-four hour composite samples were collected from the Sandy Creek pump station, Harriet
& Henderson's two cotton mills, and the ATI influent on December 7' - 8'. The Sandy Creek
and Harriet & Henderson cotton mill samples were used to initiate the RTA test (1" day) and a
portion of the sample was saved (stored at 4°C) and used again on the second day of testing. A
second composite sample of the ATI influent was collected (December 8' - 9`b) for use on the
second day of the RTA test. Insufficient sample was collected; therefore, a grab sample from the
ATI influent was collected (December 9 h) and added to the composite sample.
It was necessary to collect Americal's discharge sample one day earlier (December 6' - 7'") so
that a portion of the sample could be pretreated with activated carbon (i.e., treated overnight)
before RTA testing. A second 24-hr composite sample of Americal's discharge was collected the
next day (December 7' - 8 ") and pretreated again with carbon RTA testing. For the third
consecutive RTA study, Americal experienced a problem in collecting the first discharge
sample. When city staff arrived to pick up the first composite sample, insufficient sample had
been collected. Therefore, a grab sample was immediately collected and added to the composite
sample. The second Americal sample was a full composite sample.
Grab samples from the North Nutbush line were also collected for use as the "mock" WWTP
influent. The North Nutbush line sample was used in lieu of the planned Harris St pump station
sample because of a high urea odor in the Harris St sample, which indicated potentially toxic
ammonia concentrations. The city has recently observed ammonia concentrations as high as 70
mg/L in Harris St pump station samples. Two 15-gallon North Nutbush line samples were
collected: one on December 8' and the other on December 9' (both collected late morning).
The samples were used on the respective days of the RTA treatment.
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Thomas Spain Page 4
City of Henderson December 28, 1999
In an attempt to develop an activated sludge that would not contain background toxicity, the city
operated a "fill and draw" reactor that treated "domestic" wastewater for approximately 21 days.
On November 12'", an 8-gal return activated sludge sample was taken from the WWTP aeration
tank, placed into a 40-gal container and was fed a 15 to 17-gal 24-hr composite sample from the
Harris St pump station each day. Sludge wasting was performed as needed to maintain at least
4,000 mg/L of total suspended solids (TSS). The city monitored the reactor to ensure that
treatment performance was similar to that achieved in the WWTP (i.e., BOD, COD and
ammonia removal was adequate). On the first day of RTA testing, the mixed liquors from the
fill and draw reactor were allowed to settle, the supernatant was decanted, and the thickened
sludge was prepared for testing. An unusual green tint was observed in the reactor supernatant;
therefore, it was decided to wash the activated sludge with spring water before use in the RTA.
Ten gallons of spring water were added to approximately 7 gal of thickened activated sludge, the
mixed liquors were aerated for % hour, then allowed to settled for about 2 hours. The thickened
sludge was used directly in the nitrification treatment step of the RTA as described in Appendix
A.
Sampling information is summarized in Table 1.
RTA Tests
Test procedures followed the protocol given in Appendix A.
Previous RTA tests suggest that a constituent(s) in the WWTP influent may be masking the
measurement of toxicity in the RTA. Therefore, as recommended in EPA's updated Municipal
THE Protocol (1999), a mock influent was used instead of the WWTP influent to eliminate this
possible masking effect. The mock influent consisted of wastewater collected from the North
Nutbush line, which collects largely domestic wastewater. A potential source of toxicity on the
North Nutbush line was eliminated in September. The city required Omega, an industrial
cleaner distributor, to cease cleaning drums at the carwash that discharges to the North Nutbush
line.
The RTA treatment step normally reveals the source(s) of refractory toxicity, including toxicity
caused by treatment byproducts; however, it is possible that the toxicants may be present only
after long-term treatment (i.e., greater than the 4-hour treatment time in the W WTP activated
sludge process). The precursor chemical(s) may accumulate in the activated sludge and
breakdown slowly over time to the toxicant(s) of concern. Some surfactants breakdown slowly
to form toxic byproducts. The RTA procedures were adjusted to account for this potential case.
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Thomas Spain
City of Henderson
Page 5
December 28, 1999
Table 1. Sampling Requirements for December RTA Tests
Sample Location Type' Date/Time
Receipt
Date
Vol
(gal)
Sandy Creek pump station
24-h C
7-8 Dec
8 Dec
2
9AM-9AM
10AM
North Cotton Mill - Harriet & Henderson
24-h C
7-8 Dec
8 Dec
2
9AM-9AM
10AM
South Cotton Mill - Harriet & Henderson"
24-h C
7-8 Dec
8 Dec
2
9AM-9AM
10AM
Americal+
C& G
6-7 Dec
7 Dec
2
10AM-10AM
1OAM
24-h C
7-8 Dec
8 Dec
2
10AM-10AM
1OAM
Aeration Tank Influent (ATI)++
24-h C
7-8 Dec
8 Dec
4
8AM-8AM
8AM
C& G
8-9 Dec
9 Dec
4
8AM-10AM
10AM
North Nutbush Line#
Grab
8 Dec
8 Dec
15
10AM
10AM
Grab
9 Dec
9 Dec
15
11AM
11AM
Return activated sludge (RAS)##
Grab
7-8 Dec
23 Sep
7
12PM
10AM
` 24-hour composite or grab.
Two samples were collected from this facility: one from the J.D. mill and the other from mills #1 and
#2. The samples were combined according to the respective flow contribution to the WWTP.
+ Two Americal samples were collected for testing: a composite/grab sample collected on
December 6' - 7" and a 24-hr composite on December 7" - 8'".
++ Two ATI samples were collected: a 24-hr composite on December 7" - 8' and a 2-gal composite/
2 gal grab sample on December 8" - 9".
# Two 15-gal North Nutbush line grab samples were collected: one on December 71" - 8" and the other
on December 8'" - 9t"
## RAS was collected from the "domestic" fill and draw reactor.
The modified RTA approach involved "fill and draw" treatment using multiple samples instead
of the conventional approach of treating a single sample. The activated sludge biomass used in
the first "fill' step is saved and used in the second "fill" step. In this way, residual chemical
concentrations and/or treatment byproducts can accumulate in the biomass and may be detected
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Thomas Spain Page 6
City of Henderson December 28, 1999
in toxicity tests of treated samples. This protocol was used in RTA testing in July, August and
September 1999.
The RTA tests utilized two types of simulations: one treating the mock WWTP influent and the
other treating mock WWTP influent spiked with sewer/industry samples. The sewer/industry
spike volumes were based on the percent flow values for each sampling location. The spike
volumes and other RTA components are listed in Appendix B (Table 13-1).
Results
RTA Tests
Results of the RTA operating conditions and toxicity tests are presented as follows.
A summary of the RTA operating conditions is provided in Appendix B (Tables B-2 and B-3).
In general, the simulations effectively replicated the operating conditions of the trickling filter
and activated sludge processes at the City's WWTP.
After set up, the dissolved oxygen levels in the RTA bioreactors were set to >4 and >10 mg/L
for the Day 1 aeration step (air supply) and Day 2 aeration (oxygen supply), respectively. These
levels are typical for air -supplied and pure oxygen -supplied nitrification treatment processes and
the city usually maintains a >10 mg/L oxygen level in its pure oxygen activated sludge process.
On both days of the test, it was necessary to add lime to the reactors to maintain the pH within an
acceptable range for nitrification treatment (i.e., above 6.7). Approximately 460 mg of quick
lime in a slurry solution (5.1 % by dry weight lime) was added to the reactors, which resulted in a
57 mg/L concentration in the mixed liquors. The lime addition maintained the pH within 7.4 to
8.1 in the bioreactors. The pH of the reactors treating ATI was higher (7.8 to 8.7) because lime
had already been added at the ATI sampling point, which is the influent channel to the aeration
tank.
Removal of chemical oxygen demand (COD) by the trickling filter columns was variable (see
Table B-4). The Day 1 results were similar to the Day 2 results with the exception of the COD
level of trickling filter effluent for the Sandy Creek pump station test (300 mg/L on Day 1),
which was much higher than the other tests. The cause of this high value is not known, although
variable COD concentrations have been observed at this location.
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City of Henderson December 28, 1999
On Day 2 of the RTA, the COD level of the trickling filter effluents from the pump
station/industry-spiked and control tests varied from 21 to 200 mg/L. As would be expected, the
COD of the Americal 6.4% and 8.0% trickling filter effluents was higher (200 and 160 mg/L,
respectively) because of the COD contribution from Americal's sample. The relatively low COD
of the trickling filter effluents from the Americal carbon tests (21 and 41 mg/L COD) is a result
of carbon pretreatment of the Americal samples. The trickling filter effluent for the control
reactor had a higher COD level (140 mg/L) than that observed in the WWTP trickling filter
effluent on December 7" (80 mg/L). However, nitrification treatment reduced COD as noted
below.
After nitrification treatment on Day 2, the COD values were less variable (16 to 28 mg/L) and
were similar to the COD of the WWTP final effluent (<25 mg/L on December 8I' ). No
significant differences in COD removal were observed between the sewer/industry-spiked tests
and the control. These results indicate similar treatment of the sewer/industry-spiked and control
samples.
Results are shown in Table 2 and Figure 1. Results of the sewer/industry-spiked tests are
compared to the control results. As shown by the inhibition concentration (IC25) results, the
Sandy Creek pump station flow was more toxic than the control effluent (i.e., 37.6 vs. 50.0%).
The 95% confidence intervals for the IC25 values do not overlap; therefore, the pump station
sample contained significant refractory toxicity. Significant refractory toxicity has been
repeatedly observed at the Sandy Creek pump station (most recently in July).
Of the three discharges evaluated in the Sandy Creek sewershed, the Harriet & Henderson south
cotton mill appears to be contributing to the observed toxicity at the Sandy Creek pump station.
The effluent of the south mill reactor was more toxic than the control (IC25s of 33.1 vs. 50.0%,
respectively). The toxicity is significant given that the confidence intervals for the IC25 values
do not overlap. These results confirm the results of RTA tests performed in September, which
indicated the south cotton mill to be a source of refractory toxicity. Harriet & Henderson's north
cotton mill was not found to be a source of toxicity.
Americal's discharge did not appear to contain refractory toxicity when tested at both 6.4% and
8.0% in the RTA. The addition of Americal's discharge samples to the mock WWTP influent
actually decreased toxicity relative to the mock influent alone (i.e., 75.1 and 69.1% vs. 50.0%,
respectively). These results show that Americal was not contributing refractory toxicity on
December 6'h - 8'".
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Thomas Spain
City of Henderson
Table 2. Summary of Refractory Toxicity Assessment Results
Sample Location
Limited -scale C. dubia Chronic
Page 8
December 28, 1999
Sandy Creek P.S.
30.0
45.0
36.7
37.6
35.0
- 40.0
North Cotton Mill
45.0
67.5
55.1
51.3
49.2
- 52.0
South Cotton Mill
30.0
45.0
36.7
33.1
24.8
- 36.0
America[ (6.4% flow)
45.0
67.5
55.1
75.1
72.3
- 76.5
Americal (8.0% flow)
45.0
67.5
55.1
69.1
46.0
- 73.0
Americal (6.4% w/ carbon)
30.0
45.0
36.7
50.3
47.4
- 51.8
America[ (8.0% w/ carbon)
45.0
67.5
55.1
55.0
39.9
- 62.2
ATI
30.0
45.0
36.7
37.0
34.7
- 39.1
ATI (w/ carbon)
67.5
90.0
77.9
27.0
NC+
Control
30.0
45.0
36.7
50.0
48.0
- 51.3
WWTP Final Effluent
90.0
> 90.0
> 90.0
> 90
NC+
' Results were calculated by first pooling the control data. " 95% confidence intervals + not calculable
N
5
U
0
0
4
w
c
7
u 3
0
H
A
a 2
v
w
c
.0 1
a
v
0
w o
u
Sandy North South Americal Americal America[ Americal ATI ATI (w/ Control WWTP
Creek Cotton Cotton (6.4% (8.0% (6.4%w/ (8.0%w/ carbon) Final
P.S. Mill Mill flow) flow) carbon) carbon) Effluent
Sampling Location
Figure 1. Toxic Unit Values (100/IC25) for the December RTA Tests
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Thomas Spain Page S
City of Henderson December 28, 1999
Pretreatment of the Americal discharge samples with activated carbon actually increased the
refractory toxicity (i.e., 75.1 vs. 50.3% for the untreated and carbon treated sample tested at the
6.4% flow rate and 69.1 vs. 55.0% for the untreated and carbon treated sample tested at 8.0%
flow rate). It is important to note that carbon oxidizes materials in addition to being a sorbent.
The city has observed increases in toxicity as a result of pure oxygen -activated sludge treatment,
which may be due to the formation of a toxic byproduct. It follows that the increase in toxicity
observed in carbon/pure oxygen -activated sludge treatment of Americal's samples in the RTA
may be due to a toxic byproduct. These results cast doubt on the potential for carbon treatment
at Americal.
Further evidence for the formation of toxic byproducts was provided by the tests of the ATI
samples. Although C. dubia mortality was reduced by addition of 60 mg/L of activated carbon
to one of the ATI reactors, reproduction remained low (i.e., mean young of 31.2 in the control
compared to 22.0 mean young in the 30% test concentration). The low reproduction is reflected
in the lower IC25 value for the carbon -treated ATI sample (27.0%) compared to the untreated
ATI sample (37.0%).
The RTA control test, which is designed to simulate the city's WWTP, continues to treat toxicity
less effectively than the WWTP. A relatively high level of refractory toxicity was observed in
the control test (IC25 = 50.0%) as compared to the WWTP effluent (IC25 >90%). It is unclear
why this difference was observed, particularly after the steps taken to minimize toxicity
interferences in the RTA. As noted above, a "nontoxic" activated sludge was developed to use in
lieu of the WWTP activated sludge, which has been shown to harbor toxicity. Possible reasons
for poor toxicity treatment are that (1) the domestic fill and draw reactor was not operated long
enough to purge toxicity from the activated sludge and (2) the mock influent (North Nutbush
line) sample used in the RTA was toxic.
Recommendations
The increase in toxicity following pretreatment of Americal's samples with carbon is evidence
that a constituent in Americal's wastewater is breaking down into something more toxic. The
lack of improvement in C. dubia reproduction after carbon - activated sludge treatment of the
ATI suggests that this toxic byproduct is also present at the city's WWTP and may be
contributing to the city's effluent toxicity. Additional tests should be performed to confirm that
carbon addition at Americal or the city's aeration basin is not an appropriate measure for toxicity
control.
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Thomas Spain
City of Henderson
Page 10
December 28, 1999
Americal should investigate alternative methods for toxicity removal. As noted in reports
submitted by Americal this year, the toxicant in their discharge is more than likely a surfactant.
For example, nonyl phenols, a toxic surfactant, was identified in the polymer used for
wastewater treatment. Filtration is sometimes effective in removing toxic surfactants. An
engineering assessment and additional bench -scale tests are recommended to evaluate filtration
and other potential treatment options.
Although addition of powdered activated carbon to the city's aeration basin may not be
appropriate, post -aeration basin treatment with granula, activated carbon may successfully
eliminate toxicity. This possibility is supported by the carbon isotherm tests performed in
September and November, which showed the elimination of toxicity when the city's final
effluent was treated with carbon. To test this possibility, the city should perform bench -scale
column tests on effluent samples using GAC.
The December RTA is the second consecutive test showing Harriet & Henderson's south cotton
mill to be a source of toxicity. In the November 10' meeting at Harriet & Henderson, the city
agreed that, although the September RTA test showed toxicity in the south mill's discharge,
additional testing was needed to confirm that the mill is a source of toxicity. Given that toxicity
was again observed this month, Harriet & Henderson should be notified as soon as possible of
the RTA results and the city's decision regarding a THE requirement. According to the city's
pretreatment permit language, a THE must be initiated within thirty (30) days of reporting the
RTA results. Given the evidence of a non -domestic discharge, the city should also decide
whether or not to issue a pretreatment permit for the south mill.
Please call me [phone], if you have questions or comments about this report.
Sincerely,
John A. Botts
Principal Scientist
c.c.: Mark Warren (Assistant City Manager)
Reginald Hicks (Pretreatment Coordinator)
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Appendix C
Americal Corporation and Harriet & Henderson
Toxicity Reduction Evaluation Reports

Aquatic Sciences Consulting 15751 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
December 4, 1999
Mr. Jeff Golliher
Superintendent of Dyeing
Americal Corporation r
P.O. Box 1419
Henderson, NC 27536 Cr
Re: Results of Activated Carbon Testing
Dear Jeff:
Aquatic Sciences Consulting (ASC) is pleased to present this letter report on the potential for
treatment of toxicity using activated carbon. Laboratory tests were performed to estimate an
appropriate carbon dose for reducing toxicity to the required discharge permit level.
Recommendations for evaluating the feasibility of activated carbon treatment are included.
Summary
Test results show that toxicity in Americal's discharge is caused by a nonpolar organic
toxicant(s). Nonpolar organic toxicants generally have a high affinity to activated carbon. Many
industries have evaluated the use of activated carbon, both in powdered and granular form, as a
toxicity reduction technique for nonpolar organic toxicants. In general, two primary questions
must be answered before activated carbon can be considered for treatment at Americal:
• Will the toxicant(s) be removed at reasonable carbon doses and practical contact times?
• Can Americal's pretreatment facility be practically retrofitted to add carbon treatment?
In considering an appropriate carbon dosage for treatment, it is necessary to identify a
conservative, yet realistic, target for effluent toxicity. Americal proposes to increase its
permitted flow to 200,000 gpd or 8.0% of the flow contribution to the city's Nutbush Creek
wastewater treatment plant (W WTP). Therefore, Americal should pass at an 8.0% discharge
concentration. In addition, ASC recommends a margin of safety of at least another 1 % of the
flow to ensure consistent compliance. Therefore, the toxicity target should be a "pass" at a no
observed effect concentration (NOEC) of 9%. For the purpose of this evaluation, an inhibition
concentration (IC25) value (9%) is used because it is an extrapolated endpoint that better
explains the degree of toxicity.

Jeff Golliher Page 2
Americal Corporation 4 December 1999
Results of the carbon isotherm show that toxicity can be removed by carbon. A carbon dose of
120 mg/L appears to be sufficient to achieve an IC25 of 9.0%. However, the correlation of
carbon dose versus IC25 for the isotherm (Freundlich) is not strong (r2 = 0.56); therefore, ASC
recommends considering the 120 mg/L dose plus a safety factor of 50%, which results in a dose
of 180 mg/L. This safety factor is also recommended because the IC25 value did not
approximate the NOEC. The NOEC value for the 120 mg/L carbon dose was 6.4%, which is
below the toxicity target.
Americal plans to further evaluate carbon as part of the RTA scheduled for the week of
December 6'h. Samples of Americal's discharge will be tested with and without carbon to
determine if carbon removes refractory toxicity from the samples. If the results show that
carbon effectively removes refractory toxicity from the discharge sample, Americal plans to
evaluate the feasibility of adding carbon treatment to its pretreatment facility.
Technical Approach
An isotherm was performed by adding pulverized activated carbon (low density Centaur carbon
manufactured by Calgon Corporation) to a discharge sample collected on November 9' - 10'h.
The carbon was weighed and added to 1-L teflon-sealed glass bottles to achieve a final
concentration series of 0, 30, 60, 120 and 240 mg/L. Aliquots (1-L) of the discharge sample
were added to each bottle, the bottles were sealed and the contents were stirred on a magnetic
stir table. The purpose of this isotherm is to determine if toxicity could be removed, regardless
of the contact time. Therefore, the sample aliquots were stirred overnight (15 hours). The
isotherm tests were conducted at room temperature. Following carbon treatment, the aliquots
were filtered through glass fiber filters (1.6 µm pore size) to remove carbon fines. Recent tests
show that filtration does not remove toxicity; therefore, the toxicity reduction observed in the
isotherm test should be related to carbon treatment.
The filtered sample aliquots were tested for chronic toxicity using limited -scale Ceriodaphnia
dubia procedures. Test concentrations were 3.2, 6.4, 12.8, 25.6 and 51.2%. Each sample aliquot
was used for test initiation and renewal on day 5 of the test.
Isotherm plots were drawn using IC25 values and carbon doses. Three types of plots were
considered: the Langmuir and Freundlich isotherms and a simple linear regression. The
isotherm that exhibited the best fit for the data was used to estimate the optimum dosage of
carbon for toxicity treatment.
CAMy Documents\Word DocsVohn's Work\JoWAmericalWctivated Carbon\Carbon Isotherm (Nov 99 Sample).doc
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Jeff Golliher
Americal Corporation
Results
Page 3
4 December 1999
In considering an appropriate carbon dosage for treatment, it is necessary to identify a
conservative, yet realistic, target for effluent toxicity. Americal proposes to increase its flow
from the current permitted flow of 160,000 gpd to 200,000 gpd. As a result, Americal's flow
contribution to the city's Nutbush Creek W WTP will increase from 6.4% to 8.0%. Therefore,
Americal must pass its toxicity compliance test at 8.0%. A margin of safety of at least another
1 % of the flow is recommended to ensure consistent compliance. Therefore, the toxicity target
should be a "pass" at an IC25 of 9%.
Carbon Isotherm Results
Toxicity test results are summarized in Table 1. The 120 mg/L carbon dose removed toxicity to
the IC25 target level of 9.0%. As shown in Figures 1 through 3, the carbon doses were plotted
together with the toxicity results to help identify an appropriate treatment dosage. IC25 values
were used for these plots. The Langmuir isotherm (Figure 1) does not provide a reasonable fit of
the data. The Freundlich isotherm (Figure 2) does not provide a good linear fit of the data;
however, it does provide an indication of the appropriate carbon dosage for achieving the
toxicity target. A linear regression of the data shows that 120 mg/L is sufficient to achieve an
IC25 of 9.0%. However, the correlation of carbon dose versus IC25 for the Freundlich isotherm
is not strong (rz = 0.56); therefore, the 120 mg/L value should be considered as an estimate. A
linear plot of the data (Figure 3) shows that the preferred carbon dose can range from 61 to 120
mg/L.
Table 1. Results of Activated Carbon Isotherm
Dose (mg/L) NOEC LOEC ChV IC25 (C.I.)'
0
3.2
6.4
4.5
4.4
(1.1 - 6.7)
30
6.4
12.8
9.1
5.9
(4.3-8.1)
60
6.4
12.8
9.1
8.9
(8.3 - 9.5)
120
6.4
12.8
9.1
9.0
(7.8-10.1)
240
6.4
12.8
9.1
9.1
(8.8 - 9.7)
95 percent confidence intervals.
CAMy Documents\Word Docs\John's WorWobs\AmericaRActivated Carbon\Carbon Isotherm (Nov 99 Sample).doc
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Jeff Golliher Page 4
Americal Corporation 4 December 1999
A safety factor should be added to the 120 mg/L carbon dose because the IC25 value did not
approximate the NOEC. The NOEC value for the 120 mg/L carbon dose was 6.4%, which is
below the toxicity target.
Americal plans to further evaluate carbon as part of the RTA scheduled for the week of
December 6'. Samples of Americal's discharge will be tested with and without carbon to
determine if carbon removes refractory toxicity from the samples. For the purpose of the
planned RTA, a carbon dose of 180 mg/L (120 mg/L plus a 50% safety factor) is recommended.
A portion of Americal's discharge sample will be treated with 180 mg/L of pulverized activated
carbon (Calgon's Centaur brand) and the carbon -treated sample will be tested together with the
untreated sample in the RTA. If the results show that carbon effectively removes refractory
toxicity from the discharge sample, Americal plans to evaluate the feasibility of adding carbon
treatment to its pretreatment facility.
Recommendations
If the RTA test is positive, the next step in the carbon evaluation is an engineering assessment of
the feasibility of adding carbon treatment at Americal's pretreatment facility. This assessment is
necessary to ensure that carbon is compatible with the existing processes at the pretreatment
facility. Major issues of concern include (1) the corrosivity of carbon, which can damage
equipment at the pretreatment facility, and (2) potential changes in sludge characteristics that
may affect whether or not the sludge can continue to be applied to land.
ASC recommends that Americal utilize the services of an engineer who is experienced in the
design and implementation of carbon systems. A reputable vendor may be able to provide these
services. Also, if Americal desires, ASC can offer the assistance of William Kornegay, PhD, an
ASC Associate. Dr. Komegay worked for many years with Westvaco's Carbon Services
Division (Covington, VA) and has conducted many carbon studies. He has prepared design
specifications for many types of treatment facilities and has assessed the feasibility of retrofitting
treatment plants for GAC, PAC, and PACT treatment.
Dr. Komegay recommends two initial steps in an engineering assessment: (1) a review of the
pretreatment facility's design plans and specifications and operations and performance data and
(2) a one -day visit to review first-hand the operation and performance of the pretreatment facility
and discuss treatment options with Americal.
C:WIy Documents\Word DocsUohn's WorWoWArnericaMetivated CarbonTarbon Isotherm (Nov 99 Sample).doc
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Jeff Golliher
Americal Corporation
Proposed Schedule
Page 5
4 December 1999
The city must strive to be in compliance with its toxicity limitation as soon as possible;
therefore, Americal's carbon evaluation should proceed with all due speed. ASC recommends
the following schedule for the evaluation.
Americal performs RTA with carbon
Americal completes engineering study
Americal implements carbon treatment
Americal completes follow-up RTA
City completes two compliance tests
on its WWTP effluent
December 6, 1999 (week of)
January 3, 2000
February 1
March 1
March 31 (February & March tests)
If Americal passes the December 1999 and follow-up RTA test, the city has acknowledged that
the THE will be complete.
Please call me at [phone], if you have questions or comments about this report.
Sincerely,
John A. Botts
Principal Scientist
CAMy Doc=mts\Word Docs\John's WorWobs\AmericalWctivated Carbon\Carbon Isotherm (Nov 99 Sample).doc
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Jeff Golliher
Americal Corporation
225.0
200.0
175.0
150.0
125.0
V 100.0
75.0
50.0
25.0
0.0
Page b
4 December 1999
TUc Goal of 11.1 --
--'-----------
------------- ------------------------
-
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
C (TUc)
Figure 1. Langmuir Isotherm of Americal's November Discharge Sample
0.00
0.00 r
-0.20
-0.40
-0.60
-0.80
-1.00
-1.20
0.20 0.40 0.60 0.80 1.00 1.20 1.40
TUc Goal of 11.1
-1.40 '
Log (C)
Figure 2. Freundlich Isotherm of Americal's November Discharge Sample
CAMy Docwnents\Word DocsUohn's WorkUobs\Americal\Activated Carbon\Carbon Isotherm (Nov 99 Sample).doc
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Jeff Golliher
America[ Corporation
Page 7
4 December 1999
24.0------- RegressionofTUcvs--------------------------
22.0 - - - - - - 0 to 60 mg/L carbon : -
20.0-------- -
--------------
t Preferred dosage range
16.0------- 61to120mg/L
j 14.0 -------;-______--TUc Goal of 11.1
-------
x 12.0 --------=---------- ------ ---
--
10.0---------I------ — -'---- --
2 8.0 --------,--------,--- --------.------------------;----------- ----
L
4.0 ____ _ ---------- _--------- ___________-------- _______________
2.0 ________,___ _ ______ ____________________________
0.0 -- __
0 40 80 120 160 200 240
Carbon Dose(mg/L)
Figure 3. Linear Isotherm of Americal's November Discharge Sample
CAMy Documents\Word DocsVohn's WorkVobsWnerical\Ac[ivated Carbon\Carbon Isotherm (Nov 99 Sample).doc
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Aquatic Sciences Consulting 15 75 1 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
December 31, 1999
Mr. Jeff Golliher
Superintendent of Dyeing
Americal Corporation
P.O. Box 1419 `s
Henderson, NC 27536
Re: Results of December's Refractory Toxicity Assessment (RTA)
Dear Mr. Golliher:
In December, a Refractory Toxicity Assessment (RTA) was performed to evaluate the toxicity of
Americal's discharge and the potential for treatment of toxicity with activated carbon. This RTA
was performed to meet the city's requirement for two additional monthly RTA tests (per
November 5th meeting with the city).
Summary
Aquatic Sciences Consulting (ASC) performed the RTA test on December 7'h - 9th at the city's
Nutbush Creek Wastewater Treatment Plant (WWTP). In general, the test procedures followed
those used in earlier RTA tests performed in January, February, July, August and September of
this year. The test involved comparing the toxicity resulting from treatment of Americal's
discharge sample spiked into the city's mock treatment plant influent versus a control test
consisting of the mock influent alone. The use of activated carbon as a toxicity pretreatment
method was also evaluated.
Americal's discharge did not appear to contain refractory toxicity when tested at both 6.4% and
8.0% in the RTA. These results indicate that Americal was not discharging refractory toxicity
from December 6'h - 81h.
Pretreatment of the Americal discharge samples with activated carbon actually increased the
refractory toxicity. It is important to note that carbon oxidizes materials in addition to being a
sorbent. The city has observed increases in toxicity as a result of pure oxygen -activated sludge
treatment, which may be due to the formation of a toxic byproduct. Therefore, the increase in
toxicity observed in carbon/pure oxygen -activated sludge treatment of Americal's samples in the
RTA may be due to a toxic byproduct. These results cast doubt on the potential for carbon
treatment at Americal.

Jeff Golliher Page 2
Americal Corporation December 31, 1999
Further evidence for the formation of toxic byproducts was provided by the city's tests on
samples collected from their aeration tank influent (ATI). Although C. dubia mortality was
reduced by addition of 60 mg/L of activated carbon to an ATI bioreactor, reproduction remained
low (i.e., mean young of 31.2 in the control compared to 22.0 mean young in the 30% test
concentration). The low reproduction is reflected in the lower IC25 value for carbon -treated ATI
sample (27.2%) compared to the untreated ATI sample (34.1%).
Based on the RTA results, the following recommendations should be considered:
Additional tests should be performed to confirm that addition of activated carbon at Americal
is not an appropriate method for toxicity control. These tests can be performed as part of the
next RTA in January.
2. Americal should investigate alternative methods for toxicity removal. As discussed, the
toxicant of concern is more than likely a surfactant. Filtration is sometimes effective in
removing toxic surfactants. An engineering assessment and additional bench -scale tests are
recommended to evaluate filtration and other potential treatment options. The bench -scale
tests can be performed as part of January's RTA.
Technical Approach
Sampling
Grab samples from the North Nutbush line were also collected for use as the "mock" WWTP
influent. The North Nutbush line sample was used in lieu of the planned Harris St pump station
sample because of a high urea odor in the Harris St sample, which indicated potentially toxic
ammonia concentrations. The city has recently observed ammonia concentrations as high as
70 mg/L in Harris St pump station samples. Two 15-gallon North Nutbush line samples were
collected: one on December 8'b and the other on December 9 h (both collected late morning).
The samples were used on the respective days of the RTA treatment.
It was necessary to collect Americal's discharge sample one day earlier (December 6' - 7') so
that a portion of the sample could be pretreated with activated carbon (i.e., treated overnight)
before RTA testing. A second 24-hr composite sample of Americal's discharge was collected the
next day (December 7t6 - 8'h) and pretreated again with carbon RTA testing. Americal
experienced a problem in collecting the first discharge sample. When city staff arrived to pick
up the first composite sample, insufficient sample had been collected. Therefore, a grab sample
CAMy Documents\Word DocsUohn's WorkVObMrnerica1\RTA Round 6Uteport (Dec 30 99).doc
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Jeff Golliher
Americal Corporation
Page 3
December 31, 1999
was immediately collected and added to the composite sample. The second Americal sample
was a full composite sample.
In an attempt to develop an activated sludge that would not contain background toxicity, the city
operated a "fill and draw" reactor that treated "domestic" wastewater for approximately 21 days.
On November 12'b, an 8-gal return activated sludge sample was taken from the WWTP aeration
tank, placed into a 40-gal container and was fed a 15 to 17-gal 24-hr composite sample from the
Harris St pump station each day. Sludge wasting was performed as needed to maintain at least
4,000 mg/L of total suspended solids (TSS). The city monitored the reactor to ensure that
treatment performance was similar to that achieved in the WWTP (i.e., BOD, COD and
ammonia removal was adequate). On the first day of RTA testing, the mixed liquors from the
fill and draw reactor were allowed to settle, the supernatant was decanted, and the thickened
sludge was prepared for testing. An unusual green tint was observed in the reactor supernatant;
therefore, it was decided to wash the activated sludge with spring water before use in the RTA.
Ten gallons of spring water were added to approximately 7 gal of thickened activated sludge, the
mixed liquors were aerated for'/2 hour, then allowed to settled for about 2 hours. The thickened
sludge was used directly in the nitrification treatment step of the RTA as described in Appendix
A.
RTA Tests
Test procedures followed the protocol given in Appendix A.
Previous RTA tests suggest that a constituent(s) in the WWTP influent may be masking the
measurement of toxicity in the RTA. Therefore, as recommended in EPA's updated Municipal
THE Protocol (1999), a mock influent was used instead of the WWTP influent to eliminate this
possible masking effect. The mock influent consisted of wastewater collected from the North
Nutbush line, which collects largely domestic wastewater. A potential source of toxicity on the
North Nutbush line was eliminated in September. The city required Omega, an industrial
cleaner distributor, to cease cleaning drums at the carwash that discharges to the North Nutbush
line.
The RTA treatment step normally reveals the source(s) of refractory toxicity, including toxicity
caused by treatment byproducts; however, it is possible that the toxicants may be present only
after long-term treatment (i.e., greater than the 4-hour treatment time in the WWTP activated
sludge process). The precursor chemical(s) may accumulate in the activated sludge and
breakdown slowly over time to the toxicant(s) of concern. Some surfactants breakdown slowly
to form toxic byproducts. The RTA procedures were adjusted to account for this potential case.
CAMy DoctunmtsMord DmUohn's W OrkVObstAmericaI\RTA Round 6Uteport (Dec 30 99).doc
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Jeff Go[liher Page 4
America[ Corporation December 31, 1999
The modified RTA approach involved "fill and draw" treatment using multiple samples instead
of the conventional approach of treating a single sample. The activated sludge biomass used in
the first "fill" step is saved and used in the second "fill" step. In this way, residual chemical
concentrations and/or treatment byproducts can accumulate in the biomass and may be detected
in toxicity tests of treated samples. This protocol was used in RTA testing in January, February,
July, August and September 1999.
The RTA tests utilized two types of simulations: one treating the mock WWTP influent and the
other treating mock WWTP influent spiked with sewer/industry samples. The sewer/industry
spike volumes were based on the percent flow values for each sampling location. The spike
volumes and other RTA components are listed in Appendix B (Table B-1).
Results
RTA Tests
Results of the RTA operating conditions and toxicity tests are presented as follows.
Simulation Operating , Conditions
A summary of the RTA operating conditions is provided in Appendix B (Tables B-2 and B-3).
In general, the simulations effectively replicated the operating conditions of the trickling filter
and activated sludge processes at the City's WWTP.
After setup, the dissolved oxygen levels in the RTA bioreactors were set to >4 and >10 mg/L
for the Day 1 aeration step (air supply) and Day 2 aeration (oxygen supply), respectively. These
levels are typical for air -supplied and pure oxygen -supplied nitrification treatment processes and
the city usually maintains a > 10 mg/L oxygen level in its pure oxygen activated sludge process.
On both days of the test, it was necessary to add lime to the reactors to maintain the pH within an
acceptable range for nitrification treatment (i.e., above 6.7). Approximately 460 mg of quick
lime in a slurry solution (5.1% by dry weight lime) was added to the reactors, which resulted in a
57 mg/L concentration in the mixed liquors. The lime addition maintained the pH within
7.5 to 8.1 in the bioreactors.
Removal of chemical oxygen demand (COD) by the trickling filter columns and bioreactors is
shown in Table B4. As would be expected, the COD of the Americal 6.4% and 8.0% trickling
filter effluents was higher (e.g., 200 and 160 mg/L on Day 2, respectively) because of the COD
CAMy DocumentsMord DocsVohn's WorkVobsWmericaMTA Round 6Vtepon (Dec 30 99).doc
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Jeff Golliher Page 5
America[ Corporation December 31, 1999
contribution from Americal's sample. The relatively low COD of the trickling filter effluents
from the Americal carbon tests (e.g., 21 and 41 mg/L on Day 2) is a result of carbon
pretreatment of the Americal samples. The trickling filter effluent for the control reactor had a
higher COD level (140 mg/L on Day 2) than that observed in the WWTP trickling filter effluent
on December 7' (80 mg/L). However, nitrification treatment reduced COD as noted below.
After nitrification treatment, the COD values were values were consistent (e.g., 16 to 28 mg/L
for Day 2) and were similar to the COD of WWTP final effluent (<25 mg/L on December 8's).
No significant differences in COD removal were observed between the sewer/industry-spiked
tests and the control. These results indicate similar treatment of the sewer/industry-spiked and
control samples.
Toxicity Test Results
Results are shown in Table 1 and Figure 1. Results of the sewer/industry-spiked tests are
compared to the control results. As shown by the inhibition concentration (IC25) results,
Americal's discharge did not appear to contain refractory toxicity when tested at both 6.4% and
8.0% in the RTA. The addition of Americal's discharge samples to the mock WWTP influent
actually decreased toxicity relative to the mock influent alone (i.e., 73.9 and 69.7% vs. 48.2%,
respectively). These results show that Americal was not contributing refractory toxicity on
December 6'b - 8 s.
Pretreatment of the Americal discharge samples with activated carbon actually increased the
refractory toxicity (i.e., 73.9 vs. 49.2% for the untreated and carbon treated sample tested at the
6.4% flow rate and 69.7 vs. 56.3% for the untreated and carbon treated sample tested at 8.0%
flow rate). It is important to note that carbon oxidizes materials in addition to being a sorbent.
The city has observed increases in toxicity as a result of pure oxygen -activated sludge treatment,
which may be due to the formation of a toxic byproduct. It follows that the increase in toxicity
observed in carbon/pure oxygen -activated sludge treatment of Americal's samples in the RTA
may be due to a toxic byproduct. These results cast doubt on the potential for carbon treatment
at Americal.
Further evidence for the formation of toxic byproducts was provided by the tests of the city's
ATI samples. Although C. dubia mortality was reduced by addition of 60 mg/L of activated
carbon to one of the ATI reactors, reproduction remained low (i.e., mean young of 31.2 in the
control compared to 22.0 mean young in the 30% test concentration). The low reproduction is
reflected in the lower IC25 value for the carbon -treated ATI sample (27.2%) compared to the
untreated ATI sample (34.1%).
CAMy Documents\Word Docs\John's Work\IObs\Americal\RTA Round 6\Report (Dec 30 99).doc
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Jeff Golliher
Americal Corporation
Table 1. Summary of Refractory Toxicity Assessment Results
Sample Location
Limited -scale C. dubia Chronic
Page 6
December 31, 1999
Americal (6.4% flow)
67.5
90.0
77.9
73.9
70.7
- 75.9
Americal (8.0% flow)
67.5
90.0
77.9
69.7
54.8
- 73.3
Americal (6.4% w/ carbon)
45.0
67.5
55.1
49.2
45.6
- 51.0
Americal (8.0% w/ carbon)
45.0
67.5
55.1
56.3
39.8
- 68.6
Control
45.0
67.5
55.1
48.2
46.0
- 50.3
Citv's Final Effluent
90.0
> 90.0
> 90.0
> 90
NC"
95% confidence intervals
" not calculable
h 4.0
N
U
0 3.5
0
n 3.0
Y_
C
U
2.5
X
F 2.0
to
a
� 1.5
v
ra
c 1.0
t
0
to
0 0.5
Lj 0.0
Americal (6.4% Americal (8.0% Americal (6.4% Americal (8.0% Control Citys Final
flow) flow) w/ carbon) w/ carbon) Effluent
Sampling Location
Figure 1. Toxic Unit Values (100/IC25) for the December RTA Tests
C My Documents\Word Doc \John's Work\lobs\Americal\RTA Round 6\Report (Dec 30 99).dm
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Jeff Golliher Page 7
Americal Corporation December 31, 1999
The RTA control test, which is designed to simulate the city's WWTP, continues to treat toxicity
less effectively than the WWTP. A relatively high level of refractory toxicity was observed in
the control test (IC25 = 48.2%) as compared to the WWTP effluent (IC25 >90%). It is unclear
why this difference was observed, particularly after the steps taken to minimize toxicity
interferences in the RTA. As noted above, a "nontoxic" activated sludge was developed to use in
lieu of the WWTP activated sludge, which has been shown to harbor toxicity. Possible reasons
for poor toxicity treatment are that (1) the domestic fill and draw reactor was not operated long
enough to purge toxicity from the activated sludge and (2) the mock influent (North Nutbush
line) sample used in the RTA was toxic.
Recommendations
The increase in toxicity following pretreatment of Americal's samples with carbon is evidence
that a constituent in Americal's wastewater is breaking down into something more toxic. The
lack of improvement in C. dubia reproduction after carbon - activated sludge treatment of the
ATI suggests that this toxic byproduct is also present at the city's WWTP and may be
contributing to the city's effluent toxicity. Additional tests should be performed to confirm that
carbon addition at Americal is not an appropriate measure for toxicity control. These tests can
be performed as part of the next RTA in January.
Americal should investigate alternative methods for toxicity removal. As noted in earlier
reports, the toxicant in the discharge is more than likely a surfactant. For example, nonyl
phenols, a toxic surfactant, was identified in the polymer used for wastewater treatment.
Filtration is sometimes effective in removing toxic surfactants. An engineering assessment and
additional bench -scale tests are recommended to evaluate filtration and other potential treatment
options. The bench -scale tests can be performed as part of January's RTA.
Please call me [phone], if you have questions or comments about this report.
Sincerely,
John A. Botts
Principal Scientist
CAMy Documents\Word Docs\John's Work\Jobs\America1\RTA Round 6Vteport (Dec 30 99).doc
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Henderson Redbud Pump Station
Subject: Henderson Redbud Pump Station
Date: Thu, 10 Feb 2000 08:10:46 -0500
From: Judy Garrett <[e-mail]>
To: [e-mail], [e-mail], [e-mail]
Tom Spain informed me that the new portable pump was installed at
8:30 pm on Tuesday, 2/8/99. He said the pump combination was able to
handle all received flow(overflow ceased) and they have pumped down the
equilization basin. He also stated that the constriction in the
sewerline(200 ft of 12-inch line) was replaced with 24-inch line about 3
years ago and that there have been no line overflow problems
downstream. I informed him of the need to pump and haul if necessary,
in the future to prevent overflows. He said they will, if needed.
Plans for the upgrage of the pump station and paralleling of the
line have been with Construction Grants and Loans Section since
September, 1999. They hope to hear soon as to whether they will be
funded but Tom says the upgrade will be done with or without funding
from CG&L.
1 of 1 2 I5100 1 L04 AM

sso 48 hr
Subject: sso 48 hr
Date: Wed, 19 Jan 2000 15:03:22 -0500
From: Ted Cashion <[e-mail]>
To: Judy Garrett [e-mail]>, Randy Jones <[e-mail]>,
Kirk Stafford <[e-mail]>, Ted Cashion <[e-mail]>,
Steve Mitchell <[e-mail]>, Charles Alvarez <[e-mail]>,
Bob Mangum <[e-mail]>, Buster Towell <[e-mail]>,
Beth Barnes <[e-mail]>, Ken Schuster <[e-mail]>,
Tim Baldwin <I'[e-mail]>, John N Hunt [e-mail]>,
Charles Brown <[e-mail]>, Mitch Hayes <[e-mail]>,
Robin Simpson <[e-mail]>,
JENNE SOWELL <[e-mail]>,
Nancy Owens <[e-mail]>, Daniel Gerald <[e-mail]>
Tom Spain called for info on sso reporting. They had a sso ongoing for
5 day at redbud Pa. they did not do a press release yet, but were
waiting for the event to stop first. I told him H.B. 1160 requires a
press release within 48 hours after determining the discharge has
reached surface waters. They can include in the press release that this
event is ongoing, and that further details will be available in a public
notice for the event.
Please ensure that folks who call in with ongoing spills for 2, 3, or
more days (rainy day situations) that they know to press release within
48 hours, and to include in the release that this is ongoing, and that
more info will be available in the public notice for this event.
Any thing we need to discuss, are we all the same page on
this????????/let us know......
Let's be careful out there,,,,,
tc
1 of 1/20/00 9:15 AM

CITY OF HENDERSON
Post Office Box 1434
180 Beckford Drive
Henderson, North Carolina 27536-1434
Phone: [phone] FAX: [phone]
Mr. Kenneth Schuster
Regional Supervisor
Division of Environmental Management
3800 Barrett Drive, Suite 103
Raleigh, NC 27611-7687
RE: Infiltration/Inflow Status Report
Dear Mr. Schuster:
The following brief report will summarize the Identification and Correction of
Infiltration/Inflow for the quarter ending ,December,'99. . This being submitted to the
DEHNR Raleigh Regional Office in accordance with paragraph 9(g) of the Consent
Judgement (JOC #88-04) for the City of Henderson.
A total of 1,700 feet of 8" sewer main line was TV'd for breaks or leakage.
A total of 8,000 feet of 8 inch sewer main line was cleaned or rodded by City
maintenance personnel for problems using the Jet Vac machine.
An additional 31,875 feet of 8 inch and 10 inch sewer main line was cleaned for
preventative maintenance.
Two main line breaks (8") were repaired within the Red Bud Basin. The breaks were
capable of allowing an estimate of 10 gallons per minute into the sewer system, at a cost
of 2,050..
A total cost for labor and equipment for cleaning, rodding, and Tving the sewer lines was
$41,670.
If you have any questions regarding this report, please call me at 252-431-6105.
Sincerely,
01-w CITY OF HENDERSON
James H. Falkner
Utility Operations Director
C: Mr. Tim Donnelly, Regional Water Quality Supervisor
Mr. Mike Acquesta, Peirson & Whitman, Inc.
Mr. Mark Warren, Assist, City Manager
Mr. Tom Spain, WWTP Director

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OEC-01-1999 WED 12:32 PM FAX NO, P, 06
created July 28, 1999 1
revised December 1, 1999
Chronology: City of Henderson
NPDES Permit No. NCO020559
ISSUE: The City of Henderson has requested twelve months additional time (from September 30, 1999,
until October 31, 2000) to complete TRE activities while operating under the current SOC.
NOTE: This chronology does not contain a complete history of correspondence, meetings, activities,
etc, relative to Henderson's TRE work. It does not contain RRO correspondence with/to Henderson nor
does it contain correspondence from Pretreatment Unit staff to Ienderson. Key dates and activities are
listed below.
SUMMARY: The City of Henderson entered into a JOC in August 1993 to resolve effluent toxicity.
The City has been instructed on actions/aetivities which should be undertaken to resolve effluent
toxicity. The City was hesitant to begin initial TRE work due to the cost of a TRE. The City has
admittedly not been as "aggressive" towards it industrial users as it should have been. The City recently
allowed process changes at one SIU (Americal) which was targeted as a major contributor to refractory
effluent toxicity, knowing that the process modification (addition of a sock bleaching process) had the
potential to contribute additional toxic pollutant loading to the WWTP. The City has been reminded on
several occasions that DWQ had concerns in allowing additional time to complete TRE activities.
In early 1997, the City retained Mr. John Botts with Aquatic Sciences Consulting to assist with TRE
activities, While the City's recent TRE and refractory toxicity assessment work incorporates sound
science, DWQ staff has concerns with allowing additional time for completion of TRE activities under
the SOC. Henderson has been under Orders with DWQ for > five (5) years to resolve WET issue. To
date, compliance with a 90`yo chronic toxicity permit limitation has not been achieved.
KEY DATES:
August 16, 1993 JOC No. 88-04 was signed and added chronic toxicity as a noncompliant
parameter.
March 25, 1994
Meeting with City. City officials were informed of TRE, process and importance
of RTA testing. City reluctant to conduct a TRE.
May 11, 1994
Uttcr from Tedder to City indicating disappointment with City's TRE efforts.
Juno 28, 1994
Meeting with City. City again informed of activities to be considered while
conducting a TRE,
January 23, 1996
Meeting with City. City officials were informed that DWQ would not support all
extension of time to complete additional toxicity reduction studies beyond twelve
(12) months.
March 8, 1996
The City's proposed TRE activities had been suggested by DWQ staff back on
March 25, 1994.
September 24, 1996
Meeting with City. The City was informed of their responsibility to enforce S1U
Pretreatment Program Requirements ,
January 6, 1997
Meeting with City. City was informed that DWQ has concerns with allowing
additional time to complete TRE activities.
January 23, 1997
Meeting with City. The City stated that it had not been as "aggressive" as it
should have been with Americal.

/ ac-01-1909 WED 12:33 PM FAX NO. P. 07
• created July 28, 1999 2
revised December 1, 1999
May 6, 1997
Meeting with City. The City was informed that its SIUs were not keeping
tracking logs for process modifications.
March 11, 1999
City entered into SOC with 9/30/99 achieve compliance date for chronic toxicity.
July 27, 1999
Meeting with City. The City requests additional 12 months time to complete
TRE activities. City indicates that Americal implemented a new bleaching
process which was more toxic than clyc wastestream alone. The change
reportedly did not involve an increase in flow. City expressed their fear of sewer
moratorium and indicated that they would do "what is right" to prevent
moratorium.
September 23, 1999
Meeting with City, City presented recent RTA findings. DWQ had concerns
With potential Pretreatment Program violations. DWQ requested that City submit
information on current TRE focus and progress achieved.
October 1, 1999
Letter from City indicating past and present TRH progress.
October 5, 1992 - Memo from ATU to RRO concerning the City's Industrial Chemical
Inventory, Long -Term Monitoring Plan, and TRE Plan. Specific points of our correspondence included:
the initiation dates proposed for the activities were excessively late; there was very little file
information, if any, that would document any organized attempts by the facility to reduce effluent
toxicity; justification of the proposed schedules based on construction of a new laboratory was
unfounded; the City could not use its own lab for compliance monitoring unless it first received
certification from the Division making the City's estimate of $150,000 to $200,000 savings by
conducting its own TRE irrelevant under the current time frame.
May 12, 1993 The City received a letter written by the Regional Office for Steve Tedder's
signature approving the City's TRE.
August 16, 1993 - JOC No. 88-04 All 1I was signed which added chronic toxicity, lead,
crtdmium, chromium, nickel, and total phosphorus as -noncompliant parameters.
March 25, 1994 - Representatives from Aquatic Toxicology Unit met with City officials and
provided information on TRE activities which ATU considered important to the TRE process. These
activities included: characterization/identification of effluent toxicants, multiple concentr lion toxicity
testij2g_during the TRF,, and refractory toxicity testips. The City of Henderson openly expressed its
position to the Division that it was not in favor of conducting a TRE due to costs which may be
associated with TRE work.
April 25, 1994 - Representatives from this office met with City officials and staff from the
Office of Waste Reduction to discuss a grant proposal designed to integrate the State's Pollution
Prevention and pretreatment program features. A $17,000.00 grant was later awarded to the City.
May 11, 1994 - Correspondence from Steve Tedder to Mayor Young indicating the Division's
disappointment with the scattered nature of the City's TRE efforts, The City had conducted a number of
priority pollutant scans at its industries and submitted a large amount of data to the Division with no
formal conclusions drawn from the data.
June 28, 1994 - Representatives from the City, the Division, and the City's engineering firm met
to discuss the May 11 correspondence mentioned above, The City indicated that they were "shocked"
by the negative tone of the May I correspondence and thought they were doing everything possible to
evaluate the cause(s) of effluent toxicity,

O1-1999 WED 12:33 PM FAX N0, P. 08
created July 28, 1999 3
revised December 1, 1999
March 17, 1995 - Memo from this office to the Raleigh Regional Office concerning the City's
request for a three month time extension tinder the JOC. Our concluding comments stated, "we feel the
City has not expended the resources necessary to evaluate toxicity noncompliance in a timely manner."
August 3, 1995 - Memo from this office to the Raleigh Regional Office transmitting review
comments for the City's June 1995 THE Progress Report. The report cites foaming in the treatment
system which may be an indication of surfactants or surfactant containing compounds. ATU continues
to support the March 1, 1996, date to achieve compliance in the City's JOC,
January 23, 1996 - Meeting with City officials, BRI, and DWQ staff to discuss THE findings
and the City's request for additional lime to conduct TRF activities. The City was informed that the
Division would not support an extension of time beyond twelve months (ie, 3/l/97). The City was given
an application for a Special Order by Consent.
February 28, 1996 - Letter from the Town to the Director requesting termination of the JOC and
consideration of a SOC with a date to achieve compliance with final limits for chronic toxicity of March
1, 1997.
March 8, 1996 - Memo from this office to the Raleigh Regional Office transmitting review
comments for the City's January 1996 TRE- progress report. The City acknowledged that industrial
discharges to the Nutbush Creek WWTP represent potential sources of refractory toxicity and proposes:
to conduct industrial flow screenings at selected SIUs, to evaluate chemicals in use by the City's SIUs,
and to characterize the effluent. NOTE: The Proposed THE activities in this nroaress.renort were all
suggested to the City back during March 1994.
Septemher 24, 1996 - Meeting at the Raleigh Regional Office with City officials, DWQ staff,
and BRi to discuss problems the City encountered with acquiring chemical usage information from one
SIU. The City was informed that it is their responsibility to enforce their sewer use ordinance and to
take appropriate actions against SIUs whenever violations of the sewer use ordinance occur. BRI
presented information suggesting that the primary effluent toxicant "behaves like a suifactunt." Effluent
toxicity was refractory since WWTP sludge and biomass were not being inhibited.
January 6, 1997 - Meeting in Henderson at Americal attended by DWQ staff, BRI, City officials
and Americal staff. WWTP data suggested an improvement with conventional parameters when
Americal's pretreatment unit was functional. During this meeting the City again asked whether a
request for more time to complete THE activities was reasonable. The City was informed that ATU had
concerns over allowing additional time to complete THE activities beyond the proposed March 1, 1997.
deadline.
January 23, 1997 - Meeting requested by Henderson at the Raleigh Regional Office attended by
City officials, BRI, and DWQ staff. BRI presented information that effluent toxicant(s) are non -polar
organics and toxicity is reduced by aeration and carbon filtration. City hind EA Engineering, Science,
and Technology to conduct RTA studies. The City Manager admitted that the City had not been as
"aggressive" with Americal as it should have been and dial it would be placing Amcrical on a
compliance schedule, Copies of Waste Reduction Audits by Office of Waste Reduction had not been
received by all the industries which requested site evaluations. At this meeting the City provided several
pictures of various wastewater treatment system components which were ovciflowing with large
amounts of red foam. The City suspected the foam was from Americal.
February 18, 1997 — ATU, RRO and PT staff met at City Ball and Amcrical (SIU)
At City Hall, Henderson indicated that additional aeration lime may assist in toxicity reduction. The
City noticed an improvement in WWTP effluent quality whenever Americal was operating its
pretreatment unit, At Americal meeting, the SIU admitted that they were contributing to toxicity at the
Nutbush WWTP but felt that they may not be the only contributing source of toxicity,

of-1999 WED 12:33 PH
FAX NO, P. 09
created July 28, 1999 4
revised December 1, 1999
May 6, 1997 — Meeting with City at RRO, City presented THE findings by John Botts and
indicated they had spent $124, 358.12 on toxicity testing and evaluation. City was informed that its SIUs
were not keeping tracking logs and process changes/modifications and that would hinder THE efforts.
May 13, 1997 -- Comments from ATU on THE work. ATU supported recommendations by
Botts to conduct additional RTA testing, consider H2O2 addition as a potential treatment option, and
several others. ATU stressed that City should sit down with its SiUs and explain their problem and
discuss solutions. City should also conduct bench scale testing of any proposed WWTP modifications.
June 17, 1998 -- Meeting at RRO with City, ATU, Pretreatment, and City's engineers (McKim
and Creed) to discuss DWQ's enforcement strategy, SOC status, and recent tox results. Henderson feels
that 4 hours detention time is insufficient and is proposing a wastewater treatment upgrade (oxidation
ditches). City issued a pretreatment permit to Burkatt Carolina, a previously targeted source of toxicity.
December 4, 1998 — Comments from ATU to RRO concerning 9809 progress report. ATU not
convinced that treatment plant upgrade without corresponding source reduction activities will effectively
resolve effluent toxicity.
March 11, 1999 — Letter from Director to City transmitting SOC EMC WQ No. 96-005.
Achieve compliance date of 9/30/99 for chronic toxicity. SOC continues until 3/01/02 for Redbud Pump
Station completion
July 28, 1999 - Meeting at RRO with City, Pretreatment, and ATU staff. City discussed TIE
activities and presented a request for additional time to complete THE work. Americal (SIU) started up
a new process for bleaching socks (reportedly no increase in flow). Results of wastestream discharge
from sample collected in March showed an increase in toxicity compared to the dye wastestream sample
- 48-h LC50 of <l%, Virco Wet NSL, a wetting agent, is extremely toxic with a 48-h EC50 of 5 µg/L.
Polymer usage by Americal reduced by 213 previous level. City implementing a new toxicity tracking
system (TTS) which can be placed directly in trunklines and detects presence of non -polar organics.
The City is requesting an additional 12 month extension of the SOC. City indicates that additional time
is Justified because; toxicity is variable and hard to locate, the City will take enforcement if it is proven
that Americal is a source of toxicity, the City is working with its tad toxicity consultant and Yd toxicity
laboratory, and the City has spent $245,000.00 in a three year period to resolve toxicity issues.
September 23, 1999 — Meeting at RRO. Recent RTA'work discussed. Questions involving
potential pretreatment program violations. DWQ requested that the City provide a summary of THE
activities and how the City's focus has changed with respect to recent THE work. Accomplishments
include: hiring an Assistant City Managcr in late 1997, transferring the Pretreatment program from the
City's engineering office to the wastewater plant in January 1998, hiring of a chief plant operator in
mid-1998, providing additional staff resources to the WWTP laboratory, hiring McKim & Creed in
January 1998 to evaluate WWTP upgrade, authorizing additional TRF, work with Aquatic Sciences
Consulting, retaining environmental attorney Glenn Dunn in mid -September to assist the City with legal
issues.
Comments from ATU regarding THE Progress Reports dated: 9/29199, 8/31/99, 6/3/99,
3/17/99,12/4/98, 6/9/98, 6/5/97, 3/13/97, 3/8/96 and 8/3/95.

DEC-01-1999 WED 12:32 PM FFAX NO. ?. 0i
State of North Carolina
Department of Environment
and Natural Resources 1��
Division of Water Quality
James B. Hunt, Jr., Governor D E N R
Bill Holman, Secretary
Kerr T. Stevens, Director
December 1, 1999
Division of Water Quality
Environmental Sciences Branch & Wetlands/401 Unit
Location: 4401 Reedy Creels Road
Raleigh, N.C. 27607
Mailing Address: 1621 Mail Service Center
Raleigh, N.C. 27699
FAX: [phone]
I FAX TO: Kirk Stafford I FAX NUMBER: 919.571.4718 1
FROM: Kevin Bowden r)�
PHONE: [phone]
NO. OF PAGES INCLUDING THIS SHEET: 9
Kirk, please find naaehed two documents, 1) our 11/29/99 comments regarding Henderson's 9911 THE
progress report and 2) a selected chronology of Henderson's THE activities. T'he chronology is not
intended to be a complete history, rather it attempts to provide important information relative to
activities/meetings/etc. to substantiate the issue that Henderson has been granted sufficient time to
complete THE work.
Call if you have questions. kevin

DEC-01-1999 WED 12:32 PM FAX NO, P. 02
DIVISION OF WATER QUALITY
November 29, 1999
MEMORANDUM
To: Ken Schuster
Through: Matt Matthews rpt'
From: Kevin Bowden ,58
Subject: THE Progress Report — November 1999
City of Henderson
SOC EMC WQ No. 96-05
NPDES Permit No. NCO020559
Vance County
This office has received and reviewed the facility's quarterly November 1999 THE progress
report. The report was transmitted to the Raleigh Regional Office by cover letter from the City dated
November 9, 1999. Item 2(b)(2) of the SOC specifies that quarterly THE progress reports be submitted
to DWQ no later than the 15th day of each February, May, August, and November. The 50C specifies a
September 30, 1999 date to achieve compliance with all final effluent limitations and contains an upfront
penalty of $5140.00 for failing to achieve compliance with final permit limitations while operating under
the previous Judicial Order by Consent. The report has been prepared with assistance front Aquatic
Sciences Consulting. The NPDES Parinit requires compliance with a 909b chronic toxicity permit
limitation.
The report addresses THE activities accomplished from August 16, 1999 through November 15,
1999 and provides activities for the upcoming quarter.
Three (3) effluent multiple concentration Ceriorlophnia dubia chronic toxicity tests (August 18,
September 8 and October 27) were conducted during the study period. Chronic values measured 21.2%,
77.9%, and 21.2%, respectively.
The City initiated TIE testing on a June effluent sample. The results of this testing were reported
as inconclusive. Although toxicity was recovered front C18 solid phase extraction testing, toxicity was
not recovered in accompanying methanol eluate fractions. Testing results suggest that toxicity is spread
out among the eluate fractions and not easily detected, a characteristic of surfactants. Additional testing
is necessary to confirm or deny this assumption.
Pretreatment program initiatives include:
Y Identification of a new source of toxicity, ffaffiet & Henderson South Cotton
Mill
Review of Americal's THE efforts
➢ Review of weekly chemical usage reports
Continued toxicity monitoring of lUs
Continued quarterly inspections of major lUs
Reviuw of small IUs with water usage as low as 15,000 cubic feet per month
> Communication with IUs regarding pretreatment activities
OMEGA CLEANING PRODUCTS
Omega Cleaning Products, a local industry was targeted as potentially contributing to refractory
toxicity, The Company was taking spent drums containing cleaning solutions to a local car wash for
rinsing. Based on information provided by the Company and the potential from washdown to contribute

DEC-01-1999 WED 12:32 PM FAX NO, P. 03
surfactants to the POTW, the _.., notified Ortega that cleaning of produc tainers at a local car wash
was unacceptable,
HARRIET AND HENDERSON COTTON MILLS
Refractory Toxicity Assessment (RTA) and Toxicity Tracking Systems (TTS) results from May
and June suggested that sewer lines serving Harriet & Henderson (H&H) North and South Mills
contributed intermittent toxicity to the POTW. The City inspected the Company on August 16 and 17
and obtained "further evidence of nondomestic discharges." Harriet & Henderson Mills are permitted to
discharge only sanitary wastes to the City's system. The City issued a letter to H&H in September
describing evidence for the toxic discharges and providing a list of actions for investigating the
discharges. In late September RTA testing on discharge samples from both mills was performed. Results
indicated that the south mill discharge was a contributing source of refractory toxicity versus the control
effluent (IC25 of 19.70/6 and 36.9%), respectively.
On October 14, H&H submitted a reply to the City regarding their THE progress and indicated
that no cross connections had been found between the cooling tower discharge piping and the sanitary
sewer. The report notes that the City plans to meet with H&H representatives to discuss RTA test results
and THE progress.
AMERICAI, CORPORATION
RTA testing of Amcrieal's effluent during July suggested that the effluent was not contributing
refractory toxicity (IC25 of 69.6%). Daring August the Company replaced a softener, VircoSoft 348,
with another softening agent. Sparl-ube LB 50 which reportedly does not contain nonylphenols.
An August RTA procedure using Americal's wastestream was invalidated due to an
"interference" which was observed in the RTA sample treatments and not the RTA control. TriTest
Labs, the laboratory performing the RTA testing, observed a biological growth resembling fungi in the
RTA samples. This growth was not observed in the controls for RTA testing or for other clients during
the test period.
Results from the September RTA indicated overlapping 95% confidence intervals (C.I.) in the
Americal sample (I025 C.I. of 6.7.32.3) and control sample (IC25 C.T. of 32.3-42.2). Language in
Anterical's pretreatment permit states, "Unacceptable RTA toxicity is defined as a significant percent
difference between the chronic inhibition concentration (IC25) values for the discharge -spiked test
simulation and the control simulation as determined by a comparison of the 95% percent confidence
limits (BI)." The report notes that although the confidence interval for the Americal test was broader
than typically observed for RTA tests, test results indicate that Americal's effluent was not contributing
refractory toxicity to final POTW effluent as specified by terms of the pretreatment permit. The
pretreatment permit also requires Americal to pass two consecutive monthly RTA tests to demonstrate
that toxicity reduction measures have been successful, While RTA test results from July and September
tests indicate that this condition was met, the City is concerned about the "apparent toxicity of the
September discharge sample even though it technically passed the test criteria."
City personnel met with Americal representatives on November 5 to discuss the September IYfA
test results. At the meeting. Americal agreed to evaluate the use of activated carbon in its pretreatment
facility. Americal will perform carbon trcatability testing prior to the upcoming RTA test this quarter.
AUGUST RTA
Sample results from the August RTA testing were considered inconclusive due to biological
growth observed in RTA effluents. Samples were collected from the Harriet and Henderson Cotton
Mills, Burkhart Carolina, and Americal. The report suggests that biological growth was caused by a
component of the RTA test, possibly dilution mock influent wastewater or activated sludge. On June 24,
the City completed repairs to the first stage trickling filters. This action decreased effluent BOD values
from 50 tng/L to 30 mg/l. and lowered the F/M ratio in the activated sludge basin. Lower F/M ratios can

DEC-01-1999 WED 12:32 PM FAX NO, P. 04
contribute to pin floc, which pne city has observed since July 12, and fungal growth. The report notes
that biological growth may have been introduced by an industrial discharge. Various organisms such as
bacteria, fungi and bacteria are found in cooling tower blowdown. The report notes a wastewater
treatment plant upset during the week of August G.
SEPTEMBER RTA
Prior to conducting the September RTA, the City made several corrections to the RTA procedure
to minimize the presence of biological growth. Actions included utilizing a different source of mock
influent (North Nutbush line versus Country Club pump station) and increasing the F/M ratio of the
activated sludge process. The report notes that Harriet & Henderson's South Mill was the only source: of
toxicity noted during the September RTA,
QUARTERLY INDUSTRY MONITORING
All major industries were monitored during the quarter and included Amorical, Jlall Foster,
IAMB, J.P. Taylor and Kennametal. Samples were collected September 20 for a single sample toxicity
test. "Fail" test results were reported for Americal and Ball Foster at their respective flow contributions
to Henderson (6.4% flow for Americal, Ball Foster was tested at 1.0%; whereas, flow contribution is
actually 0.8%n). Balt Foster's observed toxicity may have been ardfactual since one of the test replicates
died causing the mean young neonate count to be significantly lower than the control. Ball Foster
installed a water recycling system several years ago and actual flow is approximately onc-fourth the
permitted flow. Based on Ball Foster's compliancc record (no toxicity failures in five years) and
information that no manufacturing or process changes have occurred since the last "pass" test result was
obtained, the City decided to resample the Company's discharge using a P/F test rather than conducting
RTA testing.
SUMMARY
The City's efforts to investigate sewer/industrial monitoring have resulted in the following
conclusions:
D Harriet & Henderson's South Mill was identified as an intermittent source of toxicity.
➢ The apparent toxicity of Americal's discharge during September is a cause for concern,
Americal has agreed to conduct an evaluation using activated carbon for toxicity reduction.
The City is considering plans to upgrade the WWTP to include biological treatment. Organic
carbon removal and biological nutrient removal are processes which will be considered in the upgrade.
The report notes that if results from biological treatability testing demonstrate that the proposed process
improvements are expected to achieve compliance with Henderson's toxicity limit then the City will
request a waiver of the TRE.
Proposed activities for the upcoming quarter are reasonable.
Our office has several comments concerning the City's TYRE work First, we acknowledge the
scope of the current TYRE invostigat ions being conducted by the City. The City is considerably more
focused with respect to its TRE, approach and has gained valuable knowledge on IU discharges to the
POTW. Second, while the current RTA work is providing information regarding sources of refractory
toxicity, we feel that the City's past history of long-term toxicity non-compliance should not be
overlooked. We are curious what action(s) the City will pursue against Ilatriet & Henderson anti if it
plans an visiting the site to verify information provided by the Company. We agree that overlapping
95%n confidence intervals obtained for the Americal September RTA testing should be scrutinized and
warrant additional toxicity testing.
The City indicated that they would request a TRE waiver if biological treatability testing
demonstrated that the now treatment processes would achieve compliance with the 90°h, chronic limit.
The City has also submitted a request for an additional twelve months to complete the TRE under the

DEC-01-1999 WED 12:32 PM FAX N0, P. 05
current SOC. We have cons Hith supporting the City's request for ar clonal twelve month time
extension to achieve compliance with final permit limits for chronic toxicity.
If you have any questions, please feel free to contact me at 733.2136,
cc; Coleen Sullins -Water Quality Section Chief
Bill Rcid-Point Source Branch
Marcia Licbcr-Point Source Compliance./F.nforcement Unit
Kirk Stafford, Raleigh Regional Office
Tom Poe -Pretreatment
Tom Spain, City of Henderson, PO Box 1434, Henderson, NC 27536
Aquatic Toxicology Unit Files
Central Files

-DEC-01-1999 WED 12:32 PM FAX N0, P. 06
created July 28, 1999 1
revised December 1, 1999
Chronology: City of Henderson
NPDES Permit No. NC0020559
ISSUE: The City of Henderson has requested twelve months additional time (from September 30, 1999,
until October 31, 2000) to complete TRL activities while operating under the current SOC.
NOTE: This chronology does not contain a complete history of correspondence, meetings, activities,
etc. relative to Henderson's TRE work. It does not contain RRO correspondence with/to Henderson nor
does it contain correspondence from Pretreatment Unit staff to Henderson. Key dates and activities are
listed below.
SUMMARY: The City of Henderson entered into a JOC in August 1993 to resolve effluent toxicity.
The City has been instructed on actions/activities which should be undertaken to resolve effluent
toxicity, The City was hesitant to begin initial TRF, work due to the cost of a TRE. The City has
admittedly not been as "aggressive" towards it industrial users as it should have been. The City recently
allowed process changes at one SIU (Americal) which was targeted as a major contributor to refractory
effluent toxicity, knowing that the process modification (addition of a soek bleaching process) had the
potential to contribute additional toxic pollutant loading -to the WWTP. The City has been reminded on
several occasions that DWQ had concerns in allowing additional time to complete TRE activities.
Tn early 1997, the City retained Mr. John Botts with Aquatic Sciences Consulting to assist with TRE
activities, While the City's recent TRE and refractory toxicity assessment work incorporates sound
science, DWQ staff has concerns with allowing additional time for completion of TRE activities under
the SOC. Henderson has been under Orders with DWQ for > five (5) years to resolve WET issue. To
date, compliance with a 9076 chronic toxicity permit limitation has not been achieved.
KEY DATES:
August 16, 1993 JOC No. 88-04 was signed and added chronic toxicity as a noncompliant
parameter.
March 25, 1994
Meeting with City. City officials were informed of TRF, process .and importance
of RTA testing. City reluctant to conduct a TRE.
May 11, 1994
Letter from Tedder to City indicating disappointment with City's TRE efforts.
Juno 28, 1994
Meeting with City. City again informed of activities to be considered while
conducting a TRE,
January 23, 1996
Meeting with City. City officials were informed that DWQ would not support ail
extension of time to complete additional toxicity reduction studies beyond twelve
(12) months.
March 8, 1996
The City's proposed TRE activities had been suggested by DWQ staff back on
March 25, 1994.
September 24, 1996
Meeting with City. The City was informed of their responsibility to enforce SIU
Pretreatment Program Requirements ,
January 6, 1997
Meeting with City. City was informed that DWQ has concerns with allowing
additional time to complete TRE activities.
January 23, 1997
Meeting with City. The City stated that it had not been as "aggressive" as it
should have been with Amcrical.

DEC-01-1999 WED 12:33 PM FAX NO. P, 07
created July 28, 1999 2
revised December 1, 1999
May 6, 1997
Meeting with City. The City was Informed that its SIUs were not keeping
tracking logs for process modifications.
March 11, 1999
City entered into SOC with 9/30/99 achieve compliance date for chronic toxicity.
July 27, 1999
Meeting with City. The City requests additional 12 months time to complete
TRE activities. City indicates that Americal implemented a new bleaching
process which was more toxic than dyc wastestream alone. The change
reportedly did not involve an increase in flow. City expressed their fear of sewer
moratorium and indicated that they would do "what is right" to prevent
moratorium.
September 23, 1999
Meeting with City, City presented recent RTA findings. DWQ had concerns
With potential Pretreatment Program violations. DWQ requested that City submit
information on current TRE focus and progress achieved.
October 1, 1999
Letter from City indicating past and present TRE progress.
October 5, 1992 - Memo from ATU to RRO concerning the City's Industrial Chemical
Inventory, Long --Term Monitoring Plan, and TRE Plan, Specific points of our correspondence included:
the initiation dates proposed for the activities were excessively late; there was very little file
information, if any, that would document any organized attempts by the facility to reduce effluent
toxicity; justification of the proposed schedules based on construction of a new laboratory was
unfounded; the City could not use its own lab for compliance monitoring unless it first received
certification from the Division making the City's estimate of $150,000 to $200,000 savings by
conducting its own TRE irrelevant under the current time frame.
May 12, 1993 The City received a letter written by the Regional Office for Steve Tedder's
signature approving the City's TRE.
August 16, 1993 - JOC No. 88-04 AD II was signed which added chronic toxicity, lead,
cadmium, chromium, nickel, and total phosphorus as. noncompliant parameters.
March 25, 1994 - Representatives from Aquatic Toxicology Unit met with City officials and
provided information on TRE activities which ATU considered important to the TRE process. These
activities included: characterization/identification of effluent toxicants. multiple concentration toxicity
testing during the TRE, and refractory toxicity testis. The City of Henderson openly expressed its
position to the Division that it was not in favor of conducting a TRE due to costs which may be
associated with TRE work.
April 25, 1994 - Representatives from this office met with City officials and staff from the
Office of Waste Reduction to discuss a grant proposal designed to integrate the State's Pollution
Prevention and pretreatment program features. A $17,000.00 grant was later awarded to the City.
May 11, 1994 - Correspondence from Steve Tedder to Mayor Young indicating the Division's
disappointment with the scattered nature of the City's TRE efforts. The City had conducted a number of
priority pollutant scans at its industries and submitted a large amount of data to the Division with no
formal conclusions drawn from the data.
June 28, 1994 - Representatives from the City, the Division, and the City's engineering firm met
to discuss the May 11 correspondence mentioned above, The City indicated that they were "shocked"
by the negative tone of the May 11 correspondence and thought they were doing everything possible to
evaluate the cause(s) of effluent toxicity,

•DEC-01-1999 WED 12:33 PM FAX NO, P. 08
created July 28, 1999 3
revised December 1, 1999
March 17, 1995 - Memo from this office to the Raleigh Regional Office concerning the City's
request for a three month time extension under the JOC. Our concluding comments stated, "we feel the
City has not expended the resources necessary to evaluate toxicity noncompliance in a timely manner."
August 3, 1995 - Memo from this office to the Raleigh Regional Office transmitting review
comments for the City's June 1995 THE Progress Report. The report cites foaming in the treatment
system which may be an indication of surfactants or surfactant containing compounds. ATU continues
to support the March 1, 1996, date to achieve compliance in the City's JOC,
January 23, 1996 - Meeting with City officials, BRI, and DWQ staff to discuss THE findings
and the City's request for additional lime to conduct TRF activities. The City was informed that the
Division would not support an extension of time beyond twelve months (ie, 3/l/97). The City was given
an application for a Special Order by Consent.
February 28, 1996 - Letter from the Town to the Director requesting termination of the JOC and
consideration of a SOC with a date to achieve compliance with final limits for chronic toxicity of March
1, 1997.
March 8, 1996 - Memo from this office to the Raleigh Regional Office transmitting review
comments for the City's January 1996 THE progress report. The City acknowledged that industrial
discharges to the Nutbush Creek WWTP represent potential sources of refractory toxicity and proposes:
to conduct industrial flow screenings at selected SIUs, to evaluate chemicals in use by the City's SIUs,
and to characterize the effluent. NOTE: The proposed THE activities in this-p osress rereport were all
suggested to the City back during March 1994.
September 24, 1996 - Meeting at the Raleigh Regional Office with City officials, DWQ staff,
and BRi to discuss problems the City encountered with acquiring chemical usage information from one
SIU. The City was informed that it is their responsibility to enforce their sewer use ordinance and to
take appropriate actions against SIUs whenever violations of the sewer use ordinance occur. BRI
presented information suggesting that the primary effluent toxicant "behaves like a surfactant." Effluent
toxicity was refractory since W WTP sludge and biomass were not being inhibited.
January 6, 1997 - Meeting in Henderson at Americal attended by DWQ staff, BRI, City officials
and Americal staff. WWTP data suggested an improvement with conventional parameters when
Americal's pretreatment unit was functional. During this meeting the City again asked whether a
request for more time to complete THE activities was reasonable. The City was informed that ATU had
concerns over allowing additional time to complete THE activities beyond the proposed March 1, 1997,
deadline.
January 23, 1997 - Meeting requested by Henderson at the Raleigh Regional Office attended by
City officials, BRI, and DWQ staff. BRI presented information that effluent toxicant(s) are non -polar
organics and toxicity is reduced by aeration and carbon filtration, City hired EA Engineering, Science,
and Technology to conduct RTA studies. The City Manager admitted that the City had not been as
"aggressive" with Americal as it should have been and that it would be placing Americal on a
compliance schedule, Copies of Waste Reduction Audits by Office of Waste Reduction had not been
received by all the industries which requested site evaluations. At this meeting the City provided several
pictures of various wastewater treatment system components which were overflowing with large
amounts of red foam. The City suspected the foam was from Americal.
February 18, 1997 — ATU, RRO and PT staff met at City Ball and Americal (SIU)
At City Hall, Henderson indicated that additional aeration time may assist in toxicity reduction. The
City noticed an improvement in WWTP effluent quality whenever Americal was operating its
pretreatment unit, At Americal meeting, the SIU admitted that they were contributing to toxicity at the
Nutbush WWTP but felt that they may not be the only contributing source of toxicity,

,DEC-01-1999 WED 12:33 PM FAX NO, P. 09
created July 28, 1999 4
revised December 1, 1999
May 6, 1997 — Meeting with City at RRO. City presented THE findings by John Botts and
indicated they had spent $124, 358.12 on toxicity testing and evaluation. City was informed that its SIUs
were not keeping tracking logs and process changes/modifications and that would hinder THE efforts.
May 13, 1997 — Comments from ATU on THE work. ATU supported recommendations by
Botts to conduct additional RTA testing, consider H202 addition as a potential treatment option, and
several others. ATU stressed that City should sit down with its SIUs and explain their problem and
discuss solutions. City should also conduct bench scale testing of any proposed WWTP modifications,
June 17, 1998 -- Meeting at RRO with City, ATU, Pretreatment, and City's engineers (McKim
and Creed) to discuss DWQ's enforcement strategy, SOC status, and recent tox results. Henderson feels
that 4 hours detention time is insufficient and is proposing a wastewater treatment upgrade (oxidation
ditches). City issued a pretreatment permit to Burkatt Carolina, a previously targeted source of toxicity.
December 4, 1998 — Comments from ATU to RRO concerning 9809 progress report. ATU not
convinced that treatment plant upgrade without corresponding source reduction activities will effectively
resolve effluent toxicity.
March 11, 1999 — Letter from Director to City transmitting SOC EMC WQ No. 96-005,
Achieve compliance date of 9/30/99 for chronic toxicity. SOC continues until 3/01/02 for Redbud Pump
Station completion
July 28, 1999 - Meeting at RRO with City, Pretreatment, and ATU staff. City discussed TIE
activities and presented a request for additional time to complete THE work. Americal (SIU) stalled up
a new process for bleaching socks (reportedly no increase in flow). Results of wastestream discharge
from sample collected in March showed an increase in toxicity compared to the dye wastestream sample
- 48-h LC50 of <1`%, Virco Wet NSL, a wetting agent, is extremely toxic with a 48-h EC50 of 5 µg/L.
Polymer usage by Americal reduced by 2/3 previous level. City implementing a new toxicity tracking
system (TTS) which can be placed directly in trunklines and detects presence of non -polar organics.
The City is requesting an additional 12 month extension of the SOC. City indicates that additional time
is justified because; toxicity is variable and hard to locate, the City will take enforcement if it is proven
that Americal is a source of toxicity, the City is working with its 2"d toxicity consultant and 3rd toxicity
laboratory, and the City has spent $245,000.00 in a three year period to resolve toxicity issues.
September 23, 1999 — Meeting at RRO. Recent RTA'work discussed. Questions involving
potential pretreatment program violations. DWQ requested that the City provide a summitry of THE
activities and how the City's focus has changed with respect to recent THE work. Accomplishments
include: hiring an Assistant City Manager in late 1997, transferring the Pretreatment program from the
City's engineering office to the wastewater plant in January 1998, hiring of a chief plant operator in
mid-1998, providing additional staff resources to the WWTP laboratory, hiring McKim & Creed in
January 1998 to evaluate WWTP upgrade, authorizing additional TRF, work with Aquatic Sciences
Consulting, retaining environmental attorney Glenn Dunn in mid -September to assist the City with legal
issues.
Comments from ATU regarding THE Progress Reports dated: 9/29/99, 8/31/99, 6/3/99,
3/17/99,12/4/98, 6/9/98, 6/5/97, 3/13/97, 3/8/96 and 813/95.

CITY OF HENDERSON
Post Office Box 1434
180 Beckford Drive NUfBUSHCREEK WASTEWATER
Henderson, North Carolina 27536-1434 TREATMENT PLANT
Phone: [phone] FAX: [phone]
November 9, 1999
Mr. Ken Schuster
Raleigh Regional Supervisor
NC DENR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: City of Henderson Nutbush Creek W WTP
NPDES #NC0020559
SOC-EMC WQ No. 96-05
November Quarterly THE Report
Dear Mr. Schuster,
I am forwarding our November Quarterly Toxicity Reduction Evaluation (TRE) report
as required by our SOC.
The City is anxiously awaiting a decision from the Division of Water Quality on our
requested extension of the toxicity compliance deadline in our SOC.
If you have any information regarding our SOC or any questions, please contact me at
[phone].
Sincerely,
Thomas M. Spain
WWTP Director
C: Eric Williams, City Manager
Mark Warren, ACM
Reggie Hicks, Lab Supervisor
Judy Garrett, DWQ-RRO
Kirk Stafford, DWQ-RRO
Matt Matthews, DWQ-ATU
Kevin Bowden, DWQ-ATU
Tom Poe, DWQ Pretreatment
Dana Folley, DWQ Pretreatment
John Botts, Aquatic Sciences Consulting
Files

Progress Report
for the Toxicity Reduction Evaluation
at the City of Henderson's Nutbush Creek Wastewater Treatment Plant
NPDES No. NCO020559
August 16 through November 15,1999
Submitted In F ulffilment of the Special Order by Consent
EMC WQ No. 96-05
Prepared for
Department of Environment, Health and Natural Resources
3800 Barrett Drive, Suite 100
Raleigh, North Carolina 27609
Prepared by:
City of Henderson
P.O. Box 1434
Henderson, NC
With Assistance by:
Aquatic Sciences Consulting
15751 Bushy Park Rd
Woodbine, Maryland 21797

t City of Henderson THE P.,,s.ess Report Page 2
NPDES No. 0020559 November 10, 1999
Introduction
This quarterly progress report is prepared and submitted to meet the November 15d' date
specified by Section 2(b)2 of the City of Henderson's draft Special Order by Consent (SOC
EMC WQ No. 96-05). This report describes the progress made in the last quarter (August 16
through November 15, 1998), the plans for the next quarter, and any significant issues that may
delay progress in completing the TRE.
Progress in the Preceding Quarter
1. Results of WWTP Effluent Toxicity Monitoring
A total of three toxicity compliance tests were performed in the preceding quarter. Monthly
effluent monitoring was performed, as required by the SOC. Results are summarized in Table 1.
Table 1. Summary of Monthly Compliance Test Results
Sample Collection Dates Test Initiation Date ChV (%)
Aug 16-17 and Aug 18-19 Aug 18 21.2 ti7"y /1
Sep 6-7 and Sep 8-9 Sep 8 77.9
Oct 26-26 and Oct 28-29 Oct 27 21.2
Cr C M ea
As with previous tests, these results show a wide variability in effluent toxicity (see Appendix
A). Following the July compliance test, which showed no chronic toxicity, the August effluent
sample was relatively toxic. Again, after the September compliance test, which showed
relatively low toxicity, the October effluent sample was toxic. These data indicate an
intermittent source of toxicity. The city recently identified an intermittent source of toxicity and
results of the industrial user's investigation of the cause(s) of toxicity are described below.
Results of a Phase R Toxicity Identification Evaluation (TIE) test of a toxic June effluent sample
were inconclusive. Although toxicity was recovered from the initial C 18 solid phase extraction
(complete mortality in 24-hours in the methanol eluate corresponding to 400% effluent), toxicity
was not recovered from the high performance liquid chromatography (HPLC) column. No
chronic effect was observed in any of the 30 methanol fractions eluted from the HPLC column
and tested at 165% effluent. These results suggest that the toxicant(s) was spread out among the
fractions and therefore, not readily detected. Surfactants have this characteristic; however,
additional testing is needed to confirm this conclusion.

t City of Henderson THE L rpess Report Page 3
NPDES No. 0020559 November 10, 1999
2. Pretreatment Program Initiatives
Progress achieved in the preceding quarter includes:
• Identifying a new intermittent source of toxicity, the Harriet & Henderson south cotton mill
(see Section 3)
• Reviewing Americal Corporation's progress in identifying and controlling source(s) of
toxicity at its textile processing facility.-
acility. i
DReceiving weekly the cal usage re orts that list daily quantities of chemicals used.
• Continuing to monitor the toxicity of industrial user discharges (see results below).
• Continuing quarterly inspections of major industrial users (i.e., all major industries have been
and will continue to be inspected each quarter).
• Reviewing small industrial users with water usage as low as 15,000 cu. 8. per month.
• Continuing frequent communication with the industries regarding pretreatment activities and
their relationship to toxicity.
In August, the city submitted a synopsis of the industrial waste survey forms to DWQ
Pretreatment Unit. Upon review of the survey forms, the city did not identify any potential
significant industrial users. The survey information was also reviewed with respect to potential
toxic discharges. No such discharges were indicated.
J2The city reviewed information submitted by Omega Cleaning Products on cleaning products.
*ZThis review indicated the potential for discharge of surfactants of concern to the sanitary sewer.
he city notified Omega that cleaning of product containers at the local car wash would not be
Pallowed. Omega has an onsite septic tank for sanitary wastes.
In October, the City met with IAMB to discuss their progress in meeting the compliance
agreement and consent order (CACO) for phosphorus. IAMB submitted a proposed schedule for
the wastewater treatment plant upgrade.
3. Harriet and Henderson's THE /V U I
Results of Toxicity Tracking System (TTS) and Refractory Toxicity Assessment (RTA) tests
performed in May and July indicated intermittent toxicity in the sewer lines serving Harriet &
Henderson's North and South Mills. Harriet & Henderson is authorized to discharge only
sanitary wastes to the city's sewers; therefore, the city was concerned about the possible
discharge of toxic nondomestic wastewater. On August 16a' - 171', the city inspected Harriet &
Henderson's cotton mills (North and South Mills). Further evidence of nondomestic discharges
was obtained.

t City of Henderson THE Progress Report
NPDES No. 0020559
Page 4
November 10, 1999
In September, the city submitted a letter to Harriet & Henderson that described the evidence for
toxic discharges and provided a list of action items for investigating the discharges. The
requirements in the letter constituted the requirements that permitted industrial users would have
to complete if a THE was required. The action items included:
• Providing information on chemical usage at the North and South Henderson Cotton Mills,
including material safety data sheets (MSDS), other available vendor data, chemical usage
rates, and frequency of discharge.
• Requiring submittal of Biocide/Chemical Pretreatment Worksheet —Form PT101 for all
biocides used at the North and South Mills.
• Completing THE date logs on a weekly basis.
• Providing maps of the sanitary and cooling water sewers at the North and South Mills,
including locations of discharge points (e.g., cooling water and sanitary flows) and the
chemicals used at each location.
(l�hL Investigating cooling water losses at the North and South Henderson Cotton Mills to
r determine if piping within the facilities is leaking and possibly discharging to the City's
sanitary sewer.
• Determining the characteristics and ultimate disposal method of wastewater from the South
Mill's Zorrella Yarn Conditioner.
• Submitting a copy of the spill prevention and control plans for the North and South Mills.
On October 14`s, Harriet & Henderson submitted a letter report on their progress in
accomplishing the action items. The report included MSDS on chemicals used in the mill
HVAC systems, PT-101 forms on all biocides used at the mills, copies of their cooling water
discharge permits, site drawings indicating the sanitary and cooling water discharge points, THE
date logs, and copies of stormwater pollution prevention plans. In their letter, Harriet &
Henderson indicated that they had not found any cross connections between the cooling tower
discharge piping and the sanitary sewer.
In late September, the city performed RTA tests on discharge samples from both Harriet &
Henderson cotton mills. The effluent of the Harriett & Henderson South Cotton Mill test was
more toxic than the control effluent (i.e., IC25s of 19.7 vs. 36.9%,respectively). The 95%
confidence intervals for the IC25 values did not overlap; therefore, the mill sample contained
significant refractory toxicity. Based on these results, the South Mill is considered a source of
refractory toxicity. The city plans to meet with Harriet & Henderson to discuss the implications
of the RTA results and the industry's progress in the TRE.

City of Henderson THE Progress Report Page 5
NPDES No. 0020559 November 10, 1999
4. Americal Corporation's THE
Americal submitted a final THE report and performed RTA tests to confirm that their efforts to
reduce toxicity have been successful. THE reports submitted to the City are presented in
Appendix B. A summary of the final THE report and the RTA test results for this quarter is
provided as follows.
Results of Americal's July RTA test suggested that effluent toxicity has abated. Nonetheless,
Americal continued to evaluate further process changes to ensure compliance with the toxicity
requirement. Americal contacted a chemical vendor about a substitute for a softening a e
VircoSoft 348 that contains nonyl phenols. In August, this soften ce another
softening agent, SparLube LB50 (manufactured by Spartan), tha :reportedl a not contain / S
nonyl phenols. -T& t at R1 �v
ct-0
C(ecL �( Cl /lY ►1 l(�
Following the process changes, Americal con ucted a second consecutive monthly RTA test in
August. This test was invalid due to an interference in the toxicity tests performed on the RTA
effluents. TriTest, the laboratory performing the toxicity tests for the RTA, observed what
appeared to be a biological growth in the sample treatments of the toxicity tests. The growth was
not found in the toxicity test controls or in any tests performed for other clients during the test
period. These results suggest that the growth was caused by a component of the RTA test such
as the activated sludge or mock influent wastewater used for diluting the sewer/industry samples.
Another RTA test was performed in September. The test involved comparing the toxicity of
Americal's discharge sample spiked into the city's mock treatment plant influent versus a control
test consisting of the mock influent alone. Although the effluent of the Americal-spiked test was
more toxic than the control effluent (i.e., ChVs of 11.5% versus 36.9%), the confidence intervals
for the tests overlapped (i.e., upper bound of the Americal's test result was the same as the lower
bound of the control test result). It should be noted that the confidence interval for the Americal
test was wider than typically observed for RTA tests. Nonetheless, the results show that
Americal was not contributing refractory toxicity by the terms specified in the discharge permit.
The permit states:
"Unacceptable RTA toxicity is defined as a significant percent difference between the chronic inhibition
concentration (IC25) values for the discharge -spiked test simulation and the control simulation as
determined by a comparison of the 95 percent confidence limits (Bl) ".
According to the discharge permit, Americal must pass two consecutive monthly RTA tests to
demonstrate that toxicity reduction measures have been successful. Both the July and September
RTA tests show that Americal has satisfied this condition. However, the city is concerned about
the apparent toxicity of the September discharge sample even though it technically passed the
test criteria.
On November 5a', the city met with Americal to discuss the September RTA results. Americal
representatives described current production activities and chemical usage. Based on the city's
concern about the potential toxicity of Americal's discharge, Americal representatives agreed to

City of Henderson THE Progress Report Page 6
NPDES No. 0020559 November 10, 1999
evaluate the use of activated carbon for toxicity reduction. Americal's evaluation will be
performed in parallel with the city's study of carbon treatment at its WWTP. Americal will
perform carbon tests prior to the RTA test to be performed this coming quarter.
5. Sewer and Industrial User Monitoring
The City conducted intensive sewer and industry monitoring in the previous quarter. RTA tests
were performed in August and September to evaluate the toxicity contribution from the Sandy
Creek sewershed and the Redbud main line.
5.1 August RTA
The August testing included samples collected from the two Harriett & Henderson cotton mills,
which are located in the toxic County Home areas. Samples were also collected from Burkart
Carolina, which discharges to the Sagefield line, and Americal. The results of the Harriet &
Henderson and Americal RTA tests are described above in Sections 3 and 4, respectively.
Unfortunately, the results of the August RTA were inconclusive due to an interference in the
toxicity tests performed on the RTA effluents. The interference was the same problem noted for
the Harriet & Henderson and Americal RTA tests (Sections 3 and 4). A biological growth
resembling fungi caused an unusual dose response in the toxicity tests. For example,
Ceriodaphnia dubia reproduction in the RTA control effluent was as follows:
Test Concentration (%): 90% 67.5% 45% 30% 15% Control
C. dubia Reproduction (Mean Young): 0 0 14.6 15.8 9.4 21.6
Mean young production was reduced to nearly equal levels in the 15, 30 and 45% concentrations.
The similarity in results may be explained by an adverse effect of the growth, which was
observed in each of the test concentrations. A review of the results suggested that the growth
was caused by a component of the RTA test such as the activated sludge or mock influent
wastewater used for diluting the sewer/industry samples.
The City has observed pin floc in the aeration basin effluent since the week of July 12`s. The pin
floc may be indicative of the recent lower organic loading to the activated sludge process. On
June 24a', the City completed repair of the first -stage trickling filters. As a result, the effluent
BOD from the trickling filters has decreased from an average of 50 mg/L to 30 mg/L. This
decrease in BOD has lowered the food to microorganism (F/M) ratio in the activated sludge
basin from 0.05 lb/lb to 0.04 lb/lb. The lower F/M can contribute to pin floc and, perhaps,
favorable conditions for fungal growth.
The fungi may also have been introduced or promoted by an industrial discharge. Fungi, as well
as algae and bacteria, can be prevalent in cooling water tower blowdown. In addition, the
biological growth may be promoted by treatment process upsets. During the week of August 6U',
the treatment process was upset by an apparent slug loading of inhibitory wastewater. The City
experienced some washout of suspended solids from the clarifiers due to floating floc.

t City of Henderson THE Progress Report
NPDES No. 0020559
5.2 September RTA
Page 7
November 10, 1999
The RTA protocol was modified to minimize the presence of the biological growth observed in
the August RTA. First, another source of mock influent was used for testing. The mock influent
consisted of wastewater collected from the North Nutbush line in lieu of the sampling point for
the August RTA (i.e., Country Club pump station). The city required Omega, an industrial
cleaner distributor, to cease cleaning drums at the carwash that discharges to the North Nutbush
line. Therefore, this potential source of toxicity was eliminated during the sample collection
period. Second, the F/M of the activated sludge process was increased to minimize pin floc and,
perhaps, favorable conditions for fungal growth.
The September testing used samples from the same sources that were sampled for the August
RTA. Results are summarized in Table 2 and Figure 1. A discussion of the Harriet &
Henderson and Americal results are provided in Sections 3 and 4, respectively. Other than
Harriet & Henderson's South Mill, no other sources of toxicity were indicated.
Table 2. Summary of Refractory Toxicity Assessment Results
Sample Location
Limited-scaleC. dubia
End
NOEC
LOEC
ChV
IC25
(IC25 C I'
Sandy Creek P.S.
30
45
37
34.4
14.9
- 35.4
North Cotton Mill
30
45
37
35.4
32.2
- 36.8
South Cotton Mill
15
30
21
19.7
18.7
- 20.8
Americal
15
30
21
11.5
6.7
- 32.3
Burkart
30
45
37
36.8
35.2
- 39.3
Redbud Main Line
30
45
37
52.7
48.4
- 57.4
Redbud Pump Station
15
30
21
30.7
22.6 - 34.6
Control
30
45
37
36.9
32.3 - 42.2
VWVfP Final Effluent
90
> 90
> 90
> 90.0
NC**
' 95% confidence intervals
not calculable
5.3 Ouarterly Industry Monitoring
Each of the major industries, including Americal, Ball Foster, IAMB, J.P. Taylor, and
Kennametal were monitored for toxicity in the preceding quarter. Results are summarized in
Table 3.

City of Henderson THE Progress Report Page 8
NPDES No. 0020559 November 10, 1999
j 15
14
c 13
12
11
j 10
u 9
O 8
F 7
A
a 6
v 5
R 4
C
a 3
a 2
O 1
d 0
l�
Sandy North South Ameriaal Burkart Redbud Redbud Control VWVrP
Creek P.S. Cotton Mil Cotton PAII Main Line Pump Final
Station Effluent
Sampling Location
Figure 1. Inhibition Concentrations Values for the September RTA Tests
Table 3. Quarterly Monitoring Results for Major Permitted Industries*
Industry Test Concentration' Pass/Fail Result
Americal
6.4%
Fail
Ball Foster'**
1.0%
Fail
IAMs
6.6%
Pass
J.P. Taylor
1.6%
Pass
Kennametal
0.8%
Pass
Samples collected September 20 for single sample test.
" Equivalent to flow contribution to the City's treatment plant.
*" Ball Foster's sample was inadvertently tested at 1.0% instead of the flow contribution of 0.8%
The monitorinj results indicate that Americal was contributing raw wastewater toxicity in
September (20 - 2l'); however, the RTA test performed by Americal in September (22nd - 241b)
showed no refractory toxicity contribution (see Section 4 above). Ball Foster's discharge was
also toxic. However, the apparent toxicity may have been an artifact of the test. One of the ten
replicates of the test concentration died, which caused the mean young value to be significantly

City of Henderson THE Progress Report Page 9
NPDES No. 0020559 November 10, 1999
lower than the control (i.e., 23.92 vs. 31.17, respectively). If this replicate is removed, the mean
young value (26.1) would not be significantly lower than the control value.
Ball Foster installed a water recycling system several years ago and as a result their current flow
is actually less than one -quarter of their permitted flow (i.e., 5,000 vs. 23,000 gpd). Therefore,
the toxicity test concentration, which is based on their permitted flow, is overly conservative.
Also, Ball Foster has not failed a toxicity test since monitoring of their discharge began more
than five years ago. In addition, Ball Foster has not changed their manufacturing process or
chemical usage since the last toxicity test, which was a "pass".
The city has decided to carefully evaluate Ball Foster's discharge together with other, more
significant, sources of toxicity. However, based on the above considerations, Ball Foster's
discharge will be retested as soon as possible using the pass/fail test procedure, rather than
proceeding to relative costly refractory toxicity assessment (RTA) testing.
5.4 Summary
The City's sewer/industry monitoring effort has yielded the following conclusions:
• Harriet & Henderson's South Mill was identified as an intermittent source of toxicity.
• Although Americal's September discharge sample technically passed the test criteria, the
apparent toxicity of the sample is cause for concern. Due to the ciWs concern, Americal
has agreed to perform an evaluation of the use of activated carbon for toxicity reduction.
Based on these conclusions, the City has developed a preliminary plan to control the sources of
toxicity as described below.
6. Biological Treatability Testing
The city is in the process of considering plans for an upgraded W WTP, which will include a new
biological treatment system. The general design of the biological treatment process will be a
multi -stage process that includes both organic carbon removal and at least some biological
nutrient removal. The current design allows for a hydraulic retention time of 16 hours in aerobic
treatment, which may oxidize toxicants.
n Although the new process will consist of several stages, the stage that is likely to achieve the
W 1 f greatest toxicity reduction is the aerobic stage. The city is in the process of testing the aerobic
process in a simple bench -scale, "fill and draw" study. The testing involves treating the WWTP
influent with the current activated sludge for a sufficient period of time to establish a biomass
that is similar to the activated sludge of the new aerobic stage. In September, the study was
started by adding W WTP influent, together with the city's biomass, to two replicate aerobic
bioreactors. Each day, the air is stopped, the biomass solids are settled and the effluent is
withdrawn and discarded. Excess biomass solids are wasted as necessary, a new W WTP influent
sample is added and the bioreactors are aerated again. It will be necessary to perform the fill and

City of Henderson THE Progress Report Page 10
NPDES No. 0020559 November 10, 1999
draw treatment for several months (at least two sludge ages) to ensure that the biomass is
acclimated to the process.
Bioreactor samples collected after a few weeks of treatment were toxic. However, it is possible
that the process had not yet stabilized. Once the city is confident that the process has stabilized,
the city will collect additional effluent samples for toxicity testing. The results will be reviewed
to examine the capability of the new process for achieving the discharge permit limit for toxicity.
If results demonstrate that the new treatment process is expected to achieve compliance with the
toxicity limit, the city will request a waiver of the TRE. 7
Plans for the Neat Quarter `
The City plans to conduct the following work in the next quarter (November 16, 1999 through
February 15, 2000):
1. Chronic C. dubia compliance tests will be performed each month as specified in the SOC
2. The City will meet with Harriett & Henderson to discuss the results of their investigation into
cross connections to the sanitary sewer, biocide usage, and the refractory toxicity of the
South Mill discharge sample collected in September. The city will request Harriett &
Henderson to submit a THE plan with an implementation schedule.
3. Americal will be required to perform a follow-up RTA test to confirm the reported toxicity
reduction. The city will also review America's evaluation of activated carbon as a toxicity
reduction method.
4. The City will continue to monitor for potential sources of toxicity in the Sandy Creek
sewershed and the Redbud main line.
5. The City will inspect all major industrial users in the next quarter. During the inspections,
the City will focus again on activities that can be performed to help minimize the discharge
of toxicity.
6. The City will conduct another Phase II TIE test on a toxic effluent sample. This test will
involve passing a very large volume of effluent sample through the C18 column to
concentrate the toxicants as much as possible. Concentrating the sample may allow detection
of the toxicants when they are fractionated on the HPLC column.
7. The City will continue to evaluate the toxicity reduction capability of the proposed treatment
plant upgrade.

Appendix A
Historical Ceriodaphnia dabia Chronic Toxicity Data
for the Nutbush Creek WWTP Effluent

ry ' N NO 0 Jm m 91
tJ + v N p W0 W mNDLCD S T�ODLL�T <L � N
�awv� �^v ��m �w < a Nn wOOa8 Uv N N
V A v v V v v V v v v v V A V A
v v v v v v v v v v v v
v v v v v v
v v v v v v v v
OOOOVoO N000 UNi (mp fW0000� (mli N O [mli m tW00 UmiN V NtAp N W m+� J � W � W N W O NOOm000000
Z O Z O A N m � a0nC1 N 000
Z Z
n n
t0 + WVCJmi0 m N m N Z m W fp O m {D p N Z O Z L A Z Z Z Z y Z tli m Ol
mN� mN V OZ Z�OZya,ZZjNZZy�omt@WW ZJ WOWJm WmN(O N(JA NZ Z2omWmnn�OOn��OO�nrnO'OOO�v2ZZZ mZJOOn�.0000�0
0 0 0 0 0
O' p N O m m O m 'O W O W (A fJ tJ m N O V N N W ut N

Ceriodaphnia dubia Chronic Values (ChVs) for City of Henderson
Nutbush Creek WWTP Effluent
51
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Appendix B
Americal Corporation
Toxicity Reduction Evaluation Reports

Aquatic Sciences Consulting 15 75 1 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
October 11. 1999
Mr. Jeff Golliher
Superintendent of Dyeing
Americal Corporation
P.O. Box 1419
Henderson, NC 27536
Re: Results of Refractory Toxicity Assessment (RTA)
Dear Mr. Golliher:
In September, a Refractory Toxicity Assessment (RTA) was performed to confirm the toxicity
reduction observed in Americal's discharge in July. This test was a follow-up to the August RTA
test, which was inconclusive due to a test interference. September's RTA test was performed to
meet the permit requirement for consecutive monthly RTA tests. The results of this testing are
described as follows.
Summary
Aquatic Sciences Consulting (ASC) performed the RTA test on September 23'd and 246' at the
city's Nutbush Creek Wastewater Treatment Plant (W WTP). Test procedures followed those
used in earlier RTA tests performed in January, February, July and August of this year. The test
involved comparing the toxicity resulting from treatment of Americal's discharge sample spiked
into the city s mock treatment plant influent versus a control test consisting of the mock influent
alone.
Although the effluent of the Americal-spiked test was more toxic than the control effluent (i.e.,
ChVs of 11.5% versus 36.9%), the confidence intervals for the tests overlapped (i.e., upper
bound of the Americal's test result was the same as the lower bound of the control test result). It
should be noted that the confidence interval for the Americal test was wider than typically
observed for RTA tests. Nonetheless, the results show that Americal was not contributing
refractory toxicity by the terns specified in the discharge permit.
According to the discharge permit, Americal must pass two consecutive monthly RTA tests to
demonstrate that toxicity reduction measures have been successful. Both the July and September
RTA tests show that Americal has satisfied this condition (Note that the August lest was invalid).

Jeff Golliher Page 2
Americal Corporation October 11, 1999
However, in consideration of the near failure of the test, it is recommended that an additional
chemical review be performed. Americal has noted that much of the bleaching operation has
been transferred to the Franklinton facility. In the meantime, the dyeing operatin-i has been
increased. Therefore, the composition of the wastewater has changed, which may have had an
effect on the RTA results. The results of the review, including recommendations for further
testing and/or chemical substitutions, should be documented in a brief report. Once the
recommendations have been implemented, tests should be performed on the discharge to confirm
compliance with the toxicity limit.
Technical Approach
Sampling
There was an error in collecting the composite sample of Americal's discharge on September 22"d
- 23`d. Americal was notified to collect one (1) gallon of their discharge; however, the city was
advised that two (2) gallons would be collected (error was made by the consultant). When the
city arrived on September 23`d (9AM) to pick up the sample, only about one gallon was in the
sampler bottle. The city started the sampler and pumped about one more gallon into the sampler
bottle. Therefore, the sample consisted of about one gallon of 24-hour composite sample and
one gallon of grab sample. Normally, a 24-hour composite sample is used to initiate the RTA
test (I at day) and a portion of the sample is saved and used again on the second day of testing. In
this case, however, the combined composite/grab sample collected on a Septem`_ -r 22"d - 23rd
was used for the first day of the test and a second full 24-hour composite sample of Americal's
discharge (collected on September 23 d - 24d') was used for the second day of the test. It should
be noted that on September 23rd the city observed that the grab sample was darker in color than
the composite sample.
Samples from the North Nutbush line and W WTP return activated sludge (RAS) line were also
collected for the RTA. The North Nutbush line sample was a 40 gallon 24-hour composite
collected on September 22"d - 23d. This sample was used for both the first and second days of
testing. Insufficient sample was available for the second day of RTA testing; therefore, an
additional 10 gallon grab sample was collected on September 24 h and added to the composite
sample. The RAS sample was a 10 gallon grab collected at 1 PM on September 23d.
RTA Tests
Test procedures followed the protocol given in Appendix A.
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Jeff Golliher Page 3
Americal Corporation October 11, 1999
Previous RTA tests suggest that a constituent(s) in the W WTP influent may be masking the
measurement of toxicity in the RTA. Therefore, as recommended in EPA's upd.:,ed Municipal
THE Protocol (Draft 1999), a "mock" influent was used instead of the WWTP influent to
eliminate this possible masking effect. The mock influent consisted of wastewater collected
from the North Nutbush line, which collects largely domestic wastewater. This location was
used again in lieu of the sampling point for previous RTA tests (i.e., Country Club pump station)
because of concerns about fungal contamination. The city required Omega, an industrial cleaner
distributor, to cease cleaning drums at the carwash that discharges to the North Nutbush line.
Therefore, this potential source of toxcity was eliminated during the sample collection period.
The RTA treatment step normally reveals the source(s) of refractory toxicity, including toxicity
caused by treatment byproducts; however, it is possible that the toxicants may be present only
after long-term treatment (i.e., greater than the 4-hour treatment time in the W WTP activated
sludge process). The precursor chemical(s) may accumulate in the activated sludge and
breakdown slowly over time to the toxicant(s) of concern. Some surfactants breakdown slowly
to form toxic byproducts. The RTA procedures were adjusted to account for this potential case.
The modified RTA approach involved "fill and draw" treatment using multiple samples instead
of the conventional approach of treating a single sample. The activated sludge biomass used in
the first "fill" step is saved and used in the second "fill" step. In this way, residual chemical
concentrations and/or treatment byproducts can accumulate in the biomass and L:ay be detected
in toxicity tests of treated samples. This protocol was used in Americal's toxicity study in
January, February, July and August 1999.
The RTA tests utilized two types of simulations: one treating the mock W WTP influent and the
other treating mock W WTP influent spiked with sewer/industry samples. The sewer/industry
spike volumes were based on the percent flow values for each sampling location. The spike
volumes and other RTA components are listed in Appendix B (Table B-1).
Results
RTA Tests
Results of the RTA operating conditions and toxicity tests are presented as follows.
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Jeff Golliher Page 4
America[ Corporation October 11, 1999
Simulation Operating Conditions
A summary of the RTA operating conditions is provided in Appendix B (Tables'3-2 and B-3).
This summary includes general conditions for the trickling filter and nitrification simulation
steps.
In general, the simulations effectively replicated the operating conditions of the trickling filter
and activated sludge processes at the City's W WTP. After set up, the dissolved oxygen levels in
the RTA bioreactors were set to >4 and > 10 mg/L for the first aeration step (air supply) and
second aeration (oxygen supply), respectively. These levels are typical for air -supplied and pure
oxygen -supplied nitrification treatment processes and the city usually maintains a >10 mg/L
oxygen level in its pure oxygen activated sludge process.
On Day 2, it was necessary to add lime to the reactors to maintain the pH within an acceptable
range for nitrification treatment (i.e., above 6.7). Approximately 360 to 411 mg of quick lime in
a slurry solution was added to the reactors, which resulted in a 45 to 51 mg/L concentration in the
mixed liquors. This amount of lime maintained the pH within 6.8 to 7.3 for the Americal-spiked
reactor and 7.0 to 7.3 for the control.
No significant differences in chemical oxygen demand (COD) removal were observed between
the Americal-spiked test and the control (see Table B-4). On the first day of testing, the effluent
COD concentration of the nitrification process effluent was similar for the spike6 and control
tests (<25 mg/L, respectively). These results indicate similar treatment of the Americal-spiked
and control samples. On Day 2, the effluent COD concentration of the spiked and control tests
was also relatively similar (24 and 40 mg/L, respectively), which indicates similar treatment
performance. However, the COD level of the control trickling filter effluent on Day 2 was more
than double the COD level of the Americal-spiked treatment. Foaming was observed during
trickling filter treatment of the control sample. It is possible that the foaming was caused by
detergent residues from washing the filter column. The detergent would impart a relatively high
COD.
Toxicity Test Results
Toxicity results are presented in Table 1. Results of the America] -spiked test are compared to the
control results. Although the effluent of the Americal-spiked test was more toxic than the control
effluent (i.e., ChVs of 11.5% versus 36.9%), the confidence intervals for the tests overlapped
(i.e., upper bound of the Americal's test result was the same as the lower bound of the control test
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Jeff Golliher
Americal Corporation
Page 5
October 11, 1999
result). It should be noted that the confidence interval for the Americal test was wider than
typically observed for RTA tests. Nonetheless, the results show that Americal was not
contributing refractory toxicity by the terns specified in the discharge permit. 1 he permit states:
"Unacceptable RTA toxicity is defined as a significant percent difference between the chronic
inhibition concentration (IC25) values for the discharge -spiked test simulation and the control
simulation as determined by a comparison of the 95 percent confidence limits (BI)".
Given that the test nearly failed, it is recommended that Americal perform an additional review
of chemicals used in the dyeing process and follow-up toxicity tests on the discharge.
Table 1. Summary of Refractory Toxicity Assessment Results
Test Limited -scale C. dubia Chronic Endpoints
NOEC LOEC ChV IC25 (C.I.)-
Americal 15 30 21 11.5 (6.7 - 32.3)
Control 30 45 37 36.9 (32.3 - 42.2)
' 95% confidence intervals
Please call me [phone], if you have questions or comments about this report.
Sincerely,
John A. Botts
Principal Scientist
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Appendix A
Refractory Toxicity Assessment Procedures for the Americal Study

Americal Corporation
Appendix A - RTA Procedures
Page A-2
October 11, 1999
Refractory Toxicity Assessment Procedures for the Americal Study
Results of in -plant monitoring at the City's Nutbush Creek W WTP show no decrease in
toxicity after treatment (in the aeration tank) and sometimes an increase in toxicity. At
the same time, little or no toxicity has been found in raw wastewater samples collected
from the Sandy Creek sewershed, the area where toxicity appears to be originating.
These results suggest that toxicity may be manifested only after treatment.
The RTA treatment step normally reveals the source(s) of refractory toxicity, including
toxicity caused by treatment byproducts; however, no clear source(s) of toxicity has been
recently identified by the RTA approach. It is possible that the toxicants may be present
only after long-term treatment (i.e., greater than the 4-hour treatment time in the W WTP).
The precursor chemical(s) may accumulate in the activated sludge and breakdown slowly
over time to the toxicant(s) of concern. Some surfactants breakdown slowly to form
toxic byproducts. An adjustment in the RTA procedures was, therefore, needed to
account for this potential case.
The general RTA approach was modified to evaluate potentially toxic breakdown
products. This approach involved "fill and draw" treatment using multiple samples
instead of the conventional approach of treating a single sample. The activated sludge
biomass used in the first "fill" step was saved and used in the second "fill" step. In this
way, residual chemical concentrations and/or treatment byproducts could accumulate in
the biomass and might be detected in toxicity tests of treated samples.
RTA treatment simulated the main treatment processes at the Nutbush Creek W WTP,
including trickling filtration, nitrification, and filtration. Although, hydrogen peroxide
(HZOZ) is currently being added at the Nutbush Creek WWTP, this oxidant was not added
in the RTA because the City is interested in reducing and eliminating the use of H202.
Also, a coarse glass -fiber filter was used in lieu of a bench -scale tertiary filter column
because a previous study had shown that filtration using glass -fiber filters provides
similar results compared to granular media filtration (Aquatic Sciences Con.._Iting,
1998).
The first "fill and draw" step, referred to as the "Toxicant Accumulation Protocol", was
performed as follows:
Two and one-half (2 '/2) gallon samples of Americal's pretreatment facility effluent
and North Nutbush line sample were collected on September 22°d -23`d. The North
Nutbush line sample was used as the "mock influent" for the control test. This test
was compared to the Americal-spiked test, which consisted of the Americal sample
spiked into the North Nutbush line sample. A portion of the North Nutbush line
sample was saved and used on the second day of testing. A second Americal sample
was collected on September 23`d - 24'h and used on the second day of testing.

Americal Corporation
Appendix A - RTA Procedures
Trick
C
(with r
Page A-3
October 11, 1999
StaltIC
imp
Figure B-1. Schematic of Trickling Filter Column Simulation
2. Wastewater samples were passed through columns, which simulated the W WTP
trickling filter process (see Figure B-1). The trickling filter columns consisted of
4-inch diameter, 3-ft PVC columns filled with stone media collected from one of the
WWTP trickling filters. A peristaltic pump fed samples to the columns in a
downflow mode. The column effluent was collected and recirculated to the top of the
column over a 2 hour period. This retention time was selected based on an earlier
study (Aquatic Sciences Consulting, 1997) that showed this treatment period to be
comparable to the W WTP process.
3. Following trickling filter treatment, the humus solids (fixed film biomass that washed
off the rocks) were allowed to settle and the supernatant was decanted for further
treatment by activated sludge (see Figure B-2).

Americal Corporation
Appendix A - RTA Procedures
Wastewater and
Return Activate"
Plastic or Glass
Container
Control Reactor
POTW Influent
(Control)
Air Supply
(Oil -Free)
Air Line
Tubing
Air Stone
Page A-4
October 11, 1999
Spiked Reactor
Sewer/Industrial
Wastewatp• ¢piked
Into POTW Influent
Figure B-2. Schematic of Activated Sludge Nitrification Simulation
4. The RAS was rinsed with distilled water to remove potential toxicants before use in
testing. An 11.5-gal RAS sample was added to a 40-gal container, 8 gal of distilled
water was added, and the mixture was aerated for about 1 hour. RAS solids were
allowed to settle and the supernatant was decanted and discarded. The rinsed RAS
was dispensed into 2 t/2 gal plastic reactors. The initial suspended solids
concentration was about three times the average mixed liquor suspended solids
(MLSS) concentration of the City's aeration treatment system (i.e., 3,500 mg/L • 3),
5. Wastewater samples were added to the reactors in three additions over about a 15-
hour treatment period. The final volume of wastewater resulted in a MESS
concentration that approximated the MLSS concentration of the City's process.
6. Air was supplied to the reactors during the treatment period to maintain a dissolved
oxygen concentration of 2 to >4 mg/L.
At the end of the 15-hour treatment period, the air was stopped and the mixed liquor
was allowed to settle. The supernatant was decanted and tested for COD.
8. The settled activated sludge biomass was saved and used for the second "fill and
draw" treatment step.
The second "fill and draw" step, referred to as the "RTA Protocol", was used to assess the
refractory toxicity of the second Americal sample collected for the study. Samples were
treated and tested for refractory toxicity using the procedures outlined below:
1. The second sample volume (North Nutbush and Americal samples collected on Day 1
and Day 2, respectively) was treated in trickling filter columns using Steps 1 and 2

Americal Corporation
Appendix A - RTA Procedures
Page A-5
October 11, 1999
noted above. The trickling filter effluents were prepared for activated sludge
treatment.
2. The RAS saved from the above Toxicant Accumulation Protocol (Steps 3-6) was
added to the activated sludge reactors.
3. Wastewater samples (total volume) were added to the reactors. The resulting MISS
concentration approximated the MISS concentration of the City's treatment process.
4. Oxygen was supplied to the reactors by a pressurized tank. A dissolved oxygen
concentration of >2 mg/L was maintained for the first hour of the 4-hour treatment
period. In the remaining 3 hours, the dissolved oxygen level was set to >10 mg/L
5. It was necessary to add lime to the reactors to maintain the pH within anacceptable
range for nitrification treatment (i.e., above 6.7). Approximately 360 to 411 mg of
quick lime in a slurry solution was added to the reactors, which resulted in a 45 to 51
mg/L concentration in the mixed liquors. This amount of lime maintained the pH
within 6.8 to 7.3 for the Americal-spiked reactor and 7.0 to 7.3 for the control.
6. At the end of the 4-hour treatment period, the oxygen was stopped and the mixed
liquor was allowed to settle. The supernatant was decanted and filtered through a
coarse glass -fiber filter (2.7 µm pore size). The filtered samples were shipped
overnight to the laboratory for testing. The samples were tested for toxicity using a
limited -scale Ceriodaphnia dubia chronic test. C. dubia tests utilized five effluent
concentrations (100, 75, 50, 25, and 12.5%) and a control with 5 replicates per
concentration. Each RTA sample was used for test initiation and renewal on days 3
and 5 of the toxicity test. Samples were held at 4°C between test renewals.
Data Evaluation
The results of the simulation spiked with the Americal discharge sample were compared
to the control simulation results. Evidence of refractory toxicity would be provided if the
effluent toxicity of the spiked simulation is greater than the effluent toxicity bf the control
simulations.

Appendix B
Refractory Toxicity Assessment Operating Conditions

Table B-1. Components for the Trickling Filter and Oxygen -Nitrification Simulations - September RTA"
Trickling Filter Components (liters)
Nitrification Components (liters)
Test
Industry/Sewer
Mock Total
Trickling Filter
Nitrification
Total
Discharge
WWTP Volume
Effluent Volume
Sludge
Volume
Wastewater
Influent
Volume+
Mock WWTP Influent (Control) (1st & 2nd day)**
0.000
8.00 8.00
5.36
2.640
8.00
Americal list day)
0.512
7.49 8.00
5.36
2.640
8.00
Americal (2nd day)
0.512
7.49 8.00
5.36
2.640
8.00
• RTA protocol involved two days of treatment; 1 st day was "Toxicant Accumulation Step" and 2nd day was "RTA Step" (see Appendix A)
Nitrification sludge biomass used on 1 st day of treatment was saved and used on the 2nd day of treatment.
Collected from North Nutbush line.
+ Collected from the return sludge line.

Table B-2. Operating Conditions for the Trickling Filter, Nitrification and Filtration
Processes
Parameters
Tricking Fitter
Hydraulic loading rate
Hydraulic retention time
Surface Area (sf)
Filter media size
Filter media depth
Activated Sludge
Flow (MGD)
Dissolved oxygen profile
Hydraulic retention time
Mixed liquor suspended
solids (MLSS)
Filtration
Media
Effective pore size
WWTP Operation' RTA Simulation
2.1 gal/hour/cu ft media
3 hours 35 min
10,053
2 - 6 inches
5ft
3.0
>10 mg/L
4 hours
3,500 mg/L
Sand
NA
Based on current W WTP flow of 2.5 mgd.
300 gal/hour/cu ft media
2 hours
0.09
2 - 6 inches
3ft
N/A
>10 mg/L
4 hours
3,200 - 3,500 mg/L
Coarse glass -fiber filter
2.7 µm

Table B-3. Operating Conditions for the Activated Sludge Stage
of the RTA
Operating Conditions
Treatment Stage Dissolved pH MLSS
Oxygen (m /L) (S.U.) m /L)
Day 1 - Air Supply
Americal-spiked Reactor 2 to >4 > 6.9 NA'
Control Reactor 2 to >4 >6.9 NA
Day 2 - Oxygen Supply"
Americal-spiked Reactor 4 to >10 6.8 to 7.3 3,500
Control Reactor 4 to >10 7.0 to 7.3 3,200
NA - not analyzed. MLSS for Day 2 was assumed to be similar to Day 2.
" 7 to 8 mL of a 5.1% lime solution was added in increments to each reactor over
the 4 hour treatment period.

Table B-4. Removal of Chemical Oxygen Demand (mg/L) in RTA Tests
RTA Test
Treatment Stage Americal Spike Control
Day 1
Trickling Filter Effluent 61 53
Aeration Effluent (unfiltered) < 25 < 25
% Removal > 59 > 53
Day 2
Trickling Filter Effluent' 69 158
Aeration Effluent (filtered) 24 40
% Removal 65 75
Foaming was observed in the control trickling filter effluent. See text for explanation. ,

0
DIVISION OF WATER QUALITY
RALEIGH REGIONAL OFFICE
WATER QUALITY SECTION
November, 1 1999
MEMORANDUM
To: Coleen Sullins
Water Quality Section Chief
From: Kenneth Schuster, P.E
Regional Water Quality Supervisor
Kirk Stafford
Environmental Chemis
Subject: City of Henderson
SOC EMC WQ 96-005
Amendment Request
NPDES Permit NCO020559
Vance County
Raleigh Regional Office
Please find enclosed a letter for your consideration and signature concerning the subject
SOC amendment request. The City has requested an amendment to the subject SOC to extend the
modified toxicity limit for one year. The limit was relaxed from PASS/FAIL at 90% to Full
range -monitor only. The present order also allows for an upgrade of the Redbud pump station
which is progressing as per the SOC.
The City initially had a JOC issued in 1988. There were several amendments made to
that JOC. After the expiration of the JOC a request was originally made for an SOC in 1996. In
the following years, there were several subsequent SOC amendment requests made and before a
signed SOC could be finalized new amended dates of final compliance were requested and
discussed. The present SOC was signed March 10, 1999.and request was recently requested to
amend the SOC to extend the compliance date for toxicity compliance.
An Up -front penalty of $5140.00 was requested and paid for failure to achieve
compliance for toxicity in JOC 88-04.
The present SOC signed in March of 1999 allows the City to accept 352,510 gpd of
additional wastewater to the WWTP. The Order requires the City to continue the THE plan, and
to comply with permit limits, including toxicity, by September 30, 1999. The Order also requires
the City to reduce I/I and/or upgrade the Redbud pump station to eliminate future overflows at
this location. The City is progressing to Phase II of the pump station upgrade/expansion and
construction of a new conveyance to the WWTP.

0
The following is a brief history of the Orders issued to the City:
JOC 88-04 Signed 6/27/88.
JOC 88-04ADI Signed 4/2/90. Includes the permit limits and conditions in accordance with new
NPDES Permit which became effective September 1, 1989. This permit had limits added for
chronic toxicity and other pollutant parameters for which the JOC had to meet compliance. It
also had monitoring requirements for chronic toxicity.
JOC 88-04 ADII Requested 4/21/94. Includes date changes in accordance with the approved
THE for toxicity. This had a requirement to achieve compliance with final effluent limitation for
chronic toxicity by March 1, 1996.Our file copy is a signed copy.
JOC 88-04 ADIII Requested 11/8/94. Includes date changes for submittal of conclusions and
method reduction for effluent toxicity. This addendum also had the requirement for a TRE,
headworks analysis, a long term monitoring program for industrial users, and a waste survey
requirement. The final chronic toxicity compliance requirement stayed at March 1, 1996. Our
file copy is an unsigned JOC.
On 2/29/96 an application was received for an SOC requesting a final toxicity compliance date of
3/l/97 . Prior to actual signature of the initial SOC request, the City worked towards compliance
of the requested compliance date of 3/1/97. This date was not met.
1-0�
The above date was not met and a subsequent verbal date for compliance of 6/98 was made. It
was verbal, in that the SOC processing was not completed in the meantime. This date passed
without compliance and a new date of 3/31/99 was requested.
SOC 96-005 was actually signed on March,11 1999 with a compliance date of September 30,
1999. They failed to achieve compliance with permit toxicity by this date as required. The
above date was not met and a subsequent date for compliance of 9/30/99 was made. This date
passed without compliance and a new date of 9/30/00 has been requested.
The RRO believes that ample time has been allotted the City to come into compliance
with their chronic toxicity permit requirements. At this time the pretreatment unit is reviewing
for Henderson's compliance with the pretreatment requirements. The RRO may recommend
stipulated penalties at a later date. The new toxicity enforcement policy is now in effect. A disc
is included with this memo with the changes for your convenience.
DWQ staff last met with the City on September 23, 1999 to discuss this matter. At that
time some additional information was requested and a written response to those questions has
been made by the City. Most of that information is connected with the pretreatment review
being made.

Brief Follow Up from our Meeting Yesterday, ay. Mav 16th •
Subject: Brief Follow Up from our Meeting Yesterday, Tuesday, May 16th
Date: Wed, 17 May 2000 16:57:48 -0400
From: "WILLIAMS,ERIC" <[e-mail]>
To: "'Tommy Stevens (NCDENR)"' <[e-mail]>
CC: "'Coleen Sullins (NCDENR)"' <[e-mail]>,
"'Kirk Stafford (NCDENR)"' <[e-mail]>,
"'Matt Matthews (NCDENR)"' <[e-mail]>,
"'Shannon Langley (NCDENR)"' <Shannon. [e-mail]>,
"'Glenn Dunn, Env Atonney"' <[e-mail]>,
'Tim Baldwin' <[e-mail]>,
"WARREN,MARK" <[e-mail]>,
"SPAIN,TOM" <[e-mail]>,
"HICKS,REGGIE" <[e-mail]>,
"'Tom S. Poe (Pretreatment)"' <[e-mail]>
Dear Tommy ... just a quick note to follow up on our meeting and discussions
yesterday:
1) First of all, thanks again for pulling together so many members of your
Staff regarding our common wastewater concerns. I realize how busy as
everyone is and I sincerely appreciate your courtesies.
2) I felt our face-to-face meeting was quite constructive and gave us an
opportunity to personally brief you on our current status with regard to our
wastewater operations (including the SOC, toxicity issues, etc.) and,
likewise, gave you and your Staff a chance to directly brief us on the
State's position with respect to these matters, including the heightened
oversight and monitoring underway by EPA and the part that Henderson, along
with other jurisdictions, have in the Federal/State/local partnership in
protecting the State-s natural resources.
3) With regard to current stipulated penalties and assessment of fines for
civil infractions (as described in the SOC), I understand I will be
receiving within the next day or so a penalty in the amount of $10,280
relative to failing to comply with the provision in the SOC requiring " full
and complete compliance" with toxicity standards by September 30th, 1999.
In addition (and I believe Ken Schuster indicated the paperwork would be
"ready to go" some time next week), I understand we can expect a total fine
of $4,000 ($1,000 for each month) for our non compliance with our toxicity
tests for the four (4) months of October, November and December of 1999 and
January, 2000 which showed toxicity test failures, although by very slight
margins in some cases.
Upon receipt of these notifications we will acknowledge their receipt and
communicate with you within the prescribed timeframe(s).
4) It was also mentioned that the State (via Tom Poe) advised us on April
13th, 2000 of issues respecting our Pretreatment Program, which we
understand is a critical component of our overall wastewater operations;
although we questioned why the review period extended back over two (2) or
three (3) years and seemed to address issues already discussed.
In any event, we have replied to that review in our May 15th quarterly THE
Report (as Appendix B) and forwarded the same to Mr. Schuster, with copies
to the appropriate NCDENR-DWQ Staff. I understood at our meeting yesterday
that Mr. Poe would arrange for a prompt review of our responses/other
information and further communicate with us. We are, as you know, committed
to a first class Pretreatment Operation and the assistance and guidance of
I of2 5/18/00 8:14 AM

Brief Follow Up from our Meeting Yesterday, ay- Mav 16th •
• the appropriate Staff in this regard is most appreciated.
5) We also indicated that our toxicity testing had revealed consistent
compliance and "passing" for the four (4) consecutive months of February,
March, April and May, 2000 and we believe that these results indicate that
our toxic discharges now show consistent evidence of "full and complete"
compliance with State and EPA standards; although we noted Ms. Sullins
indication that the State would desire to see six (6) consecutive months as
evidence that this concern was being properly managed and controlled.
In this regard, we also briefed everyone on our current pilot plant testing
and other related matters at our Nutbush Wastewater Treatment Plant.
6) We also shared information that our next (and final remaining matter I am
aware of) in the SOC, the constructions of "Redbud Pump Station/Nutbush
Interceptor", an approximate $3.8 Million project, was through design, is
awaiting State approval, we are exploring financing options and will have no
trouble meeting the SOC deadline of being under construction with this
project by February, 2001.
7) We concluded our meeting fully understanding our mutual obligations and
responsibilities and fully expecting to report to your offices our
compliance with our toxicity tests upcoming for the month of June. Within
the June - July timeframe we will further communicate with you regarding the
status of our program generally (and toxicity specifically) and at that
time, we will also follow up with you on our desire to seek some mitigation
of the previously mentioned stipulated penalty and fines along the lines
generally discussed in our meeting.
I trust this communication adequately reviews the key points we discussed
and, again, I am most appreciative of your courtesies and the continuing
assistance of the State as we continue to run a first class wastewater
operation which not only protects the environment and our natural resources,
but also provides one of the more important assets for our long term growth
and prosperity.
With my best regards to you and all your Staff ... City Manager Eric
Williams
2 of 5/18/00 8:14 AM

%,iTY OF HENDERSUN
Post Office Box 1434
180 Beckford Drive
Henderson, North Carolina 27536-1434
Phone: [phone] FAX: [phone]
May 12, 2000
Mr. Ken Schuster
Raleigh Regional Supervisor
NC DENR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: City of Henderson Nutbush Creek W WTP
NPDES #NC0020559
SOC-EMC WQ No. 96-05
May Quarterly THE Report o
SJ
Dear Mr. Schuster,
MMUSH CREEK WASTEWATER
TREATMENT PLW
I am forwarding our May Quarterly Toxicity Reduction Evaluation (TRE)4?eport as
required by our SOC.
The response to DENR (Tom Poe's April 13, 2000 letter) Notice of Violation is
included in the report.
If you have any questions, please contact me at [phone].
�Sincerely, ,(
Thomas M. Spain
WWTP Director
C: Eric Williams, City Manager
Mark Warren, ACM
Reggie Hicks, Lab Supervisor
Judy Garrett, DWQ-RRO
Kirk Stafford, DWQ-RRO
Matt Matthews, DWQ-ATU
Kevin Bowden, DWQ-ATU
Tom Poe, DWQ Pretreatment
Dana Folley, DWQ Pretreatment
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin, McKim and Creed
Files

Progress Report
for the Toxicity Reduction Evaluation
at the City of Henderson's Nutbush Creek Wastewater Treatment Plant
NPDES No. NCO020559
February 16 through May 15, 2000
Submitted In Fulfillment of the Special Order by Consent
EMC WQ No. 96-05
Prepared for
Department of Environment, Health and Natural Resources
3800 Barrett Drive, Suite 100
Raleigh, North Carolina 27609
Prepared by:
City of Henderson
P.O. Box 1434
Henderson, NC
With Assistance by:
Aquatic Sciences Consulting
15751 Bushy Park Rd
Woodbine, Maryland 21797

City of Henderson THE Progress Report Page 2
NPDES No. 0020559 May 11, 2000
Introduction
This quarterly progress report is prepared and submitted to meet the May 15`h date specified by
Section 2(b)2 of the City of Henderson's draft Special Order by Consent (SOC EMC WQ No.
96-05). This report describes the progress made in the last quarter (February 16 through May 15,
2000), the plans for the next quarter, and any significant issues that may delay progress in
completing the TRE.
Progress in the Preceding Quarter
1. Results of WWTP Effluent Toxicity Monitoring
A total of three toxicity compliance tests were successfully completed in the preceding quarter.
Monthly effluent monitoring was performed, as required by the SOC. Results are summarized
in Table 1 and Appendix A.
Table 1. Summary of Monthly Compliance Test Results
Sample Collection Dates
Test Initiation Date
ChV(%)
Feb 14-15 and Feb 17-18
Feb 16
Invalid
Feb 28-29 and Mar 2-3
Mar 1
>90
Mar 13-14 and Mar 16-17
Mar 15
>90
Apr 3-4 and Apr 6-7
Apr 5
>90
May 2-3 and May 4-5
May 3
>90
* Invalid because control results not meeting quality control standards.
The city achieved full compliance for the preceding quarter. Although the compliance test
performed in early February was invalid, the city collected, tested and passed a follow-up test
later in the month.
The city has had a chronic value (ChV) of 78% from November 1999 through January 2000 and
a chronic value (ChV) of> 90 % from February 2000 through May 2000.
2. Information Requested in Department of Environment, Health and Natural Resources'
(DENR) letter dated April 13, 2000
Information requested in Attachment A of DENR's letter of April 13 is provided in Appendix B.

1 City of Henderson THE rrogress Report
NPDES No. 0020559
Page 3
May 11, 2000
In addition, the city has provided justification for a request for waiver of notice of violations
(NOVs) cited in the April 13 letter.
3. Pretreatment Program Initiatives
Progress achieved in the preceding quarter includes:
• Monitoring the progress of the THE being performed by Harriet & Henderson at its south
cotton mill (see Section 4)
• Confirming toxicity reduction at Americal Corporation's textile processing facility (see
Section 4).
• Continuing to monitor the toxicity of other industrial user discharges (see Section 4).
• Receiving weekly chemical usage reports that list quantities of chemicals used.
• Continuing inspections of major industrial users
• Continuing frequent communication with the industries regarding pretreatment activities and
their relationship to toxicity.
The city has received data requested from car wash operators to better characterize the potential
toxicity of cleaning products. The city considers cleaners to be problematic, if known toxic
compounds, including nonyl phenols, quaternary amines or sulfonated compounds, are present.
In one case, the city has already advised a car wash operator to either provide data showing that a
cleaner containing nonyl phenols is nontoxic or find a substitute that does not contain
problematic constituents.
4. Sewer and Industrial User Monitoring
The City continues to conduct intensive sewer and industry monitoring. Weekly samples
collected from several locations in the sewer system were tested using Microtox. RTA tests were
also performed to monitor previously identified sources of toxicity. In addition, quarterly
monitoring of significant industrial users was performed.
4.1 Microtox Monitorin
Although Microtox is not a direct surrogate for Ceriodaphnia dubia, the city has observed a good
correlation in Microtox and chronic C. dubia test results. The city continued the intensive sewer
monitoring initiated in January 2000. In general, the Microtox results show a decrease in
toxicity in the Sandy Creek sewershed that coincides with the abatement of effluent toxicity at
the city's WWTP.
4.2 Ouarterh Industry Monitoring

1 City of Henderson THE rruKress Report
NPDES No. 0020559
Page 4
May 11, 2000
Results of tests performed on samples collected February 14 - 15, 2000 were not available in
time for the last quarterly progress report. These results are summarized in Table 2. The results
show that Americal, Ball Foster, IAMB and Kennametal complied with the industrial user permit
(IUP) toxicity requirement. However, J.P. Taylor's discharge was toxic. Therefore, the city
collected and tested another sample from J.P. Taylor's discharge in April. This second sample
passed the toxicity test; however, as specified in the IUP, the city required J.P. Taylor to perform
a follow-up RTA test. The results of this test are described in Section 4.3. A sample from
Harriet & Henderson's south mill discharge was also tested in April and found to be nontoxic.
Table 2. Quarterly Monitoring Results for Major Permitted
Industry Test Concentration"
Industries
Pass/Fail Result
Samples Collected February 14 —15
Americal
6.4%
Pass
Ball Foster
1.0%
Pass
IAMB
J.P. Taylor
6.6%
Pass
Kennametal
1.6%
0.8%
Fail
Pass
Samples Collected in April
Harriet & Henderson South Mill (Apr 3)
3.0%
Pass
J.P. Taylor (Apr 17)
1 6%
Pass
Equivalent to flow contribution to the City's treatment plant.
Quarterly toxicity tests were performed during the week of May 8`h, 2000; however, the results
were not available in time to present in this report.
4.3 Refractory Toxicity Assessment
Only preliminary RTA results were available at the time of this report. A description of the
results will be provided in the next quarterly report. Briefly, the preliminary results suggest no
contribution of toxicity from the Sandy Creek or Redbud sewersheds. Tests of Americal, Harriet
& Henderson's south mill and J.P. Taylor also suggest no contribution of refractory toxicity from
point discharges in the Sandy Creek sewershed. These results are consistent with the abatement
of effluent toxicity at the city's WWTP.
Attorneys for the owners of the former Burkart Carolina property (formally Heinz facility) have
requested to discharge groundwater to the city's WWTP. The city has required the owners'
representatives to perform a study on the groundwater to determine its potential effect on the
W WTP. As an initial step in the study, a test was performed on a groundwater sample as part of
the above RTA testing. The results are preliminary and must be reviewed before reporting. The
city has advised the owner's representatives that even if the groundwater is not indicated to be a

City of Henderson THE rrogress Report Page 5
NPDES No. 0020559 May 11, 2000
problem, a decision whether or not to allow the discharge will depend on the city's compliance
with the toxicity limitation and evaluation of chloride and other contaminants loading rates on
the WWTP
4.4 Summary
The City's sewer/industry monitoring effort has yielded the following conclusions:
• Harriet & Henderson's south mill and Americal appear to have reduced the toxicity of their
discharges; however, the city will continue monitoring in the next quarter.
• Although a February test indicated chronic toxicity in J.P. Taylor's discharge, follow-up
tests did not confirm toxicity.
5. Activated Carbon Treatment
Studies show that effluent toxicity at the City's WWTP is caused by a nonpolar organic
toxicant(s). These toxicants were shown to have a high affinity for activated carbon; therefore,
the city initiated a study to evaluate the toxicity reduction capability of carbon.
The city's consultants reviewed desiin information for the existing and planned WWTP upgrade
and met with city staff, on March 3 to discuss carbon treatment options. The city and its
consultants identified several options for carbon treatment, including (1) adding PAC to the
activated sludge aeration basin and (2) replacing some or all of the tertiary filter media with
granular activated carbon (GAC), and (3) adding a dedicated GAC contactor after the multi-
media filters. It was agreed that these options should be evaluated in pilot or bench -scale tests to
determine if carbon treatment can eliminate chronic toxicity and, if so, which option is most
appropriate for the city. The city has concentrated on the GAC since it appears to be a promising
and most practical method to eliminate toxicity.
The findings of the engineering assessment were incorporated into a plan for evaluating GAC
treatment. A GAC pilot unit was designed, constructed and started up in late March. Results of
toxicity tests performed on the influent and effluent of the first two GAC columns show that the
carbon is removing toxicity. The influent sample (WWTP filter effluent) had a ChV of <15%,
whereas, both GAC column effluents were nontoxic (i.e., ChV >90%). It should be noted that
the toxicity observed in the filter effluent is currently being eliminated by hydrogen peroxide
treatment (prior to disinfection).
It is anticipated that results of the GAC pilot study will be available within 4 to 6 months (July to
September).
Plans for the Next Quarter
The City plans to conduct the following work in the next quarter (May 16 through August 15,
2000):

City of Henderson THE rrogress Report Page 6
NPDES No. 0020559 May 11, 2000
1. Chronic C. dubia compliance tests will be performed each month.
2. The City will review Harriet & Henderson's progress in their TRE. Americal's discharge will
also continue to be monitored.
3. The city will continue to update its chemical use data base on industrial users. The city will
focus on obtaining additional product stewardship data, including toxicity data, on cleaners,
biocides and other chemicals that contain surfactants.
4. The City will continue to monitor for potential sources of toxicity in the Sandy Creek
sewershed and the Redbud main line. The tools for evaluating potential sources may include
Microtox, RTA tests and fill and draw bioreactors.
5. The City will inspect all major industrial users in the next quarter. During the inspections,
the City will focus again on activities that can be performed to help minimize the discharge
of toxicity.
6. The City will continue to evaluate the toxicity reduction capability of activated carbon
treatment.

Appendix A
Historical Ceriodaphnia dubia Chronic Toxicity Data
for the Nutbush Creek WWTP Effluent

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Appendix B
City of Henderson's Response to DENR's Letter Dated April 13, 2000

Response to DENR Notice of Violation Dated April 13, 2000
Violations of Part III, B of the City's NPDES Permit
1. Failure to perform monitoring of industries for toxicity as required by Industrial User
Pretreatment Permits (,UPS).
a) Failure to perform quarterly chronic toxicity tests at Ball Foster, Iams and
Kennametal for first, third and fourth quarters of 1998 (the first quarter tests were
invalid and were not made up), and the first and fourth quarters on 1999. 5 of 8
required monitoring events not completed.
b) Failure to perform quarterly toxicity tests at J.P. Taylor for the first and third
quarters of 98 (the first quarter tests were invalid and were not made up), and the
first and fourth quarters of 1999. 4 of 8 required monitoring events not
completed.
c) Failure to perform quarterly chronic tests of Americal for the first and fourth
quarters of 1999. 2 of 8 required monitoring events not completed.
In summary, 21 of 40 required toxicity tests were not performed. This represents a
cost savings to the POTW of approximately $6,300 based on a typical cost of $300
per test.
General Response to I:
The Chronic Toxicity Monitoring and Special Conditions (B 1) in the pretreatment
permits of significant industrial users include the following statement — "The city
reserves the right to increase or decrease this monitoring requirement." This condition is
intended to apply to all toxicity monitoring, including chronic toxicity monitoring as
stated in B 1. The city decided that it was not necessary to monitor Ball Foster, Iams and
Kennametal because toxicity had not been observed in the Ball Foster and Iams
discharges since monitoring began in 1994 and Kennametal's discharge had not been
toxic since October 1996 when a toxic aluminum cleaner was identified and eliminated.
J.P. Taylor's discharge has been toxic twice since 1995 (March 1997 and February,
2000). The city's effluent toxicity has been more frequent than the rare toxicity observed
in J.P. Taylor's discharge; therefore, the city focused its efforts on the principal sources
Of toxicity, notably Softspun, Burkart Carolina, Americal and Harriet & Henderson's
south cotton mill. Nonetheless, a follow-up chronic toxicity test and RTA test were
performed on J.P. Taylor discharge samples as a result of the February, 2000 failure, and
the city plans to monitor J.P. Taylor's discharge until the discharge is shown to be no
longer toxic. In summary, the city believes that the terms of the IUP were properly
applied and the notice of violation (NOV) should be waived.
The city is concerned about DENR's decision to issue an NOV for this case. DENR was
notified in several quarterly progress reports (November 1998, February 1999, May
1999) that the city did not believe that toxicity monitoring was needed every quarter for
Ball Foster, Iams, J.P. Taylor, and Kennametal. The city understands that each quarterly

City of Henderson
Response to NOVs Issued by DENR on
13, 2000
Page 2
11, 2000
report is reviewed by DENR and the city is concerned that DENR did not indicate the
need to continue quarterly monitoring as part of their review. The Division of Water
Quality's (DWQ) review of the November 1998 progress report (dated December 4,
1998) acknowledges that nontoxic industrial users were not monitored in the preceding
quarter. That review does not mention the need to continue monitoring of the users.
Response to La:
Tests performed in the first quarter of 1998 were invalid (per DENR Mini -Chronic
Procedure, 1995) because the tests were extended an additional day (i.e,, 8 days) so that
the control organisms could produce the P brood of young. However, the tests were
valid according to EPA procedures; therefore, the results can be used to indicate the
presence or absence of toxicity. A review of the results indicates that none of the
discharges were chronically toxic. Please see the attached results and data interpretation
from Burlington Research, Inc (Appendix A). This information provides further
justification for waiving the NOVs for the first quarter of 1998.
TriTest, the laboratory that performed the December 1999 tests, submitted a letter on
January 10, 2000 that describes the nature of the test problems encountered in the fourth
quarter of 1999. A copy of this letter is included in Appendix B. Please see Section 4.3
of the May 2000 quarterly report regarding the results of repeated tests of the SIUs,
which were performed on samples collected February 14 - 15, 2000. This information
provides further justification for waiving the NOVs for the fourth quarter of 1999.
Response to Lb:
Please see response to La.
Response to 1.c:
Refractory toxicity assessment (RTA) tests were performed in lieu of chronic tests on
Americal's discharge in the first and fourth quarters of 1999. RTA tests were performed
because the city understands that the RTA test provides a better indication of a
discharger's potential to contribute toxicity than a chronic toxicity test of the raw
discharge. The RTA test measures the toxicity resulting from treatment of the sample (in
a bench -scale simulation of the W WTP), which is the toxicity that is expected to pass
through the W WTP. Furthermore, the RTA test accounts for potential interactive effects
(additive or antagonistic) that may occur through mixture of the discharge sample with
the WWTP influent. This information provides further justification for waiving the
NOVs for the first and fourth quarters of 1999.
Regarding the purported "cost savings" of not performing quarterly monitoring, the
quarterly RTA tests performed on Americal's discharge are more than seven times more
costly than the chronic toxicity test (i.e., $2,000 vs. $275, respectively). The two RTA
tests performed by Americal in the first and fourth quarters of 1999 were $3,450 more

City of Henderson
Response to NOVs Issued by DENR on
13, 2000
Page 3
11, 2000
than would have been paid in routine monitoring. In addition, the city has included a
summary of the costs of the THE program (Appendix C) that demonstrates the city's
commitment to achieving compliance with the NPDES permit limit for toxicity.
2.
c)
d)
Failure to enforce pretreatment program requirements, including enforcement of IUP
conditions including the following:
a) Americal's failure to collect representative samples as required by Part 1, 3, of
the IUP. The P paragraph on page 3 of the December 28, 1999, Aquatic
Sciences Consulting letter indicates insufficient sample was collected to run
Refractory Toxicity Assessment (RTA) test for 3 consecutive RTA tests, so the
extra volume was made up using a grab.
b) Americal's failure to obtain permission to change its process, especially for
failure to make complete evaluation to determine the effect of this change on the
SIUs ability to comply with toxicity requirements.
• The reports indicate that the SIU's increase in production of the bleach line
began in March 1999 and continued through May 1999 at which time they
were at "full production." It did not clarify whether the increase had begun
before or after the SIU's written notification dated March 17, 1999. The
reports indicate the evaluation of the potential impact of the bleach line
began in late March of 1999. A May 3, 1999, SIU report and a May 12,
1999, POTW report both indicated that testing to date "suggest that the
bleach waste stream is contributing toxicity." This is the month that the SILT
reached full production, yet the POTW took no action then to require the
SIU to reduce or eliminate this discharge. In a June SILT report, it was
determined that two chemicals added to the bleach line process were
causing toxicity. The SILT eliminated these chemicals by substituting new
chemicals, however once again, these new chemicals were not evaluated for
impact on toxicity until after they were in use. It was only to subsequent
reports that the SIUs consultant was able to further investigate and reach a
final conclusion of no impact in August 1999, a full 3 months after the SIU
had increased to full bleach production.
• The POTW's March 10, 2000, letter to the Division's Raleigh Regional
Office indicated Americal instituted another product substitution and this
new softener was not evaluated for its potential to impact the POTW until
after it had been in use for a month.
Americal's failure to obtain percussion to change it's process to substitute sodium
sulfate for sodium chloride in its dye line, especially for failure to make complete
evaluation to determine the effect of this change on the SIU's ability to comply
with toxicity requirements.
Americal's failure to submit adequate monthly Toxicity Reduction Evaluation
(TRE) reports for April and June 1999.
Report due April 15 1999:1 The POTW's response indicates this requirement
was met by a one page March 22, 1999, letter from John Botts to the POTW.
While Mr. Botts is the SIU's consultant, he is also the POTW's consultant. The
referenced "report" contains general information about a number of POTW

City of Henderson
Response to NOVs Issued by DENR on
13, 2000
Page 4
11, 2000
THE efforts at the POTW effluent and several other locations, including
Americal. Discussion in the letter about Americal's THE efforts is limited to 2
sentences, and only states when to collect a sample, and how much volume to
obtain. These tests were completed long before the April 15 due date, so the
April 15 report should discuss the results of the tests, not just state how much
sample volume was required.
Report due 6/15/99: The POTW's response indicates this requirement was met
by a 6/9/99 report. This report only covered the evaluation of the new bleach
line, whereas a THE report would cover all wastestreams discharged.
Response to 2.a:
During the August 1999 RTA, Americal reported that the automatic sampler did not
collect the proper sample volume because the peristaltic tubing was worn and had to be
replaced. In lieu of a composite sample, two grab samples were collected and combined
on August 24h. Normally, a 24-hour composite sample is used to initiate the RTA test
(1" day) and a portion of the sample is saved and used again on the second day of testing.
In this case, however, a full 24-hour composite sample of Americal's discharge was
collected on August 25'h - 26'h for use on the second day of the RTA. As described in the
RTA protocol, the first sample was used to condition the RTA bioreactor, whereas, the
second sample was used to determine the refractory toxicity of the discharge.
The consultant made an error as part of the sampling event for the September 1999 RTA.
Americal was notified to collect one (1) gallon of their discharge; however, the city was
advised that two (2) gallons would be collected. When the city arrived on September 23'd
to pick up the sample, only about one gallon was in the sampler bottle. The city started
the sampler and pumped about one more gallon into the sampler bottle. Therefore, the
sample consisted of about one gallon of 24-hour composite sample and one gallon of grab
sample. Again, a second sample was collected, which was a full 24-hour composite
sample, to use on the second day of the RTA. This second sample was used to evaluate
the refractory toxicity of the discharge
During the December 1999 RTA, city staff inspected the automatic sampler to verify that
a composite sample was being collected. The next day, Americal informed the city that
the sampler did not collect enough sample. Upon inspection of the sampler, it was
discovered that the sampler's power switch was set between the "on" and "off' positions.
It is possible that the switch may have been bumped by either Americal or city staff
during sampling. Again, a second sample was collected, which was a full 24-hour
composite sample, to use on the second day of the RTA. Once again, the second sample
was used to assess the refractory toxicity of the discharge.
In consideration of (1) the consultant's error in one of the noted sampling events, (2) the
sampler problems that apparently were out of Americal's control, and (3) the fact that an
additional composite sample was collected and used to determine refractory toxicity in
each case, the city believes the NOV should be waived.

City of Henderson
Response to NOVs Issued
Response to Z.b, first bullet:
DENR on April 13, 2000
Page 5
11, 2000
The city's believes that its letters to DENR dated September 14 and October 1, 1999
answer most of DENR's questions regarding Americal's increase in bleaching production
in 1999. Responses to other issues noted in DENR's April 13, 2000 letter are addressed
as follows.
The city's Pretreatment Coordinator notes a telephone call from Americal on March 11,
1999 in which Americal advised of the need to increase its bleaching production. The
Pretreatment Coordinator stated that Americal should formally notify the city in writing
before implementing the change. Americal submitted the written notification on March
17, 1999. Furthermore, Americal informed the City during a March 25, 1999 meeting that
they had collected samples on test bleach stream to evaluate the effect on discharge
toxicity. The City did notify Americal verbally to discontinue the increased bleaching
process as soon as the May tests indicated increased toxicity. Americal ceased all of the
increased bleaching process by the end of May. The city contacted Americal on May 5,
2000 to clarify whether the increase in bleaching occurred before or after their written
notification dated March 17, 1999. Americal confirmed verbally that the bleaching
increase occurred after the March 171h notification.
Toxicity data were available for one of the substituted products, VircoWet NSL, and its
reported, relatively high toxicity (i.e., 48-hr EC50 = 5 µg/L) appeared to be related to
nonyl phenols. Due to the high toxicity potential of VircoWet NSL, Americal quickly
identified and started using a substitute that did not contain nonyl phenols. The vendor's
data on this substitute indicated that it would be less toxic than VircoWet NSL.
Americal's approach was to identify and substitute products that contain compounds that
are known to be less toxic and, as a result, reduce toxicity as soon as possible. Americal
began to eliminate products that contain nonyl phenols, quaternary amines and sulfonated
compounds, which have been implicated as toxicants in other TREs. The product
substitutions apparently reduced toxicity as demonstrated by Americal's ability to achieve
compliance within the IUP deadline.
Americal's notified the city of the product substitutions in a timely manner as specified
under 4.(a) of the IUP. The city understood that changes in chemical use that were
intended to eliminate known toxic materials were necessary as part of the THE process.
This approach is described in EPA guidance [Generalized Methodology for Conducting
Industrial Toxicity Reduction Evaluations (EPA/600/2-88/070) and Toxicity Reduction
Evaluation Guidance for Municipal Wastewater Treatment Plants (EPA 8338-99/002)].
DENR's guidance (Whole Effluent ToxicityReduction Guidance, rev. 12/97) for TREs
also states - "the position of NC Water Quality Section is that the goal of this [TRE]
process is to reduce the observed toxicity in the effluent. Finding the most efficient
means of reaching this goal is encouraged so that unnecessary testing and costs are not
incurred". Therefore, in consideration of the city's understanding of the THE process and
Americal's successful effort, this NOV should be waived.

City of Henderson
Response to NOVs Issued
DENR on April 13. 2000
Page 6
11, 2000
As stated in the city's September 14, 1999 letter to DENR, it took "about 60 days (March
25 to May 20, 1999)", not "3 months after ... fall production" (as stated in DENR's letter)
to answer the question of whether or not the bleaching process would adversely affect
Americal's discharge or the city's WWTp.
Response to 2.b, second bullet:
Please see our above response to Item 2.b, first bullet.
Response to l.c:
Please be advised that the city does not consider sodium sulfate to be a concern with
respect to toxicity. At the time Americal offered to substitute sodium chloride with
sodium sulfate, the city's consultant presented data showing that the proposed usage,
together with the background concentration in the city's treatment plant effluent, would
be well below toxic levels. Based on this information, the city gave Americal permission
to use sodium sulfate in lieu of sodium chloride during a progress meeting held at city
hall on August 10, 1999. Therefore, in consideration of the city's approval of the product
change, this NOV should be waived.
Response to 2.d:
The city considers Americal's April and June 1999 reports to be adequate. The city
inadvertently submitted the wrong letter in its September 14, 1999 letter to DENR.
Please find attached the March 22, 1999 progress report (received by the city in April
1999), which describes a plan for evaluating hydrogen peroxide addition as a method for
reducing Americal's toxicity (Appendix D). The June report describes the results of tests
performed to evaluate the cause of toxicity in Americal's bleach waste. At that time,
Americal's THE efforts were focused on the bleach waste because it appeared to be
contributing toxicity to their discharge. The city believes that the report is adequate
because Americal was evaluating the primary wastewater of concern, which is the
recommended approach for TREs [Generalized Methodology for Conducting Industrial
Toxicity Reduction Evaluations (EPA/600/2-88/070) and Toxicity Reduction Evaluation
Guidance for Municipal Wastewater Treatment Plants (EPA 833/B-99/002)]. Therefore,
in consideration that the reports adequately described THE progress, this NOV should be
waived.
Attachment A - Comments on Quarterly Progress Report
Section 2, Page 3, 0 paragraph. How will the POTW determine if the cleaners used
by various car washes should be removed?
Response:

City of Henderson
Response to NOVs Issued
DENR on April 13, 2000
Page 7
11, 2000
On March 1, 2000, the city submitted a letter to each of the car washes requesting a list of
chemicals used and their material safety data sheets (MSDS) and available product
stewardship data. The city has received all of the requested data and has requested some
car wash operators to provide additional information to better characterize the potential
toxicity of cleaning products. The city considers cleaners to be problematic, if known
toxic compounds, including nonyl phenols, quaternary amines or sulfonated compounds,
are present. In one case, the city has already advised a car wash operator to either
provide data showing that a cleaner containing nonyl phenols is nontoxic or find a
substitute that does not contain problematic constituents. The city will require other car
washes to remove cleaners, if the constituents noted above are present. Alternatively, the
car washes must provide toxicity, biodegradability and inhibition data showing that the
cleaners will not cause toxicity in the city's WWTP effluent.
2. Section 3.3, page 6, P paragraph. The report did not describe the nature of the
"laboratory problems" for the December 1999 chronic toxicity tests conducted at the
city's 5 SIUs. Please include this information in the next quarterly reports. Also,
please note the February 2000 tests are being run to make up for the 4`h quarter 1999
tests, and thus do not count for I" quarter 20001UP testing requirement.
Response:
TriTest, the laboratory that performed the December 1999 tests, submitted a letter on
January 10, 2000 that describes the nature of the test problems encountered in the fourth
quarter of 1999. A copy of this letter is included in Appendix B. Please see Section 4.3
of the May 2000 quarterly report regarding the results of the 4'h quarter chronic toxicity
tests of the SIUs, which were performed on samples collected February 14 - 15, 2000.
Results for the I" quarter of 2000 were not ready in time for this report and will be
presented in the next quarterly report.
3. Section 4. As the South Harriet & Henderson Yams, Inc. plant has been identified as
contributing to toxicity, it must now be considered a SIU. Please issue them an IUP
that includes appropriate toxicity limits, monitoring and THE language. We are
aware of the THE requirements of the city's February 10, 2000 letter. You may
incorporate these conditions into the city's regular IUP toxicity language. Include
some level of monitoring for all LTMP Pollutants of Concern (POC), preferably from
the same sample that is used for toxicity testing. Also, include conductivity and other
parameters that may help to confirm if the wasteflows are process or domestic, and
also possibly identify and/or rule out pollutants of concern. Please submit the IUP and
appropriate supporting documentation to the Pretreatment Unit by June 2, 2000, with
a copy to the Regional Office and the Aquatic Toxicology Unit. Unless the IUP
includes limits for these pollutants, these data should be judged for compliance
against local limits from the POTW's Sewer Use Ordinance (SUO). Please note this
SIU may be considered for dropping from SILT status after the toxicity problems are
solved.

e
City of Henderson
Response to NOVs Issued
Response:
DENR on April 13, 2000
A draft lUP was submitted to DWQ on April 24, 2000 for review.
Page 8
11, 2000
4. Section 5.1. The report indicates after the concerns with the September RTA,
Americal had "agree to perform another RTA," which was conducted in December
1999. The lUP requires that after the SIU passes two consecutive monthly RTAs that
quarterly RTAs will be required for one year. It is understood the POTW considers
the July and September 1999 RTAs to meet the "two consecutive monthly passes"
requirement, since the August test was invalid, If this is the case, then an RTA was
already required to be conducted in the 0 quarter of 1999.
Response:
The noted RTA test was performed in December 1999 in conformance with the IUP
5. Section 6. This section discussed the POTW's evaluation of the potential for an
upgraded WWTP with increased aeration basin hydraulic retention time to remove
toxicity. The section states that toxicity testing to date on a bench scale unit indicates
the process will not remove toxicity. In other sections of this and other THE reports,
the POTW has found their testing bioreactors to be toxic. You may wish to consider
whether the bioreactors for these WWTP upgrade tests are also toxic by themselves
and thus the test failures cannot really be used to rule out the effectiveness of the
upgrade. Also, you may wish to consider the possibility that 16 hours of aerobic
treatment may not be long enough to reduce toxicity to acceptable levels.
Response:
Repeated toxicity tests of the fill and draw bioreactor effluents show that toxicity is not
reduced to the compliance level (ChV 2:90%). The bioreactors are being operated in a
batch mode that reasonably simulates that aerobic stage of the planned five -stage
biological nutrient removal (BNR) process, which is the type of process that generally
removes the majority of the toxicity. The city has performed initial tests that show that
toxicity can be removed by addition of powdered activated carbon to the bioreactors.
These results indicate that, although the toxicant is a nonbiodegradable, it adsorbs to
carbon. The city has invested significant effort in setting up a pilot unit to evaluate
toxicity removal by granular activated carbon. This unit has been in operation since
March 24, 2000 and Ceriodaphnia dubia test results show that toxicity is being removed.
6. Section 7. This section states that the POTW's toxicity is caused by non -polar organic
toxicant(s). Have you sampled your SILT and collection system sample points for this
type of pollutant to identify sources?
Response:

City of Henderson
Response to NOVs Issued
DENR on April 13, 2000
Page 9
11, 2000
Yes, as described in the May and August 1999 quarterly progress reports, the city's sewer
system and an industrial user were sampled for nonpolar organic toxicants. The
characteristics of the city's effluent toxicity (i.e., intermittent, complex, and at low levels)
make it difficult to track sources of toxicity. Therefore, the city developed a new long-
term sampling device (Toxicity Tracking System M that can continuously collects
nonionic, nonpolar organic toxicants. The TTS consists of a semipermeable membrane
system (SPMS) for sample collection and procedures for recovering nonpolar organic
toxicants for subsequent toxicity and toxicant analysis.
The City was concerned about the experimental nature of the TTS; therefore, additional
monitoring of the sewer lines was performed using a different method for quantifying
nonpolar organic toxicity. The testing involved EPA -recommended procedures for
identifying nonpolar organic toxicity [i.e., C18 solid phase extraction (SPE)]. Although
these procedures are not generally applied to raw (untreated) sewer samples,
modifications were made to minimize potential interferences. Samples were filtered,
passed through a C18 SPE, the column was eluted with methanol, and the eluates were
tested for toxicity.
The above monitoring indicated intermittent toxicity in a sewer line serving Harriet &
Henderson's south cotton mill. Follow-up monitoring using conventional RTA
procedures confirmed that the south cotton mill was discharging toxicity. As a result, the
city required Harriet & Henderson to conduct a THE to reduce toxicity. The city may
utilize the above methods again, should toxicity reappear in the city's WWTP effluent.
December 28, 1999, Aquatic Sciences Consulting letter, Page 3, last paragraph. Has
the POTW made any effort to trace the source of the high ammonia?
Response.
The Hams St pump stations serves only residential homes. The occasional occurrence of
relatively high ammonia levels in domestic wastewater (e.g., 70 mg/L) is not uncommon,
especially when relatively high amounts of household cleaning products are being used.
In addition, ammonia and other nutrients can accumulate in the wet wells of pump
stations, if the frequency of pumping is low. The relatively high ammonia levels in the
Harris St pump station are not a concern as evidenced by the domestic levels of ammonia
typically observed in the WWTP influent and the city's continued compliance with its
effluent ammonia limit. Ammonia is not considered to be an effluent toxicity.

Appendix A
Results and Interpretation of the Chronic Toxicity Tests of
Significant Industrial Users Performed in the First Quarter of 1998

Iii`r' td 'Ex3 �73 1N"e4 Egy%LlII IbL'cti-p.1_ri
1 AX Transmission Sheet
Burlington Research, Ina;.
1302 Belmont Street
Burlington, NC 27215-6935
Phone: [phone]
FAX: [phone]
DATE: May la, 1998
TO: Mr. Reggie Hicks
CITY OF HENDERSON
FAX Ih [phone]
FROM; Rick Diehl
SUBJECT: SIU Toxicity Tests
You should receive I page(s) including this cover sheet. If you do not receive all pages, or
have a question regarding content, please call nie at [phone], Ext. 209.
Con111TENTS:
Surwnary of industrial discharge chromic bioassays conducted Ate week of February 9 is noted
below. 17te tests were conducted as BRI Work Order RB224 should you need to refer, to the
reports. Hope this is helpful, Reggie. Give me a call if I can be of further assistance.
Composite discharge samples collected February 9-10 at Atnerieal, J.P. Taylor, Kennametal,
Softspun, Iams, Ball Foster, and the Sandy Creek Pump Station were received on February
11. Discharges were monitored for toxicity at their respective flow contributions to the
Nutbush WWTP using the DWQ protocol for C. dubia single effluent concentration
,Pass/fail" chronic toxicity testbtg.
Bioassay results indicated that none of the discharges were chronically toxic. Tests for
Americal and Iams met test criteria. Tests for J.P. Taylor, Kennamelal, Softsptui, Ball Foster,
tuncl the Sandy Creek Purnp Station, however, were extended art additional day (i.e. 8 days)
before control orgattisrns produced die 3rd brood of ,vowng required by test protocol.
'I7ie absence of chronic toxicity bt these point source samples corresponds «-ith an absence of
chronic toxicity in WWTP effluent collected that same week. Additional point source
nloidtoring during weeks that WWTP effluent is being collected for toxicity testhng will
fwlher clarify any exisibig relationship ln:tween industrial discharge and WWTP toxicity. It
Is noteworthy that America) discharge was non -toxic both this and the previous week; tills
disc:luirae historically has Nken chronically toxic.
Ell

Aquatic Bioassay Testing • Aquatic Toxicity Reduction Evaluations
Chemical Product Environmental Assessments • NPDES Testing
Reporting 8 Data Handling Services
BURLINGTON
E S E A R C H 1302 Belmont Street • Burlington, NC 27215-6935 • [phone] • Fax [phone]
ANALYTICAL REPORT
CUSTOMER: City of Henderson WORK ORDER #: 811224-007
Nutbush Creek WWTP
REPORT TO: Mr. Reginald Hicks RECEIVED: 02/11/98
SAMPLE DESC: THE MONITORING REPORTED: 02/24/98
SAMPLE TYPE: WASTEWATER, COMPOSITE PO NUMBER: VERBAL:R. HICKS
COLLECTED: 02/09/9810:45 to 02/10/9810:55 SITE: Ball Foster
PARAMETER DATEMME/ANALYST MQL RESULT
Ceriodaphnia Pass/Fail Chronic Started 02/11/9815:30 N/A Invalid Pass/Fail
NCDEM 9/89 Analyzed 02/23/98 by JCB
MQL = Minimum Quantitation Limit
<80% 3rd brood in Controls on Day 7: test INVALID per DWQ
protocol. Test extended to Day 8: PASS w/ Control reproduc-
tion of 16.6 and 0.4% discharg a reproduction of 22.0.
Certifications:
NC Chemistry: #85, Biomonitoring: #002, Drinking Water: #37743, Radiation License: #001-0904-OG
VA SWCB ID: #000061, Drinking Water: #00018
SC Environmental: #00018
EPA Chemistry Lab ID: NC00137, Bioassay Lab ID: NC2721500
Page

R Aquatic Bioassay Testing • Aquatic Toxicity F _ _ ___ion Evaluations
Chemical Product Environmental Assessments • NPDES Testing
Reporting & Data Handling Services
BURLINdTON
SEARCH 1302 Belmont Street • Burlington, NC 27215-6935 • [phone] Fax [phone]
ANALYTICAL REPORT
CUSTOMER: City of Henderson
Nutbush Creek WWTP
REPORT TO: Mr. Reginald Hicks
SAMPLE DESC: THE MONITORING
SAMPLE TYPE: WASTEWATER, COMPOSITE
COLLECTED: 02/09/9810:55 to 02/10/9811:15
WORK ORDER #:
RECEIVED:
REPORTED:
8B224-002
02/11/98
02/24/98
PO NUMBER: VERBAL:R.HICKS
SITE: JP Taylor
PARAMETER DATE/TIME/ANALYST MQL _ RESULT
NCDEIv19/89 — - —
... QUIRUu UL/11/V?J14:4U N/A Invalid Pam/Fail
Analyzed 02/23/98 by JCB
MQL = Minimum Quantitation Limit
<80% 3rd brood on Day 7; Inval id test per DWQ protocol.
Test extended to Day 8; PASS w/ reproductions of 16.6 for C
and 12.1 for 0.9% discharge co ncentration.
Page 2
sm �

-[E]III
I Aquatic Bioassay Testing • Aquatic Toxicity F ion Evaluations
Chemical Product Environmental Assessments • NPDES Testing
Reporting & Data Handling Services
BURLINGTON
-SEARCH 1302 Belmont Street • Burlington, NC 27215-6935 • [phone] • Fax [phone]
ANALYTICAL REPORT
CUSTOMER: City of Henderson
Nutbush Creek WWTP
REPORTTO: Mr. Reginald Hicks
SAMPLE DESC: THE MONITORING
SAMPLE TYPE: WASTEWATER, COMPOSITE
COLLECTED: 02/09/9810:50 to 02/10/98 11:05
PARAMETER
WORK ORDER #:
RECEIVED:
REPORTED:
8B224-003
02/11/98
02/24/98
PO NUMBER: VERBAL:R. HICKS
SITE: Kennametal
DATE/TIME/ANALYST MOIL
Ceriodaphnia Pass/Fail Chronic Started 02/11/9815:29 N/A
NCDEM 9/89 Analyzed 02/23/98 by JCB
MQL = Minimum Quantitation Limit
<80% 3rd brood on Day 7: INVA LID test per DWQ protocol.
Test extended to Day 8: PASS w/ Control reproduction of 16.6
and 0.4% discharge reproductio n of 19.1.
RESULT
Invalid Pass/Fail
Page 3
,e., Imo.

Aquatic Bioassay Testing • Aquatic Toxicity F on Evaluations
Chemical Product Environmental Assessments • NPDES Testing
Reporting & Data Handling Services
P"RLIN&ON
SEARCH 1302 Belmont Street • Burlington, NC 27215-6935 • [phone] • Fax [phone]
ANALYTICAL REPORT
CUSTOMER: City of Henderson WORK ORDER #: 8B224.004
Nutbush Creek WWTP
REPORT TO: Mr. Reginald Hicks RECEIVED: 02/11/98
SAMPLE DESC: THE MONITORING REPORTED: 02/24/98
SAMPLE TYPE: WASTEWATER, COMPOSITE PO NUMBER: VERBAL:R. HICKS
COLLECTED: 02/09/9811:10 to 02/10/9811:40 SITE: Soft Spun
PARAMETER DATE/TIME/ANALYST MOIL RESULT
NCDEM 9/89 Y .. aiarteu UL/11/WJ 1�:J1 N/A Invalid Pass/Fail
Analyzed 02/23/98 by JCB
MQL = Minimum Quantitation Limit
<80% 3rd brood on Day 7: Test INVALID per DWQ protocol.
Test extended to Day 8: PASS w/ Control reporoduction of 16.6
and 0.5% discharge conc. repro duction 27.0.
Page 4

Appendix B
TriTest Letter Describing the Cause of the Invalid Toxicity Tests Performed in the
Fourth Quarter of 1999 and Corrective Actions Taken

Tritest,Inc
January 11, 2000
Mr. Tom Spain
Henderson WWTP
P.O. Box 1434
Henderson, NC 27536
Dear Mr. Spain,
Phone [phone]
Fax [phone]
This letter regards samples in process during the period December 20-21, 1999. All tests
in process during the time period of December 20-21, 1999 were affected by Methylene
Chloride contamination in the culture water. We detected this contamination by
performing a variety of inorganic and organic tests on our water, food, algae and various
other components that are used in the laboratory. The volatile test, EPA 8260, showed a
substantial hit of Methylene Chloride and Ether. Both compounds are common lab
contaminants. We have taken corrective action in the entire lab area to ensure this
contamination does not affect future testing. The following list outlines these changes:
1. Technicians extracting with solvents will not be allowed in the bioassay laboratory.
2. Culture water will be monitored for volatiles on a continuous basis.
3. A regular schedule has been established to change the carbon filter on the aeration
system.
4. Employee training to increase awareness in the organics lab so waste solvents are
handled properly (i.e., handled under a hood and ventilated properly when used).
A chronic reference test was performed the week after this incident and shows all criteria
have been met to ensure quality data. I have enclosed a copy of our Reference Toxicity
Data for your review. If you have any questions or need further information, please
contact me at 919-834-4984.
S' erely,
thin A. Moore
Bioassay Laboratory Supervisor
3909 Beryl Road, Raleigh, NC 27607 ♦ P.O. Box 33190, Raleigh, NC 27636

bZ#66/6Z/ZI
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84.33
187.92
835.08
1210.92
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7/8/98 #7
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1010.71
168.65
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1188.82
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984.50
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975.00
102.65
210.84
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965.90
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205.29
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99.07
201.93
198.13
763.97
1167.83
12/I6/98 #12
953
957.83
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94.47
188.94
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1156 40
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Tritest, Inc-
Decembp, 1999

Appendix C
Summary of City of Henderson's Costs for the
Toxicity Reduction Evaluation Program

THE Program Costs for Fiscal Years 1996 to Present*
Year
Cost
1996-97
$97,591.12
1997-98
$95,092.68
1998-99
$76,126.06:•
1999-2000
$56,068.25 '*•
Total
$324,878.11
Fiscal year starting July 1 and ending June 30
The reduction in costs from 1996 to 1999 was the result of (1) reduced
monitoring of certain industries and sewers because no toxicity was present and
(2) the increased in-house use of Microtox to screen for toxicity.
* ' As of May 1, 2000

1 3', •
Appendix D
America] Corporation's Progress Report Dated March 22, 1999

Aquatic Sciences Consulting
March 22, 1999
Mr. Jeff Golliher
Superintendent of Dyeing
Americal Corporation
P.O. Box 1419
Henderson, NC 27536
Re: Jar Test Plan
Dear Jeff:
15751 Bushy Park Rd
Woodbine, Maryland 21797
[phone] phone
[phone] fax
As discussed, your treatment facility will be changing the type of potassium permanganate used
for treatment (i.e., fro'.a 30% potassium permanganate plus diatomaceous earth to 100%
potassium permanganate). Therefore, further testing with the treatment additives, as outlined in
the recent report, is postponed until the new permanganate feed is online. A primary objective of
the planned tests was to evaluate the potential for toxicity reduction by addition of an oxidant
followiU the current treatment process. As discussed, we can address this objective by
performing some jar tests this week. The scope of work and costs for these jar tests are described
below.
Scope of Work
A total of four jar tests, consisting of an Americal discharge sample spiked with a range of
hydrogen peroxide concentrations, will be performed on March 24`s. Hydrogen peroxide (H2O2)
was selected because it is currently being used at Americal's treatment facility and it is less
expensive than potassium permanganate.
A twenty-four hour composite sample of Americal's discharge will be collected from I OAM
March 22nd to I OAM March 23`d. The City will pick up the sample and refrigerate it until testing
on March 20. On March 24 h, I plan to meet with you to discuss the current H2O2 dosages and
pH adjustments used at the treatment facility. At that time, I will obtain samples of the H2O2
and, if necessary, caw: do and acid used for pH adjustment.
The range of H2O2 dosages for testing will depend on the level of oxidant residual maintained in
Americal's discharge (anticipated to be zero) and the concentration that is nontoxic to
Ceriodaphnia dubia, the City's toxicity test species. Previous studies have shown that H2O2 is

Jeff Goliiher Page 2
Americal Corporation 22 March 1999
chronically toxic to C. dubia at concentrations above 10 mg/L. Therefore, the maximum dosage
should not exceed 10 mg/L, after accounting for dilution of Americal's discharge in the City's
combined influent (i.e., 6.4%) and the anticipated reduction of H2O2 in the City's sewer and
treatment plant. The jar test samples will not undergo treatment in a simulation of the City's
treatment plant; therefore, it will be necessary to reduce residual oxidant concentrations that are
greater than 10 mg/L. Sodium thiosulfate can be used to reduce oxidant levels because it is
relatively nontoxic to C. dubia; however, background levels of sulfate will be considered to
ensure that toxic sulfate concentrations do not occur.
The range of H2O2 and sodium thiosulfate dosages for jar testing will be defined following
discussions on March 25 h. It is anticipated that the H2O2 dosage will range from 10 to 50 mg/L
(a total of three concentrations will be tested). A control consisting of the discharge sample
without added H2O2 will be used to evaluate the toxicity reduction by H2O2.
The jar test effluents (four total) will be tested for toxicity using the limited -scale C. dubia test
procedure. This test consists of five sample concentrations and a control with five replicates per
concentration.
Results of the jar tests will be submitted in a letter to you. Recommendations for post treatment
with H2O2 or further testing will be included.
Proposed Cost
The total cost of this testing is $2,220, including labor for jar tests and preparation of the letter
report and travel costs. T -,._
I will see you this Wednesday morning (8AM). Please call me today or tomorrow in the office at
[phone] if you have questions or comments
Sincerely,
John A. Botts
Principal Scientist
CAMy DocumentsMord DocsVoWs WorkUobsWnerlcII\RTA Round 2Var Test Plen.doc
03/24/99 12:37 AM

DIVISION OF WATER QUALITY
May 8, 2000
MEMORANDUM
To: Ken Schuster
Raleigh Regional Office
Through: Matt Matthews YO r
From: Kevin Bowden M
Subject: Proposed Whole Effluent Toxicity Enforcement Action
TX 00-016
City of Henderson WWTP
NPDES Permit No. NC0020559 `
Vance County
This office has reviewed the subject facility's whole effluent toxicity compliance data for the
review period September 1999 through February 2000. This action has been prepared because the
facility did not achieve compliance with its chronic toxicity permit limit for the above -mentioned review
period.
Enclosed please find a proposed Civil Penalty Assessment, Administrative Hearings Waiver
Form and copies of AT test form(s) for your files. All procedures for mailing the assessment,
distributing copies and tracking the enforcement action, once issued, are identical to procedures for
issuing fast track enforcement actions from the Regional Offices. Aquatic Toxicology Unit Staff have
entered initial case information into the Division's Enforcement Tracking System.
We have proposed the number of assessable toxicity limit violations. Civil penalty assessments
for chronic toxicity permit violations will be based on facility performance for the review period
(quarter).
Our office recommends the subject enforcement action be processed.
If you have any questions, please contact me or Matt Matthews at 733-2136.

DI%,TSION OF WATER QUALITY - CI-V1L PEAL I Y A�bi �awtr � t
violator:
Countv U4rez
Case Number.
ASSESSMENT FACTOR
I) The degree and extent of harm to the natural resources of the State, to the public health, or to
pr' ate property resulting from the violation;
(V)not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
2) T e duration and gravity of the violation;
)not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
3) TM
ieffect on ground or surface water quantity or quality or on air quality;
( )not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant t
4) T cost of rectifying the damage;
ot significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
5) The amount of monev save by noncompliance;
( )not significant ( oderately significant ( )significant
( )very significant ( )extremely significant
6) )N her the violation was committed willfully or intentionally;
( not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
7) The prior record of the violator in complying or failing to comply with programs over which the
Enyfronmental Management Commission has regulatory authority; and
( not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
8) Th ost to the State of the enforcement procedures.
not significant ( )moderately significant ( )significant
( )very significant ( )extremely significant
S 1 az
Date
Water Quality Regional Supervisor
REMISSION FACTOR
() Whether one or more of the civil penalty assessment factors were wrongly applied to the
detriment of the petitioner;
() Whether the violator promptly abated continuing environmental damage resulting from the
violation;
() Whether the violation was inadvertent or a result of an accident;
() Whether the violator had been assessed civil penalties for any previous violations; and
() Whether payment of the civil penalty will prevent payment for the remaining necessary remedial
actions.
Date
Kerr T. Stevens

' Effluent Aquatic Toxicity
'--iori Form i Pnase ii Chronic
C -indaphnia
11/4199
Facility
NPDES#.
0020559 Pipe#; 00i
County:
w:�\CE
Laboratory Performing Test T` f5t.
I .'
I Comments
linden ✓umber:
--
t191 r1_Il
1354
x . 1, i^7� (
0 R.Cm _ �ig �5u(erv"
Signature o�Y
)r
atLL3b-%
Isor
j
Sample Information Sample
Sample 2 Control
Test
Start Date
End Date
Stan Time End
Time
Collection Start Date 1025-99
10 28'99 -
information'
In =' 99
11
199
s: U
9:i 1
'
Stan Renewl
Renew3
Start
Renewl
Renewl
Grab
Treatment
90
90
90
Control
Control
Control
Composite (Duration) '4
-
_14
pH Initial
7.9
7.9
7.8
'.S
7.7
7.9
Hardness (mgl0 'w
46
pH Final
8.1
S 2
8.1
7.8
7.9
7.8 1
Spec. Cond. (umhos/cm) 65U
720 46
I
D.O. Initial
8.0
8.0
8.2
8.0
7.9
8.1-1
Chlonne (mg/I) 0.1
0.1 gg
D.O. Final
8.0
8.0
7.8
7.9
7.9
Zft
Sample temp. at receipt -4
LO 'C
Temp. Initial
"
24.8
24.4
_5 '
'1 7
'4.7
'S"0
I Temp. Final
25.9
25.4
26.0
2T.9
25.4
26.0'
Revle' 7y • . T Organism# Chronic Test Results
2 3 4 5 6 7 8 9 10 _ 11_. 12 Mean Final Control Mortality % 0
I • /�� #-Y' ounrtT- Sli 35 31 35 36 38 32 39 34 32 0 0 34.2 % Control 3rd Broodl too
"-Control - - -- ----
Adult L L L L L L L L L L
(L)ive (D)ead - 5 .-
3 4 M
2 -_ - 5 --3 9 to 11 ----..--- 12ean -
Effluent% #Young 31 1 35 2 35 40 0? 30 36 35 37 33 0 0 34.3
�15 Adult L L D L L L D L L D N/A
(L)ive (D)ead
Effluent °,re # Young
30 Adult
�(L)ive (D)ead
Effluent% # Young
45 Adult
(L)ive (D)ead
Effluent % # Young
67 5 Adult
(L)ive (D)ead
Effluent % # Young
90 Adult
(L)ive (D)ead
1 2 3 4 5 6 7 a 9 10 . Mean
15 28 30 19 32 14 29 30 28 28 25..3
1 2 3 4 5 6 7 8 9 10 Mean
13 17 19 15 16 18 22 14 18 23 17 5
D D D D D D D D D D NIA
1 2 3 4 5 6 7 8 9 10 Mean
19 18 20 13 19 15 15 21 14 15 16.9
D D D D D D D D D D N/A
3 1 5 6 7 8 9 10 "Aean
16 "15 14 '17 14 12 17 14 19 16 15.4
D D D D D D D D D D r4%A
MAIL { 1 r N C. Department cr "NLt
DWO/Envlronmerdal Sciences
TO. Brancn
i621 Mall Seivit1C C ei ier
48 Hour Mortality
Control IWC -
Uof10 0of10
Final Mortality Significant @
;n or No Conc.
j Reproduction Analyss
'Rarro. '-OE'-'= ;
NOEC= I i
-
iMetho[: Dunn:tt"
Normal Distrib?: 1'e,
Method: Shapiro
Statistic: 0.948
Critical: 0.919 _
Variances?: Yes
Method: Bartlett's
(Equal
Statistic: 8.994
Critical: 11.345
EfFluent% Rank Sum Critical Sum
Result = PASSIFAIL or
Test LOEC = 't ;l) ; NOEC =
Chronic Value = ? 1.2
I
' Should use niohest test concentration ^t
�r•��, ��gheet ,pneer,hdiion with D.0 >5 Ongr:
1 .., R-17 jclin., trnm C:,nt of Reproduction "dear
r)FIVI „ mr ,,T_. :Rr911 Rev

i+iuent Aquatic Toxicity )ort Form If Phase II Chronic C-`-)daphnia 11i18/99
Facility L.cr,,,,Ird`ATP NPDES#: N00020Pipe#: ool County: V,mce
Laboratory Performing Test 'Tritest -hie. comments: Order Number: 'd911- n:!!9;
orgnar.,re of O.R.0 � ure of Lab Supervisor
i
Sample Information
Collection Start Date
Grab
Composite (Duration)
Hardness (mg/1)
Sp6c. Conti. (umhosicm;
Chlorine (mg/1)
Saml)re •Lmp. :mot fcceipi
Sample 1 Sample 2 Control
11 1 /99 1 1 .4199 _-
700 780
0.5 C- I.0 is
43
160
Test
Start Date End Date
Start Time End Time _
Information'
1113,99
111),,),)
Start Ranawl
Renew2
Stan
aenewt
Aenew3
Treatment
90
90
67.j
Control
Control
Cortrol
pH Initial
7.8
7.9
7,S
-.
8.0
''.S
pH Final
8.3
3.4
8.1
8.1)
7.7
7.8
D.O. Initial
8.0
8.0
7.9
8.0
8.0
7.9 j
D.O. Final
8.0
8.0
8.0
8.2
8.2
8.0
r
-
Temp. Initial
24.6
24.7
242
. 24.0
_45
24.1
Temp. Final
24.7
243
24.5
24.7
2_4 :i
-14.5
Organism #
--ate ' 2 3 4 5 6 7 8 9 10 11 12 Mean
Control Adult
(L)ive (D)ead
Effluent% #Young
ISi Adult
(L)ive (D)ead
Effluent % # Young
-170 Adult
I(L)ive (D)ead
Effluent% # Y"oung
451 Adult
!L)ive (D)ead
Effluent % # Young
6ZSI Adult
i(L)ive (D)ead
Effluent % # Young
90 Adult
1(L)ive (0)ead
31 �32 30 37 30 27 33 34 28 22 0 0 30A
L L L L L L L L L L
1 2 3 _ 45_ 678 _ 9 10 11 12 Mean
_
27 29 30 31 29 2! _ 34 23 24 3 0 0 25.9
L L L L L L L L L D s.4
1
2
3
4
5-
6
7-
8-
9
10
Mean
29
31
33
24
M
28
23.30
25
33
29.1
L
L
L
L
L
L
L
t.
L
L
a3
2
3
4
5
6
7
8
9
10
mean
25
22
33
31
31
27
10
29
24
24
25.6
L
L
L
L
L
L
L
L
L
L
15.8
1
2
3
4
5
6
7
8
9
10
Mean
15
27
26
26
29
28
26
16
28
32
25.3
D
L
L
L
L
L
L
D
L
L
1es
1
2
3
4
5
6
7
3
9
10
Mean
4
6
12
5
3
7
3
5
0
5
5
D
D
D
D
D
D
D
D
D
D
NiA
MAIL ATT N C Denartmen.f of ENIR
UWO/Environmental Sciences
0; Branch
Mail Service Celitei
R ,i " N.C. 2"9 162 i
Pal e 8 99?G
Final Control Mortality'/3 11;ap
% Control 3rd Brood
Control Repro CV 13
48 Hour Mortality
Control IWC
0of10 0Of 10
Significant? +es _
Final Mortality Significant @
9Cl or No Conc.
'pro. LOEC= coo
. QEC=
ethod: DunneTt
xmal Distrib?: No
Method: clgtpiru
Statistic: 0.2;4
Critical. 0.2673.0.2S73
dual Variances?: )',,
Method: Bardett's
Statistic: II.711
Critical: I5.U86
Effluent! Rank Sum Criticai Sum
=PASSIFAIL or
)EC = 90 ; NOEC = 67 j
c Value = 7'1 9
!:no:tld u¢r nighes, to i( -pnrpntrarlcn .,)f
niyhest cuncenuauen •.vim D.O.:o.Qmgtl
n •.q::::f ll"` 4t'In CJ'llroI PCr.roc UU 101 Mean

- - •� - - -y -t- • r Vt ul 1 rud6e tt t nrunic
t,erroaapnnla
12120/99
Facility HENDERSON WWTP
NPDES#: 0020559 Pipe#: County:
V,aNCE
Laboratory Performing Test Tritevf�nC.
Comments:
Order Number: 9912-0025,
x*KILLED
IN TRANSFER
Signature of O.R.C.
f
ature of Lab Supervisor
Sample Information Sample 1 Sample 2 Control
Test Start Date End Date Start Time End Time
Collection Start Date
I _/G/99
2�
I _� 9/99
Information'
-
_I 2/8/99 12/ I_4/99
--4.�G
--------0----
Grab
'
_-- _
start . Renewl Renew2
Stan
Renewl
Renew2
__
Treatment
_
90 90 90
Control
Control
_ _
Control
Composite (Duration)
24HR
24HR
pH Initial
7.9-- 8.1 7.9
7.7
7.9
7.9
Hardness (mg/1)
48
--
Spec. Cond.(umhos/cm)
780
_ _
810 170
pH Final
8.1 8.1 8.0
7.6
8.1
_
7.9
Chlorine(mg/1)
<0.1
<0.1
D.O. Initial
8.28.0 8.0
3.0
8.0
8.0
D.O. Final
7.5. 7.8 7.8
7.7
7.8---7.8
Sample temp. at receipt
1.0 °C
1.0 °C
-- -- --
- -
-
Temp.Initial e
24.7! -4.7 24.0
24.8
25.0
24.6
Re• ie, ed 1w - r-
Temp. Final
24.3! 24.6 25.5
--
24.3
24.6
255
Control
3
Organism#
3
4
5 6 7 8
9
10 11
12 Mean
I # Young
33 31 24
37
29 34 18 34
33
38 0
0 32.6
Adult
L 1 L L
L
L L L
L
L
_
1 2_ _ _3_4
_
5 6 7 8
9
10 11
12 Mean
# You
36 28 36
Effluent % ng 1 25 30 26 29 25 37 0 0 30.3
15
Adult
L
L
L
LPL L L
L! L L
(L)ive-(D)ead
_
1_
2
5
6
7 8 9 10
Mean
Effluent%
#Young
24
31
-3
31
-4
29
27
29
31
, 25 34
29.0
30
Adult
(L)ive (D)eati-
L
L
L
L
L
L
L
129
L L L
110
1
2
3
4
5
6
7 8 9 10
Mean -
Effluent %
# Young
32
29
32
31
32
27
30
28 31 25
29.7
45
Adult
L
L
L
L
(L)ive (D)ead
-
_
-10
1_--
2
3
_4
5--
6
7 8 9
Mean
Effluent %
# Young
27
30
30
29
33
32
33
33 33I24
30.4
�67.5
Adult
L
L
L
L
L
L
L
L L L
5.75
(L)ive (D)ead
-
--
..
-9�10
1
2
3
4
56-7
8
Mean
Effluent%
#Young
12
14
7
14
7
15
16 1
16 17 ! 6
12.4
90
Adult
D
L
D
L
D-,
L
L
D L D
nis
(L)ive (D)ead
_.D
MAIL ATT: N.C. Department of ENR 5 ?non
TO:Sciences JAI$
TO: Branch
1621 Mail Service Center
Raleigh. N.C. 27699-1621 .,.-.^lt.'r,
Chronic Test Results
Final Control Mortality % to
% Control 3rd Brood go
Control Repro CV1 13
48 Hour Mortality
Control IWC
,r L __ _ V Ut tv
Significant? ES
Final Mortality Significant @
90 or No Conc.
epro. LOEC= 90 ; NOEC= 67.5
ethod: BONFERRONI
ormal Distrib?: Yes Method: Shapiro
Statistic: 0.282 Critical: 0.2671.0.2873
qua[ Variances?: Yes Method: Bartlett's
Statistic: 5.180 Critical: 15_086
Effluent°/ Rank Sum Critical Sum
it=PASS/FAIL or
LOEC = 90 ; NOEC = 67.5
nic Value = 77.9
Should use highest test concentration or
highest concentration with D.O. >5.0mg/I
1 % Reduction from Control Reproduction Mean
DEM form AT-3 (8/91) Rev 11/95

­,IIUt9I I L' 4U=Ul I Vnl VlLy f\CtlVIL f-Ul 111 If IJ"QC 11 �I11 Vlllt. vC1lVuaf./I1tua ..t tNu
Facility HL-NDERSON W'WTP NPDES#:
Laboratory Performing Test Trite
x !.�,� __ x L Gl
Signature of O.R.C. ure of Lab Supervisor
Sample Information
Sample 1
Sample 2 Control
Collection Start Date
1/31/00
2/3/00
Grab
Composite (Duration)
24 }trs.
24 hrs.
Hardness (mgA)
47
Spec. Cond. (umhos/cm)
400
650 190
Chlorine (mgA)
<0.1
<0.1
Sample temp. at receipt
u.05 'C
0.05 "C
Control
Comments: Order Number: 0002-00051
This is a January sample
Test
Start Date End Date
Start Time End Time
Information"
2/8/00
9:37_
I1_:07
_JJ00
Start Renew
_
Renew2
_
Start
Renewt
Rene 2
Treatment
901
90
90
Control
Control
Control
pH Initial
7.71
7.7
7.81
7.8
7.9
7.9
pH Final
S.1 i
8.1
8.0'
7.9
8.1
1 7.9
D.O. Initial
82;
8.0
8.2
8.0
8.0
8.2
D.O. Final
8.01
8.0
8.01
8.0
8.0
8.0
Temp, Initial
24.11
24.1
24.0'!
24.9
24.5
24.9
Temp. Final
24.41
24.5
24.31
24.4
24.5
24.3
Organism #
3 4 5 6 7 8 9 10 11 12 Mean
ung 35 36
37
28 34
26 30 38 • 31 34
0
1 0 32.9
Adult L L
Mive Dead I
L
L L
L L L L L
1 9 3 4 5 6 7 8 9 10 11 19 Mean
Effluent% # Young 31 35
32
34
30
31 32
31
2B
31
0 0 31.5
15
Adult L L
(L1ive(D)ead�
L
L
L
L L
L
L L
a.26
# Young 34 32 32 36 34
33 29
35
31 31 32.7
Effluent %
�30
Adult L L
L L L
L L
L
L L 10.608
L ive (D)eadI
1
2
3
4
5
6
7
8
9
10
Mean
# Young
32
27
32
28
32
34
29
1 31
1 35
39
131.9
Effluent %
45
Adult
L
L
L
L
L
L
LIL
I L
L
3.04
viaD1ead
-9
1
2
3
4
5
6
7
8
10
Mean
Effluent % # Young 28 26
34
33
28 33 31 29 31 1 36
130.9
67.5
Adult L L
L)ive (D)eadi
L
L
L 1 L L L
L L
s.08
1 2 3 4 5 6 7 8 9 10 Mean
#Young 15 28
17 28
16
32 29
28
14 i 6
21.3
Effluent%
90
Adult D
D
L.
L -L_-
L
D
35.2
ive (D1ead I
�
`.• FEB 1 7-2000,
MAIL ATT: N.C. Department oiNR 1W43RANEH V V�
DWQ/Environ ental Sciences
TO- Branch
1621 Mail Berke Center
Raleigh, N.C. 27699-1621
Final Control Mortality
% Control 3rd Brood
Control Repro CV
48 Hour Mortality
Significant? Yes
Final Mortality Significant @
90 or No Conc.
epro. LOEC= 90 ; NOEC= 67.5
ethod: Durtmett's
ormal Distrib?: Yes Method: Shapiro
Statistic: 0.272 Critical: 0.2673,0.28"
dual Variances?: No Method: Bartlett's
Statistic: 28.830 Critical: 15.086
Effluent% Rank Sum ' Critical Sum
rail Analysis
ult = PASS/FAI L or
t LOEC = _ _ _ go; NOEC = 67.5
onic Value = 77.9
" Should use highest test concentration or
highest concentration with D.O. >5.Omg/I
% Reduction from Control Reproduction Mean
DEM form AT-3 (8/91) Rev. 11/95

JAMES B. HUNT JR.
GOVERNOR
BILL HOLMAN
SECRETARY
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
RALEIGH REGIONAL OFFICE
DIVISION OF WATER QUALITY
Mr. Eric M. Williams
City Manager
City of Henderson
P.O. Box 1434
Henderson, NC 27536
Subject: Department of Environment and Natural Resources and
Environmental Management Commission vs.
City of Henderson
EMC SOC WQ 96-005
NPDES Permits NCO020559
Stipulated Penalties
City of Henderson WWTP
Vance County
Dear Mr. Williams:
The City of Henderson entered into a Special Order by Consent EMC SOC WQ 96-005
with the North Carolina Environmental Management Commission. The SOC placed the
subject facilities under interim effluent limitations with an enforceable schedule while
the City conducted a Toxicity Reduction Evaluation.
Under paragraph 2(c)5 of the Special Order by Consent, the City was required to
achieve compliance with all final effluent limitations contained in NPDES Permit No.
NCO020559 by September 30, 1999. The City failed to meet this schedule date and was
found to be noncompliant for toxicity for the months October 1999, November 1999,
December 1999, and January 2000.
You were notified of the violations and of your right to justify the City's failure
to meet the interim effluent monthly average limitations in the Notice of Violation letters
dated February 21, 2000 and March 24, 2000.
I have reviewed the City's replies dated February 24, 2000 and April 7, 2000.
After careful review of this matter, I have not found sufficient justification to waive the
stipulated penalty.
You are reminded that payment of said penalties mentioned in this letter will not
foreclose further penalties for any future or continuing violations, failure to me
1626 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27699-1626
PHONE [phone] FAX [phone]
AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/10% POST -CONSUMER PAPER

City of Henderson
SOC EMC WQ 96-005
Page Two
deadline dates, or interim effluent violations.
If you wish to contest any portion of the civil penalty assessment, you must request an
administrative hearing. This request must be in the form of a written petition to the Office of
Administrative Hearings and must conform to Chapter 150B of the North Carolina General
Statutes.
You must file your original petition with the:
Office of Administrative Hearings
6714 Mail Service Center
Raleigh, North Carolina 27699-6714
and mail or hand deliver a copy of the petition to:
Mr. Dan McLawhom, General Council
Department of Environment and Natural Resources
1601 Mail Service Center
Raleigh, North Carolina 27699-1601
If you have any questions concerning this notification please contact Kenneth Schuster at
919/571-4700 in our Raleigh Regional Office.
Sincerely,
Kerr T. Stevens., P.E.
cc: Attorney General's Office
SOC Files -- Compliance Group
Raleigh Regional Office -Kirk Stafford

Division of Water Quality
Raleigh Regional Office
April 17, 2000
To: Coleen Sullens
Through: Ken Schuster
From: Kirk Stafford
Subject: Stipulated Penalty Demand
City of Henderson
SOC EMC WQ 96-005
NPDES Permits NC0020559
Vance County
Raleigh Regional Office
Attached is a Stipulated Penalty Demand letter for the Director's signature assessing a
stipulated penalty for the subject facility's failure to achieve compliance with all final effluent
limitations contained in NPDES Permit No. NC0020559 by September 30, 1999. This date is
stipulated in Part 2(c)5 of the subject SOC. The SOC specifically relaxes the limit for toxicity
and allows for upgrades of the Redbud Pump Station and the construction of a new gravity sewer
from the Redbud Pump station to the Henderson WWTP. The subject facility has been cited with
NOV's for toxicity for the months October 1999, November 1999, December 1999, and January
2000. The City of Henderson is conducting a Toxicity Reduction Evaluation as per the SOC.
Paragraph four of the SOC states the stipulated penalty is not due if the City satisfies the
Division that noncompliance was caused by an act of God, an act of war, an intentional act or
omission of a third party (not a defense if the third party has a contractual relationship with the
Permittee), an extraordinary event beyond the Permittee's control, or any combination of the
above causes. There were no reasons given by the City that satisfy the above criteria for the
noncompliance so the City is not relieved from being assessed the stipulated penalty. Therefore,
the Raleigh Regional Office recommends the letter assessing the stipulated penalty be put before
the Director for signature.
Also included per Standard Operating Procedure is a stipulated penalty demand letter
waiving the stipulated penalty. However, since the facility has been on a JOC or SOC since
1988 for toxicity, the Region recommends assessing the stipulated penalty of $10,280 as per Part
3 of the order.
Please review; if you have questions or comments, please advise.

NORTH CAROLINA DEPARTMENT OF
'Q� ENVIRONMENT AND NATURAL RESOURCES
i0�
KDENRDIVISION OF WATER QUALITY
RALEIGH REGIONAL OFFICE
DIVISION OF WATER QUALITY
JAMES B. HUNT JR.
GOVERNOR CERTIFIED MAIL
RETURN RECEIPT REQUESTED
BILL HOLMAN
SECRETARY
Mr. Eric M. Williams
City Manager
City of Henderson
P.O. Box 1434
Henderson, NC 27536
Subject: Department of Environment and Natural Resources and
Environmental Management Commission vs.
City of Henderson
EMC SOC WQ 96-005
NPDES Permits NCO020559
Stipulated Penalties
City of Henderson W WTP
Vance County
Dear Mr. Williams:
The City of Henderson entered into a Special Order by Consent EMC SOC WQ 96-005
with the North Carolina Environmental Management Commission. The SOC placed the
subject facilities under interim effluent limitations with an enforceable schedule while
the City conducted a Toxicity Reduction Evaluation.
Under paragraph 2(c)5 of the Special Order by Consent, the City was required to
achieve compliance with all final effluent limitations contained in NPDES Permit No.
NC0020559 by September 30, 1999. The City failed to meet this schedule date and was
found to be noncompliant for toxicity for the months October 1999, November 1999,
December 1999, and January 2000.
You were notified of the violations and of your right to justify the City's failure
to meet the interim effluent monthly average limitations in the Notice of Violation letters
dated February 21, 2000 and March 24, 2000.
I have reviewed the City's replies dated February 24, 2000 and April 7, 2000.
After careful review of this matter, I have found sufficient justification to waive the
stipulated penalty.
You are reminded that payment of said penalties mentioned in this letter
foreclose further penalties for any future or continuing violations, failure to me
deadline dates, or interim effluent violations.
1629 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27609-1628
PHONE [phone] FAX [phone]
AN EQUAL OPPORTUNITY / AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/10% POST -CONSUMER PAPER

City of Henderson
SOC EMC WQ 96-005
Page Two
If you have any questions concerning this notification please contact Susan Wilson at 919/733-
5083 ext. 510 or Kenneth Schuster at 919/571-4700 in our Raleigh Regional Office.
Sincerely,
Ken T. Stevens., P.E.
cc: Attorney General's Office
SOC Files -- Compliance Group
Raleigh Regional Office -Kirk Stafford

r/. H
t y of Henderson Office of
P. O. Box 1434 City Manager
180 Beckford Drive Eric M. Williams
Henderson, NC 27536
[e-mail]
Phone:[phone] Fax:[phone]
April 5, 2000
Ms. Coleen Sullins
Water Quality Section Chief
NCDENR — Division Of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Update on Toxicity Compliance
Special Order by Consent Toxicity Limit
EMC WQ 96-005
City of Henderson
NPDES Permit NCO020559
Vance County
Dear Ms. Sullins:
On March 2, 2000 the City of Henderson received your response regarding our request for an
extension of the subject order to extend the modified toxicity limit for one year. The City was
disappointed in the recommendation to not approve the extension; however, we respect the decision
made by your Office and we will continue to strive to resolve our toxicity issues. The City
understands the State has certain parameters and regulations in which to grant such an extension
and we are trusting all of your staff researched this matter very thoroughly before this decision was
reached.
Since receiving your subject letter the City has received some encouraging results of our
latest Cerodaphnia chronic toxicity test, which appear to be moving us further toward compliance.
The City Wastewater Treatment staff, along with Aquatic Sciences Consulting, have been diligently
working toward sources of toxicity and based on our laboratory results There are early irdications
that we may have found a potential source.
The chronic toxicity of the Wastewater Treatment Plant effluent has shown considerable
improvement and more stability over the past five (5) months. The City had chronic values of
77.9% for the months of November, December, and January and > 90% for February and March
for the WWTP effluent. In addition the City has not had any toxic Micotox samples in the past
60 days from industry or the WWTP. The City plans to run a Cerodaphnia chronic toxicity test for
the week of April 3`d, but will not have the results until April 13" . We are certainly working very hard
with the two suspect industries of Americal and Harriet Henderson Yarns South -Mill to reach our goal
of consistently passing at > 90%.
H?Letters from C\Coleen Sullins SOC April 5, 2000 do, Page 1 of

While the results mentioned above are very encouraging, the City is also investigating some
other options to eliminate chronic toxicity. Presently, we are working with Aquatic Sciences
Consulting and McKim & Creed Engineering to conduct pilot bench scale tests to evaluate activated
carbon's ability to remove toxicity in the most efficient way. The pilot scale tests were installed at the
plant beginning the first of April and we should have the results within 90/120 days. There have
been some early indications, based on preliminary lab results, that indicate that activated
carbon will remove toxicity at the WWTP.
We will continue to keep you abreast of our effluent toxicity testing and particularly our April
13`h test, and also we will advise you of our pilot test studies on activated carbons. The City will
continue to devote all of its resources available, including City staff and Consultants, to achieve
compliance with chronic toxicity. Hopefully the City is heading in the right direction and all
indications seem to indicate such. We will continue to keep you updated and if you have any
further questions please do not hesitate to contact me.
With best regards, I am
Sincerely,
CITY OF HENDERSON
Eric iams
City Manager
EMW/pg
C: Kenneth Schuster, P.E. Regional Supervisor
Kirk Stafford-RRO
Shannon uangly-NPDES Compliance
Mark R. Warren, Assistant City Manager
Tom Spain, WWTP Director
Linda Leyen, Chief Operator
Reggie Hicks, Lab Supervisor
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin. McKim and Creed
H.'Letters from CColeen Sullins SOC April 5, 2000 doc Page 2 of

y of Henderson Office of
P. O. Box 1434 City Manager
180 Beckford Drive Eric M. Williams
Henderson, NC 27536
[e-mail]
Phone:[phone] Fax:[phone]
March 10, 2000
Mr. Kenneth Schuster, P.E.
Regional Supervisor
NC DENR
Division Of Water Quality
1628 Mail Service Center
Raleigh, NC 27699-1628
RE: Response to February 281h letter
November, 1999 Quarterly THE Report
Special Order of Consent
City of Henderson
NPDES Permit NCO020559
Vance County
Dear Mr. Shuster,
The City of Henderson received your letter dated February 28, 2000 in
regard to questions that the Division Of Water Quality has pertaining to our
November 1999 quarterly THE Report. Since receiving your letter, the City Staff
has been assembling information and data in responding to your questions and
we hope we have addressed each issue effectively and to your satisfaction.
Attached you will find a letter from Tom Spain our Wastewater Treatment
Plant Director who has outlined in detail a response to each question dated in
your February 28th letter. I think you will find that Mr. Spain has documented
each concern that was addressed and that his answers will provide you the
necessary assurances that our Wastewater Treatment operations are both
efficient and environmentally sound. As always, we are most appreciative of the
support and guidance of you and your staff as we all work toward the
management and operation of our wastewater system in a environmentally
sound, prudent and physically responsible manner.
After you have had the opportunity to review our responses, if you or your
staff should need any further information or if a meeting is necessary to further
discuss our responses, please do not hesitate in contacting us.
Thank you for you time and attention in this matter. If further information
is needed during the course of your reviews, please contact us.
\WDMIN\PGLOVER$\Letters from C\Kenneth Schuster SOC tttr March 10. 2000doc.doc
Page 1 of 2

With best regards, I am
Sincerely,
CITY OF HENDERSON
Zinil iams
City Manager
EMW/pg
Attachment
C: Kirk Stafford-RRO
Shannon Langly-NPDES Compliance
Mark R. Warren, Assistant City Manager
Tom Spain, WWTP Director
Linda Leyen, Chief Operator
Reggie Hicks, Lab Supervisor
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin, McKim and Creed
1WDMI WGLOVER$\Letters from C\Kenneth Schuster SOC Mr March 10. 2000doc.doc Page 2 of 2

CITY OF HENDERSON
Post Office Box 1434 Nutbush Creek Wastewate
180 Beckford Drive Treatment Plant
Henderson, North Carolina 27536-1434
Phone: [phone] FAX: [phone]
March 8, 2000
Mr. Kenneth Schuster, P. E.
Raleigh Regional Supervisor
NC DEHNR DWQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Subject: Response to February 28'h letter
November, 1999 Quarterly THE Report
Special Order of Consent
City of Henderson
NPDES Permit NCO020559
Vance County
Dear Mr. Shuster,
I am writing in response to your February 28`b letter to Henderson City Manager, Eric
Williams, since the management of the THE Program and Redbud Pump Station
operation is my direct responsibility.
I anticipate that Mr. Williams will include a cover letter to this response because of his
desire to maintain a direct positive working relationship with the State and the vital
importance to the City to resolve any wastewater issues promptly to the State's
satisfaction.
Response to Questions and Comments in the Division of Water Quality's Letter
(Dated February 28, 2000)
Harriet & Henderson south cotton mill was identified as a new source of toxicity.
The facility is authorized to discharge domestic waste only but evidence of
nondomestic discharges was obtained. What evidence did the City obtain? Did the

City investigate for cross connections during subsequent visits? Why has the City not
investigated this facility before now considering its size and potential for toxic
discharges? Did the city issue a Notice of Violation (NOV) or assess civil penalties?
Response: The evidence of nondomestic discharge from the Harriett & Henderson
south mill was an indication ofrefi-actory toxicity in the discharge. A sample of the
Harnett & Henderson south mill discharge collected in September 1999 failed the
refractory toxicity assessment (RTA) test as described in the November 1999
quarterly progress report (please see last paragraph on page 4 of the report).
In September, the city directed Harriet & Henderson to investigate possible cooling
water losses at the south mill (city letter dated September 20, 1999). The city was
concerned that cooling water piping was leaking and biocides or other cooling water
chemicals were possibly being discharged to the City's sanitary sewer. Harriet &
Henderson performed the investigation; however, the results of dye tests reportedly
did not show evidence of cross connections (Harriet & Henderson letter dated
October 14, 1999).
In addition to all other major industries, the city has been investigating the Harriet &
Henderson north and south cotton mills since 1997. In 1998, MicrotoxTM tests
performed on samples collected from the sewershed and the two cotton mills
indicated toxicity. However, a follow-up RTA test performed in August 1998 did not
indicate a potential to contribute refractory toxicity to the Nutbush Creek WWTP.
Also, tests performed in March 1999 with Ceriodaphnia dubia did not show toxicity
at concentrations corresponding to the mills' flow contribution to the WWTP.
The monitoring results suggested a potential for toxicity in the mills' discharges,
which appeared to be intermittent. Toxicity tracking procedures available at the time
were not helpful in identifying intermittent toxic sources; therefore, the city
committed significant resources to developing a new monitoring tool, which is
designed to capture intermittent toxicity by continuously collecting samples over a
14-day period. In late May 1999, this tool, referred to as a semipermeable membrane
system (SPMS), was deployed in a sewer receiving the south mill discharge. A
toxicity test performed on the SPMS sample showed a relatively high level of chronic
toxicity to C. dubia. These results indicated the potential for the south mill to
contribute toxicity to the Nutbush Creek WWTP. It was necessary to test the
discharge by the RTA method to determine if the toxicity would be refractory (i.e.,
contribute to effluent toxicity at the city's WWTP). A follow-up RTA test of the
sewer serving the south mill discharge did not show toxicity (July 1999).
The city finally obtained evidence of refractory toxicity in the south mill discharge in
September 1999. The city met with Harriet & Henderson in November 1999 and
presented the evidence of refractory toxicity. However, Harriet & Henderson
expressed concern that the RTA results were inaccurate because their investigation
showed no cooling water discharges to the sanitary sewer and, even if cooling water
was being discharged, the cooling water chemicals were not being used at levels that

would cause toxicity. Since permitted industries require two failures (raw sample test
followed by a RTA test) before a THE must be conducted the City agreed to retest the
south mill's discharge. Harriet & Henderson sealed the two wash down pits at South
Henderson Cotton Mill to eliminate the possibility of a potential toxicant being wash
down to the sanitary sewer. A RTA test performed in December 1999 confirmed
refractory toxicity in the mill discharge (see February 2000 quarterly report);
therefore, the city issued a letter requiring Harriet & Henderson to perform a THE
(city letter dated February 10, 2000).
The City will issue a NOV to Harriet & Henderson for a toxic discharge.
2. Omega Cleaning Products was identified as cleaning product containers in a local
car -wash when an onsite septic tank for treating wastewater was to be utilized. Did
the city issue a NOV or assess civil penalties and if not what was the reason?
Response: When Omega Cleaning Products was identified as a potential source of
toxicity, the city inspected the facility. During the inspection, it was discovered that
Omega was on a septic tank system and did not discharge to the city's sanitary sewer.
Nonetheless, a chemical inventory list was requested and received for review. Later,
when Omega called with questions about possibly relocating to a facility that
discharges to the sanitary sewer, the City determined that chemical containers were
being washed at a local car wash that discharges to the sanitary sewer. Omega was
notified to immediately cease the container rinsing and they complied (city letter
dated September 23, 1999).
The November 1999 quarterly report may have given the impression that Omega was
washing all of their product containers at the carwash. However, the city was told
that only those containers purchased and used at the car wash were rinsed (after the
contents were emptied). The city does not believe that a NOV or civil penalty is
necessary in this case because (1) the cleaning products were being used at the car
wash and are specified for use in car washes by the manufacturers, (2) an initial
review of the data, using a toxicity modeling program (Aquatox), did not indicate a
potential to cause toxicity at the city's WWTP, and (3) Omega complied immediately
with the city's order.
The city is continuing to investigate Omega's products and all car washes by
reviewing chemical inventories at each car wash. On March 1, 2000, the city
submitted a letter to each of the car washes requesting a list of chemicals used and
their material safety data sheets (MSDS) and product stewardship data. If the
chemicals pose a potential toxicity risk, the city will request additional information
and testing.
3. In August 1999, Americal Corporation replaced VircoSoft 348 with SparLube LB50.
Did the city require Americal to test the new product prior to use?

Response: During Americal's TRE, VircoSoft 348 was found to contain nonyl
phenols, which are potentially toxic. In August 1999, Americal substituted VircoSoft
348 with another softener (SparLube 50), which reportedly does not contain nonyl
phenols. The city decided to evaluate the effect of the substitution in a RTA test
performed in September 1999. In this test, Americal's discharge was not found to
contain refractory toxicity. A follow-up RTA test performed in December 1999
confirmed that Americal's discharge was not toxic. The city interpreted these results
as evidence that the substituted softener was not contributing to the WWTP effluent
toxicity.
Although Americal's discharge has not been toxic since the TRE, the city plans to
issue a letter to Americal requesting product stewardship data on SparLube LB50.
4. Mr. Tom Spain informed Ms. Judy Garrett, of the Raleigh Regional Office (RRO),
that a portable pump had been installed at the Redbud Pump Station and that the
pump combination will now be able to handle all received flow. Mr. Spain also
stated that the constriction in the downstream sewer line had been repaired three years
ago and that there have been no overflow problems since. What was the reasoning
for not installing this pump sooner since it would have eliminated a number of
overflows at this pump station? In addition, Mr. Spain has stated that any additional
pump capacity at the station would result in overflows downstream. Mr. Garrett also
informed Mr. Spain to pump and haul if necessary in the future to prevent overflows.
Please comment on why the City has not done this in the past to prevent overflows.
Response: I had been working on February 8, 2000 with the representatives of
Reynolds Construction Company, Godwin Pumps of American, Inc. and the WWTP
staff for over 16 consecutive hours with very little sleep before contacting Judy
Garrett of the Raleigh Regional Office on February 9, 2000 to notify her that the
portable bypass pump was in place and the Redbud bypass was stopped at 8:30 PM
on February 8, 2000.
My response to a question about potential overflows at Radio Lane was that we no
longer had any overflows at Radio Lane because a section of pipe downstream from
Radio Lane had been upgraded to larger pipe 3 or 4 years ago.
My memory was inaccurate because the pipe restriction was actually upgraded when
the City was required by the State to convert Redbud from a single pump to a lead/lag
two -pump operation in the early 1990's because the line could not handle a dual
pump flow without this upgrade.
This did stop the bypasses at Radio Lane but did not solve the hydraulic overload of
the interceptor to the WWTP in the Ross Mill Road area where the Sandy Creek and
North Henderson gravity lines combine with the Redbud gravity line.
Line surcharges from rainfall are now a problem in the Ross Mill Road area and the
Sandy Creek and North Henderson gravity lines.

McKim and Creed Engineers have clearly identified the areas of the gravity
interceptors from Interstate 85 to the Nutbush Creek WWTP that need upgrade to
accommodate the wastewater flow.
This is part of a project to permanently upgrade the Redbud Pump Station and main
gravity interceptor to the WWTP. Plans for this upgrade have been under review by
the State since July, 1999.
The portable pump was not installed sooner because hydraulic upgrade of the gravity
interceptor to the Nutbush Creek WWTP should have been completed first since
some overflows are likely to be shifted from the more rural Redbud Pump Station
area to the more densely populated Ross Mill Road area during heavy rainfall with
Redbud Pumping at a higher discharge rate.
When the portable pump was put on line on February 8's, the Redbud Station had
almost stopped bypassing and the line in the Ross Mill area was not in a surcharge
condition.
I was concerned of the possibility that the pump would still cause a bypass and had
the staff stationed in the Ross Mill Road area to be sure the line did not overflow
during start up.
We have not had sufficient rainfall since February 8th for the portable pump to create
a bypass but some bypass problems are likely to occur during heavy rainfall, which is
supported by the engineering study.
The City did not pump and haul from the Redbud Station in the past because it did
not appear to be a viable alternative and the State had never requested that the City
take this action until my conversation with Ms. Judy Garrett on February 9`", 2000.
All of the bypasses during the hurricane weather were beyond our capacity to haul
and access to the station with a tanker truck would have been infeasible during this
time.
Access to the station was impossible during the bypasses from snow just prior to the
portable pump being installed.
The City will make every effort in the future to pump and haul any wastewater that is
bypassing but there will be times when it is infeasible.
If any questionable pump and haul situations arise in the future, the City will contact
the State for a determination of the course of action to follow.

The City has met every deadline established in our Special Order of Consent (SOC)
with the State for upgrade of the Redbud Pump Station and Nutbush Creek gravity
interceptor.
The SOC requires all bypasses at Redbud to be eliminated by March 1, 2002.
The City plans to meet this schedule with a 20-year design that will be much more
than a temporary upgrade.
I trust this letter has sufficiently answered your questions.
The City of Henderson is striving to be proactive in meeting environmental concerns
that have been heightened considerably by new legislation, the State and increased
press coverage, but it is a reality that much of our infrastructure is aging and
repairs/replacement will be costly and require a reasonable time frame to accomplish.
If you have additional questions, please contact me at 252-431-6081
Sincerely,
�hoYn« o M.
Thomas M. Spain,
WWTP Director
C: Eric Williams, City Manager
Mark Warren, Assistant City Manager
Linda Leyen, Chief Operator
Reggie Hicks, Lab Supervisor
John Botts, Aquatic Sciences Consulting
Glenn Dunn, Poyner and Spruill
Tim Baldwin, Mckim and Creed

Henderson enforcement
Subject: Henderson enforcement
Date: Wed, 08 Mar 2000 17:15:39 -0500
From: Marcia Lieber <[e-mail]>
Organization: NCDENR-DWQ
To: Kirk Stafford <[e-mail]>
Kirk, We got the green card back from the City of Henderson indicating
they have received Coleen's letter today. the Region can now go ahead
and proceed with enforcement of the SOC. If you have any question call
me. --Marcia
1 of 1 3/9/00 8:33 AM

State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
3800 Barrett Drive Raleigh, North Carolina 27609
March 24, 2000
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
Mr. Tom Spain
City of Henderson
P.O. Box 1434
Henderson, North Carolina 27536
SUBJECT: NOTICE(S) OF VIOLATION
Effluent Toxicity Testing
NPDES Permit No. NC0020559
City of Henderson WWTP
Vance County
Dear Mr. Spain:
This is to inform you that a review of your toxicity self -monitoring report forms for the months
of October 1999, November 1999 and January 2000 indicate violations of the toxicity limitation
specified in your NPDES Permit.
You should take whatever remedial actions are necessary to eliminate the conditions causing the
effluent toxicity violation(s). Your efforts may include conducting a Toxicity Reduction Evaluation
(TRE) which is a site -specific study designed to identify the causative agents of effluent toxicity, isolate
the sources of toxicity, evaluate the effectiveness of toxicity control options, and then confirm reductions
in effluent toxicity. Please be aware that North Carolina General Statutes provide for assessment of civil
penalties for violations of NPDES permit limitations and requirements.
You are requested to respond in writing to Mr. Kirk Stafford at DENR/DWQ, 1628 Mail Service
Center, Raleigh, NC 27699-1628, within 15 days of receipt of this notice detailing what actions have
been or will be undertaken to address the effluent toxicity violation(s).
The reverse side of this Notice contains important information concerning your Whole Effluent
Toxicity Monitoring and Reporting Requirements. Please note updated mailing addresses for submitting
your Discharge Monitoring Reports (DMRs) and Aquatic Toxicity (AT) Test Forms. We encourage you
to review this information and if it would be helpful to discuss this situation or possible solutions to
resolve effluent toxicity noncompliance, please contact Mr. Stafford with this office at [phone].
Sincerely,
4'a2�
Kenneth Schuster, P.E.
Regional Water Quality Supervisor
cc: Aquatic Toxicology Unit
Central Files
Kttct- '5MreroR0