NC0043176_NPDES Draft Permit_20061025

Mr. Ronald Autry, Director of Public Works
City of Dunn
P.O. Box 1065
Dunn, North Carolina, 283�
OCT 2 6 2006
140
Dear Mr. Autry:
Michael F. Easley
Govemor
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
October 25, 2006
Subject:
NPDES Draft Permit
Permit No. NC0043176
Dunn WWTP
Harnett County
Please find enclosed the DRAFT permit for the subject wastewater treatment plant for your review and comment.
The draft permit includes the following modifications to your existing permit:
• The permit includes weekly average ammonia limits of 6 mg/L during the summer and 12 mg/L during
the winter. All permits with monthly average limits will receive weekly average limits as required in
federal regulations.
• . For the 2006 permit renewal cycle the Division developed a permitting strategy to address nutrient
concerns in the Cape Fear River Basin. This strategy is being applied at permit renewal to existing
discharges on the basin. The strategy calls for reporting of nitrogen species to support the efforts of the
Modeling and TMDL Unit in developing special studies and TMDL projects. The permit also includes a
re -opener special condition. The Division may reopen the permit if deemed necessary to include
conditions to support water quality protection and restoration efforts.
• A special condition was added to the permit requiring annual pollutant scan monitoring of the effluent.
•The Division is implementing the annual monitoring requirement for all POTW with effluent flows.
greater than 1.0 MGD or with a.pre-treatment program. The total set of samples collected during the
permit cycle must represent seasonal variations. The requirement to monitor for these pollutants is part of
the information required by federal regulations for municipal dischargers.
Please provide any comments you have regarding the draft permit to this office by December 1, 2006. At this
time, the Division is also publishing a notice in the newspapers of general circulation in Harnett County, inviting
public comment on the draft permit. Following the 30-day comment period, we will review all pertinent comments
received and take appropriate action on the permit renewal.
If you have any questions concerning the draft permit or the other requirements for your facility, please call me at
[phone], extension 553.
Sincerely,
Teresa Rodriguez
NPDES Unit
Cc: NPDES Files _
,: ayetteville_Regional Office - Surface Water Protection ___'t
Aquatic Toxicology Unit
EPA Region 4
NorthCarolina
Naturally
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone] Customer Service
Internet: h2o.enr.state.nc.us 512 N. Salisbury St. Raleigh, NC 27604 FAX [phone] • 1-877-623-6748
An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper

Permit NC0043176
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful standards and regulations
promulgated and adopted by the North Carolina Environmental Management Commission, and the Federal Water
Pollution Control Act, as amended, the
City of Dunn
is hereby authorized to discharge wastewater from a facility located at the
Black River WWTP
Susan Tart Road
Harnett County
to receiving waters designated as the Cape Fear River in the Cape Fear River Basin in accordance with
effluent limitations, monitoring requirements, and other conditions set forth in Parts I, II, III and IV hereof.
This permit shall become effective.
This permit and authorization to discharge shall expire at midnight on September 30, 2011.
Signed this day.
Alan W. K]imek, P.E. Director
Division of Water Quality
By Authority'of the Environmental Management Commission

Permit NC0043176
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked, and as of
this issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive authority
to operate and discharge from this facility arises under the permit conditions, requirements, terms, and provisions
included herein.
The City of Dunn is hereby authorized to:
1. Continue to operate a 3.75 MGD wastewater treatment facility located at the Black River
WWTP on Susan Tart Road near Dunn in Harnett County. The facility includes the
following treatment components:
■ Influent pumps
• Mechanical bar screen
■ Aerated grit removal
• Influent flow measurement
■ Aeration basins- 4 cells
• Three final clarifiers
■ Dual gas chlorination and dechlorination
■ Dual chlorine contact tanks
• Effluent pumps
• Effluent flow meter .
■ Cascade discharge .
• Sludge handling including DAF sludge thickener, aerobic sludge digester, aerated
sludge holding tank, and sludge drying beds (optional use)
2. Discharge from said treatment works at the location specified on .the attached map into
the Cape Fear River, classifiedWS-V waters in the Cape Fear River Basin.

City of Dunn — Black River WWTP
State Grid/Quad: F24SW/Erwin
Receiving Stream: Cape Fear River
Stream Class: WS-V
Latitude: 35° 17' 31" N
Longitude: 78° 41' 09" W
Drainage Basin: Cape Fear River
Sub -Basin: 03-06-15
North
NPDES Permit No. NC0043176
Harnett County

Permit NC0043176
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is
authorized to discharge treated wastewater from Outfall 001. Such discharges shall be limited and monitored by
the Permittee as specified below:
EFFLUENT
CHARACTERISTICS
:
DISCHARGE*LIIVIITATONS
'
'. MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily ,:
Maximum
Measurement
Frequency;,
Sample
:Type
Sample Locarion1.;
Flow
3.75 MGD
Continuous
Recording
Influent or Effluent
BOD, 5-day, 200Cber
(April 1 — October31)2
12.0 mg/L
18.0 mg/L
Daily
Composite
Influent and Effluent
BOD, 5-day, 200C 2
(November 1 — March 31)
24.0 mg/L
36.0 mg/L
Daily
*Composite
Influent and Effluent
Total Suspended Solids2
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and Effluent
NH3 as N
(April 1 — October 31)
2.0 mg/L
6.0 mg/L
Daily
Composite
Effluent
NH3 as N
(November 1— March 31)
4.0 mg/L
12.0 mg/L
Daily
Composite
Effluent
Dissolved Oxygen3
-
Daily
Grab
Effluent
Fecal Cok mean) rm
(geometric .
200/100m1
400/100mI
Daily
Grab
Effluent
Total Residual Chlorine
28 pg/L
_ Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent:.
TKN (mg/L)
Monitor and report
Monthly
Composite
Effluent
NO3-N + NO2-N (mg/L)
Monitor and report
Monthly
Composite
Effluent
Total Nitrogen4
Monthly
Composite
Effluent
Chronic Toxicity5
Quarterly
Composite ,
Effluent
pH5
Daily
Grab
Effluent
Temperature
See note 7
Grab
Upstream & Downstream
Dissolved Oxygen?
See note 7
Grab
Upstream & Downstream.
NOTES:
1.
2.
3.
4.
Upstream = at NC Highway 217. Downstream = approximately 1400 feet below discharge.
The monthly average effluent B OD and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
The daily average dissolved oxygen concentration as measured in the effluent shall not be less than 5.0
mg/L.
TN = TKN + NO3-N + NO2-N, where TN is Total Nitrogen, TKN is Total Kjeldahl Nitrogen, and NO3-
N and NO2-N are Nitrate and Nitrite Nitrogen, respectively.
5. Chronic Toxicity (Ceriodaphnia) limit at 1% with testing in March,' June, September, and December (see
Special Condition A. (2)).
6. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
7. Insream monitoring shall be waived as long as the permittee maintains membership in the Middle Cape
Fear River Basin Association (MCFRBA), which conducts comprehensive instream monitoring. If the
permittee cancels membership in the MCFRBA, the facility shall begin collecting the listed instream samples
immediately at a frequency of 3/week Oune-September) and weekly (October -May).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NC0043176
1
A. (2) CHRONIC TOXICITY PERMIT LIMIT (Quarterly) — OUTFALL 001
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to
Ceriodaphnia dubia at an effluent concentration of 1.0%.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures outlined in the "North
Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised February 1998, or subsequent versions or "North
Carolina. Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -February 1998) or subsequent versions.
The tests will be performed during the months of March, June, September and December. Effluent sampling for
this testing shall be performed at the NPDES permitted final effluent discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV below the permit limit,
then multiple -concentration testing shall be performed at a minimum, in each of the two following months as
described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -February 1998) or
subsequent versions.
The chronic- value for multiple concentration tests will be determined using the geometric mean of the highest
concentration having no detectable impairment of reproduction or survival and the lowest concentration that does
have a detectable impairment of reproduction or survival. The definition of "detectable impairment," collection
methods, exposure regimes, and further statistical methods are specified in the "North Carolina Phase II Chronic
Whole Effluent Toxicity Test Procedure" (Revised -February 1998) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR-1) for the months in which tests were performed, using the parameter code TGP3B for the
pass/fail results and THP3B for the Chronic Value. Additionally, DWQ Form AT-3 (original) is to be sent to the
following address:
Attention: NC DENR / DWQ / Environmental Sciences Section
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Section no later than 30 days
after the end of thereportingperiod for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate signature.
Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for
disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the
permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility
name, permit number, pipe number, county, and the month/year of the report with the notation of "No Flow" in the
comment area of the form. The report shall be submitted to the Environmental Sciences Branch at the address_cited
above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring will be
required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of Water
Quality indicate potential impacts to the receiving stream, this permit may be re -opened and modified to include
alternate monitoring requirements or limits.
NOTE: ' Failure to achieve test conditions as specified in the cited document, such as minimum control organism
survival, minimum control organism reproduction, and appropriate environmental controls, shall constitute an invalid
test and will require immediate follow-up testing to be completed no later than thelast day of the month following the
month of the initial monitoring. -

Permit NC0043176
A. (3) EFFLUENT POLLUTANT SCAN
The permittee shall perform an annual Effluent Pollutant Scan for all parameters listed in the table below (in accordance
with 40 CFR Part 136). The annual effluent pollutant scan samples shall represent seasonal (summer, winter, fall, spring)
variations over the 5-year permit cycle. Unless otherwise indicated, metals shall be analyzed as "total recoverable."
Additionally, the method detection level and the minimum level shall be the most sensitive as provided by the
appropriate analytical procedure.
Ammonia (as N) Trans-1,2-dichloroethylene Bis (2-chloroethyl) ether
Chlorine (total residual, TRC) 1,1-dichloroethylene Bis (2-chloroisopropyl) ether
Dissolved oxygen 1,2-dichloropropane Bis (2-ethylhexyl) phthalate
Nitrate/Nitrite 1,3-dichloropropylene 4-bromophenyl phenyl ether
Total Kjeldahl nitrogen Ethylbenzene Butyl benzyl phthalate
Oil and grease Methyl bromide 2-chloronaphthalene
Total Phosphorus Methyl chloride 4-chlorophenyl phenyl ether
Total dissolved solids Methylene chloride Chrysene
Hardness 1,1,2,2-tetrachloroethane Di-n-butyl phthalate
Antimony Tetrachloroethylene Di-n-octyl phthalate
Arsenic " Toluene Dibenzo(a,h)anthracene
Beryllium 1,1, 1 -trichloroethane 1,2-dichlorobenzene
Cadmium 1,1,2-trichloroethane 1,3-dichlorobenzene
Chromium Trichloroethylene 1,4-dichlorobenzene
Copper Vinyl chloride 3,3-dichlorobenzidine
Lead Acid -extractable compounds: Diethyl phthalate
Mercury P-chloro-m-cresol , Dimethyl phthalate
Nickel 2-chlorophenol 2,4-dinitrotoluene
Selenium 2,4-dichlorophenol 2,6-dinitrotoluene
Silver 2,4-dimethylphenol 1,2-diphenylhydrazine
Thallium 4,6-dinitro-o-cresol Fluoranthene
Zinc 2,4-dinitrophenol Fluorene
Cyanide 2-nitrophenol Hexachlorobenzene
Total phenolic compounds 4-nitrophenol - Hexachlorobutadiene
Volatile organic compounds: Pentachlorophenol Hexachlorocyclo-pentadiene
Acrolein Phenol Hexachloroethane
Acrylonitrile 2,4,6-trichlorophenol Indeno(1,2,3-cd)pyrene
Benzene . Base -neutral compounds: Isophorone
Bromoform Acenaphthene • Naphthalene
Carbon tetrachloride Acenaphthylene Nitrobenzene
Chlorobenzene Anthracene N-nitrosodi-n-propylamine
Chlorodibromomethane Benzidine N-nitrosodimethylamine
Chloroethane Benzo(a)anthracene N-nitrosodiphenylamine
2-chloroethylvinyl ether Benzo(a)pyrene Phenanthrene
Chloroform 3,4 benzofluoranthene Pyrene
Dichlorobromomethane Benzo(ghi)perylene 1,2,4-trichlorobenzene
1,1-dichloroethane Benzo(k)fluoranthene
1,2-dichloroethane Bis (2-chloroethoxy) methane
Test results shall be reported to the Division in DWQ Form- DMR-PPA1 or in a form approved by the Director, -
within 90 days of sampling. A copy of the report shall be submitted to Central Files to the following address: Division
of Water Quality, Water Quality Section, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617.

DENR/DWQ
FACT. SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NC0043176
Facility Information
Applicant/Facility Name:
City of Dunn, Dunn WWTP
Applicant Address:
P.O. Box 1065, Dunn; North Carolina, 28335
Facility Address:
Susan Tart Road, Dunn, NC 28335
- Permitted Flow
3.75 MGD, : -
Type .of Waste:
Domestic
Facility/Permit Status:
Renewal
County: ,.
Harnett
...Miscellaneous.'
Receiving Stream: --
Cape Fear River
Regional Office:::
Fayetteville
Stream Classification: .`."'
WS-V
USGS Topo Quad:
F24SW
303(d) Listed:.
No
Permit Writer:. '
Teresa Rodriguez
Subbasin:
03-06-15
Date:
October 5; 2006
Stream index:
18-(20.7)
l'''-,'
,
Drainage Area (mi2):— -
3464
Summer 7Q10 (cfs) :
586.E
Winter 7Q10 (cfs):
Average Flow (cfs):
3601--
IWC (%) @3.75 MGD:
1
SUMMARY..
The City of Dunn submitted a: permit renewal request on, April 3, 2006. There have been no major
changes to the facility from the previous permit renewal. They operate a 3:75 MGD facility consisting of
three influent screw pumps, one suction lift pump, mechanical bar screen, aerated grit removal,_influent
flow meter; activated sludge aeration basin, three clarifiers; dual chlorine contact basin, dechlorination
system, effluent pumps and cascade aerator.
BASINWIDE PLAN
All waters in this sub-basinare impaired on an evaluated basis in the fish consumption category.
COMPLIANCE SUMMARY- .,
Data was reviewed for 2004-2006. The facility received four NOVs in 2004, two weekly -average total
residual chlorine violations in December 2004, one average, monthly flow violation in September 2004 and
a pH violation in December 2004.. All other pararneters.were within permit limits for the period 'examined.
Average values for monitoring parameters were as follows:
,.PARAMETER,
;>Ydl
iR(
NF3N.
Flow �F,>
VERAG
3.7 mg/L
7.3 mg/L
4.6 mg/L
1.4 mg/L
0.1 mg/L
2.2156 MGD
Whole Effluent Toxicity.- The permit requiresquarterly chronic effluent toxicity test (Ceriodaphnia) at
1.0 %. The facility passed all the toxicity tests.
Priority Pollutant Analysis= The city submitted results of three pollutant analyses. No parameter was
detected above the allowable concentration.
INSTREAM MONITORING
This facility is required to monitor dissolved oxygen and temperature. These.. monitoring is waved since
they participate in the Cape Fear Basin Association.
PROPOSED CHANGES
• Weekly average ammonia limits of 6 mg/L during the summer and 12 mg/L during • the winter. All permits with monthly average limits will receive weekly average limits
as required in federal. regulations.
• Reporting of nitrogen species (TKN and NO3-N + NO2-N) - The Division is
implementing nutrient monitoring strategy on all Cape Fear permits to gather data
necessary for future modeling efforts.
Fact Sheet •
NPDES Renewal NC0043176
Page 1

• Annual Effluent Pollutant Scan - All major municipal permits are required to do the
annual pollutant scan to collect data required for permit renewal.
PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice: October 25, 2006
Permit scheduled to issue: December 18, 2006
STATE CONTACT:
If you have any questions on any ofthe above information or on the attached permit, please. contact
Teresa Rodriguez [phone] ext. 553.
NAME: � �� DATE: / // v0 ..�_.
REGIONAL OFFICE COMMENTS
NAME: DATE:
Fact Sheet
NPDES Renewal NC0043 I76