NC0046728_Permit (Issuance)_20080506

NPDES DOCUMENT $CANNIN`: COVER SHEET
NPDES Permit:
NC0046728
Mooresville / Rocky River WWTP
Document Type:
Permit Issuance
J..�
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File
- Historical
Engineering Alternatives (EAA)
Approval
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Permit
History
Document Date:
May 6, 2008
This document is printed on reuse paper - ignore any
content on the reverse side

©'ICE
NCDENR
The Honorable William Thunberg, Mayor
Town of Mooresville
413 North Main Street
Mooresville, NC 28115
Dear Mayor Thunberg.
Division personnel have reviewed and approved your application for renewal and modification of
the subject permit. The modification includes the expansion to 5.5 MGD wasteflow. Accordingly, we are
forwarding the attached NPDES discharge permit. This permit is issued pursuant to the requirements of
North Carolina General Statute 143-215.1 and the Memorandum of Agreement between North Carolina
and the U.S. Environmental Protection Agency dated October 15, 2007 (or as subsequently amended).
This final permit includes the following major changes from the draft permit sent to you on
February 27, 2008:
• A weekly average CN limit and monitoring have been added to the permit to correct an error.
The Division has reviewed your request to provide a 3-year compliance schedule to evaluate
mercury. This request cannot be granted; the mercury limit is based on the result of the statistical analyses of
the effluent data, which clearly show a significant number of samples with high mercury concentration.
Mercury is also a parameter of concern. The mercury limit type (weekly average) and the sampling frequency
is based on the Division's current guidance with regard to mercury implementation. "Clean sampling"
techniques must be used in the collection of mercury samples.
The Division has reviewed your request to change the BOD limit to 16 mg/L, the request cannot be
granted since your submission clearly indicates that a 15 mg/L limit is necessary to protect DO levels in
Rocky River. The Division is also unable to grant your request to add winter limit for BOD and NH3 since
you did not provide any modeling information, which would demonstrate that winter limits will protect the
water quality in the receiving stream.
The Division has also reviewed your request to remove the 5.2 MGD effluent page. This request
cannot be granted until the re -rating request is approved by the Construction Grant and Loans Section.
Michael F. Easley
Governor
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
May 6, 2008
Subject Issuance of NPDES Permit
Permit NC0046728
Rocky River WWTP
Iredell County
N. C. Division of Water Quality / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617
Internet: h2o.enr.state.nc.us
Phone: [phone]
fax: [phone]
DENR Customer Service Centec 1 800 623-7748

Letter to Mr. Thunberg, page2.
Dye Branch is listed as an impaired stream on North Carolina's 303(d) list. This means that
the stream does not meet all water quality standards. Although non -point sources are the main
contributor to this degradation, the Division will continue to monitor compliance at your facility.
Ultimately, the removal of this discharge may be necessary.
It is the plan of the Division to work for the improvement and recovery of the river. In the event of
the continuance of problems, the future may require the removal of direct point source dischargers to Dye
Branch for the health of the stream. If there is noncompliance with permitted effluent limits and
degradation of the Dye Branch can be attributed to the Rocky River WWTP discharge, then removal of the
discharge may be necessary. The Town of Mooresville may determine in the future that an alternative to
surface water discharge may be more appropriate,
If any parts, measurement frequencies or sampling requirements contained in this permit are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty (30)
days following receipt of this letter. This request must be in the form of a written petition, conforming to
Chapter 150B of the North Carolina General Statutes, and .filed with the Office of Administrative Hearings
(6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this
decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division
may require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Quality or permits
required by the Division of Land Resources, the Coastal Area Management Act or any other Federal or
Local governmental permit that may be required. If you have any questions concerning this permit, please
contact Sergei Chernikov at telephone number [phone], extension 594.
cc: NPDES Files
Central Files
Mooresville Regional Office -Surface Water Protection
Aquatic Toxicology Unit
Marshall Hyatt, EPA Region IV
John Vest, Public Utilities Director, Town of Mooresville
Bill Kreutzberger, CH2MHILL,
4824 Parkway Plaza Blvd. Suite 200, Charlotte, NC 28217

Permit NC0046728
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
Town of Mooresville
is hereby authorized to discharge wastewater from a facility located at the
Rocky River WWTP
Johnson Dairy Road
Mooresville
Iredell County
to receiving waters designated as Dye Creek in the Yadkin -Pee Dee River Basin in accordance
with effluent limitations, monitoring requirements, and other conditions set forth in Parts I, II,
III, and IV hereof.
The permit shall become effective June 1, 2008.
This permit and the authorization to discharge shall expire at midnight on May 31, 2013.
Signed this day May 6, 2008.
Coleen H. Sullins, Director
Division of Water Quality
By Authority of the Environmental Management Commission

Permit NC0046728
SUPPLEMENT- TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of this permit
issuance, any previously issued permit bearing this number is no longer effective. Therefor e, the exclusive authority to
operate and discharge from this facility arises under the permit conditions, requirements, terms, and provisions included
herein.
The Town of Mooresville is hereby authorized to:
1. Continue to operate and maintain the existing 5.2 MGD wastewater treatment facility that
includes the following components:
➢ Influent screw pump station
➢ Dual aeration basins (mechanical fixed aerators)
> Dual final clarifiers
> Dual aerobic digesters (diffused air)
> Chlorine contact chamber (C12 gas)
> Dechiorination
> Post aeration
> Standby electric power
This facility is located at the Rocky River Wastewater Treatment Facility on Johnson Dairy
Road near Mooresville in Iredell County.
2. Discharge from said treatment works at the location specified on the attached map into Dye
Creek which is classified as C waters in the Yadkin -Pee Dee River Basin.
3. After receiving an Authorization to Operate permit from the Division, operate the facility
at a maximum flow limit of 5.5 MGD.

Rocky River WWTP - NC0046728
USGS Quad Name: Mooresville
Receiving Stream: Dye Creek (Branch)
Stream Class: C
Subbasin: Yadkin -Pee Dee - 03-07-11
Lai.: 35°31'33"
Long.: 80°46'56"
Facility
Location
•
Not to SCALE

Permit NC0046728
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [5.2 MGD]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is authorized to
discharge from outfall 001. Such discharges shall be limited and monitored by the Permittee as specified below:
PARAMETER
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Locations
Flow
5.2 MGD
Continuous
Recording
Influent or
Effluent
BOD, 5 day, 20 °C2
24.0 mg/L
36.0 mglL
Daily
Composite
Influent Efflueni
Total Suspended Solids2
30.0 m /L
9
45.0 mg/L
9
DailyComposite
Cp
Influent &
Effluent
NH3 as N
(April 1 to October 31)
2.0 mg/L
6.0 mg!L
Daily
Composite
Effluent
NH3 as N
(November 1 to March 31)
4.0 mg/L
12.0 mg/L
Daily
Composite
Effluent
Dissolved Oxygen
Daily average > 6.0 m,g/L
Daily
Grab
Effluent
Dissolved Oxygen
3/Week
Grab
U & D
Fecal Coliform
(geometric mean)
200 / 100 mL
400 / 100 mL
Daily
Grab
Effluent
Total Residual Chlorine3
18 pg/L
Daily
Grab
Effluent
Temperature °C
Daily
Grab
Effluent
Temperature °C
3/Week
Grab
U & D
Total Nitrogen
(NO2 + NO3 + TKN)
Monthly
Composite
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Chronic Toxicity4
Quarterly
Composite
Effluent
Total Mercury5
12.0 ng/L
Weekly
Grab
Effluent
Cyanide6
5.0 pg/L
Weekly
Grab
Effluent
Total Lead
2/Month
Composite
Effluent
Total Copper
Month
Composite
Effluent
Total Zinc
2/Month
Composite
Effluent
pH
> 6.0 and < 9.0 standard units
Daily
Grab
Effluent
Notes:
1) U: upstream approximately'/z mile from the outfall. D: downstream at NCSR 2420 and NCSR 1394. Instream samples
shall be grab samples collected three times per week from June through September then once per week during the other
months of the year. (As a participant in the Yadkin Pee -Dee River Basin Association, the subject facility is not responsible for
conducting the instream monitoring requirements listed above. Should your membership in the agreement be terminated, you shall
notify the Division immediately and the instream monitoring requirements specified in your permit will be automatically reinstated.)
2) The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective
influent value (85% removal).
3) Limit and monitoring requirements only apply if chlorine is used for disinfection.
4) Chronic Toxicity (Ceriodaphnia) at 90%: February, May, August & November (see A. (4.)).
5) Effluent samples must be analyzed by an EPA -approved 1631 low level mercury analysis method.
6) The Division shall consider all cyanide values reported below 10 µg/L to be "zero" for compliance purposes. However,
Discharge Monitoring Reports (DMRs) shall record all values reported by a North Carolina -certified laboratory (even if
these values fall below 10 µg/L).
The permittee may request that the Division review effluent metals and cyanide limits after twelve months of data
has been collected to determine if monitoring and/or limits are still appropriate.
There shall be no discharge of floating solids or foam visible in other than trace amounts.

Permit NC0046728
A. (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [5.5 MGD]
During the period beginning on the effective date of the Authorization to Operate and lasting until expiration, the Permittee is
authorized to discharge from outfall 001. Such discharges shall be limited and monitored by the Permittee as specified below:
PARAMETER
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample Locations
Flow
5.5 MGD
Continuous
Recording
Influent or Effluent
BOD, 5 day, 20 °C2
15.0 mg/L
22.5 mg/L
Daily
Composite
Influent & Effluent
Total Suspended Solids2
30.0 mglL
45.0 mg/L
Daily
Composite
Influent & Effluent
NH3 as N
2.0 mg/L
6.0 mg/L
Daily
Composite
Effluent
Dissolved Oxygen
Daily average > 6.0 mg/L
Daily
Grab
Effluent
Dissolved Oxygen
3/Week
Grab
U & D
Fecal Coliform
(geometric mean)
200 / 100 mL
400 / 100 mL
Daily
Grab
Effluent
Total Residual Chlorine3
17 pg/L
Daily
Grab
Effluent
Temperature °C
Daily
Grab
Effluent
Temperature °C
3/Week
Grab
U & D
Total Nitrogen
(N0
(NO2+ NO3+ TKN)
MonthlyComposite
p
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Chronic Toxicity4
Quarterly
Composite
Effluent
Total Mercury5
12.0 ng/L
Weekly
Grab
Effluent
Cyanides
5.0 pg/L
2/Month
Grab
Effluent
Total Lead
2/Month
Composite
Effluent
Total Copper
21Month
Composite
Effluent
Total Zinc
2/Month
Composite
Effluent
pH
> 6.0 and < 9.0 standard units
Daily
Grab
Effluent
Notes:
1) U: upstream approximately 1 mile from the outfall. D: downstream at NCSR 2420 and NCSR 1394. Instream samples
shall be grab samples collected three times per week from June through September then once per week during the other
months of the year. (As a participant in the Yadkin Pee -Dee River Basin Association, the subject facility is not responsible for
conducting the instream monitoring requirements listed above. Should your membership in the agreement be terminated, you shall
notify the Division immediately and the instream monitoring requirements specified in your permit will be automatically reinstated.)
2) The monthly average effluent BODS and Total Suspended Solids concentrations shall not exceed 15% of the respective
influent value (85% removal).
3) Limit and monitoring only apply if chlorine is used for disinfection.
4) Chronic Toxicity (Ceriodaphnia) at 90%: February, May, August & November (see A. (4.)).
5) Effluent samples must be analyzed by an EPA -approved 1631 low level mercury analysis method.
6) The Division shall consider all cyanide values reported below 10 µg/L to be "zero" for compliance purposes. However,
Discharge Monitoring Reports (DMRs) shall record all values reported by a North Carolina -certified laboratory (even if
these values fall below 10 µg/L).
The permittee may request that the Division review effluent metals and cyanide limits after twelve months of data
has been collected to determine if monitoring and/or limits are still appropriate.
There shall be no discharge of floating solids or foam visible in other than trace amounts.
A. (3) PHASE II STORMWATER APPLICATION
The Town of Mooresville is required to submit its Phase II application prior to August 1, 2008.

Permit NC0046728
A. (3) CHRONIC TOXICITY PERMIT LIMIT (Quarterly)
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality
to Ceriodaphnia dubia at an effluent concentration of 90%.
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 February, May, August and
November. 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 Branch no later than
30 days after the end of the reporting period 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.
If the Permittee monitors any pollutant more frequently then required by this permit, the results of such monitoring
shall be included in the calculation & reporting of the data submitted on the DMR & all AT Forms submitted.
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 the last day of the month following the
month of the initial monitoring.

Permit NC0046728
A. (5) 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(ah)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 24-dichlomphenol 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 Hexachlorocydo-pentadiene
AcroIein 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.

Mooresville NPDES Permit
w
t
Subject: Mooresville NPDES Permit
From: <[e-mail]>
Date: Mon, 5 May 2008 08:56:25 -0600
To: <[e-mail]>
CC: <[e-mail]>
Sergei - We have determined that we can comply with the 15 mg/L - BOD/2mg/L NH3-N limits at 5.5 mgd
based on some equipment/operations improvements that have been made. So we are OK for you to
proceed with issuance of the permit.
Please call with any questions - Bill
Bill Kreutzberger I CH2M HILLS Charlotte Office [phone] x217 'Mobile [phone] 'Email -
[e-mail]
1 of 1 5/5/2008 1:20 PM

Tan of 5liioores''ille
NORTH CAROLINA
Mr. Sergei Chernikov, Ph.D.
Environmental Engineer II
NCDWQ NPDES Unit - West
1617 Mail Service Center
Raleigh, NC 27699-1617
ROCKY RIVER W.W.T.P.
SUPERINTENDENT'S OFFICE
TELEPHONE [phone]
FAX [phone]
POST OFFICE BOX 878
MOORESVILLE, NORTH CAROLINA 28115
Subject: Mooresville Rocky River WWTP - Draft Permit Response
NPDES Permit #NC0046728
Rocky River WWTP, Iredell County
Dear Mr. Chernikov:
The Town of Mooresville greatly appreciates the effort of the Division of Water Quality
(DWQ) staff in developing this draft permit allowing increased capacity at the Town's
Rocky River WWTP. The Town and our consultants have reviewed the draft permit for the
renewal and modification of the Town's Rocky River WWTP. The Town is providing the
following comments regarding the draft permit.
1) Addition of a weekly average mercury limit
We have reviewed the results of the statistical analysis of quarterly mercury analyses. We
cannot replicate the data in your table and believe that you may have used some results of
split samples as two separate results. Attached is a table of our available mercury analyses
with the dates of the samples. Despite this difference in data, we cannot dispute that the
results indicate that there is a reasonable potential to exceed the standard. However, we
have no known sources of mercury to our POTW. We are a rural but developing community
and our only Significant Industrial Users (SIUs) manufacture food and beverage items. Our
facility is also down -wind of three Coal-fired electric power facilities. For this reason, we are
going to put an increased emphasis on proper "clean" sampling techniques and laboratory
quality control (QC) in addition to investigations of mercury from non-SIU sources.
The mercury analysis is a very expensive test plus it requires significant manpower for
sample collection. We believe that the minor number of results close to and above the
standard do not warrant a requirement for weekly monitoring. Also, many of our samples
were analyzed in duplicate, but neither of the highest reported samples included duplicates
to verify the results; hence our emphasis on sampling and QC.

For these reasons, we would like to propose the following actions related to the
proposed mercury limit and monitoring requirement
• We request that we are provided a three (3) year compliance schedule to evaluate
mercury and take any actions - whether they are related to sampling and analysis
methods, source identification and reduction, or treatment changes to address
mercury.
• We request that the sampling frequency be reduced to twice monthly to reduce the
high manpower and analytical cost of these analyses.
• We propose that our limit be expressed as a monthly average so that one high result
does not become a permit limit violation.
• We also propose that we submit an annual report of our efforts regarding mercury to
the regional office for their review and comment.
In addition, we would like to note two errors in the draft permit. Footnote (9) for the
mercury requirement on the "Effluent Limitations and Monitoring Requirements" tables
should be footnote (7). Also, it is inconsistent to require a "composite" sample and use of
EPA approved low level sampling techniques since these techniques require the use of
clean hands/dirty hands handling of a "grab" sample. The sample type for mercury
should be listed as "grab".
1) Reduction in the monthly average BOD limit to 15.0 mg/L
Modeling analyses performed by the Town's consultant and discussed in a meeting with
DWQ on January 25, 2008 (see attached minutes) suggested a summer monthly average
BOD limit of 16 mg/L (rather than the 15 mg/L included in the draft permit) for a
capacity of 5.5 mgd. However, we also requested that a winter BOD monthly average
limit of 24 mg/L (November through March) be included in the permit.
2) Reduction in the monthly average NH3-N limit to 2.0 mg/L
While your cover sheet indicates that this is a change in our permit requirement, we
would like to note that our current NH3-N monthly average limit in the summer is 2
mg/L. We also request that the current winter monthly average limit of 4 mg/L also be
included for a capacity of 5.5 mgd.
3) Change in the DO limit to 6.0 mg/L
This change is based upon the modeling analyses performed by the Town's consultant
and is consistent with future DO limits to be required for expanded facilities.
4) Reduction in daily maximum TRC limit to 17 ug/L
This limit is only a slight change from the current limit of 18 ug/L and the Town does
not object to this change.
t-•.4 6) Increase in flow limit to 5.5 MGD
This is our requested increase in flow and we have already submitted our technical
analysis to support re -rating to DWQ. If this analysis is accepted by DWQ, there is no
need for a permit page based on 5.2 MGD.

Addition of a CN limit to the permit
Although not noted in the draft NPDES permit dated February 27, 2008, a subsequent
email communication to our consultant indicated that DWQ was going to include a
Cyanide limitation in the permit. We have several comments regarding a proposed
Cyanide limitation:
• Review of the statistical analysis conducted by DWQ indicates that there were
varying reporting limits used for the cyanide results ranging from 2 to 5 ug/L. While
the Town did report the data in this manner, it is our understanding that the DWQ
Laboratory generally considers 10 ug/L to be the lowest reasonable reporting value
for cyanide results in a complex matrix such as an effluent and at one point, was
using a higher reporting value for analyses reported by the DWQ laboratory. It was
also our understanding that upon request, DWQ will include a 10 ug/L reporting
limit in NPDES permits or a higher value if supported by a specific study of an
effluent.
• The only value above the water quality standard of 5 ug/L was 7.5 ug/L which is
less than a reporting value of 10 ug/L.
For these reasons, the Town requests that a 10 ug/L reporting level be included in the
draft NPDES permit and that Cyanide remain as a monitor and report value with a
twice per month reporting frequency.
The Town has also recently responded to a Notice of Violation (NOV) related to Whole
Effluent Toxicity Testing and DWQ's Copper and Zinc Action Level Policy. At this time,
we have selected an option to address the NOV and policy that does not include
limitations for copper and zinc.
The Town appreciates Division of Water Quality's cooperation so far in the issuing of
this draft permit and looks forward to a continued cooperative approach to meeting
future needs.

If you have any questions, please do not hesitate to contact me at [phone] or our
consultant, Bill Kreutzberger at [phone] ext. 217.
Sincerely,
Mike Lamberth
Wastewater Treatment Plant Superintendent
CLT/ DWQ_03282008_PermitResponse.doc
cc: Susan Wilson/DWQ
Rob Krebs/DWQ MRO
The Honorable William Thunberg, Mayor - Town of Mooresville
Mr. John Vest, Public Services Director - Town of Mooresville
file

Table 1
Town of Mooresville Rocky River WWTP: 2004 - 2007 Effluent Mercury Sampling
Year Date Sample Value (ng/L)
2004
2005
2006
2007
3/16
6/17
7/15
8/11
9/15
10/14
11/18
12/16
1/12
2/9
3/10
4/19
6/15
9/20
12/20
3/21
6/21
9/13
12/6
3/7
6/13
9/14
12/5
6.32
4.99
2.15
3.21
3.25
2.55
17.00
5.45
5.10
10.75
16.00
2.10
1.35
1.40
0.77
1.50
1.25
3.00
2.50
6.15
0.00
1.60
1.70

MEETING SUMMARY CH2MHILL
Town of Mooresville WWTP Path Forward Meeting
ATTENDEES:
COPIES:
FROM:
DATE:
PROJECT NUMBER:
Town of Mooresville:
Mayor Bill Thunberg
Commissioner Frank Radar
Jamie Justice
John Vest
NC DENR DWQ:
Susan Wilson/DWQ Western
NPDES
Jackie Newell/DWQ, SPS
Matt Matthews/DWQ, PSB
Paul Rawls/DWQ, SWPS
Deborah Gore/DWQ, PERCS
Town of Mooresville; DWQ; File
CH2M HILL
January 25, 2008, 2 pm
342497
Handouts
Draft Sewer Capacity Allocation Policy
Presentation Slides
Ken Pohlig/ DWQ, CG&L
By Phone from Regional Office:
Rob Krebs/DWQ MRO
Dee Browder/DWQ MRO
Mike Parker/DWQ MRO
CH2M Hill:
JD Solomon/RDU
Jim Nagel/CLT
Bill Kreutzberger/CLT
Jaime Robinson/CLT
tiro L
t APR 2 2O08
1
is w
Introductions
After introductions, Town of Mooresville Mayor Bill Thunberg opened the meeting by
providing background on the Town's situation, undergoing tremendous growth while
looking to the future with planning based from the 2005 Master Plan. He covered the
Town's status as the "Micropolitan" City of America in Site Selection magazine and a
summary of the Town's desire to be an employment center as well as maintain its
residential character. Keys to employment include Lowe's home improvement headquarters
and the motorsports industry.
Other key points include the Town's policy to adjust utility rates annually, with 11, 000
customers currently and growing. The Town now has an inclining block rate structure for
water service. The Mayor also mentioned that a stormwater management program is being
phased in early as will be required by the NPDES Phase II permit. Other planning activities
include a plan to remove several small package plants within its service area and the
development of a Draft Allocation Policy for sewer capacity.
To plan for sound financial management, the Town is using a phased approach to meet 2030
wastewater projections so that as the Town's customer base grows, they are building a
reserve of funds over time.
CLT/MR SERGE! CHERNIKOV 8
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Town of Mooresville WWTP Path Forward Meeting
It was also stated that the Town board receives monthly briefings on its sewer capacity
allocation numbers so that both staff and elected officials are up to date.
After the Mayor's statements, three members of the Mooresville DWQ regional staff joined
via conference call to participate in the meeting.
Bill Kreutzberger reviewed the presentation agenda and proceeded with the presentation.
Background on Town of Mooresville
The project is considering WWTP capacity expansions from 5.2 mgd to 15 mgd, and
subsequently to 19 mgd, over the next 20 years. Currently, the facility is operating at about
60% of its permitted maximum month capacity or about 3 mgd.
An overview of the Town and its interbasin transfer (IBT) situation was presented. The
Town pulls its water from Catawba, discharges its wastewater to Dye Branch (Rocky River,
Basin) and also has consumption use in the South Yadkin River Basin. The Town's
grandfathered IBT amount is 9.54 million gallons per day (mgd).
A review of the Town commitments includes
• Maintaining compliance at the plant
• Addressing Inflow & Infiltration issues (I &I)
• Planning for Reuse (primarily in Catawba River Basin)
• Continued Development of a Stormwater Program
Regarding I &I, John Vest summarized their contract with USI, including metering of
subbasins, in-house maintenance and rehab of manholes, etc. The Town also plans an aerial
sewer elimination program.
A question was posed about enforcing illicit discharges. It was confirmed that the Town is
looking for illicit discharges and will be conducting smoke testing, etc. to find I & I.
A question was posed on how to address problems with connections to their lines. The
Town has no formal policy as of yet for that. However, The Town will identify some of these
problems with their I & I program.
After a summary of the current stormwater program, Susan Wilson encouraged the Town to
set a target date for submittal of its NPDES Phase II application. Matt Matthews stated that a
Phase II application and accelerated stormwater program will help sell the re -rating and
interim phase of the WWTP expansion. DWQ asked about status of this. John Vest replied
that the Town had been given a submittal deadline and also needed to work on an
education program.
Current Flow Commitment
The Town's draft allocation policy was brought to the meeting, and the Town will also
provide a copy to regional office. The Town will also have a public meeting to discuss the
policy. The Mayor stated the Town is open to comments related to best practices, expressing
the Town's hopes it could become a model for other municipalities. Commissioner Radar
stressed the importance of getting the community input in order to make sure that there will
be no unintended consequences.
CLT/MR SERGE! CHERNIKOV 9
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Town of Mooresville WWTP Path Forward Meeting
Phased Planned Expansions
The Town's request for an additional 300,000 gallons of capacity via re -rating of the facility
was briefly discussed. This buys the Town time to further develop its next steps and
investigate regional approaches.
The next step, referred to as the Interim Phase, will be a 2 to 4 mgd expansion accomplished
with a package plant design. The plant would continue to discharge to Dye Branch. This
upgrade would:
• Integrate package plant into future plans
• Need filters and UV upgrades so the whole plant can function at 5/1 limits for BOD and
ammonia -nitrogen
A clarification of nomenclature related to phases included identifying:
• Re -rating: Increase from 5.2 to 5.5 mgd permitted capacity
• Interim Phase: 2 - 4 mgd expansion (total of 7.5 to 9.5 mgd)
• Phase I: Additional capacity to a total of 10-15 mgd
The Mayor described how these early steps let them move forward as they explore
regionalization/reuse, etc. Matt Matthews summarized it as an iterative process. The Mayor
and JD Solomon described how short term plans allow the Town to build a customer base
before incurring large capital cost of going to Lake Norman with a big discharge pipe to
address IBT, and to build demand of reuse.
The review of long term options included the review of a regionalization approach and how
long term plans (10 -15 mgd, etc.) may be clarified later based on interest and feasibility.
Review of Re -Rating Application Package
Review of application package covered:
• Summer limits of 16/2 (justified in modeling memo previously provided to DWQ)
• Winter limits of 24/4 would stay in place
• Discharge of flow would stay in Dye Branch
Matt Matthews posed a question whether, long term, Dye Branch will be still in the plan as
a discharge, with still 2 discharges. In response it was confirmed that there will be still 2
discharges at Dye Branch and Lake Norman. Further, it was explained that this allows for
the use of package plant in later stages of growth period and for the possibility that the
consumptive use goes up in the Rocky River Basin and that then Dye Branch discharge
would go down.
In response to the question of whether the grandfathered IBT amounts expire, it was stated
that there is no changing the grandfathered amount - it does not expire. IBT certificates also
do not expire but typically have a re -opener clause at the discretion of the Environmental
Management Commission (EMC). Susan Wilson also stressed that getting discharge out of
Dye Branch is not a "have to." Bill Kreutzberger provided a review of IBT basics.
CLT/MR SERGE! CHERNIKOV 10
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Town of Mooresville WWTP Path Forward Meeting
As part of the review of the re -rating request, Susan Wilson stated that DWQ Constructions
Grants &Loans (CG&L) still needs to review the memo supporting re -rating. CG&L will do
that once DWQ develops a draft pernmit. It is anticipated that further discussion with CG&L
may be necessary.
The Town is proceeding with its Interim Phase planning while the re -rating is bein
processed. The re -rating will buy the Town some time as it conducts the necessaryg
permitting for the Interim Phase. An EA is required for the package plant and will be
submitted quickly. It was agreed that the EA would not focus on the still -developing lon
term plan while regionalization is being investigated. A cover letter will go to CG&L g
emphasizing that the Interim Phase leaves out a Lake Norman discharge. This will seed
permitting of the Interim Phase. P
It was stated that Duke Energy provided comments on the Lake Norman model before
Christmas of last year. The comments focused on dissolved oxygen (DO) and temperature.
CH2M HILL 's focus has been on nutrients and chlorophyll a at the request of DWQ. It was
noted that CH2M HILL will meet with Duke in February to resolve any additional
comments or questions.
As part of the review of future timeline discussion, it was brought to the attention that the
NPDES permit may require modification 3 times, with the third time being the long-term
regional option. While it was acknowledged that this is not necessarily a desired approach
by DWQ, it will allow for further investigation of a regional option which DWQ supports.
It was agreed that the goal is a single EA, however two EAs are likely. JD stated that the
Town will need an interim solution online by 2009 or a regional alternative..
Susan provided a summary timeline:
• 2007 to 2009 - 5.5 mgd re -rating in place
• 2009 to 2013 - Package Plant adds additional capacity
• 2013 and beyond - New expanded plant and/or potential regional solution to capacity
needs
JD stated that this was likely the case but that we would be sensitive to how flows (actual
and allocated) matched up to the projected flows curve. Projections are for about 1 mgd
increase per year. The Mayor stressed that a regionalization study is complex because it
needs to also consider withdrawals because of water, wastewater and IBT issues.
Bill Kreutzberger stated the CH2M HILL is proceeding ahead with EA. Susan stated that
DWQ is going out on limb with the Town because the limits being required for the re-ratin
differ from the Basin Plan. The Mayor responded with a commitment to get the NPDES g
Phase II application in as soon as possible. Matt Matthews expressed concerns similar to
those of Susan Wilson. The Mayor asked for DWQ to identify any further actions that the
Town can take to facilitate the process. Susan Wilson thanked CH2M HILL for runnin the
water quality model for the re -rating to speed up the process of submitting to EPA. g
Susan Wilson asked whether the Regional Office staff had questions. Susan Wilson agreed
to touch base Monday with the Regional Office.
CLT/MR SERGE' CHERNIKOV
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
11

Town of Mooresville WWTP Path Forward Meeting
DWQ made the recommendation for the Town to send the draft allocation policy to the
Regional Office, to be followed by a later meeting to allow for review time prior to the
meeting.
DWQ summarized the allocation situation by stating that the way the Town manages
allocation is solely up to the Town, and the way the Town complies with its permit is up to
the Town. DWQ expressed their appreciation for the time and effort put into the policy
development. DWQ also pointed out that many other municipalities do not know where
they are in terms of allocation. They also stressed that the State only reviews the policy, but
does not officially approve policy because the Town bears the responsibility to manage it.
The Mayor concluded the meeting by stating that the Town views DWQ as partners in this
effort. He stressed the Town's commitment to getting this task done the right way, and
therefore the Town values DWQ's input. The Mayor reiterated the Town's hopes that their
allocation policy could become a model for other communities. The suggestion was made to
share the policy with the League of Municipalities for this purpose.
CLT/MR SERGE' CHERNIKOV
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
12

g SED s)11
A yZ
� �
i �
r44 PRONG
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 4
ATLANTA FEDERAL CENTER
61 FORSYTH STREET
ATLANTA, GEORGIA 30303-8960
MAR 1 0 2008
Sergei Chernikov, Ph.D
North Carolina Department of Environment and
Natural Resources
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJ: Draft NPDES Permit
Mooresville Rocky River WWTP
Permit No. NC0046728
Dear Dr. Chernikov:
In accordance with the EPA/NCDENR MOA, we have completed review of. the draft. _
permit referenced above and have no comments. We request that we be afforded an. additional
review opportunity only if significant changes are made to the draft permit prior to issuance or if
significant comments objecting to the draft permit are received. Otherwise, please send us one
copy of the final permit when issued.
Sincerely,
Marshall Hyatt, Environmental Scientist
Permits, Grants, and Technical Assistance Branch
Water Management Division
Internet Address (URL) • http://www.epa.gov
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

a
. Statesville Record & Landmark
Advertising Affidavit
North Carolina Community Newspapers
PO Box 968
Hickory, NC 28603
NC DENR/DWQ
BUDGET OFFICE
1617 MAIL SERVICE CENTER
RALEIGH, NC 27699
Account Number
3142720
Date
February 29, 2008
Date
Category Description
Ad Number
Ad Size
02/29/2008
Legal Notices
PUBLIC NOTICE STATE OF NORTH CAROLINA E
PUBLIC NOTICE
STATE OF NORTH CAROUNA
ENVIRONMENTAL MANAGEMENT
COMMISSION/NPDES UNIT
1617 MAIL SERVICE CENTER
RALEIGH. NC 27699-1617
NOTIFICATION OF INTENT
TO ISSUE A NPDES WASTEWATER PERMIT
On the basis of thorough staff review and applica-
tion of NC General Statute 143.215.1 and 1SA NCAC
02H.0109 and other lawful standards and regula-
tions, the North Carolina Environmental Manage-
ment Commission proposes to Issue a National
Pollutant Discharge Elimination System (NPDES)
wastewater discharge permit to the peron(s) list-
ed below effective 25 days from the publish date
of this notice.
Written comments regarding the proposed permit
will be accepted until 30 days after the publish
date of this notice. All comments received prior to
the date are considered in the final determina-
tions regarding the proposed permit. The Director
of the NC Division of Water Quality may decide to
hold a public meeting for the proposed permit
should the Division receive a significant degree of
public interest.
Copies of the draft permit and other supporting in-
formation to be used to determine the conditions
present in the draft permit are available upon re-
quest and payment of the costs of reproduction.
Mall comments and/or requests for information to
the NC Division of Water Quality at the above ad-
dress or call Dina Sprinkle 919-733-5083 extension
363 at the Point Source Branch. Please include the
NPDES permit number (below) In any communica-
tion. Interested persons may also visit the Division
of Water Quality at 512 N. Salisbury Street, Ra-
leigh, NC 27604-1148 between the hours of 8:00
a.m. and 5:00 p.m. to review information on file.
The Town of Mooresville (P.O. Box 878, Mooresville
NC 28115) has applied for a modification to its
NPDES permit NC0046728 for the Rocky River
WWTP in Iredell County. The town wishes to ex-
pand the wastewater permit to 5.5 MGD with a
continued discharge of treated wastewater to Dye
Creek in the Yadkin -Pee Dee River Basin. Current-
ly BOD, TSS, ammonia nitrogen total mercury, and
total residual chlorine are water quality limited.
This discharge may affect future allocations in this
PUBLISonn of the Yadkin -Pee Dee River Basin.
February 29, 2008
0000692480
Media General Operations, Inc.
Publisher of
Statesville Record & Landmark
Iredell County
2 x 55 L
Before the undersigned, a Notary Public of Catawba County, North
Carolina, duly commissioned, qualified, and authorized by law to
administer oaths, in said County and State; that he/she is authorized to
make this affidavit and sworn statement; that the notice or other legal
advertisement, a copy of which is attached hereto, was published in the
Statesville Record & Landmark on the following dates:
02/29/2008
and that the said newspaper in which such notice, or legal advertisement
was published, was a newspaper meeting all the requirements and
qualifications of Section 1-597 of the General Statutes of North Carolina.
Newspaper reference: 0000692480
As ' rant Bookkeepe
,,,111 1111t�
�P MCKVNMILO ;l%
Sworn to and subscribed before me, this y o
My Commission expires:
2008
‘"\,p��-�q
'UBL�G
/,;:41e ��, ,,
a� a-� t s cots,,
THIS IS NOT A BILL. PLEASE PAY FROM INVOICE. THANK YOU

NCDENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NC0046728
Town of Mooresville, Rocky River WWTP
Facility Information 11111111111111111111111111111
(1.) Facility Name:
Rocky River WWTP
(2.) Permitted Flow
(MGD):
T
5.2/5.5
(6.) County:
Iredell
(3.) Facility Class:
IV 1 (7.) Regional Office:
Mooresville
(4.) Pretreatment Program:
Full/inactive 1 (8.) USGS Topo Quad:
E15SE
(5.) Permit Status:
Renewal/Re-rating ! (9.) USGS Quad Name:
Stream Characteristics
(1.) Receiving Stream:
Dye Creek
(7.) Drainage Area
z
(mi ):
4.8
(2.) Sub -basin:
03-07-11
(8.) Summer 7Q10 (cfs):
0.5
(3.) Stream Index
Number:
13-17-2b
(9.) Winter 7Q10 (cfs):
0.9
(4.) Stream Classification:
C
(10.) 30Q2 (cfs):
1.1
(5.) 303(d) Status:
Impaired due to
sediment
(11.) Average Flow (cfs):
5.0
(6.) 305(b) Status:
(12.) IWC %:
94/95
SUMMARY
The Town of Mooresville has applied for permit renewal and re -rating to 5.5 MGD for their Rocky
River WWTP. This facility is currently permitted for a 5.2 MGD discharge. There are no industrial
users discharging to the plant (previous models conducted had high industrial input). The Town's
consultants conducted modeling for the increased flow using a QUAL2E model. The model, with
updated ratios and inputs, predicted that the proposed limits for BOD and NH3 will be adequate to
protect the DO level in the receiving stream. The increase in the permitted capacity will serve as a
temporary relief measure for the growing community.
Dye Creek is listed on the 2008 303(d) list based on biological impairment. Potential sources are listed
as municipal pretreatment (indirect), agriculture and urban runoff/storm sewers (no stressor studies
have been conducted to specifically determine the biological impairment, but hydraulic impact from
urban runoff is suspected). In response to this and at the impetus of the Division, the Town will be
submitting their Phase II stormwater application prior to the required December 2009 date. A special
condition has been placed in the permit to require the submission by June 1, 2008. Per the Town, the
application is substantially complete and the Town has already adopted construction ordinances.
Another constraining issue for the Town is the Interbasin Transfer (IBT) issue with its water source.
The Town is located on three water subbasins (as determined by the Division of Water Resources). The
water allocation issue is very complex and will be part of the determining factor with the amount of
future discharges to Dye Creek (and/or the Catawba River Basin).

NPDES Permit Fact Sheet — 05/05/08 Town of Mooresville/ Rocky River WWTP
Page 2 NC0046728
In conclusion, the Division of Water Quality determined that the incremental impact of the increased
discharge will not result in contravention of applicable water quality standards or loss of the Creek's
designated uses. The Division concluded that expansion of the existing treatment plant and continued
discharge to Dye Creek is the most feasible alternative. The Division has determined that the facility
expansion is important for economic and social development in the area of the discharge. As stated
previously, this re -rating is a temporary measure for the Town of Mooresville. The Town is moving
forward with an Environmental Assessment (EA) for further expansion (to 9.5 MGD on Dye
Creek/Branch) and possibly an expansion up to 15 MGD (to Dye Creek/Branch and/or the Catawba
River Basin). Tertiary -type limits will be required at that time.
INSTREAM MONITORING
The Mooresville - Rocky River WWTP is a member of the Yadkin Pee Dee River Basin Association, so
its instream monitoring requirements are waived. At this time, however, there are nocoalition
monitoring stations in the vicinity of the discharge.
RPA
Reasonable potential analyses (RPA) were conducted for As, Cd, Cr, Cu, CN, Pb, Hg, Mo, Ni, Se, Ag,
and Zn. Please see attached.
TOXICITY TESTING
Chronic P/F @ 90% at 5.2/5.5 MGD using Ceriodaphnia.
No change to the toxicity testing condition is recommended at this time. The facility passed all whole
effluent toxicity (WET) tests for the period of review (2003 — 2007) except May 2006. The subsequent
test passed.
COMPLIANCE SUMMARY
A review of the facilities compliance data indicates good performance. There were two NOVs issued
during the review period (2004-2008): 07/21/06 — Tox. Test; 12/14/05 — fecal coliforms.
SUMMARY OF PROPOSED CHANGES
• The weekly average mercury limit was added to the permit based on the results of the statistical
analyses of the effluent data.
• The monthly average BOD limit has been reduced to 15.0 mg/L based on the results of the
QUAL2E model.
• The monthly average NH3 N limit has been reduced to 2.0 mg/L based on the results of the
QUAL2E model.
• The DO limit has been changed to 6.0 mg/L based on the results of the QUAL2E model.
• The daily maximum TRC limit has been decreased to 17 µg/L due to the increased flow.
• The flow limit has been increased to 5.5 MGD.

NPDES Permit Fact Sheet — 05/05/08 Town of Mooresville/ Rocky River WWTP
• Page 3 NC0046728
PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice:
Permit Scheduled to Issue:
February 27, 2008 (est.)
April 25, 2008 (est.)
NPDES DIVISION CONTACT
If you have questions regarding any of the above information or on the attached permit, please contact
Sergei Chernikov at [phone] ext. 594.
REGIONAL OFFICE COMMENTS
Staff report was received February 5, 2008.
CHANGES TO THE FINAL PEMIT:
• CN limit was added to correct an error.

REASONABLE POTENTIAL ANALYSIS
Rocky River WWTP
NC0046728
Time Period 2005-2007
Qw (MGD) 5.5
7Q10S (cfs) 0.5
7Q10W (cfs) 0.9
3002 (cfs) 1.1
Avg. Stream Flow, QA (cfs) 5
Reeving Stream Dye Creek
WWTP Class IV
IWC (%) @ 7Q10S 94.46
@ 7Q10W 90.451
@ 30Q2 88.571
@ QA 63.031
Stream Class C
Outfall 001
Qw = 5.5 MGD
PARAMETER
TYPE
(1)
STANDARDS &
CRITERIA (2)
PQL
'
Units
REASONABLE POTENTIAL RESULTS
RECOMMENDED
ACTION
n 0 bet. Max And Cw Allowable Cw
NC WQS / Y, FAY/
Chronic Acute
Arsenic
C
50
ug/L
13 0
2.5
Acute: N/A
--_
Chronic: 79
() (
-----------_-_-_-_-_-
Cadmium
NC
2 15
ug/L
13 0
0.5
Acute: 15
_-----------
Chronic: 2
. • )1-
---itl°-• I I‘__ ----------------
NC
50 1,022
ug/L
13 0
5.7
Acute: 1,022PO<<
___--____---_-----_-------_-_-_-_-_-_-
Chronic: 53
1.--
iChromium
j
Copper
NC
7 AL 7.3
ug/L
28 27
421.2
Acute: 7
_ _ _--_
Chronic: 7
p ---_
/
I t��)---
( -- _---_
� i-d
Cyanide
NC
5 N 22
10
ug/L
53 8
13.1
Acute: 22
_ _ _ _ _
Chronic: 5
A he
/ I l mit
Lead
NC
25 N 33.8
ug/L
53 2
23.4
Acute: 34
_ ---_ _-
Chronic: 26
J/ 0 I
-_------------_---_
l Wt"�' _
---•-_-
Mercury
NC
12
2.0000
ng/L
27 25
52.1600A
Acute: N/A
Chronic: 13
4-
I -_-
Molybdenum
A
3,500
ug/L
13 12
30.5
Acute: N/A
Chronic: 3,952 -
�%/
�"
--------------
( %
/-
----_-_-_-_-
Nickel
NC
88 261
u
13 0
2.5
Acute: 261
_ _ _
Chronic: 93
i ,;
9 I
Selenium
NC
5.0 56
ug/L
14 0
10.5 1___—_____
Acute: 56
Chronic: 5
, / 1r,
__ _ %� _� 1�__'�
14
L._j___,
_ _ -_-_-
,f
Silver
NC
0.08 AL 1.23
ug/L
13 1
5.5
Acute: --- 1 --
0
----- ---)
AChronic:
r i o v
t
(fi�
--- r--- -----
JJ c� •
Zinc
NC
50 AL 67
ug/L
26 26
280.5
Acute: 67
_--__
53
.1
---- /V)t
I,� i� itiel
Ad
_Chronic:
• Legend:
C = Carcinogenic
NC = Non -carcinogenic
A = Aesthetic
•• Freshwater Discharge
46728-rpa-2008, rpa
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Arsenic
Date Data BDL=1/2DL Results
1 < 5.0 2.5 Std Dev. 0.0000
2 < 5.0 2.5 Mean 2.5000
3 < 5.0 2.5 C.V. 0.0000
4 < 5.0 2.5 n 13
5 < 5.0 2.5
6 < 5.0 2.5 Mult Factor = 1.0000
7 < 5.0 2.5 Max. Value 2.5 ug/L
8 < 5 2.5 Max. Pred Cw 2.5 ug/L
9 < 5 2.5
10 < 5 2.5
11 < 5 2.5
12 < 5 2.5
13 < 5 2.5
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
-1-
46728-rpa-2008, data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Cadmium
Chromium
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
<
1
1
1
1
1
1
1
1
1
1
1
1
1
BDL=1/2DL
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.50
0.50
0.50
0.50
0.50
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
0.0000
0.5000
0.0000
13
1.0000
0.5 ug/L
0.5 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
<
BDL=1/2DL
2 1.0
2 1.0
2 1.0
2 1.0
2 1.0
5 2.5
2 1.0
5 2.5
5 2.5
2 1.0
2 1.0
5 2.5
5 2.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
0.7596
1.5769
0.4817
13
2.2700
2.5 ug/L
5.7 ug/L
- 2 -
46728-rpa-2008, data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Copper
Cyanide
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
BDL=1l2DL
3.00 3.0
4.90 4.9
6.20 6.2
2.00 1.0
4.10 4.1
11.00 11.0
6.00 6.0
4.80 4.8
3.30 3.3
8.90 8.9
10.00 10.0
2.40 2.4
5.40 5.4
90.00 90.0
7.00 7.0
6.80 6.8
5.50 5.5
5.80 5.8
5.50 5.5
80.00 80.0
16.10 16.1
7.90 7.9
5.20 5.2
8.20 8.2
4.90 4.9
5.50 5.5
6.70 6.7
6.00 6.0
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
20.9017
11.8607
1.7623
28
4.6800
90.0 ug/L
421.2 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
2.4
2
2
2
2
2
2
2
2.4
2
2
2
2
2
5
5
5
5
5
5
5
5
5
5
5
8
5
5
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
3
2
3
2
2
BDL=1/2DL
2.4
1.0
1.0
2.0
1.0
1.0
1.0
1.0
2.4
1.0
1.0
1.0
1.0
1.0
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
7.5
2.5
2.5
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
2.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
2.0
3.3
1.0
3.0
1.0
1.0
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
1.1018
1.6811
0.6554
53
1.7500
7.5 ug/L
13.1 ug/L
-3-
46728-rpa-2008,data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Lead
Mercury
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
1
<
5
2.5
Std Dev.
1.6190
1
Apr-2006
15
15.0
Std Dev.
4.5185
2
<
5
2.5
Mean
2.3491
2
6.5
6.5
Mean
4.0778
3
<
5
2.5
C.V.
0.6892
3
1.5
1.0
C.V.
1.1081
4
<
3
1.5
n
53
4
1.1
1.0
n
27
5
5
5.0
5
1.4
1.0
6
<
5
2.5
Mult Factor =
1.8000
6
3
3.0
Mult Factor =
3.26
7
<
5
2.5
Max. Value
13.0 ug/L
7
1.4
1.0
Max. Value
16.0 ng/L
8
13
13.0
Max. Pred Cw
23.4 ug/L
8
1.3
1.0
Max. Pred Cw
52.2 ng/L
9
<
5
2.5
9
3.0
3.0
10
<
5
2.5
10
3.2
3.2
11
<
5
2.5
11
1.8
1.0
12
<
5
2.5
12
5.1
5.1
13
<
5
2.5
13
Feb-2005
15.0
15.0
14
<
5
2.5
14
6.5
6.5
15
<
5
2.5
15
4.9
4.9
16
<
5
2.5
16
7.4
7.4
17
<
5
2.5
17
<
1.0
1.0
18
<
5
2.5
18
<
1.0
1.0
19
<
5
2.5
19
1.3
1.0
20
<
5
2.5
20
1.4
1.0
21
<
5
2.5
21
1.3
1.0
22
<
5
2.5
22
2.4
2.4
23
<
5
2.5
23
2.4
2.4
24
<
5
2.5
24
2.6
2.6
25
<
5
2.5
25
1.6
1.0
26
<
5
2.5
26
Mar-2005
16.0
16.0
27
<
5
2.5
27
5.1
5.1
28
<
5
2.5
28
29
<
3
1.5
29
30
<
3
1.5
30
31
<
5
2.5
31
32
<
3
1.5
32
33
<
5
2.5
33
34
<
3
1.5
34
35
<
3
1.5
35
36
<
3
1.5
36
37
<
5
2.5
37
38
<
3
1.5
38
39
<
3
1.5
39
40
<
3
1.5
40
41
<
3
1.5
41
42
<
3
1.5
42
43
<
3
1.5
43
44
<
3
1.5
44
45
<
3
1.5
45
46
<
5
2.5
46
47
<
3
1.5
47
48
<
3
1.5
48
49
<
5
2.5
49
50
<
3
1.5
50
51
<
3
1.5
51
52
<
3
1.5
52
53
<
3
1.5
53
54
54
55
55
56
56
57
57
58
58
59
59
60
60
199
199
200
200
-4-
46728-rpa-2008, data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Molybdenum
Nickel
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
BDL=1/2DL
13 13.0
5.7 5.7
13 13.0
13 13.0
9.2 9.2
7.8 7.8
12 12.0
7.8 7.8
5.1 5.1
15.0 15.0
13_0 13.0
5 2.5
6.5 6.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
3.91
9.51
0.41
13
2.0300
15.0 ug/L
30.5 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<,
<'
<
<
<.
h47
y.
..�
?
.+�
BDL=112DL
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
0.0000
2.5000
0.0000
13
1.0000
2.5 ug/L
2.5 ug/L
-5-
46728-rpa-2008, data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Selenium
Silver
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
<
<
BDL=1/2DL
5 2.5
5 2.5
5 2.5
5 2.5
5 2.5
1 0.5
5 2.5
10 5.0
10 5.0
5 2.5
5 2.5
10 5.0
10 5.0
5 2.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
1.3708
3.0714
0.4463
14
2.1000
5.0 ug/L
10.5 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
BDL=1/2DL
2 1.0
2.5 2.5
2 1.0
2 1.0
2 1.0
5 2.5
2 1.0
5 2.5
5 2.5
2 1.0
2 1.0
5 2.5
5 2.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
0.7783
1.6923
0.4599
13
2.2000
2.5 ug/L
5.5 ug/L
- 6 -
46728-rpa-2008, data
2/14/2008

REASONABLE POTENTIAL ANALYSIS
Zinc
Date Data BDL=1/2DL Results
1 62.5 62.5 Std Dev. 24.9889
2 56 56.0 Mean 65.4423
3 62 62.0 C.V. 0.3818
4 50 50.0 n 26
5 56 56.0
6 61 61.0 MuIt Factor = 1.6500
7 60 60.0 Max. Value 170.0 ug/L
8 49 49.0 Max. Pred Cw 280.5 ug/L
9 92 92.0
10 170 170.0
11 70 70.0
12 20 20.0
13 53 53.0
14 57 57.0
15 75 75.0
16 72 72.0
17 68 68.0
18 56 56.0
19 64 64.0
20 75 75.0
21 82 82.0
22 56 56.0
23 62 62.0
24 61 61.0
25 54 54.0
26 58 58.0
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
- 7 -
46728-rpa-2008, data
2/14/2008

To: Permits and Engineering Unit
Water Quality Section
Attention: Sergei Chernikov
SOC PRIORITY PROJECT: No
Date: January 31, 2008
NPDES STAFF REPORT AND RECOMMENDATIONS
County: Iredell
NPDES Permit No.: NC0046728 (Modification)
PART I - GENERAL INFORMATION
1. Facility and address: Rocky River WWTP
% Town of Mooresville
Post Office Box 878
Mooresville, N.C. 28115
2. Date of last site investigation: July 1, 2004
3. Report prepared by: Michael L. Parker, Environmental Engineer II
FEB- 5 2008 I
4. Person contacted and telephone number: Mike Lambreth, WWTP Superintendent, (704)
663-2840.
5. Directions to site: From the jct. of NC Hwy. 3 and Johnson Dairy Rd. (SR 1142) southeast
of the Town of Mooresville, travel west on Johnson Dairy Road approx. 0.7 mile. The
entrance to the WWTP site is on the right (north) side of Johnson Dairy Road via a paved
access road.
6. Discharge point(s), list for all discharge points: -
Latitude: 35° 31' 33"
Longitude: 80° 46' 56"
Attach a USGS Map Extract and indicate treatment plant site and discharge point on map.
USGS Quad No.: E 15 SE
7. Site size and expansion area consistent with application: Yes. Area is available for
expansion, if necessary.
8. Topography (relationship to flood plain included): Rolling topography, 2-8% slopes. The
WWT facilities have been constructed above the flood plain elevation.

Page Two
9. Location of nearest dwelling: Approx. 500+ feet from the WWTP site.
10. Receiving stream or affected surface waters: Dye Creek
a. Classification: C
b. River Basin and Subbasin No.: Yadkin 030711
c. Describe receiving stream features and pertinent downstream uses: Flow was
observed in the receiving stream which is approx. 4-5 feet wide and 4-8 inches deep
at the point of discharge. Downstream uses are primarily agriculture. The receiving
stream is listed on the FY 2007 303(d) list as impaired for biological integrity. A
municipal point source (Mooresville) and urban storm water runoff are listed as the
causes of impairment. Aquatic life (fish) have been observed immediately below the
discharge point.
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1. a. Volume of Wastewater: 5.2 MGD (Design Capacity)
b. What is the current permitted capacity: 5.2 MGD
c. Actual treatment capacity of current facility (current design capacity): 5.2 MGD
d. Date(s) and construction activities allowed by previous ATCs issued in the previous
two years: There have been no ATCs issued in the past two years.
e. Description of existing or substantially constructed WWT facilities: The existing
WWT facilities consist of an influent screw pump station, dual static screens,
influent flow measurement, dual aeration basins with mechanical (fixed) aerators,
dual final clarifiers, sludge thickening, dual aerobic digestors, gaseous disinfection
with contact chamber, dechlorination, post aeration (cascade), vacuum sludge drying
beds (abandoned), and stand-by power.
f. Description of proposed WWT facilities: There are no proposed WWT facilities at
this time. The Town's engineers have determined that the existing faciltities are
capable of meeting the proposed increase to 5.5 MGD without constructing
additional facilities (see Part IV).
g•
Possible toxic impacts to surface waters: Chlorine is added to the waste stream and
dechlorination was added in 2006. The Town is evaluating UV disinfection, and
eventually plans to replace the existing gaseous chlorination system with a UV
disinfection system. The Town has passed recent toxicity tests performed under the
terms of the NPDES Permit.
h. Pretreatment Program (POTWs only): The Town has an approved pretreatment
program.

Page Three
2. Residual handling and disposal scheme: Residuals are currently taken for disposal to a
private (BFI) landfill in Cabarrus County. Land application is also available under the
authority of Permit No. WQ0014213.
3. Treatment Plant Classification: Class IV (no change from previous rating).
4. SIC Code(s): 4952 Wastewater Code(s): 01 MTU Code(s): 02002
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant Funds or are any public monies
involved (municipals only)? Public monies were used in the construction of this facility and
will be used in any future expansion.
2. Special monitoring or limitations requests: None recommended at this time.
3. Important SOC or Compliance Schedule dates: The Town is not under an SOC nor is one
being considered at this time.
PART IV - EVALUATION AND RECOMMENDATIONS
The Town of Mooresville requests a re -rating of this facility to allow for an increase of
permitted flow from 5.20 to 5.50 MGD. There are no physical changes or modifications planned at
this facility in order to meet the increased flow. The Town's engineering firm (CH2M Hill) has
determined that the existing WWT facilities are capable of accepting and treating the additional
flow without an upgrade or expansion based on actual plant data and modeling.
Process Modeling
In reviewing the supporting information submitted by CH2M Hill, it was noted that there are
areas of the existing WWTP that may limit influent flows at or above the current hydraulic (design)
capacity. These limiting WWT processes include:
• Aerobic digestion - 2.39 MGD (Based on meeting Class B requirements). Currently this
facility dewaters and disposes of residuals at a local landfill, which does not require Class B
stabilization. If the facility is allowed to continue this practice, aerobic digestion will not be
a limiting factor, however, this disposal option could change at any time.
• RAS pumping system - 5.2 MGD (Limited by RAS pipeline velocity)
• Secondary treatment - 5.5 MGD

Page Four
• Aeration System - 7.51 MGD
• Disinfection system - 2.88 MGD This capacity is based on a historical peaking factor
(4.03:1 peak hour flow) and the limiting peak hour treatment flow (12.1 MGD).
These capacity limiting processes should be evaluated and a determination made as to whether these
limiting processes will hinder the ability of the WWTP to comply with the NPDES Permit
limitations prior to granting authorization for this re -rating request.
Instream Modeling
In 2005, a QUAL2E model was prepared for the Town in preparation for a planned
expansion of the Town's discharge to Dye Branch. The 2005 model was a compilation of 1980's
data and late 1990's data, which reflected a time frame when the Town's waste stream was
dominated by industrial wastewater sources. This model predicted that under existing conditions,
the Town's discharge would (significantly) violate the instream standard for Dissolved Oxygen
(DO) of 5.0 mg/1 (the predicted DO level was 1.0 mg/l). The model also indicated that the DO
standard would be protected at reuse levels (BOD5 - 10 mg/1 and NH3 as N - 4 mg/1). DWQ
subsequently issued speculative limits for an expanded discharge of 19.0 MGD, which included a
BOD5 limit of 5.0 mg/1, NH3 as N limit of 1 mg/1, and a DO of 6.0 mg/1 based on recommendations
contained in the 2003 Yadkin -Pee Dee Basinwide Water Quality Management Plan. In this Plan,
DWQ expressed concerns about the contribution of any increased discharges to the impairment
status of the stream and recommended additional modeling analysis.
In 2007, additional model runs were undertaken by CH2M Hill using updated cBOD/BOD5
ratios. The older cBOD/BOD5 ratio of 5 used in the 2005 model accounted for more industrial
wastewater entering the drainage basin and the existence of package plants that may have since
come off-line. The recent 2007 model utilized a cBOD/BOD5 ratios of 2 and 3 at existing limits and
the DO sag was 4.6 and 3.7, respectively. These values are much higher than the DO results
predicted in the 2005 model. At the proposed 5.50 MGD permitted flow, the predicted DO sag at
ratios 2 and 3 are 5.3 mg/1 and 4.7 mg/1, respectively. Although the 2007 model does appear to
predict some improved DO conditions, a determination on the applicable cBOD/BOD5 ratio that
should apply to this segment of stream is necessary in order to accurately predict whether WQ
standards will be protected.

Page Five
Pending a determination that instream WQ standards can be protected and the existing
WWT facilities are capable of handling the 0.300 MGD increase in permitted flow, it is
recommended that the Permit modification be approved.
/
ature of Report Preparer / D> to
Water Quality Regional Supervisor
h:\dsr\dsr081moorvlle.dsr
Date

l/z //Z6CJc�'i
1 ;,/, R0-0 ,Ii.cier-e, cr,--f----,----
v
20 63 4.1..- iC l,,i w iwcA/✓L t.nz4s
6 —
cr/
16
fr $ a "-A/ k 24 3 °/ /hqt 1 c/1yr l---( j
( 41h'4'""1
fJ
K{1 VVV Th/pK/ l/Q ry ./L i!/c'nr"y
,(„ W
rW/I/lf
t
11r
IVf V
f r�, ,�
cJv iY
4116 utr,G..�.�,a
4 L 7
P t4,. f�f u,e ,c/
' — 21)5 fitut-ripi-LuLJ 4- wW
0-4''t't4. .`x``) 4 / r 1u2 /A «- f,, .,,,...„, Ail q5 °/M J4
-�, y�� fist iq
No-
4
604
6<<l 11/✓ /� — zoo(,
w� _ - / fr)r /
fA. 17, -u f /1. _ 7L � f
Zo / 7Aoe /fAta.
`/',x, fivile /fx
jit,krbfol
, ,(4t,,t,c,11
e+ - 0 G,- w S

•
U
6.164y f t ,-- vci/A' / /,
— 1' A lv-47,hl
- T�
L'AlIc- /
Aar r �v L/ N 67/ g
Ll
/
7
Jct) /teeru,i _ U ear.."‹4 / r 1 ,2(f "., d-'
gy- /-1,/ 71,.--vir1/4. , +II --'"( 1 4) d2L-14:
11,f Gtg--7CV,t- 4
Atv4X ww c7c,,,, -- 3, l R460 0 7 z
ifiy. ft, "
S Z,tw2 74 S r-46- ,�0-0 wa
if,....

b4e,cee,,,,<„, (...,/ 6 g — L.N...e.e,e
M7-
____________Ljz
-y
7454 /Z 74 9 .el w /a/ h J
x d-/ --
4,z. 4t.-.-L
,_7
/Jt ) f 7E/. 1 S.C/fw
/
-/dosE- /J / t
i/
-z
AkrL i /r7— /s-gce
la:"7 7 z 9 z it(
.� V l ' 10 —
94/24.,
ri,r46-e
7
r /
1,4, fir D
;_b - /er/r~
w,�/
r-ciA4(61- ,e,e44d. "Pd:
?,r1,2 / .Pwc(f
71

�r�
/jt,Q)' 'JC ern v c "' f
, y ,1Nc
Pr
f_,,,,/,,,) ftt4 f A
Iw/ CAI, G /' /' am e t
/ /L
-L
4
17!--$6,77/70,„wk
-em, 42- i-),) --- 6-1<- %447---
nAat-t-
i't7
h/
Ick,ilm ‘ 0419 2„-v
Sol/ 60 Colo r, {y (• co-m- ^. ri Dc,Yl Zii-.i {''iuSr c
L
I ,J1 c=fr a4 to-IrAw
---, ,c,fAlcd 4,-,Ai /:( ei,,, /,`,“ 4 73----A i'f. r'
''-e)
ttA� or itl-L 1 z "4 - 10� / a /4 G,9

OF.WA .1-€9
Michael F. Easley, Governor
f■`+■ ■ ��+� y William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
February 14, 2008
John Vest
Public Services Director
413 North Main Street
P.O. Box 878
Mooresville, NC 28115
Subject: Rocky River WWTP, NC0046728
Residential Flow Reduction Approval
Iredell County
Dear Mr. Vest:
On January 25, 2008 the Division of Water Quality received a flow reduction request for
residences in the Town of Mooresville served by the Rocky River WWTP (Permit No. NC0046728).
The request presented two methods for calculating the wastewater reduction. The first method
presented is the preferred method.
The DMR data between December 2006 and November 2007 was analyzed by central office
staff. The highest monthly average was observed in January 2007. Based upon this data the Division
hereby approves your request for the reduction in flow to 104 gallons per day per bedroom (minimum
of 208 gpd for 1 and 2 bedroom residences) for sewer extension permits issued tributary to the Town
of Mooresville Rocky River wastewater treatment plant.
Regardless of the adjusted design daily wastewater flow rate, at no time shall the wastewater
flows exceed the effluent limits defined in the NPDES permit for the treatment facility or exceed the
capacity of the sewers downstream of any new sewer extension or service connection(s).
If you have any questions or comments regarding this matter, please contact Deborah Gore at
[phone] ext. 593, email [[e-mail]].
Sincerely,
_7Coleen H. Sullins
cc: Rob Krebs, Mooresville Regional Office
Dee Browder, Mooresville Regional Office
Central Files NC0046728
NIWDES permit file NC0046728
PERCS Flow Reduction File
One Pretreatment, Emergency Response and Collection Systems Unit Internet http://h2o.enr.nc.state.us/ndpu
NorthCarolina 1617 Mail Service Center, Raleigh, NC 27699-1617 An Equal Opportunity Action Employer
Natural,
Telephone [phone] Fax [phone]% recycled/10% post -consumer paper

ASP
CH2MHILL
January 3, 2008
Ms. Susan A Wilson, PE
Supervisor, Western NPDES Program
NCDWQ
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Mooreseville Rocky River WWTP - 0.3 mgd capacity increase
NPDES Permit #NC0046728
Iredell County
Dear Ms. Wilson:
4824 Parkway Plaza Blvd.
Suite 200
Charlotte, NC
28217-1968
Tel [phone]
Fax [phone]
The Town of Mooresville, in its efforts to meet the capacity needs of a growing community,
is requesting a minor increase in permitted capacity from 5.2 to 5.5 million gallons per day
(mgd), or an increase of 0.3 mgd. This increase in capacity can be achieved with the existing
facilities with a decrease in permitted load as discussed in this documentation.
This package includes data and analyses documenting the need for this increase, the Town's
plans to meet long-term capacity needs for its growing population, and the NPDES permit
form itself. The short-term focus of this request is aimed at providing a small amount of
capacity relief while the Town continues forward with its plans for phased major
expansions.
Attached is a compliance matrix summarizing the permit package materials. Data and
analyses presented document the ability of the facility to operate at 5.5 mgd without
increasing loading and address your concerns about the impacts this increased effluent
amount will have on dissolved oxygen downstream in Dye Branch and the Rocky River.
Alternatives to a 0.3 mgd increase in discharge are also discussed in the attached
Engineering Alternatives Analysis document. The Town is planning for reuse and a water
reclamation approach in its long term goals to both minimize non -potable water demands
through reuse and address potential interbasin transfer issues. The Town is also exploring
regional approaches to wastewater treatment to address long term needs.
To continue to work closely with Division of Water Quality during this process, the Town is
looking forward to a meeting with staff in January 2008. The agenda would focus on a
discussion of the Town's long term plans to address wastewater capacity needs and its
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Ms. Susan A Wilson, PE
Page 2
January 3, 2008
plans to meet them through a combination of reuse, a pair of discharges into Dye Branch
and the Catawba River Basin (Lake Norman), and potentially regional partnerships.
The Town appreciates Division of Water Quality's cooperation so far in the issuing of
speculative limits for Lake Norman and looks forward to a continued cooperative approach
to meeting future needs.
If you have any questions, please do not hesitate to contact Bill Kreutzberger at 704-329-0073
ext. 217.
Sincerely,
CH2M HILL
Bill Kreutzberger
JD Solomon, PE
CLT/DWQ01032008 300k.doc
cc: Mr. Jamie Justice, Town Manager - Town of Mooresville
Mr. John Vest, Public Works Director - Town of Mooresville
file
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Town Of Mooresville
BIOSOLIDS A NUAL REPORT
2003

BIOSOLIDS MANAGEMENT PLAN
This plan is based on the design criteria for the Town of Mooresville's Rocky River
Wastewater Treatment Plant. The plant is rated at 5.2 MGD and was designed to
effectively treat 200 mg/1 of total suspended solids at maximum flow.
Calculations are based on total suspended solids as follows.
(if) 200 mg/I X 5.2 MGD X 8.34= 8,673.6 lbs. per day influent. 8,673.6
X 7 days = 60,715 lbs.
(then) 60,715 lbs. divided by 5 days thickener operation =12,143lbs per day to
waste.
Wasted solids at 35,O00 rng/l times .0416 MGD times 8.34 =12,143 lbs wasted.
At this rate it would take 12 days of thickener operation to fill a digester.
(This calculation is for worst case scenario)
We are currently operating under the following conditions.
262 mg/1 total suspended solids
2.7MGD
Calculations for current operating conditions are as follows.
262 mg/1 X 2.7MGD X 8.34= 5,900 lbs. per day influent. 5,900
X 7 days = 41,300 lbs.
41,300 lbs. divided by 5 days thickener operation = 8,260 lbs per day to waste.
Wasted solids at 35,00O mgll times .0283 MGD times 8.34 = 8,260 lbs wasted.
At this rate it would take 18 days of thickener operation to fill a digester.
These calculations are statistical formulas and are not intended to be strictly
adhered to, as daily operations and plant performance can vary,
Normally we .fill a digester in 30 days, which gives us 30 days of digestion time while
the other digester is being filled. to other words we must dispose of one digester
gcstcr
every 30 days by one of the methods listed on the next
page. We are currently
utilizing the landfill method 75% of the time, due to the numerous constraints we
face with the land application method.
•

BIOSOLIDS MANAGEMENT PLAN
Primary desired method is land application' of liquid bio-solids.
Using this method requires the following for each event.
1. One digester filled with bio-solids that meet's at least one Vector attraction
option and fecal coliform limits,
2. Available acreage needed, approximately 70 acres depending on condition of
fields.
3. Scheduling with the contract hauler,'farmer and item (1) above.
4. Appropriate weather conditions. For example no rain, snow, ice or frozen
ground is permitted during a land application event.
5. Lime is applied to fields that have a low ph.
6. Cost of lime and contract hauler fee.
The second method is pressing the hio-solids and hauling to the CMS landfill.
Using this method requires the following for each event.
1. One digester filled with bio-solids.
2. Belt press rental.
3. Hauling operation consisting of contract and/or Town Of Mooresville dump
trucks.
4. Cost of press rental, polymer, power consumption, transport cost and tipping
fee's.
The third method is pressing the bio-solids and storing on site. This is not disposal
but has been utilized in emergency situations.
Using this method requires the following for each event.
1. One digester filled with bio-solids.
2. Belt press rental.
3. Hauling operation consisting of Town Of Mooresville dump truck.
4. Cost of press rental, polymer and power consumption.
5. Notifying DENR of your intentions to store on site.

.%'%. .-11‘.1 --,-„) 7,-!.,-.L.1•:::,'0A..,:\;';z;'--..,-..-•.til
r11l •:-i.l\•,.-
'
.,f.'f'17.0'1,.7.-/-A-,-•;,'',-.'-1;-.si- l, *L-
I'-/'7Yi)
(. si,c..._-..-4_::,:,:,:„.:/
O//-2•..'. -''''...1'.:3. i (
..7.-.±-...-...4... }.. ' •;..;-......'., ' -.2',v,.,...„....,.,, % ' , .4.,).„,....,1. -....._4,..i',?./ .._?. ,.I..,-,.-./-P-- ,: .4-/•-,I24IL'i):.Y1• ---',1-4%-. ''i--07l,".•-•--.',•.-•".".,).".1• , . e.-,..j.-.I
I
...,,:-2..1.;
CI .-.i-,:',• ,,IcS•r•;,.; ,
,
•
,a..-,..• ./ ,..:.
..:- .%. I,_." -•.. ....-"iI
...,'•/.. f▪ --.-.•.7•ct,-...4.,f...e..1s-'..-Nl.,i...'t,, •47N'
.'
1
•,'''''.''-,.-,..•., "•.•,•,.'/
:..,,., ..-
v' J'-
'.s
I led-it,0-R-1
1 --,/, -'7..
'vi at L. ti1-//--/
^ '% , k <
\ -' 1 )i ,\ I
,C4:i).„C.,"l4lI 4
..' i1
/.I ▪ I‘.) ..-•.-"
o
.
..,...:.,-._ i L. ,... 1 .1 • - i ° L.• , li; ... -
-- ..• I Z L. ..,::\ .--. • .. i
r (
/ I ''...,•:2*-..?'....-
ff. ,.....-. , \ '‘. --:—, . I / _.,.. yi 1 1 ii\ (31-- ....-:•,,-....e., ? ,
fCk.•••:.▪ :- .::,v- v••• • ....... .,' i .. I _..., . , - ,
• 1
,.... i i
.1'---
1 ' - -..
N• % .....„, ..,. ) .., /... „if I/ 1 , — „,..-„.. ,,, .„.
,,$e" • • N.''::.• , '',..,. ,....\-,-_-//'"V"!,./.;
/ ./ ,•• ,), .• / I. 1'. "11,1, ) tj . • :7._..----:.-.. •.--:- -•-...•.:, ' /
, fy I ei, .--- ,....-- _ .
•/..aze.
-, .70.,... .„, .,, ...„, ,....: .....
q„ " ,......,„ ---, Jeri. 1 .'" I I ., I !( 1 , 1 ..-? .- 1.,,. f .-`...1_f , p...,
f .i."- .. . -•.,
'N....I. 4: '.• ..\‘\ .../ li i ' ,‘ ' . ... ", ' • I \,. 1.• '-‘,.', .. (i'',;•,4,Jr.lki...,1) -1-
.---.,.. -..,.;.__:-..,..-... .... ,.. , N -....--, 1 .. - -• \ .. ' i v. / " ' - %.•:At - -.- - ' -.. . s • - •••••••%:••-` - --- ..•••• , , %..„._ . \ • ' I
-.- ,,.---•-•-,-:ei.:;..; ..., ' - ...s..;\ •,..,:••••1 1 1 i r , ,„ i 1 l' .11-•-,:"..;,--r -1t--"." '''• f
-4,.....,-.7....--_—N, 0......-.. ---.. , ,..,.. % i I 'I •,.'''. 1 i r / I
--"-
,,,---/•-'*-:.,..."..•:%N"::` ) "'-'s
4-" -•,' •V....• ..4-,<1,..:..e44..,.:..0,• u,,c,,-fz.,0,,-kv7.',,-,...••,•••r-l7-,•....',.`..;'.-".1t-.4:,•.. -... .rs.• -.-% -•
-1---( • i"-e --,-7,'r/I r..:•1f-_-e/.*:.-;Ae. :.yI,/.V,I
,
","..k,--.:-,J..•,:,.,,:.: "-. 4:-,
,1"_;:•• .• ...$•'•k'•.'. \'.VC.-. ... ) • ,17"-.1 '..--.1-.:/ . t'.4---, _i. •- .t.---,-i.:..'.(.,', "•,.•''•\
.....,:k''...., /I
••• i1f..1.-:i-▪ -v4,
.i \!-•s-i l"-"‘'"-r --./
*..,-. :,V , '.(('•.
74.4
e, 4i % "4 •_(1 -l‹,-_i / I1 --
'1,;,.-l,•i
.,.:,„::,.•-.-.i-.,•":-.i •_-I_
I (
1▪ ..• ,1..,-,▪ t.Al'_4,N4.V,%-. ...... --••• \s 1,.. *- --- —-- --', .:.‘--Ii-‘t%,•'•.•%,-,'.,- ....: -.,r-.,....1"--:."...s\.•"'•Z \'"XN*..„1.I,‘,....,.,,.1, 's.,. .'\,..1•. •"•\'s‘,,A, ,..•'.''• : 'Z..:k1 .f y -,-..I4I ...- ,„-,,--,.-•--,-•,:'":-...-:
-,..•-•-r-7e..."/."("/-*":::Z-:.-.:"..-e"::.: I ( •,....I:\
-%.-17e-:•._/.a.4„2..._
1
\i-'"
7" -;-------Z-4'...:',•:.1.11' l' C, {2%4 , "N.:- -,... ^••••_ -
' 1 , 1 r , • • .•••1,N.'"- •. ''•,,'
,
. 1.. V., g., ,
_,,t•
.
4 h" ▪ ' .e; \••••-'• I '. M • .iiri
. . ., ,..,
il .:„-L..,:
1._,•,.:,..\_..1,1 i.j.i.....-.-:....,,..:.,1jsYJLs. . . ,"'--) ci
..,..e."'.....- t) .."---_-44., I:t iiij.9..j C'tk. ..7.-.:•• ...--: -11."-..'
. . Wk, , ii .671.Th.:/
7?1.> ',....r. ....,. i :‘.... 1., S. 111:kt:C:' C"...c..-...„,_,...,,--.))'!.. II ..: •
.‘• N s_, h
li 11 --,-..,_,
....,,, ,,,,. ....t:,............,,,.::::,>.....,, ,-,--..„../ .-, 11..4, , ...,_
1 ,..,
„.,...,,„
,0,..,----
......- , i
,
4
....__,- , , , ,... s, ...„,,,,,-- ,, , ...... ...-,...-„,..,-;..s •••. • - i j i ji P‘ I v--
... , ,„:„,__,....,,,....././,,),;,
0......„..---",,Ar f / 1 7 .1 ?..., _ — -_ .1 % '-``NN..."-' ? ... • 1 e 1
:-- . ).i 1 I i / r ' ' — - - - - / i - • ''' .s s * 0 ' 1 1 i i ' V ' ' ' - - - . - '
r.P.
11i. %, '1 ,t1i.•.-: -.1: ,.-.' Y;1.ii1.'
II. / „I
1(
r/ii.i
,1., ,./l.,..;i•-';..;//fi'A..;
.r...e,:-„_•,..,
-,;.
'-.
-•,4,'i .C
i•,-.'. ,....?..
(.
s./...-...,..7).-..` ......,:n.pI%•.'..V-
...../
„ I• ;r',,1.1...,‘7•7%•
...-../...
.
,6 ...' %1
:li .„..‘..7)/.•-, !. I,' /...':•.1(.y-• I- .• I.L1./- r.........r .,.i•k'••'7.,".--%•--1•7-;4'..$-*
-:.'.:-.•.:'.:'.:' ,,,,,-„z'-,. ..-,....•..,...-L''.,'.._'..,..-
.:.......,...!,.,c..1,
a/-f11•/•. .,..,.-s-
,„1 it -z. 1,4".
▪ iI I I4\II /) '*11 " I :-..
-
-
i1/..a:-\jy/._'---'-
...
!
I
-
.
/
1
-
-,I , , rC.,,* •p••1.'
/ i11
„.
•
1
•„•
_
1
•
--
-
.
.
.
-
-
.
1
-
"•:
,.
.
.A1. )1.:% i•,,,'.N,. I.-'.N......k...;"..I,.:•:,:";-.'.:1.//..`-„i.-.•i:.„' ;''.4.
1"/..„• ,• ..//.:-,:.„...'„i12l„: ;;-,.7],:.L..I .-.....e.w-.1.j.....,- f.i', .1t 1 1, \4•1• ,.(...itIiiie,•.'
r,,a,..'r..-.A.•.vc1,..:.-..t.X,..-i•....;....k,.-..-.e%'.,,_
. :.• .1..' 1;;T:::1:,s'k"\.
-..1..."-.c 1.'.-.•.'..i:N\.:U
•'..,j'F\'-'l-;"I 'C',..I".-.t?i)... ( t 1i •i
1- I, •
-r1.:._-..
.-...•.-.t
;
..r.:.;"...
f.?
= k
:'. 11iI:1..11 T:
, 1 „'/i''' -Sci
„`1•1
..‘'...
...1
••"•
1.-
k ..L--.•=r;=°-
'.0 :IiI)•1I ..*-t
777I
iP'- i"1:_=,;".-'
"• I'i
k ....
.e.e''JII i VA
l'. 1 ' r) il 'I. ' ;_e) IVA:. ..: ... ‘'.1 ...‘ ••• ..- I I /I '..1!(..-7- --'.'-:t-i---..,-=7,;-.21_ _.-4-"k--1.:7?....1'.:.„ '.. '1 , er:"...., /-:
1
O 1,250
Lat 35 3133"
Long 80 4656"
1
2,500
USGS Quad Name: Mooresville
Receiving Stream: Dye Creek (Branch)
Rocky River WWTP
5,000 Feet Town of Mooresville
NC0046728 Form 2A-Part B.2

MANHOLE SCHEDULE
CENTER LINE LOCATION PM S12E
DISTANCE FROM STATION
LETTER BASE LINE STATION FT. &INVERT IN a INVERT OUT.
A 6+60.0 66.0 12" - 70820
24" - 708,10 24" - 706.03
B 0+120 88.0 12" - 708,50
24" - 708,74 24" - 708,30
C 11+09.0 178.0 24" • 708.51 21" - 70841
D 13+75.0 113.0 12" - 710.50 IFROM M)
12" - 708.73 (FROM El 24" - 708,73
Y 14450.0 113.0 12^-706.6E 12" - 706.00
✓ 16477.0 337,0 12" - 709.70 12" - 709.70
O 6+60,0 175.0 12"-712.40(F0DMA.811
12", 711.90 (FROM H) 12" - 710.50
N S160.0 225.0 12"-714.00(71101.1 1)
12"- 712.20(FROM J) 12" -/12.10
1 6+60.0 295.0 12" - 712.40 12" • 712.30
J 74.65.0 255.0 12"-715.40 12" , 775.39
K 0+18.0 412.0 0•• • 710,50 (PROM 14
8" • 709.00(FROM BASIN) 2" - 706.17
L 9+16.0 300.0 8" • 716.00
8" • 716.00 6" - 715.80
M 11+94.0 202.0 12+ • 721.75 12"-134.00
N 14+59.0 360.0 12" • 750.77 (FROM BEDS)
12" • 741.80 (FROM 0) 12" - 742.09
O 15*17.0 459.0 12" • 750.77 12" • 749,00
P 0+10.0 144.0 12"• 700.05
4" • 709.00 12". 708.6E
O 0118,0 372.0 8" • 716,70 8" • 716.50
R 0453.0 69.0 42" • 70623 42" • 706,23
Z 19.62 O 447.0 12"- 710.20 a"- 710.1 O
CATCH BASIN SCHEDULE
NUMBER a INVERT IN
PC 5 2E
2 12"-708J3
s
4 • 12" • 708,0
6 12" • 714.6
7
6 I Z" - 721.8
6 12" - 717.0
10 12". 710.7
11 12"- 715.0
12 12" • 714.6(FROM 11)
12" • 711.0IFROM 61
IJ
14
15
12".71471FROM 131
8" -715,0 (FROM ADMIN.)
12•' - 714,3 (FROM 14)
l6" • 713_0 )FROM 123
36`TEE Q EL.722.0
WJ MJ PWG•
a INVERT OUT
12"- 701,0
12" - 708.7
12"- 7090
12"-708.7
12"-714.8
12" -714.5
12" - 722.0
12"• 721.7
12" - 7169
12" - 718.4
12"• 714.9
18•' • 713.9
12"• 715.5
12" •714.6
115" • 712.9
1/2" TO STILLING WELL
END OF CONTRACT 5.0
PROVIDE STUBOUT OF
M.H.R FOR CONNECTION
8Y CONTRACT 70
BY CONTRAC\ .0
AuL
I0
MH.R
42"
STA.0t00 @ MONUMENT
FLANT 'RASE LINE
36"
HY0.5
C.5.I
HEADWALL SCHEDULE
CENTKI*LINE LOC/..10"
LETTER BASE LINE 57A710N DISTANCE FROM STAT• . T ' A INVERT
A 9+69.0 30,0 42'
tl 2+26 25,0 12" - 708.7
• 7+76.0 20,0 12"- 7D7,2
D 10+34.9 75.0 18" - 708.7
n
HYD. 7
HYD.8
rt-
CB.2
rcHW,a
F
rT
HYD.II1= a
NYD.10 II MH.H 12
MATCH LINE
MATCH LINE
r)YO.I2
HYD.8 dHY0.9
5400
C.B. 8
AHWC
4
arm 70 CRvK
'D.15
TWO 8"
4401014
1. ALL PLANT WATER LINES SHALL BE 6 IN. DIAMETER UNLESSOTHERRISE
DESIGNATED.
2. SEE SHEET M -4 FOR CLARIFIERAND SLUDGE PIPING.
3, ALL YARD DRAINS SHALL BE PART OF .CONTRACT S.0 UNLESS OTHERWISE
DESIGNATED. CONTRACT 5.3 SHALL EXTEND ADMINISTRATION BUILDING
DRAINS TO 5 FT.OUISIOEOF STRUCTURE FOR CONNECTION BY CONTRACT5.0
4. ALL PIPES SHALL HAVE A MINIMUM OF 3 FT. OF COVER UNLESS OTHERWISE
DESIGNATED.
5. ALL PRESSURE P1PSNGSHJLLL HAVE THRUST BLOCKING• AT ALL TEES AND
ELBOWS IN ACCORDANCE WITH DETAILS ON SHEET Tf - 8 UNLESS OTHERWISE
DESIGNATED.
CONNECT TO DRAIN BY CONTRACT 5.3
M,H, C
COVER A ET TOP� L. 715MANHO-E
HNC D
( DITCH WJ 1' - 0" ARMOR COURSE
H.W.A I TO CREEK
(SEE DETAIL SHEET G-at
f
10400
(SEE SHEET G-7 FOR PIPING AT DRYING BEDS)
M.N. D
SAHITARYSEWERS
STORM SEWERS
73,AMT WATER
12" MIRE
1 I.141a1.9.
JMD
CON
DWG
MLW
50'
0
50
100'
_ 400.
DATA"
""T•
a 0QRIEN&tiEi�E
TOWN OF MOORESVILLE
WASTEWATER FACILITIES
PIPING PLAN
Ms1O48.t14)
G-3
NOM
"�
CM=
I
95J81
MANHOLE Z
CDH
Ha�1I37g

NC0046728: Town of Mooresville Rocky River WWTP
Process Flow Schematic NPDES Form 2A
B.3. Process Flow Diagram
Aeration
Basin Influent (ABI)
5.34 MGD
Influent
Flo
Measurement
•
Mechanical
Fine
Screens
Raw Influent
Sewage (RS, Pump
5.20 MGD Station
Coarse
Screening
C j
Landfill
Total Recycle
138, 694 GPD
S
Dewatering
Effluent
(DWE)
4, 191 GPD
Dewatering
Recycle (DR)
27, 976 GPD
Aeration Basins
Dewatering
Influent (DWI)
32, 166 GPD.
Portable
BFP
00
lJ
Thickening
Recycle (THR)
110, 718 GPD
Secondary
Clarifier
Influent (SCI)
7.94 MGD\
00
Aerobic
•
�Digestiory
Land Application
(LA)
13, 786 GPD
Secondary
Clarifier
Effluent (SCE)
5.18 MGD\
RAS
2.60 MGD
Seconda
Clar fier
Thickening
r
Aerobic
Digestion
Influent
(TWAS/ADI)
45, 952 GPD
Chlorine
Contact
Cham ber
WAS
156,670 GPD
Plant Effluent
(PE)
5.18 MGD
Dye Branch

NC0046728
TOWN OF MOORESVILLE ROCKY RWER WWTP
NPDES FORM 2A
13.3. PROCESS FLOW DIAGRAM
Town of Mooresville Rocky River WWTP PFD Description
Headworks
The plant headworks consist primarily of influent pumping and screening. Raw wastewater
enters the facility through a 48-inch sewer line and flows through a coarse bar screen. A 24-
inch sidestream collector pipe also enters at the same location. Archimedean screw pumps
convey the wastewater to a pair of fine screens.
Aeration Basins
Raw wastewater from the Parshall flume is split between two 5.2-MG aeration basins.
Mechanical aerators provide oxygen and mixing to the biological process. Mixed liquor
from each basin exits the process by flowing over an effluent weir. Flow from the Aeration
Basin No. 2 (east basin) is conveyed via a pipeline to Aeration Basin No. 1 (west basin)
where the effluent flow combines and is conveyed to the secondary clarifiers.
Secondary Clarifiers
Effluent flow from the aeration basins is split between two secondary clarifiers. The flow
enters through a feed well where a quiescent environment allows for a separation of solids
from the liquid stream. Clarified effluent flows over a v-notch weir and is collected in a
collection launder. The launder, which encompasses the clarifier, conveys the flow to a
collection box where flow from both sides of the clarifier combines before exiting through a
pipeline.
RAS!WAS Pumping
The existing RAS piping consists of an 18-inch gravity pipeline from each clarifier to the
RAS/WAS wet well and a 16-inch diameter force main from the RAS/WAS pumping
building to the head of the aeration basins. WAS is pumped to the digesters via an 8-inch
force main from the RAS/WAS pumping building.
Disinfection System
Secondary effluent wastewater is disinfected using a gaseous chlorination system. The
RRWWTP uses a one ton chlorine gas cylinder with a 150-Ib chlorine gas cylinder as a
backup. Both cylinders are connected to a Regal automatic switchover gas chlorinator. The
gas is injected using a Regal Smart valve with a 2501b/day injector and 1001b/day
rotometer. A 5001b/day rotometer and injector with manual controls are available as a
backup. A 55-gallon drum of sodium hypochlorite with metering pump is also available on
a temporary basis.
Chlorinated effluent is held in two concrete chlorine contact basins. The basins are designed
to provide 30 minutes of contact time at a design flow of 5.2 mgd. Dechlorination is
accomplished through a package dechlorination system which was installed in December,
2006. Effluent leaving the basins is re -aerated using cascade aeration prior to discharge.
Effluent sampling is conducted at the end of the cascade aeration steps utilizing an ISCO

•
NC0046728
TOWN OF MOORESVILLE ROCKY RIVER WIMP NPDES FORM 2A
B.3. PROCESS FLOW DIAGRAM
3710FR automatic sampler. The sampler is flow proportional utilizing the effluent flow
meter (Millitronics Hydroranger).
Biosolids Management
The existing biosolids management system consists of two aerobic digesters, a rotary drum
thickener, and a leased belt filter press.
Aerobic Digesters
WAS pumped from the recycle pump station is conveyed to two aerobic digesters. Each
digester is 70-ft in diameter, 19-ft deep, and has a volume of 592,600 gallons. The digesters
have a design solids loading rate of 16, 850 lbs/day, a hydraulic loading rate of 403,800
gallons per day, and a design solids residence time of 20 days. Three Hoffman multi -stage
centrifugal blowers, each with a 1,800 scfm capacity and a 100-hp motor, deliver air to the
digesters.
Rotary Drum Thickener
Sludge is thickened using a Roediger Rotary Drum Thickener. The thickener has a capacity
of 200 gpm and typically thickens to between 3 percent and 3.5 percent solids. Utilities staff
prefer to thicken the WAS sludge with the thickener prior to aerobic digestion.
Belt Filter Press
A leased, portable two -meter belt filter press (BFP) is located adjacent to the digesters. The
BFP is used only if both digesters are full and land application is not readily available.
Vacuum drying beds and its control building are also located onsite, but are abandoned.
The control building is used for storage space.
2

TECHNICAL MEMORANDUM CH2MHILL
Engineering Alternatives Analysis
PREPARED FOR:
PREPARED BY:
DATE:
NC Division of Water Quality, NPDES Unit
Town of Mooresville, NC
CH2M HILL, Inc.
January 2008
This technical memorandum (TM) summarizes the Engineering Alternatives Analysis
(EAA) for the Town of Mooresville Wastewater Treatment Plant (WWTP) re -rating from 5.2
to 5.5 million gallons per day (mgd). This EAA, following guidance prepared by the North
Carolina Division of Water Quality (DWQ), provides a preliminary assessment of various
discharge alternatives for this 300,000 gallon per day permit modification. The request is one
step in a long term expansion program by the Town, aimed at meeting the Town's 20-year
growth projections.
The memo is organized as follows:
Description 2
Population Projections 3
Population -Based Flow Projections 6
Discharge Alternatives 8
Connection to Existing Facility 8
Land Application 8
Wastewater Reuse 8
Surface Water Discharge 8
Combination 8
Economic Feasibility 9
CLTIMOORESVILLE_EAA V4 01032007.DOC 1
COPYRIGHT 2008 BY CH2M HILL, INC.. COMPANY CONFIDENTIAL

ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
Contact Information
Applicant: CH2M HILL
4824 Parkway Plaza Boulevard
Suite 200
Charlotte, North Carolina 28217
704.329.0072
Facility: Town of Mooresville
Rocky River Wastewater Treatment Plant
369 Johnson Dairy Road
Mooresville, NC 28115
{704) 662-8470
Preparer: CH2M HILL
4824 Parkway Plaza Boulevard
Suite 200
Charlotte, North Carolina 28217
704.329.0072
Contact: Bill Kreutzberger
CLTIMOORESVILLE_EAA V4 01032007.DOC
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
2

ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
•
1. Description
The Town of Mooresville (Town), which is located in southern Iredell County, has been
experiencing significant growth. Mooresville's proximity to the state's largest city,
international aviation facilities, two major interstates, and Lake Norman contribute greatly
to growth in the area. The Town of Mooresville population is projected to increase from
approximately 22,792 in 2004 to 51,239 in 2025, an increase of 31 percent.
One facility, the Rocky River WWTP, serves the Town of Mooresville. The facility lies within
the Yadkin -Pee Dee River watershed (Figure 1) and discharges to Dye Branch upstream of
its confluence with the Rocky River. The permited maximum month discharge for this
facility is 5.2 mgd.
Anticipated future demand for wastewater capacity in the the Town of Mooresville service
area led the Town to begin a long term plan to address capacity needs over a 20-year
planning period. Expansions will be phased in over time, first meeting immediate needs and
then addressing longterm needs possibily through regional cooperation. This document
focuses on the re -rating of the WWTP from 5.2 to 5.5 mgd, which meets immediate needs
and allows the Town sufficient time for examining regional solutions and making final
decisions on future growth. Long term needs forcasted over a 20-year planning period,
include a 2 mgd to 4 mgd expansion package facility and major expansion of the WWTP in a
phased approach. Under the State Enviromental Management Act (SEPA), these future
phased expansions require the preparation of an Environmental Assessment (EA). This
process has begun under the guidance of Construction Grants & Loans (CG&L).
1.1 Population Projections
An overview of the historical population for the Town of Mooresville from the U.S. Census
Bureau is presented in Table 1. While the Town population doubled during the 1990s, the
population growth after the year 2000 has been estimated at only 1.4 percent per year
(Figure 2). The Town's current population is over 23,000.
The use of Warren population projections alone may not be appropriate for estimating the
future service area population. This is noted because the Warren population projections do
not distinguish between the residents served by the Town water and sewer utilities and
those served by private utilities within the service area boundaries as well as those residents
on well/septic systems. The Warren population projections also assumed that all vacant
lands would be developed. Two additional growth trends were used to provide other
estimates of the potential service area population within the planning years as shown in
Table 2. The lower boundary was developed on the more recent annual population growth
rate of 1.4 percent, applied as the uniform growth rate over the entire planning period. The
moderate rate was developed as the average between the upper and lower boundaries. Per
discussions with the Town, the moderate growth population forecast was selected for
projecting water and wastewater treatment capacity needs. The projected growth is
dependent on planning, zoning, and ordinances established by the Town. Figure 2 shows
the current and projected populations of the Town of Mooresville.
CLT/MOORESVILLE_EAA V4 01032007.DOC 3
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Alexander County
I -dell County
Legend
2004 Service Area
2025 Service Area
Major Road
Interstate Highway
Major Hydrology
Watershed Boundaries
County Boundary
® Rocky River WWTP
CH2MHILL 0
idok
Troutman.
4
8 Miles
Iredell County, NC
Rowan County
Rocky River WWTP
Figure 1
Rocky River WWTP
Town of Mooresville
Iredell County, NC

TABLE 1
Historical Population of Town of Mooresville
Engineering Alternatives Analysis
Year Town Population Population Change Population Growth
(People) (People) (% per year)
1970 8,808
1980 8,575 -233 -0.3
1990 9,317 742 0.8
2000 18,823 9,506 7.3
2003a 19,606 783 1.4
2004 b 22,792 3185 16.2
Black & Vetch, 2006 (US Census Bureau)
a Estimated population by the U.S. Census Bureau
b 2004 population is projected service area based on residential water accounts in February 2005 and a
population of 2.62 per dwelling unit (2000 US Census).
0
0
a
Historical Town Populations & Future Growth
Trends
120,000
100,000
80,000
60,000
40,000
20,000
1 1 1 1 1 1 1 1 1 1 1 1 1 1
—0—Historical Data
—II—Projected Population (Warren Report)
-o--Moderate Growth
—a—Undorm Growth Population (1.4%
Increase)
0
19701980
Min
19902000
Year
20102020
2030
Source: Black Sr Veatch, 2006
FIGURE 2
Historical Town Population and Future Projected Growth Trends
CLTIMOORESVILLE_EAA V4 01032007.DOC 5
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
TABLE 2
Population Growth Trend Projections
Engineering Alternatives Analysis
Population Projection
2004 2010 2025
(People) (People) (People)
Warren Report 22,792 49,438 98,623
Moderate Growth 22,792 31,674 74,031
Uniform Growth 22,792 24,707 29,895
Black & Vetch, 2006
1.2 Population -Based Flow Projections
The population growth projections in the previous section demonstrate the potential for
rapid growth in this area. As the Town grows and its service area increases, the demand for
wastewater treatment would also increase. The projection for wastewater flow production at
the WWTP is shown in Table 3. According to current inflow projections, the current 5.2-
MGD capacity will be exceeded by approximately 2009 (Black & Veatch, 2006).
TABLE 3
Unit Wastewater Production
Engineering Alternatives Analysis
User Class Percent WW Wastewater No. of Persons Unit WW Production
Produced (MGD) (gpcd)
Residential 64 1.89 20,551
Non -Residential 36 1.06 10,799
Total 100 2.95
91.9
98.3
Black & Vetch, 2006
1.3 Historical Flow Summary
Figure 3 illustrates how the Town's population growth is reflected in its increasing
wastewater flows. Table 4 presents historical flow data for the period of July 2003 through
October 2007. This shows that the current maximum month flow average at 3.57 mgd. These
data support the need for future expansion plans. This EAA for the re -rating is a part of that
long-term planning process.
CLT/MOORESVILLE_EAA V4 01032007.DOC 6
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
TABLE 4
Historical Rows and Loadings - July 2003 through October 2007
Parameter Avg Day Max Month Max Week Max Day Peak Hour
Flow (mgd)
2.78 3.57 5.04 9.10
4.00
3.80
3.60
3.40
3.20
Ito
3.00
2.80
2.60
2.40
2.20
2.00
■
3.57
3.1)
. -
3.26
"
.
I'
'
2.89
3.01
MI
2.98
- • -
•
2.97 . .
. .
2.93
2.80
-
■
2.80
.
. • "
_ + -
♦.
2.75
♦
- '
- "
t .
'2.49
- ^
♦, .
2.56
' -
-
•
2.52
2.64
2.4
1999
2000
2001
2002
2003
I004
2005
• ADF ■ MMQ - ' ' Expon. (MMQ) - - - Expon. (ADF)
Figure 3 - Mooresville RRWWTP Average Daily and Maximum Monthly Flows
2006
2007
2008
CLT/MOORESVILLE_EAA_V4 01032007.DOC 7
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

2. Discharge Alternatives
2.1 Connection to Existing Facility
This re -rating from 5.2 mgd to 5.5 mgd is being supported by recent actual plant data and
modeling of the facility. This effort involves no new construction, using the existing
infrastructure and discharge to Dye Branch. Therefore, the proposed re -rating is considered
the best use of the existing facility. This is the preferred alternative.
2.2 Land Application
The purpose of this section is to provide a preliminary assessment of land application as an
alternative to direct discharge of treated effluent. Land application of biosolids is currently
part of the facility's operating procedures. This process will continue. Land application as an
alternative to direct discharge of treated effluent is not a preferred option because the 0.3
mgd increase is such a small percent, approximately 5.5 percent, of the total effluent
discharge. This method would not be cost effective when compared to the option of using
the existing facility without the addition of new infrastructure or additional operation
activities. The cost of land application would include finding nearby suitable land, trucking,
and application infrastructure.
2.3 Wastewater Reuse
The Town is continuing to develop long term plans to utilize wasterwater reuse at the
Municipal Mooresville Golf Course (MMGC). The MMGC is located within the Catawba
River Basin and reuse of effluent would be credited in reducing the Town's future IBT.
Other reuse options are being investigated at this time. The Town is committed to exploring
reuse options as part of the long term plan, however it is not cost effective at this time for
the increased 0.3 mgd in permitted flow because new infrastructure would be required for
this small volume of effluent.
2.4 Surface Water Discharge
This alternative would utilize the existing outfall to Dye Branch, requiring no additional
pump station, transmission line, or outfall construction. Additionally, the small increase in
flow will not result in an increase to the total load to Dye Branch, maintaining existing water
quality in the receiving stream. Historical operations data from the facility indicate that the
Town can achieve the quality of effluent presented in Table 4.
2.5 Combination
It is the commitment of the Town to pursue a combination of discharge alternatives as a
long-term solution. This approach was not considered as part of the 0.3 mgd re -rating
because operations data support show the plant is meeting its current permit limits and the
increase in flow is minor in comparision to the upgrades being planned to address long
term needs. These upgrades are currently being planned under the guidelines of the CG&L
and EA processes.
CLTIMOORESVILLE_EAA V4 01032007.DOC 8
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
3. Economic Feasibility
Direct discharge using the existing facility infrastructure is the preferred discharge
alternative, which requires no new construction. Therefore, this is the most cost effective
solution to meet immediate needs of the Town of Mooresville and gives the Town a small
buffer period of capacity while the Town undergoes planning, permitting, and construction
of larger expansions.
CLTIMOORESVILLE_EAA V4 01032007.DOC
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
9

•_
ROCKY RIVER WWTP ENGINEERING ALTERNATIVES ANALYSIS
References
Black & Veatch. 2006. Final Report Water and Wastewater Planning Study for the Town of
Mooresville. Town of Mooresville Draft Water and Wastewater Planning Study. Charlotte,
North Carolina.
CH2M HILL. 2007. Rocky River WWTP Expansion - Draft Engineering Report. Charlotte,
North Carolina.
CLT/MOORESVILLE_EAA V4 01032007.DOC
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
10

TECHNICAL MEMORANDUM CH2MHILL
Modeling of 0.3 mgd Increase in Permitted Flow for
the Town of Mooresville
PREPARED FOR: Susan Wilson/DWQ
PREPARED BY: CH2M HILL
COPIES: John Vest/Mooresville
DATE: December 31, 2007
Purpose
The purpose of this memorandum is to provide results for updated water quality modeling
for the Town of Mooresville s discharge to Dye Branch. Specifically, the modeling is to
examine the impact of re -rating the wastewater treatment plant (WWTP) from a capacity of
5.2 million gallons per day (mgd) to a capacity of 5.5 mgd (based on maximum monthly
average conditions) and the limits necessary to protect water quality.
Background
The Town of Mooresville discharges to Dye Branch in the Rocky River subbasin of the
Yadkin -Pee Dee River Basin. A Technical Memorandum (TM) was prepared in September
2005 and updated in November 2005 (attached) that presented modeling results for an
expanded discharge to Dye Branch (CH2M HILL, 2005a). The model used was a QUAL2E
model that had been developed for other dischargers to the Rocky River and included
modeling pieces based on relatively new (late 1990's) data for the lower Rocky River below
Goose Creek and older (1980's) data for the upper Rocky River. In 2001, a QUAL2E model
was developed for the lower Rocky River (from NCSR 1145 to the USGS gaging station near
Norwood); the calibration of this model was outlined in reports submitted to Division of
Water Quality (DWQ) in February 2001 and January 2005 (CH2M HILL, 2001 and 2005b).
This model was merged with an existing model of the Rocky River that was developed by
DWQ for the river segment from the Mooresville WWTP to the Muddy Creek WWTP (just
downstream of NCSR 1145, the starting point of the lower River model). This merged model
was used as a basis to examine the impacts of the Mooresville WWTP on predicted
Dissolved Oxygen (DO) in the Rocky River.
The model predicts that under existing permitted conditions with a capacity of 5.2 mgd,
BOD5 of 24 mg/L, NH3-N of 2 mg/L, and effluent DO of 5 mg/L (5.2/24/2/5 conditions),
the predicted DO would be considerably lower than North Carolina's standard of 5 mg/L
(Figure 1). Under the increased flow scenarios analyzed in the previous modeling
(CH2M HILL, 2005a), the instream DO standard is protected under all permit limit scenarios
analyzed of which reuse requirements (BOD5 of 10 mg/L and NH3-N of 4 mg/L) were the
CLTNPDATED RR WQ MODELING TM-123107V2.DOC 1
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

least restrictive limits analyzed. This analysis supported the conclusion that the Town of
Mooresville should be able to expand its WWTP and not negatively impact instream DO.
Despite this modeling, speculative limits issued by DWQ for an expanded facility to a
capacity of 19 mgd included a B0D5 of 5 mg/L, NH3-N of 1 mg/L, and effluent DO of 6
mg/L based on the recommendation of the Yadkin -Pee Dee River Basinwide Water Quality
Management Plan (DWQ, 2003) and the recent approaches DWQ has been taking related to
best available technology limits for oxygen -consuming wastes for POTWs. In addition,
DWQ has expressed concern about contributions of the increased discharge rate on the
impairment status of the stream and required additional modeling analyses to address this
issues.
Additional Model Runs
Additional model runs were conducted in December 2007 to identify limits that would
protect water quality in the Rocky River at a slight increase in permitted capacity since the
previous analysis had shown that existing limits resulted in DO predictions below the water
quality standard.
It is important to note that the upper portion of the Rocky River model is an old model
developed with 1980's data. This model was developed when there was significantly more
industrial waste being contributed to the Mooresville WWTP (see the cBOD/ B0D5 ratio of 5
used in the model in Table 2 in previous modeling report - attached), there appeared to be
numerous package plants discharging to tributaries (also Table 2 in previous report), and
deoxygenation rates used in the model were typically higher than are used today with more
highly treated wastes. Typically, a cBOD/B0D5 ratio of 2 is used by DWQ for a POTW if no
data is available and a ratio of 3 is used for an industrial facility if no data is available.
Based on these observations on the old modeling, it is highly likely that the predicted DO
sag in the river based on the existing limits illustrated in Figure 1 is significantly
exaggerated. Figures 2 and 3 show the modeling results at the existing limits with
cBOD/ B0D5 ratios of 2 and 3, respectively. These results show a predicted DO sag due to
Mooresville of 4.6 mg/L with a cBOD/ B0D5 ratio of 2 and of 3.7 mg/L with a cBOD/ B0D5
ratio of 3. Since the river is presently not impaired for DO, these results seem more
consistent with the existing situation than the results depicted in Figure 1 which show a DO
sag due to Mooresville to less than 1 mg/L.
Figure 4 presents the predicted DO profile for Mooresville discharge with a capacity of 5.5
mgd, B0D5 of 15 mg/L, NH3-N of 2 mg/L, and effluent DO of 6 mg/L with a cBOD/ B0D5
ratio of 2 and Figure 5 shows the same limits with a cBOD/ B0D5 ratio of 3. These results
show a predicted DO sag to about 5.3 mg/L due to the Mooresville discharge with a
cBOD/B0D5 ratio of 2 and a DO sag to 4.7 mg/L with a cBOD/B0D5 ratio of 3. There is a
slight secondary sag below the Mallard Creek WWTP to a DO of about 4.7 mg/L in either
case.
CLTIUPDATED RR WO MODELING TM - 123107V2.DOC 2
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Summary
This updated modeling shows much improved DO conditions with the existing permit
limits using more realistic cBOD/BOD5 ratios. Also, it appears that limits of BOD5 of 15
mg/ L, NIA t of 2 mg/ L, and effluent DO of 6 mg/ L with a re -rating to 5.5 mgd will be
adequate to protect DO levels in Rocky River. These limits will protect water quality until
additional treatment facilities are constructed which can achieve proposed speculative
limits.
References
CH2M HILL. 2005a. Rocky River QUAL2E Modeling. Technical Memorandum prepared for
Town of Mooresville on September 2, 2005 and updated on November 10, 2005.
CH2M HILL. 2005b. QUAL2E-LINCAS Application to Rocky River from Mooresville VWVTP to
USGS Flow Gauge near Norwood in North Carolina. Technical Memorandum prepared for
Union County Public Works Department on January 19, 2005.
CH2M HILL. 2001. QUAL2E-LINCAS Application to Rocky River from Mooresville WWTP to
USGS Flow Gauge near Norwood in North Carolina. Technical Memorandum prepared for
Water and Sewer Authority of Cabarrus County, Charlotte -Mecklenburg Utility
Department, and Union County Public Works Department on February 19, 2001.
North Carolina Department of Natural Resources - Division of Water Quality. 2003. Yadkin -
Pee Dee River Basinwide Water Quality Plan.
North Carolina Division of Environmental Management. 1988. QUAL2E Model for
Mooresville VWVTP. Memorandum dated November 30,1988.
CLT/UPDATED RR WQ MODELING TM-123107V2.DOC 3
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

€a
0
❑
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
River Mile
FIGURE 1
Predicted DO profile for existing permitted conditions (from CH2M HILL 2005a)
rn
E 4
0
0
Mooresville at 24/2/5 limits @ 5.2 mgd
CBOD:BOD5=2
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68
River Mile
FIGURE 2
Predicted DO profile for Mooresville Discharge at 5.2 mgd, existing permit limits, with a c80DIBOD5=2
CLT/UPDATED RR WQ MODELING TM - 123107V2.DOC 4
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

E 4
0
0
Mooresville at 24/2/5 limits @ 5.2 mgd
CBOD:BOD5=3
4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68
River Mile
FIGURE 3
Predicted DO profile for Mooresville Discharge at 5.2 mgd, existing permit limits, with a cBOD/BOD5 =3
rn
E 4
0
0
Mooresville at 15/2/6 limits @ 5.5 mgd
CBOD:BOD5=2
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68
River Mile
FIGURE 4
Predicted DO profile for Mooresville Discharge at 5.5 mgd, BOD5INH3-N/DO limits of 15/2/6, with a cBODIBOD5=2
CLTAJPDATED RR WO MODELING TM-123107V2.000 5
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

E 4
0
Q
Mooresville at 15/2/6 limits @ 5.5 mgd
CBOD:BOD5=3
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68
River Mile
FIGURE 5
Predicted DO profile for Mooresville Discharge at 5.5 mgd, BODs1NH3-NIDO limits of 151216, with a cBODIBOD5=3
CLT/UPDATED RR WQ MODELING TM - 123107V2.DOC 6
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Attachment 1
Previous Mooresville Water Quality Modeling TM
CLT/UPDATED RR WO MODELING TM-123107V2.DOC
COPYRIGHT 2008 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL
7

TECHNICAL MEMORANDUM No. 301 CH2MHILL
Rocky River QUAL2E Modeling
PREPARED FOR: Town of Mooresville
PREPARED BY: CH2M HILL
DATE: September 2, 2005; updated November 10, 2005
Executive Summary
This technical memorandum (TM) details the application of a QUAL2E water quality model
from the Mooresville wastewater treatment plant (WWTP) to the USGS gaging station at
Norwood, a distance of 77.6 miles. The model was used to assess the river's assimilative
capacity for oxygen -consuming waste with respect to an increase in permitted flow for the
Town of Mooresville. Model runs were conducted to assess the impact of the Town of
Mooresville's WWTP on predicted dissolved oxygen (DO) in the Rocky River. The model
runs included existing permitted conditions; the Mooresville WWTP at 19 mgd at limits of 5
mg/1 BOD5 and 2 mg/1 NH3-N and other facilities at existing permitted conditions; and the
Mooresville WWTP at 19 MGD, Charlotte Mecklenburg Utility's (CMU) Mallard Creek
WWMF at twice its permitted flow, and the proposed Northern Union County facility
discharging at a flow of 15 MGD. The limits of 5 mg/1 BOD5 and 2 mg/1 NH3-N were
based on a review of the recommendations included in the Division of Water Quality's
(DWQ) Yadkin -Pee Dee Basinwide Plan (NCDENR, 2003) and discussions with the Town.
Model runs were also performed with the Town of Mooresville permitted at 19 mgd with
reuse limits of 10 mg/1 BOD5 and 4 mg/1 NH3-N to determine if reuse levels of treatment
would protect the DO standard. To address potential ammonia toxicity issues, the model
was also run at 10 mg/1 BOD5 and 2 mg/1 NH3-N.
The model predicts that under existing permitted conditions, predicted DO would be lower
than North Carolina's standard of 5 mg/I. Under the increased flow scenarios, the instream
DO standard is protected under all permit limit scenarios. Thus, the Town of Mooresville
should be able to expand its WWTP and not negatively impact instream DO.
Introduction
The Town of Mooresville, North Carolina is experiencing a high rate of growth. The Towri s
proximity to the City of Charlotte and its location on Lake Norman has attracted businesses
and residents to the area. The Town is planning its infrastructure to meet the needs of this
growth. The Town currently operates a WWTP that has a capacity of 5.2 mgd and
discharges to Dye Branch, a tributary of the Rocky River (Figure 1). The facility and its
outfall are located approximately 0.4 miles above the Dye Branch confluence with the Rocky
River. Although the current flows are approximately 3.0 mgd, the expected high growth
rate will increase the demand for municipal sewer service in southern Iredell County. The
Town anticipates a need for 19 mgd capacity at its WWTP in approximately 2025.
MVILLE TM V611102005.DOC 1

ROCKY RIVER QUAL2E MODELING
In order to determine the impacts of this increased wastewater treatment capacity on Dye
Branch and the Rocky River, the QUAL2E model was run. In 2001, a QUAL2E model was
developed for the lower Rocky River (from NCSR 1145 to the USGS gaging station near
Norwood); the calibration of this model was outlined in reports submitted to DWQ in
February 2001 and January 2005 (CH2M HILL, 2001 and 2005). This model was merged
with an existing model of the Rocky River that was developed by DWQ for the river
segment from the Mooresville WWTP to the Muddy Creek WWTP (just downstream of
NCSR 1145, the starting point of the lower River model). This merged model was used as a
basis to examine the impacts of the Mooresville WWTP on predicted DO in the Rocky River.
Description of Rocky River Basin
The Rocky River is located within the Yadkin -Pee Dee Basin in the south-central portion of
North Carolina and flows generally eastward across the piedmont. The river drains
approximately 1,500 square miles (sq. mi.) and is approximately 86 miles long. Its major
tributaries include Dye Branch, Mallard Creek, Coddle Creek, Irish Buffalo Creek, Goose
Creek, and Crooked Creek (see Figure 1).
The river originates just east of Mooresville, North Carolina, and flows southward before
beginning its eastward flow just north of Harrisburg, North Carolina. The river is located
mostly in rural areas comprising farms, small towns, and undisturbed natural areas.
However, some tributaries flow through rapidly developing areas in northeastern
Mecklenburg, southern Iredell and southern Cabarrus County. Much of the undisturbed
area of the river basin consists of bottomland hardwood forests. The river eventually forms
the boundary of Anson and Stanly Counties and flows into the Pee Dee River upstream of
Blewett Falls Reservoir.
Description of QUAL2E Model
QUAL2E is a water quality model used extensively for wasteload allocations and for
descriptive simulations of conventional pollutants. The basic equation solved by QUAL2E is
a one-dimensional advection-dispersion mass transport equation, which is numerically
integrated over space and time for each water quality constituent (EPA, 1987). The model is
steady-state and assumes complete mixing in the water column. The QUAL2E model allows
for multiple point source discharges and withdrawals, and incremental inflow.
Model Modifications
When the model was run at existing conditions, the predicted DO was 0 mg/1 for much of
the original upstream modeled area. This was due to two major factors:
1. The data provided by DWQ in 2000 included an extremely high CBODu:BOD5 ratio
for the town of Mooresville (8.45). A ratio this high is unusual for municipal
wastewater. Thus, the ratio was reduced to 5 to be more representative of effluent
ratios observed in other highly treated municipal wastewater. In the 2005 modeling
report (CH2M HILL, 2005), an effluent concentration of 24.5 mg/1 CBODu was
included in the model for the Mooresville discharge. A future effluent BOD5
MVILLE TM V611102005.000 2

ROCKY RIVER QUAL2E MODELING
concentration of 5 mg/1 and a CBODu:BOD5 ratio of approximately 5 was assumed
for consistency with the previous modeling of the river.
2. The model decay rates were high and more typical of secondary treated effluents.
These model decay rates were modified to be more representative of highly treated
POTW effluent. DWQ originally calibrated the Rocky River model near the
Mooresville WWTP in 1988, and based it on instream data collected in 1986. At this
time, the instream CBOD ranged from 10 to 15 mg/1, and there were instream BOD5
data as high as 23 mg/I at the ambient station (DEM, 1988). A BOD decay rate of 0.3
/day was used in the original model; all values were modified to 0.1 /day to match
the more recent data collected in the downstream reaches of the Rocky River. This
value is in line with BOD decay rates included in most models where point sources
achieve high levels of treatment. Similarly, the organic nitrogen hydrolysis rate,
organic nitrogen settling rate, and ammonia oxidation rate were reduced to match
the rates included in the downstream model (all rates changed to 0.05 /day). Again,
the modified rates are in line with rates included in models where high levels of
treatment are achieved. Appendix A includes the model input for existing permitted
conditions.
Model Allocation
The merged model was run to determine the impacts of the proposed expansion of the
Mooresville WWTP on predicted DO in the Rocky River. DWQ provided WWTP effluent
data in 2000, and these data were used for model allocation. Appendix B contains the input
data set for the proposed expansion of the Mooresville WWTP to 19 mgd.
Background Conditions
The model was run under 7Q10 low flow and summer temperature conditions. The
headwater conditions were established when the existing DWQ model was developed.
Table 1 summarizes these conditions.
TABLE 1
Headwater Conditions for Rocky River QUAL2E Model
Parameter Dye Branch West Branch Mallard Creek
Temperature (°F) 75.2 75.2 75.2
Flow (cfs) 0.5 1.5 1.4
DO (mg/L) 9.46 7.6 7.1
CBODu (mg/L) 3.12 2.0 4.28
NH3-N (mg/L) 0.04 0.22 0.056
Organic Nitrogen 0.46 0.0 0.28
NOx-N 0.24 0.0 0.26
Incremental Inflow
The USGS low -flow report (Weaver and Fine, 2003) was used to estimate the headwater and
tributary upstream flows. For tributaries lacking a 7Q10 flow estimate in the low -flow
MVILLE TM V611102005.DOC 3

ROCKY RIVER QUAL2E MODELING
report, the old 7Q10 estimates that were available were applied. Current wastewater flows
were then added. This process resulted in a flow estimate of approximately 30 cfs in the
Rocky River upstream of Irish Buffalo Creek. Omission of the WWTPs resulted in a flow of
approximately 15 cfs upstream of Irish Buffalo Creek. These flows compare favorably to the
flows listed in the USGS report (Weaver and Fine, 2003) at that location. Thus, zero
incremental inflow was included in the upstream reaches of the model.
Inclusion of zero incremental inflow in the downstream reaches resulted in an estimated
flow of 64.9 cfs when current wastewater flows were input. This value is high when
compared to the 7Q10 estimate of 45 cfs reported by USGS at Norwood. Thus, a negative
incremental inflow of 0.8 cfs/mile was included in the model below Stanfield to result in a
flow of approximately 45 cfs at Norwood under current wastewater flow. Inclusion of a
negative incremental inflow is supported by the evidence of a losing reach presented by
USGS (Weaver and Fine, 2003). The pollutant levels associated with the incremental inflow
were assumed to be zero for the analysis. Likely, this is a conservative assumption, as some
oxygen -consuming waste will be lost to groundwater.
Tributaries and Point Sources
Tributaries in the model were considered point sources. Tributary stream flows were
obtained from the USGS flow report (Weaver and Fine, 2003) when available. When
tributary flows were not provided in the report, an attempt was made to back -calculate the
low flow based on mainstem flows provided. If there were insufficient data to calculate a
low flow, earlier flows provided by USGS were used. The water quality data input into the
model for the tributaries were the same data used for the calibration model run for the
tributaries. Flow and water quality parameters for each tributary point source for the model
are included in Table 2 along with permit limit input values for the other point sources. The
data in these tables represent the most recent information available from DWQ.
TABLE 2
Point Source Allocation Input Data
Q DO BOD5 CBODu: CBODu NH3-N ORG N NOx
Location (cfs) (mg/L) (mg/L) BOD5 (mg/L) (mg/L) (mg/L) (mg/L)
Mooresville WWTP1 8.1, 29.5 6 5 5 25 2 1.6 6.2
Rocky River
0.3 7.3 1.4 0.025 0.075 0.325
Mid -South
0.9 5 23 1.5 34.5 3.1
WR Odell
0.02 6 18 1.5 27.0 6.0
Clarke Creek
1.0 6 2.5
CMUD Mallard Creek 18.6, 6 5 1.81 9.07 1 1.1
WWTP2 37.2
Coddle Creek
6 7.74 12.5 0.1 0.27 0.24
Back Creek
1 7.45 9.5 0.9 0.47 0.37
Reedy Creek
3.4 8.14 28.5 5.2 2.35
LRRR WRF (Concord) 52.7 6 12 5.24 62.88 2 3.85 7.33
Coldwater Creek
7.4 7.5 2.0 0.02 0.05 0.02
Dutch Buffalo Creek
0.5 7.5
2.0 0.02 0.05 0.02
Muddy Creek WWTP 0.47 5 10.0 4.22 42.0 4.0 0.0 0.0
Proposed NUC WRF 0, 23.3 6 10.0 2 20.0 4.0 1.0 12.0
MVILLE_TM V611102005.DOC 4

ROCKY RIVER QUAL2E MODELING
Location
Q DO BOD5 CBODu: CBODu NH3-N ORG N NOx
(cfs) (mg/L) (mg/L) BOD5 (mg/L) (mg!L) (mg/L) (mg/L)
Goose Creek
0.50 8.7 3.6 0.04 0.4 0.9
Long Creek 2.60 9.30 4.0 0.03 0.7 1.2
Richardson Creek
0.8 8.4
5.7 0.2 0.9 8.4
Lanes Creek
0.0 8.5 4.8 0.14 0.6 0.5
1 The Town of Mooresville WWTP input at current permitted flow of 5.2 mgd (8.1 cfs) and an expanded flow of 19 mgd (29.5
cfs).
2 The CMUD Mallard Creek facility was input at its current permitted flow of 12 mgd (18.6 cfs) as well as an expanded Sow
of 24 mgd (37.2 cfs)
3 The Proposed Northern Union County WRF was input at 0 mgd and 15 mgd (23.3 cfs).
Model D0 Simulation Runs
Existing Permit Conditions
The first model run simulates existing permitted conditions (model input file in Appendix
A). This model run included the existing major WWTPs: Mooresville (5.2 mgd), CMU's
Mallard Creek WWTP, and the Water and Sewer Authority of Cabarrus County (WSACC)
Lower Rocky River Regional WWTP along with several smaller WWTPs. Figure 2 shows
the DO concentration along the mainstem of the Rocky River. The model predicts a DO of
0.53 mg/1 at the sag point upstream of the confluence with Mallard Creek. A secondary sag
to a DO of 4.1 mg/1 is noted upstream of Reedy Creek, and the predicted DO at the model
endpoint is 4.9 mg/1.
E 4
0
0
0
4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
River Mile
FIGURE 2
Predicted D0 for existing permitted conditions
MVILLE TM V611102005.000 5

ROCKY RIVER QUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD at Advanced Limits; Other Point Sources at Existing
Permit Conditions
Under this modeling scenario, the Town of Mooresville WWTP was expanded to 19 mgd;
permit limits of 5 mg/1 BOD5, 2 mg/1 NH3-N, and 6 mg/1 DO were assumed based on
recommendations in the Yadkin -Pee Dee River Basinwide Plan (NCDENR, 2003). All other
input parameters were identical to the existing permit conditions run. Figure 3 shows the
DO concentration along the mainstream of the Rocky River. The model predicts a DO of 5.3
mg/1 at the model endpoint. Other sags to DO levels of 5.6 mg/1 and 6.5 mg/1 are observed
upstream of Reedy Creek and upstream of Mallard Creek, respectively.
E 4
0
O
0
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
River Mile
FIGURE 3
Predicted DO with Mooresville WWTP at 19 MGD at Advanced Treatment
MVILLE_TM_V611102005.DOC
6

ROCKY RIVER QUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD at Reuse Limits; Other Point Sources at Existing
Permit Conditions
Under this modeling scenario, the Town of Mooresville WWTP was expanded to 19 mgd;
permit limits of 10 mg/1 BOD5, 4 mg/1 NH3-N, and 6 mg/1 DO were assumed based on
requirements for wastewater reuse. All other input parameters were identical to the
existing permit conditions run. Figure 4 shows the DO concentration along the mainstream
of the Rocky River. The model predicts a DO sag of 5.2 above Reedy Branch, and a DO
concentration of 5.2 at the model endpoint.
7/7
E 4
0
0
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 69 72
River Mile
FIGURE 4
Predicted DO with Mooresville at 19 MGD at Reuse Levels of Treatment
MVILLE TM_V611102005.DOC
7

ROCKY RIVER QUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD at 101216 Limits; Other Point Sources at Existing Permit
Conditions
Although the model predicts that reuse limits will protect the DO standard, lower ammonia
limits may be needed to protect the stream from ammonia toxicity impacts since the
majority of the flow in Dye Branch during low flow conditions will be from the Mooresville
WWTP. Thus, limits of 10 mg/1 BOD5, 2 mg/1 NH3-N, and 6 mg/1 DO were assumed for
this model run. All other input parameters were identical to the existing permit conditions
run. Figure 5 shows the DO concentration along the main stem of the Rocky River. The
model predicts a DO sag of 5.3 mg/1 above Reedy Branch, and a DO concentration of 5.2
mg/1 at the model endpoint.
21 41 61 81 101 121 141 161 181 201 221 241 261 281 301 321 341 361
River Mile
FIGURE 5
Predicted DO with Mooresville at 19 MGD and 10/2/6 Limits
MVILLE 7M V611102005.DOC 8

ROCKY RIVER QUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD; Proposed Northern Union County WRF at 15 MGD;
CMU Mallard Creek Wastewater Management Facility (WWMF) Doubles to 24 MGD
This modeling scenario was run to determine the potential impacts on instream DO under
future conditions (5/2/6) if other new dischargers occur within the watershed. Northern
Union County is planning a new water reclamation facility to meet its wastewater treatment
needs in the future. This proposed plant was input at 15 mgd. CMU is also planning on
expanding its Mallard Creek WWMF; specific planned flows for the CMU facility were not
available, but it was assumed the plant would double in size for this scenario. The
predicted DO under this scenario is illustrated in Figure 6. The model predicts a DO of 5.6
mg/1 at the model endpoint. Other sags to DO levels of 6.5 mg/1 and 6.0 mg/1 are
predicted upstream of Mallard Creek and upstream of Reedy Creek, respectively.
E 4
Q
0
4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
River Mile
FIGURE 6
Predicted D0 with Mooresville WWfP at 19 MGD, CMU Mallard Creek WWMF Expanded, and Northem Union County
WRF Online
MVILLE TM V611102005.DOC 9

ROCKY RIVER DUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD at Reuse Limits; Proposed Northern Union County at
15 MGD; CMU Mallard Creek Wastewater Management Facility (WWMF) Doubles to 24 MGD
This modeling scenario was run to determine the potential impacts of Mooresville
discharging at reuse limits (10/4/6) on instream DO under future conditions if other new
dischargers occur within the watershed. The proposed Northern Union County plant was
input at 15 mgd, and CMU was input at 24 mgd. The predicted DO under this scenario is
illustrated in Figure 7. The model predicts a DO of 5.5 mg/1 at the model endpoint. Other
sags of 5.7 mg/1 and 5.5 mg/1 are predicted upstream of Reedy Creek and Mallard Creek
respectively.
E 4
0
0
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72
River Mile
FIGURE 7
Predicted DO with Mooresville at 19 MGD at Reuse Levels of Treatment, CMU Expanded, and Northern Union County
Online
MVILLE TM V611102005.DOC 10

ROCKY RIVER QUAL2E MODELING
Mooresville WWTP Expanded to 19 MGD at 101216 Limits; Proposed Northern Union County at
15 MGD; CMU Mallard Creek Wastewater Management Facility (WWMF) Doubles to 24 MGD
Although the model predicts that reuse limits will protect the DO standard, lower ammonia
limits may be needed to protect the stream from ammonia toxicity. Thus, this model run
was completed under future flow conditions for Northern Union County and CMU, and
Mooresville was input at 10 mg/1 BOD5, 2 mg/1 NH3-N, and 6 mg/1 DO at 19 mgd. The
model predicts a DO of 5.5 mg/1 at the model endpoint. Other sags of 5.8 mg/1 and 5.7
mg/1 are predicted upstream of Reedy Creek and Mallard Creek respectively.
71
E 4
O
0
0
4 8 12 16 20 24 28 32 36 40
River Mile
44
48
52
56
60
64
FIGURE 8
Predicted DO with Mooresville at 19 MGD at 10/2/6 Limits, CMU Expanded, and Northem Union County Online
Discussion of Modeling Results
68
72
Figure 2 indicates that under existing permitted conditions, DO violations would be
observed in the upper reaches of the Rocky River. Since Mooresville has been treating its
effluent to higher quality than required by its permit, these predicted low DO
concentrations have not been observed in the Rocky River.
Figures 4 and 7 show that Mooresville can expand its treatment plant at reuse levels of
treatment and protect the DO standard in the Rocky River. In addition, other facilities can
expand their treatment plants, and the predicted DO standard will not be violated. The
modeling results indicate that higher effluent flows actually increase the predicted DO in
the river. This is likely due to the fact that the model predicts higher reaeration under
MVILLE TM V611102005.DOC 11

ROCKY RIVER QUAL2E MODELING
higher flow conditions. The model was also run at limits of 10 mg/1 BOD5 and 2 mg/1 NH3-
N to protect against ammonia toxicity; under these scenarios, instream DO increases very
slightly above the levels predicted under reuse levels of treatment. Finally, the model was
run at limits of 5 mg/I BOD5, 2 mg/1 NH3-N and 6 mg/ 1 DO based on the
recommendations within the Yadkin -Pee Dee Basinwide Plan. The predicted DO under
these model scenarios was highest, but only slightly higher than predicted DO under other
modeling scenarios (less than 5 percent higher).
The model does show decreasing DO near the model endpoint. The hydraulic equations
and reaeration rates were modified in the lower three reaches of the river, and these changes
largely explain the reductions in predicted DO.
Conclusions
The QUAL2E model that extends from the Mooresville WWTP to the USGS gaging station
near Norwood (77.6 miles) on the Rocky River was run to determine the impacts of a
proposed expansion of the Mooresville WWTP on DO in the Rocky River. The model
included other tributaries in order to determine the interaction of other major and minor
point source discharges on water quality in the Rocky River.
Model runs were then conducted for scenarios representing existing permitted conditions,
the expanded Mooresville facility, and the expanded Mooresville facility along with a new
discharge from the proposed Northern Union County WRF and an expansion of CMU's
Mallard Creek WWTP.
The model results indicate that under existing permitted conditions, predicted DO
violations would occur. However, this is not occurring due to the level of treatment the
facility is providing. Under the expanded facility scenarios (with Mooresville at effluent
limitations ranging from 5 mg/1 BOD5 and 2 mg/1 NH3-N to 10 mg/1 BOD5and 4 mg/1
NH3-N), the DO standard is protected. Thus, the Town of Mooresville can expand its
WWTP and not impact instream DO concentrations.
References
CH2M HILL. 2005. QUAL2E-UNCAS Application to Rocky River from Mooresville WWTP to
USGS Flow Gauge near Norwood in North Carolina. Technical Memorandum prepared for
Union County Public Works Department on January 19, 2005.
CH2M HILL. 2001. QUAL2E-UNCAS Application to Rocky River from Mooresville WWTP to
USGS Flow Gauge near Norwood in North Carolina. Technical Memorandum prepared for
Water and Sewer Authority of Cabarrus County, Charlotte -Mecklenburg Utility
Department, and Union County Public Works Department on February 19, 2001.
North Carolina Department of Natural Resources - Division of Water Quality. 2003. Yadkin -
Pee Dee River Basinwide Water Quality Plan.
North Carolina Division of Environmental Management. 1988. QUAL2E Model for
Mooresville WWTP. Memorandum dated November 30,1988.
MVILLE TM V611102005.DOC 12

1
ROCKY RIVER OUAL2E MODELING
U. S. Environmental Protection Agency, 1987. The Enhanced Stream Water Quality Models
QUAL2E and QUAL2E-UNCAS: Documentation and User Model. USEPA Environmental
Research Laboratory, Athens, GA 30613. EPA/600/3-87/007.
Weaver, J. Curtis and Jason M. Fine. 2003. Low Flow Characteristics and Profiles for the Rocky
River in the Yadkin -Pee Dee River Basin, North Carolina, through 2002. U.S. Geological Survey,
Water -Resources Investigations Report 03-4147. Raleigh, North Carolina.
MVILLE_TM_V611102005.DOC
13