NC0020354_Issuance of Permit_20011228

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
Gregory J. Thorpe, Ph.D., Acting Director
December 28, 2001
Mr. Hugh Montgomery, Town Manager
Town of Pittsboro
P.O. Box 759
Pittsboro, North Carolina 27312
1 � •
NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
Subject: NPDES Permit Issuance
Pittsboro WWTP
Permit No. NCO020354
Chatham County
Dear Mr. Montgomery:
In accordance with the application for discharge permit, the Division is forwarding
herewith the subject NPDES 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 May 9, 1994.
The Division is in receipt of your comments on the draft permit and offers the following
comments in return:
• Temperature: The daily monitoring required by the permit is intended for the effluent only.
Instream monitoring is required 3/Week during June, July, August, and September, and once
per week during the remainder of the year (specified in footnote 1).
Nickel: In order to allow the Town time to re-evaluate its changing pretreatment facilities, the
Division will allow the Town to monitor nickel monthly for one year after the effective date of
the permit (through January 31, 2003). The nickel limit will become effective February 1,
2003. The monitoring frequency at that time will be weekly (the draft permit inadvertently
stipulated 2/month). After a minimum of 10-12 data points (over at least a 10 month period)
have been collected, Pittsboro may request that the Division re-evaluate the nickel data to
determine if the limit can be eliminated. The Division recommends (but will not require) that
Pittsboro conduct more frequent monitoring than monthly monitoring in order to have a larger
data base to evaluate.
Nutrients: As stated in the cover letter to the draft permit, Roberson Creek is listed as partially
supporting and not supporting its designated uses on North Carolina's 303 (d) list. The 303(d)
list is mandated by the Clean Water Act and requires states to list any impaired water, then
develop a management strategy to restore the waterbody to its designated use. One of the
water quality parameters affected on Roberson Creek is chlorophyll a, a measurement of algal
activity that responds to excess nutrients (phosphorus and nitrogen). Information is currently
being obtained by the Division in order to develop a management strategy (or total maximum
daily load - TMDL) for Roberson Creek.
1617 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27699-1617 -TELEPHONE [phone]/FAX [phone]
AN EQUAL OPPORTUNITY AFFIRMATIVE ACTION EMPLOYER - 50% RECYCLED/ 10% POST -CONSUMER PAPER
VISIT US ON THE WEB AT http://h2o.enr.state.nc.us/NPDES

Mr. Montgomery
Page 2 =
Nutrients (continued)
Additionally, House Bill 515, passed during the 1997 session, specifies an average annual
mass load limit for total nitrogen and/or phosphorus, if one or both of these nutrients are
deemed to be a parameter of concern. Senate Bill 1366 was also passed in 1997, which
allowed an extension date for compliance with nitrogen and phosphorus discharge limits until
such time that a calibrated nutrient response model was developed. The Town of Pittsboro is a
member of the Jordan Lake Coalition, which has proposed a schedule to comply with the
stipulations of Senate Bill 1366 and is not currently required to meet nutrient limits.
For this permit renewal, no changes will be made with regard to nutrients, with the exception
of -an increase in monitoring frequency for total nitrogen (weekly monitoring will be required
with this renewal). A special condition has been placed in the permit noting that the Division
may revise the permit based on the outcome of the Jordan Lake Coalition modeling effort.
However, as also stated in the speculative letter, any potential expansion of the treatment
plant will be affected by both the waterbody impairment and House Bill 515.
Although not required as part of this permit, the Division encourages Pittsboro to gather total
phosphorus and. total nitrogen data upstream of the discharge. Because the Town is a
member of the Upper Cape Fear Basin Association, no upstream data is collected at this time.
This information may better assist the Town and the Division of any nutrient impacts directly
attributable to the Town.
• Chlorine: A footnote has been added to the permit stating that total residual chlorine must be
monitored if chlorine is used as a disinfectant or elsewhere in the process.
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, Mail Service Center 6714, Raleigh, North Carolina
27699-6714. Unless such a demand is made, this permit shall be final and binding.
Please take notice that this permit is not transferable except after notice to the Division of
Water Quality. The Division of Water Quality 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, the Division of Land Resources, the Coastal Area Management Act, or
any other federal or local governmental permit.
If you have any questions regarding the NPDES permit, please contact Susan Wilson at
(919) 733 - 5083, extension 510.
Sincerely,
Original Signed By
David A. Goodrich
Gregory J. Thorpe
cc: Raleigh Regional Office/Water Quality Section
Central Files
Point Source Compliance and Enforcement Unit
NPDES Unit
Aquatic Toxicology Unit

Permit NCO020354
Permit No. NCO020354
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELINHNATION SYSTEM
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards and
regulations promulgated and adopted by the North Carolina Water Quality Commission, and the Federal
Water Pollution Control Act, as amended,
Town of Pittsboro
is hereby authorized to discharge wastewater from a facility located at
Pittsboro Wastewater Treatment Plant
Off Small Street Extension
Chatham County
to receiving waters designated as Roberson Creek in the Cape Fear River Basin
in accordance with the discharge limitations, monitoring requirements, and other conditions set forth in Part
I, II, III, and IV hereof.
This permit shall become effective February 1, 2002.
This permit and the authorization to discharge shall expire at midnight on April 30, 2006.
Signed this day December 28, 2001.
Original Signed By
David A. Goodrich
Gregory J. Thorpe, Ph.D., Acting Director
Division of Water Quality
By the Authority of the Environmental Management Commission
Pittsboro WW'I?
NPDES No. NCO020354

_ Permit NC00203547�
SUPPLEMENT TO PERMIT COVER SKEET
The Town of Pittsboro is hereby authorized to:
1. Continue to operate an existing 0.75 MGD extended aeration wastewater treatment system
consisting of the following components:
■ Manual and mechanical barscreen
■ Diffused aeration basins
■ Clarifiers
■ Phosphorus removal
■ High -rate sand filters
■ Sludge thickening
• Aerobic sludge digestion
■ W disinfection,
■ Effluent flow measurement
■ Cascade post -aeration
r
The facility is located at the Pittsboro WWTP on the Small Street Extension southeast of Pittsboro
in Chatham County.
2. Discharge from said treatment works at the location specified on the attached map into Roberson
Creek, classified WS -IV NSW waters in the Cape Fear River Basin.
Pittsboro WWTP
NPDES No. NCO020354

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Latitude 35°4246" 5uV5a5iw 03-06-04
Lm itudly 7910' 12"
Quad #: E22NW, f ittsboro
Stream Class: W5 -1V, N5W
Receiving Stream- Roberson Creek, Cape Fear River Basin
Permitted Flow: 0.75 MGD

Permit NCO02035A
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REgUIREMENTS — FINAL
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:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Measurement
Frequency
Sample Type
Sample Location/
Flow
'r
0.75 MGD
Continuous
Instantaneous
Influent or Effluent
BOD, 5 day (202C)2
[Apr. i — Oct. 31
5.0 mg/I
7.5 mg/I
3/Week
Composite
Influent & Effluent
BOD, 5 day (202C)2
Nov.1 — Mar. 31
10.0 mg/I
15.0 mg/I
3/Week
Composite
Influent & Effluent
Total Suspended Residue2
30.0 mg/I
45.0 mg/I
3/Week
Composite
Influent & Effluent
NH3 as N
2.0 mg/I
3/Week
Composite
Effluent
Dissolved Oxygen3
3/Week
Grab
Effluent,
U stream & Downstream
Fecal Coliform (geometric mean)
200/100 ml
400/100 ml
3/Week
Grab
Effluent,
U stream & Downstream
Total Residual Chlorine?
3/Week
Grab
Effluent
Temperature
Daily
Grab
Effluent
Temperature
3/Week
Grab
Upstream & Downstream
Total Nitrogen (NO2+NO3+TKN)
Weekly
Composite
Effluent
Total Phosphorus4
2.0 mg/I
Qtrl Avg)
Weekly
Composite
Effluent
Conductivity
3/Week
Grab
Effluent
Upstream & Downstream
Chronic Toxicity5
Quarterly
Composite
Effluent
pH6
3/Week
Grab
Effluent
Copper
Monthly
Composite
Effluent
Nickel
[Feb. 1, 2002 through Jan. 31,
2003
Monthly
Composite
Effluent
Nickel
[February 1, 2003 through
expiration]
25 ugA
(Weekly
avg.)
261 ug/I
(Daily
m
Weekly
Composite
Effluent
Zinc
MonthlyComposite
Effluent
Footnotes on following page
Pittsboro WWTP
NPDES No. NCO020354

Footnotes:
Permit NCO020354
I. Sample locations: Upstream = at least 100 yards above the outfall; Downstream = at least 100
yards downstream from the outfall. Instream monitoring shall be conducted 3/ Week during June,
July, August, and September, and once per week during the remainder of the year. Instream
monitoring is provisionally waived in light of the permittet's participation in Upper Cape
Fear River Basin Association. Instream monitoring shall be conducted as stated in this
permit should the permittee end its participation in the Association.
2. The monthly average BOD5 and Total Suspended Residue concentrations shall not exceed 15% of
the respective influent value (85°x6 removal).
3. The ;daily dissolved oxygen effluent concentration shall not be less than 6.0 mg/l.
4. Compliance shall be based on a quarterly average of weekly samples. Also see Special Condition
A.(3). regarding nutrients (especially nitrogen).
5. Chronic Toxicity (Ceriodaphnia) E;jat 90%; March, June, September & December (see Condition
A.(2.)).
6. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be
monitored three times per week at the effluent by grab sample.
7. Total residual chlorine shall be monitored if chlorine is added as a disinfectant or used elsewhere
in the process.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
A (2). CHROMC TOXICITY PERNHT LBUT (QRTRLY)
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality
to Cerlodaphnia dubia at an effluent concentration of 90%.
The permit holder shall perform at a minimum, quarterlu monitoring using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised February 1998, or subsequent
versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -February
1998) or subsequent versions. The tests will be performed during the months of March, June, September,
and December. Effluent sampling for this testing shall be performed at the NPDES permitted final effluent
discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV
below the permit limit, then multiple -concentration testing shall be performed at a minimum, in
each of the two following months as described in "North Carolina Phase lI 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
Pittsboro WWTP
NPDES No. NCO020354

I .•
Permit NC002035;
code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally, DWQ Form AT.
(original) is to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch - -
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 emplbyel for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form
indicating the facility name, permit number, pipe number, county, and the month/year of the report with
the notation of "No Flow" in the comment area of the form. The report shall be submitted to the
Environmental Sciences Branch at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring
will be required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of
Water Quality indicate potential impacts to the receiving stream, this permit may be re -opened and
modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival, minimum control organism reproduction, and appropriate environmental controls, shall
constitute an invalid test and will require immediate follow-up- testing to be completed no later than the
last day of the month following the month of the initial monitoring.
A. (3.) NUTRIENT LMTS SPECIAL CONDITION
Limits on total nitrogen have not been included at this time because the facility is participating in the
Lake Jordan Coalition. If compliance with any element of this strategy, or subsequent approved
revisions to the strategy is not maintained, the Division reserves the right to reopen this permit to
include nitrogen limits. If requirements other than those listed in this NPDES permit are adopted as
_
part the results of the Jordan Lake model, the Division reserves the right to reopen this permit to
include these requirements.
Pittsboro WWTP
NPDES No. NCO020354