NC0020354_Permit Modification_19990302

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
March 2, 1999
Mr. Ken Cornatzer
Town Manager
P.O. Box 759
Pittsboro, North Carolina 27312
A1 • •
ov NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
Subject: NPDES Permit Modification
NPDES Permit NC0020354
Pittsboro WWTP
Chatham County
Dear Mr. Cornatzer:
On September 25, 1998, the Division modified the subject permit in conjunction with approval of
the Town's pretreatment program. A review of the permit file by personnel from the Division's Raleigh
Regional Office noted typographical errors on the Supplement to Permit Cover page and in the
description of instream sampling locations. This permit modification is being issued to correct those
errors.
Please find enclosed the revised permit pages. These pages should be inserted into your permit.
The old pages may then be discarded. All other terms and conditions contained in the original permit
remain unchanged and in full effect. This permit modification is issued under the requirements of
North Carolina General Statutes 143-215.1 and the Memorandum of Agreement between North
Carolina and the U. S. Environmental Protection Agency.
If any parts, measurement frequencies or sampling requirements contained in this permit
modification 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 a written petition
conforming to Chapter 150B of the North Carolina General Statutes, filed with the Office of
Administrative Hearings, Post Office Drawer 27447, Raleigh, North Carolina 27611-7447. Unless such
demand is made, this decision shall be final and binding.
If you have any questions concerning these permit modifications, please contact Charles Weaver
at [phone], extension 511. - -
Scerely,
Preston Howai,Jr., P.E.
cc: [Central FilesA
Raleigh Regional Office, Water Quality Section
Point Source Compliance Enforcement Unit
NPDES Unit
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled / 10% post -consumer paper

Permit NC0020354
SUPPLEMENT TO PERMIT COVER SHEET
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:
■ Mechanical barscreen
■ Diffused aeration basins
■ Clarifiers
■ Phosphorus removal
■ High -rate sand filters
■ Sludge thickening
■ Aerobic sludge digestion
■ W disinfection
■ Cascade post -aeration
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.

Permit NCO020354
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - SUMMER
(April 1 - October 31)
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 -
­7
ire .ae.��_. _<i
CHARACTERISTICS
.
�§ LIMITS ' if
yr,
MONITORING REQUIREMENTS
Monthly
?� Avera e.,
Weekly
:,gAve "e
Measurement "
Fre uenc
Sample Type
Sam le Locafionla
<
Flow
0.75 MGD
Continuous
Instantaneous
Influent or Effluent
BOD, 5 day (20°C)2
5.0 mg4
7.5 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/l
3/Week
Composite
Effluent
Dissolved Oxygen3
3/Week
Grab
Effluent,
Upstream & Downstream
Fecal Coliform (geometric mean)
200/100 ml
400/100 ml
3/Week
Grab
Effluent,
Upstream & Downstream
Total Residual Chlorine
3/Week
Grab
Effluent
Temperature
Daily
Grab
Effluent,
Upstream & Downstream
Total Nitrogen (NO2+NO3+TKN)
Quarterly
Composite
Effluent
Total Phosphorus
2.0 mg1l
Weekly
Composite
Effluent
Conductivity
3/Week
Grab
Upstream & Downstream
Chronic Toxicity4
Quarterly
Grab
Effluent
pH5
3/Week
Grab
Effluent
Footnotes:
1. Sample locations: Upstream = at least 100 yards above the outfall; Downstream = at least 100
yards downstream from the outfall.
2. The monthly average BOD5 and Total Suspended Residue concentrations shall not exceed 15% of
the respective influent value (85% removal).
3. The daily dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
4. Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September & December (see Condition
A.(3.)).
5. 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
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NC0020354
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS — WINTER ,
(November 1 — March 31)
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:
EFFLUENTS
C_ H�4RACTERISTICS
:_
e_.
LIMITS
MONITORING
REQUIREMENTS
Monthly ��
Avera a"
Weekly
:.:
Avere e -
; Measurements
<
�. Fre uenc_.
�Sample_Type ,
�a�
e.
Sam le Location'
Flow
0.75 MGD
Continuous
Instantaneous
Influent or Effluent
BOD, 5 day (20°C)2
5.0 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,
Upstream & Downstream
Fecal Coliform (geometric mean)
200/100 ml
400/100 ml
3/Week
Grab
Effluent,
Upstream & Downstream
Total Residual Chlorine
3/Week
Grab
Effluent
Temperature
Daily
Grab
Effluent,
Upstream & Downstream
Total Nitrogen (NO2+NO3+TKN)
Quarterly
Composite
Effluent
Total Phosphorus
2.0 mg/I
Weekly
Composite
Effluent
Conductivity
3/Week
Grab
Upstream & Downstream
Chronic Toxicity4
Quarterly
Grab
Effluent
pH5
3/Week
Grab
Effluent
Footnotes:
1. Sample locations: Upstream = at least 100 yards above the outfall; Downstream = at least 100
yards downstream from the outfall.
2. The monthly average BODS and Total Suspended Residue concentrations shall not exceed 15% of
the respective influent value (85% removal).
3. The daily dissolved oxygen effluent concentration shall not be less than 6.0 mg/l.
4. Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September & December (see Condition
A.(3.)).
5. 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
There shall be no discharge of floating solids or visible foam in other than trace amounts.