NC0020354_technical correction_20070110

Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
January 10, 2007
Mr. Sam Misenheimer
Town of Pittsboro
P.O.Box759
Pittsboro, NC 27312
Subject: Correction to NPDES Permit NC0020354
Town of Pittsboro WWTP
Chatham County
Dear Mr. Misenheimer:
It has been brought to our attention there was an oversight in the permit sent to the. Town on December
15, 2006. The previous permit included language that exempted the town from conducting instream
monitoring as long as it remained a member of the Upper Cape Fear River Basin Association, which
conducts stream monitoring for its members. In the recently issued permit, that language was
mistakenly left out of the permit.
Attached, please find a corrected page for the footnotes associated with the limits and monitoring
requirements for the NPDES permit. In footnote 1, the following language has been added:
Instream monitoring is provisionally waived in light of the permittee's participation
in the 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.
No other changes have been made to the terms or conditions of the permit issued on December 15,
2006. Please remove the page that omitted the language cited above and replace it in the permit with
the attached page. We regret any inconvenience this error may have caused.
If you have any questions concerning this permit, please contact Bob Sledge at telephone number (919)
733-5083, extension 547.
Sincerely,
fort -Alan W. Klimek, P.E.
cc: Central Files
Raleigh Regional Office/Surface Water Protection Section
NPDES Unit
Jennie Atkins — Environmental Sciences Section
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone]
Internet: www.ncwateraualitv.org Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
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Permit NC0020354
Footnotes from Limits and Monitoring Requirements:
1. 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 permittee's
participation in the 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% removal).
3. The daily dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
4. Total residual chlorine shall be monitored if chlorine is added as a disinfectant or used
elsewhere in the process.
5. TN = TKN + NO3-N + NO2-N, where TN is Total Nitrogen, TKN is Total Kjeldahl Nitrogen,
and NO3-N and NO2-N are Nitrate and Nitrite Nitrogen, respectively.
6. TN or TP Load is the mass quantity of Total Nitrogen or Phosphorus discharged in a given
period of time. See Special Condition A. (4.), Calculation of Mass Loads.
7. See Condition A. (5.) for prospective Total Phosphorous summer effluent limit to be
included in future permits.
8. The quarterly average for total phosphorus shall be the average of composite samples
collected weekly during each calendar quarter (January -March, April —June, July —September,
October -December).
9. Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September & December (see
Condition A. (2.)).
10. 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.