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HomeMy WebLinkAboutNC0047384_Permit Modification_19980225State 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 Mr. Arthur White City of Greensboro 2350 Huffine Mill Road McLeansville, North Carolina 27301 Dear Mr. White: DEN R February 25, 1998 Subject: NPDES Permit Modification Permit No. NC0047384 T. Z. Osborne WWTP Guilford County A permit modification request was received by the Division on December 29, 1997. After review of the request, the modification to your NPDES permit has been approved. This letter replaces the correspondence sent to you February 11, 1998, after a typographical error was corrected and language in both the cover letter and effluent page specifying when new limits become effective was clarified. The following changes are incorporated upon operation of the aeration tanks and clarifiers specified in this modification: • Permitted flow is 22.0 MGD instead of 20.0 MGD. • BOD monthly average (summer) is 10.0 mg/1, weekly average is 15.0 mg/l. • BOD monthly average (winter) is 20.0 mg/1, weekly average is 30.0 mgfl. • Ammonia limits are 2.7 mg/1 (summer) and 5.4 mg/I (winter). In light of information available regarding cyanide measurement techniques, the Division feels it is reasonable to specify the total cyanide quantitation limit as 10 µg/l (10 ppb) as of March 1, 1998 in your NPDES permit. Levels reported as "<10 µg/1" will be considered zero for compliance purposes. Please find enclosed the amended Effluent Limitations page for outfall 001, which should be inserted into your permit after the Effluent Limitations pages permitting 20.0 MGD. Limits for flow at 22.0 MGD will be effective when aeration tanks 9 through 12 and final clarifiers 5 and 6 are placed into service. Effluent pages for flow at 30.0 MGD and 40.0 MGD specify the new cyanide quantitation limit, and the old effluent sheets for these flows should be discarded. All other terms and conditions contained in the original permit remain unchanged and in full effect. This permit modification is issued pursuant to 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 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, Post Office Drawer 27447, Raleigh, North Carolina 27611-7447. Unless such demand is made, this decision shall be final and binding. P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone (919) 733-5083 FAX (919) 733-0719 An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper If you have any questions regarding this modification to your permit, please contact Bethany Bolt at (919) 733-5083, Ext. 551. Sincerely, fj,\X. Preston Howard, Jr., P.E. cc: Central Files Winston-Salem Regional Office/Water Quality Section NPDES Unit Point Source Compliance Enforcement Unit Aquatic Toxicology Unit Technical Assistance and Certification Unit EPA/Roosevelt Childress A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS FINAL Permit No. NC0047384 During the period beginning March 1, 1998 and lasting until aeration tanks 9 through 12 and clarifiers 5 and 6 are placed into service, the Permittee is authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Weekly Average Daily Maximum Measurement Frequency Sample Type Sample Location' Flow 20.0 MGD Continuous Recording I or E BOD, 5 day, 20°C (April 1 - October 31)2 . 11.0 mg/I 16.5 mg/1 Daily Composite E, BOD, 5 day, 20°C (November 1 - March 31)2 22.0 mg/I 33.0 mg/I Daily Composite E, Total Suspended Solids2 30.0 mg/I 45.0 mg/I Daily Composite E, I NH3 as N (April 1 - October 31) 3.0 mg/1 Daily Composite E NH3 as N (November 1 - March 31) 6.0 mg/I Daily Composite E Dissolved Oxygen3 Daily' Grab E, U, D1, D2 pH4 Daily Grab E Fecal Coliform (geometric mean) 200 / 100 ml 400 / 100 ml Daily' Grab E, U, D1, D2 Temperature °C Daily' Grab E, U, D1, D2 Total Nitrogen (NO2 + NO3 + TKN) Monthly Composite E Total Phosphorus5 2.0 mg/I Weekly5 Composite E Total Residual Chlorine Daily Grab E Selenium 5.3 µg/I 20 µg/I Weekly Composite E Cadmium 2.1 µg/l 5.0 µg/l Weekly' Composite . E, U, D1 Copper 2/Month Composite E Zinc 2/Month Composite E Cyanides 5.3 µg/1 21..2 µg/1 Weekly Grab E Fluoride 1.9 mg/1 Weekly Composite E Conductivity Weekly' Grab U, D1, D2 Chronic Toxicity' Quarterly Composite E Notes: * Sample locations: E - Effluent, I - Influent, U - Upstream at Old US Highway 70, D1 - Downstream at SR 2821 (Harvest Road), D2 - Downstream at Huffine Farm Road. Upstream and Downstream monitoring shall be grab samples and shall be conducted three times per week during the months of June, July, August, and September, and once per week during the remaining months of the year, except for Cadmium, which shall be monitored monthly. 2 The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent value (85% removal). 3 The daily average dissolved oxygen, effluent concentration shall not be less than 5.0 mg/I. 4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 5 Total Phosphorous compliance shallbbe based upon a quarterly average of weekly samples. 6 The quantitation limit for cyanide shall be 10 µg/1 (10 ppb). Levels reported as "<10 µg/1" shall be considered zero for compliance purposes. 7 Chronic Toxicity (Ceriodaphnia) at 90%; January, April, July, and October; See Part III, Condition G. There shall be no discharge of floating solids or visible foam in other than trace amounts. A. (2). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS FINAL Permit No. NC0047384 During the period beginning upon placing aeration tanks 9 through -Wand clarifiers 5 and 6 into service, and lasting until construction to expand to 30.0 MGD is complete, the Permittee is authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Weekly Average Daily Maximum Measurement Frequency Sample Type Sample Location' Flow 22.0 MGD Continuous Recording I or E BOD, 5 day, 20°C (April 1 - October 31)2 10.0 mg/I 15.0 mg/I • Daily Composite E, I BOD, 5 day, 20°C (November 1 - March 31)2 20.0 mg/i 30.0 mg/I Daily Composite E, I Total Suspended Solids2 30.0 mg/I 45.0 mg/1 Daily Composite E, NH3 as N (April 1 - October 31) 2.7 mg/I Daily Composite E NH3 as N (November 1 - March 31) 5.4 mg/I Daily Composite E Dissolved Oxygen3 Daily' Grab E, U, D1, D2 pH4 Daily Grab E Fecal Coliform (geometric mean) 200 / 100 ml 400 / 100 ml Daily' Grab E, U, D1, D2 Temperature °C Daily' Grab E, U, D1, D2 Total Nitrogen (NO2+ NO3+TKN) Monthly Composite E Total Phosphorus5 2.0 mg/I Weekly5 Composite E Total Residual Chlorine • Daily Grab E Selenium 5.3 µg/I 20 µg/I Weekly Composite E Cadmium . 2.1 µg/I 5.0 µg/I Weekly' Composite E, U, D1 Copper 2/Month Composite E Zinc 2/Month Composite E Cyanides • 5.3 µg/I 21.2 µg/I Weekly Grab E Fluoride 1.9 mg/I Weekly Composite E Conductivity • Weekly' Grab U, D1, D2 Chronic Toxicity' Quarterly Composite E Notes: * Sample locations: E - Effluent, I - Influent, U - Upstream at Old US Highway 70, D1 - Downstream at SR 2821 (Harvest Road), D2 - Downstream at Huffine Farm Road. ' Upstream and Downstream monitoring shall be grab samples and shall be conducted three times per week during the months of June, July, August, and September, and once per week during the remaining months of the year, except for Cadmium, which shall be monitored monthly. 2 The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent value (85% removal). 3 The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/I. 4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 5 Total Phosphorous compliance shall be based upon a quarterly average of weekly samples. 6 The quantitation limit for cyanide shall be 101.41 (10 ppb). Levels reported as "<10 µg/1" shall be considered zero for compliance purposes. 7 Chronic Toxicity (Ceriodaphnia) at 90%; January, April, July, and October; See Part III, Condition G. There shall be no discharge of floating solids or visible foam in other than trace amounts. A. (3). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS FINAL Permit No. NC0047384 During the period beginning after expansion to 30.0 MGD and lasting until construction to expand to 40.0 MGD is complete, the Permittee is authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Weekly Average Daily Maximum Measurement Frequency Sample Type Sample Location' Flow 30.0 MGD Continuous Recording I or E CBOD, 5 day, 20°C (April 1 - October 31)2 4.0 mg/1 6.0 mg/I Daily Composite E, I CBOD, 5 day, 20°C (November 1 - March 31)2 8.0 mg/I 12.0 mg/I Daily Composite E, I Total Suspended Solids2 3 m /I 45.0 mg/1 Daily Composite E, I NH3 as N (April 1 - October 31) 2.0 m Daily Composite E NH3 as N (November 1 - March 31) \4.0 mg/I Daily Composite E Dissolved Oxygen3 Daily1 Grab E, U, D1, D2 pH4 Daily Grab E Fecal Coliform (geometric mean) 200 / 100 ml 400 / 100 ml Daily1 Grab E, U, D1, D2 Temperature °C Daily' Grab E, U, D1, D2 Total Nitrogen (NO2 + NO3 + TKN) Monthly Composite E Total Phosphorus5 2.0 mg/I Weekly5 Composite E Total Residual Chlorine 18 µg/I . Daily Grab E Selenium 5.2 µg/I 20 µg/I Weekly Composite E Cadmium 2.1 µg/I 5.0 µg/I Weekly1 Composite E, U, D1 Copper 2/Month Composite E Zinc 2/Month Composite E Cyanides 5.2 µg/l 20.8 µg/I Weekly Grab E Fluoride 1.9 mg/I Weekly Composite E Conductivity Weekly1 Grab U, D1, D2 Chronic Toxicity' _ Quarterly Composite E Notes: * Sample locations: E - Effluent, I - Influent, U - Upstream at Old US Highway 70, D1 - Downstream at SR 2821 (Harvest Road), D2 - Downstream at Huffine Farm Road. I Upstream and Downstream monitoring shall be grab samples and shall be conducted three times per week during the months of June, July, August, and September, and once per week during the remaining months of the year, except for Cadmium, which shall be monitored monthly. 2 The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent value (85% removal). 3 The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/I. 4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. s Total Phosphorous compliance shall be based upon a quarterly average of weekly samples. 6 The quantitation limit for cyanide shall be 10 µg/l (10 ppb). Levels reported as "<10 µg/1" shall be considered zero for compliance purposes. 7 Chronic Toxicity (Ceriodaphnia) at 90%; January, April, July, and October; See Part III, Condition G. There shall be no discharge of floating solids or visible foam in other than trace amounts. A. (4). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS FINAL Permit No. NC0047384 During the period beginning after expansion to 40.0 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Weekly Average Daily Maximum Measurement Frequency Sample Type Sample Location' Flow 40.0 MGD Continuous Recording I or E CBOD, 5 day, 20°C (April 1 - October 31)2 4.0 mg/I 6.0 mg/I Daily Composite E, I CBOD, 5 day, 20°C (November 1 - March 31)2 8.0 mg/I 12.0 mg/I Daily Composite E, I Total Suspended Solids2 30 m /i 45.0 mg/I Daily Composite E, I NH3 as N (April 1 - October 31) 2.0 mg Daily Composite E NH3 as N (November 1 - March 31) 4.0 mg/I Daily Composite E Dissolved Oxygen3 - Daily' Grab E, U, D1, D2 pH4 Daily Grab E Fecal Coliform (geometric mean) 200 / 100 ml 400 / 100 ml Daily' Grab E, U, D1, D2 Temperature °C Daily' Grab E, U, D1, D2 Total Nitrogen (NO2 + NO3 + TKN) Monthly Composite E Total Phosphorus5 2.0 mg/I Weekly5 Composite E Total Residual Chlorine 18 µg/l Daily Grab E Selenium 5.2 µg/I 20 µg/I Weekly Composite E Cadmium 2.1 µg/I 5.0 µg/l Weekly' Composite E, U, D1 Copper • 2/Month Composite E Zinc 2/Month Composite E Cyanides • 5.2 µg/l 20.8 µg/I Weekly Grab E Fluoride 1.9 mg/I Weekly Composite E Conductivity Weekly' Grab U, D1, D2 Chronic Toxicity' . Quarterly Composite E Notes: . * Sample locations: E - Effluent, I - Influent, U - Upstream at Old US Highway 70, D1 - Downstream at SR 2821 (Harvest Road), D2 - Downstream at Huffine Farm Road. ' Upstream and Downstream monitoring shall be grab samples and shall be conducted three times per week during the months of June, July, August, and September, and once per week during the remaining months of the year, except for Cadmium, which shall be monitored monthly. 2 The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective influent value (85% removal). 3 The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/I. 4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 5 Total Phosphorous compliance shall be based upon a quarterly average of weekly samples. 6 The quantitation limit for cyanide shall be 10 µg/i (10 ppb). Levels reported as "<10 µg/I" shall be considered zero for compliance purposes. 7 Chronic Toxicity (Ceriodaphnia) at 90%; January, April, July, and October; See Part III, Condition G. There shall be no discharge of floating.solids or visible foam in other than trace amounts.