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HomeMy WebLinkAboutNC0071463_Permit Modification_19961216State of North Carolina Department of Environment, Health and Natural Resources 0 Division of Water Quality James B. Hunt, Jr., Governor Jonathan B. Howes, Secretary p E H N F� A. Preston Howard, Jr., P.E., Director December 16, 1996 Mr. John L. Hank Apex Oil Company 6900 West Market Street Greensboro, North Carolina 27409 Subject: Permit Modification NPDES Permit NCO071463 Apex Oil Company Guilford County Dear Mr. Hank: As you may be aware, the public in the Paw Creek area near Charlotte is very concerned with any activities associated with the oil terminals (including renewal of NPDES permits). The Division held a public hearing on May 16, 1996, for the renewal of several oil terminal NPDES permits in the Paw Creek area. Many people attended the hearing and the Division received numerous comments at the hearing and during the public comment period. As a result of these comments, the Division re- examined and researched several issues, including chlorophenols. Chlorophenols required a more extensive research effort than other issues raised during the public comment period. This letter documents and summarizes changes to chlorophenols requirements in your permit, and also addresses some other changes to the permit which reflect concerns raised by the public. It should be noted that changes to permits pertain to facilities that discharge to water -supply classified waters only. Permits will not change for facilities discharging to non -water -supply waters. In response to comments pertaining to the chlorophenol monitoring requirements in the draft permits, the Division re -investigated the following two questions: (1) Why was there a requirement to monitor for eight individual chlorophenols in addition to those specified in EPA Method 625; and (2) What is the proper laboratory procedure to analyze for these eight chlorophenols? After some additional research and discussion, two determinations were made. First, although all chlorophenols have the potential to cause taste and odor problems in drinking water supplies and tainting of fish tissue, the eight chlorophenols n.4t covered by EPA Method 625 (and singled out for individual monitoring in the permit) are not considered to be carcinogens. Second, when phenol is exposed to chlorine, certain chlorophenols form before others. This is significant because a few key "early -forming" chlorophenols can be used to "screen" the stormwater discharge for the presence of chlorophenols. Specifically, the five chlorophenols included in EPA Method 625 can be used as indicators of all chlorophenols because these five compounds would be the first to form when chlorine reacts with phenol. Therefore, EPA Method 625 will be used as an initial screen. If no chlorophenols are detected, no additional monitoring will be required. However, if one or more chlorophenols are detected at concentrations greater than 50 µg/1, then the oil terminal would be required to monitor for the eight additional chlorophenols beginning with the next scheduled monitoring event and continue to monitor 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 110% post consumer paper semi-annually until the permit expired. The additional chlorophenol monitoring would include identifying and quantifying all chlorophenols present in the sample(s). Although the chlorophenol monitoring requirement change was the most significant, another concern raised by the public pertained to xylene monitoring. Several members of the public noticed that xylene monitoring was not required in the draft permits. Xylene is not included in EPA Methods 624/625 and therefore, the Division acknowledges that xylene monitoring should and will be included in the oil terminals' final NPDES permits. Please find enclosed the modified section of the permit referenced in the preceding paragraphs. Replace the original sections in your permit with the newer enclosed sections and discard the original sections. All other terms and conditions contained in the original permit remain unchanged and in full effect. These permit modifications are 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, an 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, please contact Charles Weaver at (919) 733-5083 extension 511. Sincerely, ��Ho C Presto , Jr , cc: Central Files Winston-Salem Regional Office, Water Quality Section Roosevelt Childress, EPA Permits and Engineering Unit Facility Assessment Unit Aquatic Survey and Toxicology Unit A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL Permit No. NCO071463 During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is authorized to discharge from outfall serial number 001. Such discharges shall be limited and monitored by the Permittee as specified below: EFFLUENT `, CHARACTERISTICS LIMITS ;. MONITORING > REQUIREMENTS Monthly Avers a Weekly Average Daily Maximum Measurement Frequency Sample Type Sample Location' Flowl Weekly 1 Effluent Total Suspended Solids 45.0 m I 2/Month Grab Effluent Oil and Grease2 45.0 mg/I 2/Month Grab Effluent Turbidity 50 NTU3 2/Month Grab Effluent Phenol 0.001lbs/da 2/Month Grab Effluent Toluene6 6 Grab Effluent Benzene6 6 Grab Effluent Eth Ibenzene6 6 Grab Effluent MTBE6 6 Grab Effluent Lead6 6 Grab Effluent X lene Semi-annually Grab Effluent EPA Methods 624/6254 Semi-annually Grab Effluent Acute Toxicit 5 5 Grab Effluent Footnotes: 1 All volumes of wastewater leaving the facility shall be monitored. If continuous flow monitoring is not feasible, record the approximate time that discharge began and ended, along with the instantaneous flow at the time of effluent sampling. 2 Where possible, the grab sample for oil and grease should be skimmed from the surface of a quiescent (calm water) zone. 3 If the turbidity exceeds 50 NTU due to natural background conditions, the discharge level cannot cause any increase in the turbidity of the receiving water. 4 EPA Method 625 includes five (5) chlorophenols. If one or more chlorophenol(s) is detected at concentrations greater than or equal to 50µg/l, the permitee will be required to analyze for the eight chlorophenols listed below in addition to EPA Method 625. This additional required monitoringwill begin with the permittee's next scheduled monitoring event, occur on a semi-annual basis and will last for the duration of the permit. Eight chlorophenols include the following: 3-chlorophenol; 4-chlorophenol; 2,3-dichlorophenol; 2,5-dichlorophenol; 2,6-dichlorophenol; 3,4- dichlorophenol; 2,3,4,6-tetrachlorophenol and 3-methyl-6-chlorophenol. 5 Acute Toxicity (Fathead Minnow 24 hour) Monitoring: see Part III, Condition E. 6 Monitoring shall be conducted during the first five discrete discharge events after resumption of operations, then on an annual basis thereafter. The annual period will begin in January of the next calendar year. There shall be no discharge of floating solids or visible foam in other than trace amounts. There shall be no direct discharge of tank solids, tank bottom water or the off -specification product. There shall be no direct discharge of tank contents following hydrostatic testing unless benzene concentration is less than 1.19 µg/I and toluene concentration is less than 11 µg/l.