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Home My WebLink AboutDEQp00021449�C W a rF9Q Michael F. Easley �O G Governor : r William G. Ross, Jr., Secretary -i North Carolina Department of Environment and Natural Resources O `C Alan W. Klimek, P.E., Director Division of Water Quality May 25, 2007 Clean Water for North Carolina Ms. Jill Logeman and Ms. Hope Taylor-Guevarra 2009 Chapell Hill Rd. Durham, NC 27707 Subject: NPDES Permit NC0003573 DuPont Fayetteville Works Dear Ms. Logeman and Ms. Taylor-Guevatra: The Division received your letter offering comments on the draft NPDES permit for DuPont Fayetteville Works. All the letters received during the permit comment period presented many common concerns with the draft permit. With this response the Division would like to address the major issues raised and explain the basis for the permit conditions that were subject to comments. We have considered all comments offered by individuals in developing the final permit and modified the permit accordingly. The Division offers the following responses (public comments are highlighted in bold): Parameters with daily limits should be sampled daily (BOD and COD at outfall 001) - Measurement frequencies for industrial NPDES permits are defined in 15A NCAC 2B .0508 according to industrial SIC codes and facility classification. The draft permit for DuPont is consistent with this regulation. The wastewater treatment plant is classified as a Grade III facility, and as such, sampling frequencies for BOD and COD are established as three times per week. For toxicants that present reasonable potential to exceed water quality standards, Division guidelines establish weekly monitoring. In the case of parameters not listed in the regulation, specific monitoring frequencies will be defined by individual permit conditions. Hexachlorobenzene should be tested daily, the permit language should be more specific regarding testing - The testing frequency for this parameter was determined based on an evaluation of reasonable potential. Reported data shows no detections of hexachlorobenzene. The requirement to use a sufficiently sensitive test is intended to require the facility to use the more sensitive method that is available that can detect to levels below the permit limit. Sometimes approved methods do not detect at levels below the permit limit. In those cases the most sensitive method must be used until a new method is approved that can detect lower levels, which then becomes the most sensitive analytical method. 3. All parameters should have monthly average as well as daily maximum limits, BOD, COD, DO, total phosphorus and total nitrogen for outfall 002 - Outfall 002 is the combined outfall from the process and non -process wastewaters, which include stormwater and cooling waters. This outfall is not subject to effluent guidelines. Any limit developed for this outfall would be based on best professional judgement. The Division does not impose limits on all monitored parameters unless there is reason to believe the discharge would cause instream standards or criteria to be exceeded. 4. The permit carries over a waiver regarding testing requirements - The waiver was not carried forward from the previous permit. The permittee requested the waiver at permit renewal time. Data was submitted with the permit application to support the request for a waiver. After data review, the testing requirements for parameters listed in 40 CFR 414 Subpart I were waived in accordance to 40 CFR 122.44 for the period the permit is effective. 5. Lower the fluoride limit in Outfall 002 - The fluoride limit for outfall 002 is based on the fluoride water quality standard for freshwater of 1.8 mg/1 and the instream waste concentration for the discharge. In this case the discharge flow of 20.6 MGD gives an instream waste concentration is 3.7 %, resulting in an allowable concentration of 47 mg/l or 8,195 lb/day. The limit of 7,917 lbs/day is more stringent as it was North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone (919) 733-5083 Internet: h2o.enr.state.nc.us 512 N. Salisbury St. Raleigh, NC 27604 FAX (919) 733-0719 An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper NoCarolina oNaturally Customer Service 1-877-623-6748 Page 2 established from a previous waste load allocation under slightly different flow conditions. The more stringent limit always prevails in the permit. The Division considers this limit protective of water quality. 6. Remove the mixing zone of 4500 feet — The permit does not authorize a mixing zone. Compliance for all limited parameters is determined at the end of pipe. The location of the downstream sampling station is 4500 feet downstream from the discharge location, but this does not constitute a mixing zone. The instream monitoring locations are established by the Cape Fear River Monitoring Coalition and the Division to obtain representative data of the conditions of the river. 7. Add testing for vinyl chloride at outfall 001 — Vinyl chloride has not been identified as a pollutant of concern. This parameter was not detected in outfalls 001 or 002 in testing required for the permit renewal application. 8. Add a limit for PFOA, include in the permit the outside disposal of PFOA, and require proof that all waste has been taken off-site. The interim groundwater standard for PFOA is not protective of human health — The Division will include monthly monitoring of PFOA at outfall 002 in the final permit. A limit can not be established at this time because there is no approved criteria or standard to develop a limit. When such criteria is developed the Division can then calculate an applicable limit. The Division and the Environmental Protection Agency are actively researching the effects of PFOA to determine safe levels. The NPDES program does not have authority to establish or modify a groundwater standard or to regulate the disposal of waste off-site. 9. DuPont has ongoing violations of the instream turbidity standard and sediments are accumulating on the river carried by the wastewater and stormwater that erodes the channel. Include daily monitoring for turbidity immediately downstream of the discharge point — DuPont is addressing the issue of erosion of the effluent channel. The Division is currently evaluating a proposal from DuPont to relocate the discharge and install an effluent diffuser. 10. The facility should retain an aliquot of all samples to re -test if the results are not normal. The Division should do at least one annual split sample analysis — It is up to the permittee to establish procedures such as obtaining additional aliquots when they sample the effluent. The Division does not routinely perform split *samples. But the Division performs a separate sampling of the effluent at least once, often more, per permit cycle. 11. Request for a public hearing — In light of the above responses the Director of the Division has determined not to hold a public hearing on the subject permit. Thank you for your comments. If you have question, please contact Teresa Rodriguez at telephone number (919) 733-5083, extension 553. Sincerely, ,ly, Gil Vinzani NPDES East Supervisor Cc: NPDES Files Company Clean Water for North Carolina Cape Fear River Watch Willis Creek A.M.E. Zion Church email addresses D. Hanning JoAnne M. Likens No address William L. Murray Jr. Title First Last Street City ST Zip Ms. Jill Logeman and Ms. Hope Taylor-Guevarra 2009 Chapell Hill Rd. Durham NC 27707 Mr. Paul Nelson 617 Surry Street Wilmington NC 28401 Ms. Pamela Carter 3690 Turner Rd Fayetteville NC 28306 Ms. Mable Council 3641 County Line Rd. Fayetteville NC 28306 Revere Selvyn Lyndo 3614 Turner Rd. Fayetteville NC 28306 Mr. Jacob Evans 608 Cobblestone Dr. Wilmington NC 28405 Ms. Beth Hansen 1116 Shelby Court Wilmington NC 28409 Mr. & N Roy Patterson 263 Windchime Way Lelans NC 28451 Ms. Linda Sealen 449 W. Parkton-Tobermory Parkton NC 28371 Ms. Nancy Edge 3282 County Line Rd. Fayetteville NC 28306 Ms. Laura Bath 996 Point Hill Dr. Fayetteville NC 28306 Ms. Tracy Eaton 4171 Marshwood Lake Road Fayetteville NC 28306 diandon@webtv.net 4oannavla@aol.com ptt Yq4 Lj u w JUN -' 07