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Home My WebLink AboutNC0025453_speculative limits_19901103 �Yd A State of North Carolina Department of Environment, Health and Natural Resources Division of Environmental Management 512 North Salisbury Street • Raleigh,North Carolina 27604 James G.Martin,Governor A. Preston Howard,Jr.,P.E. William W. Cobey,Jr., Secretary Acting Director Regimal Offices November 3, 1990 Asheville 704/251-6208 Mr,Robert Hyatt Fayetteville Town Manager 919/486-1541 Town of Clayton P.O. Box 879 Mooresville Clayton,North Carolina 27520 704/663-1699 Subject: Speculative NPDES Permit Limitations Raleigh Town of Clayton WWTP 919/571-4700 NPDES Permit No.N00025453 Johnston County Washington 919/946-6481 Dear Mr. Hyatt: Wilmington The North Carolina Division of Environmental Management(NCDEM)is in receipt of 919/395-3900 your letter dated October 16, 1992,requesting speculative NPDES permit limitations for a proposed expansion of the subject facility to 2.5 MGD. In your letter you request speculative Winston-Salem limits at five different locations. NCDEM Technical Support Branch has completed the review 919/896-7007 of your request and provides the following recommendations: Nose River at NC 42 and NCSR 2509 The NeUSP Rivf,-r:s regulated by Falls Dam. The DrCp 3cd "sdliar e site st"C „ In^Ain't'1P r0-.i'pi3.trly 10 rnles downs�eam r'o ''.'.R2-eigh L _ V'T >'i"Jvis ,.: -� °..~7 '1. e ••• •• •. �ti:..16. �VUvv i'i YN� 11aJ..aiitr��.u�a4 aY..J miles upstream from the T�}wn of Smithfield water intake. This river segment is classified a:, WS-IV waters. At this point, the river has a drainage area of 1,150 sq.miles and an estimated minimum now of 189 cfs. It is recommended that the discharge be located at least 1,000 ft downstream from the NC 42 bridge to avoid interference with both the NCDEM ambient station and.the USGS gaging station located at this site. 'I'he proposed discharge point at NCSR 2509 is located approximately 2.0 miles downstream from the Raleigh Neuse WWTP discharge,7.3 miles upstream from NC 42 and 22.0 miles upstream from the Town of Smithfield water intake. This river segment is classified as C- NSW waters. However,the stream is classified WS-V NSW less than 0.1 miles downstream from this proposed discharge site. It is estimated that at NCSR 2509 the Neuse River is characterized by a minimum flow of 187 cfs. Pollution Prevention Pays P.O.Box 29535,Raleigh,North Carolina 2762E-0535 Telephone 919-733-7015 An Equal Opportunity Affirrnative Action Employer Mr.Robert Hyatt Page 2 For both the NC 42 and NCSR 2509 sites,the following permit limitations are recommended based on a field calibrated water quality model for the Neuse River mainstem,and NCDEM's current procedures for wasteload allocations. Also,these limitations reflect current industrial waste contributions to the WWTP: Parameter Summer Winter BOD5(mg/l) 5 10 NH3-N(mg/l) 2 4 DO(mg/1) 6 6 Fecal Coliform(mg/1) 200 200 TSS(mg/1) 30 30 Total Residual Chlorine(ug/l) 28 28 Cadmium(ug/1) Monitor Monitor Copper(ug/1) Monitor Monitor Nickel(ug/l) Monitor Monitor Lead(ug/1) Monitor Monitor Silver(ug/1) Monitor Monitor Total Phosphorus(mg/l) 2 2 PH(SU) 6-9 6-9 Little Creek at Current Discharge Point According to USGS flow statistics provided to NCDEM in June 1992,Little Creek at the current discharge site is characterized by a drainage area=6.01 sq. miles,S7Q10= 0.1 cfs,30Q2=0.79 cfs and QAVG= 6.9 cfs. As indicated in previous correspondence to the Town dated February 20, 1990, September 27, 1991 and May 8, 1992,this facility discharges into the headwaters of a pond located approximately 2.5 miles downstream from the discharge site. Information collected in the pond during the summer 1990 indicated a high probability of algal blooms to occur under appropriate conditions. Although the 1990 study indicated nutrient enrichment,the actual eutrophic response indicators (i.e. chlorophyll-a,pH and dissolved oxygen)were not far from meeting State standards in the pond. In order to address some of the uncertainty regarding water quality conditions,eutrophication potential and hydraulic characteristics of the receiving stream,a field visit was conducted by NCDEM on August 26, i992. A heaver dam was discovered upstream from the discharge which resulted in very low flow at the discharge point. Near NCSR 1560,approximately 2.0 miles downstream from the discharge, the stream did not have significant advective transport as far upstream as the field crew could observe from the bridge. Sediments have accumulated in the headwaters of the pond resulting in a dam like situation at the headwaters of the pond. This condition creates a second impoundment of the creek upstream of the pond during low flow periods. Although a substantial rainstorm event had occurred the week prior to NCDEM's field visit that should have flushed the pond,eutrophication of the pond was apparent as evidenced by supersaturation of dissolved oxygen (DO). The information and data collected during the August 26, 1992 survey were used to develop a Level B model to simulate DO concentrations in the receiving waters from the discharge site to the headwaters of the pond. The model predicts that substandard DO concentrations are likely to occur at existing discharge limitations. Therefore,advanced tertiary treatment will be required at this location upon expansion from 1.5 MGD. i i i I Mr.Robert Hyatt Page 3 However,since 1)NCDEM has placed the receiving stream in North Carolina's 303 (d)list which contains impaired streams in the State(i.e.Little Creek is only partially supporting its intended uses),and 2)future expansions above 1.5 MGD will result in an instream waste concentration(IWC) greater than 33%,an Environmental Analysis(EA)will be required as part of the NPDES permit application process for this discharge site. The EA should include an economic analysis of all other waste disposal alternatives and include potential waste disposal requirements for the next 30 years. Should a discharge alternative at this location be the most economically and environmentally feasible alternative,the following NPDES permit limitations are being recommended: Parameter Summer Winter BOD5(mg/1) 5 10 NH3-N(mg/l) 1 1.8 DO(mg/1) 6 6 Fecal Coliform(mg/l) 200 200 TSS(mg/1) 30 30 Total Residual Chlorine(ug/1) 17 17 Cadmium(ug/1) 2.1 2.1 Chromium(ug/1) 51 51 Copper(ug/1) Monitor Monitor Nicke(ug/1)I 90 90 Lead(ug/1) 26 26 Zinc(ug/1) Monitor Monitor Cyanide(ug/1) Monitor Monitor Silver(ug/1) Monitor Monitor Total Phosphorus(mg/l) 0.05 0.05 pH(SU) 6-9 6-9 Little Creek below Barnes Pond The N.C.Division of Land Resources has informed NCDEM that Barnes Pond is not subject to minimum release regulations. Therefore,in the absence of a minimum release flow this location is not feasible for relocation of the subject discharge. Due to the existent conditions in the headwaters of the pond.this office estimates that the flow from the Pond during 7010 floe,Conditions-W] be,neorligible.if any. Therefore,discharge at this site will not LW allowed unless a minimum release Flow is Y air.��inecl ar. thedam.. Howe a`^• Towe ver+as previously discussed in our May R, 1992 letter,V1rYVnr1 iIfVliati Qi1 11di V arV,'s r,4. presence of a second pond approximately 2.0 miles downstream from Barnes Pond. Therefore,even if a minimum release from Barnes Pond is achieved,the issues of eutrophication in this second pond and low flow conditions in the receiving stream will require wastewater treatment using state-of-the art technologies to mitigate downstream impacts. Swift reek below Little Creek According to the Neuse River Basinwide,Managemcni Pl n prepared by NCDEM and scheduled for approval by the Environmental Management Commission prior to April, 1993, the lower portion of Swift Creek has no additional assimilative capacity for oxygen-consuming wastes as evidenced by a field calibrated water quality model. Therefore,the plan recommends that no new discharges be allowed unless it can be shown that no more environmentally sound alternatives are available. The long range strategy for the creek includes eventual removal of the existing discharges as alternatives become available. Mr.Robert Hyatt Page 4 Existing discharges are being required to meet advanced tertiary treatment limits in order to protect water quality standards. Also,the presence of an endangered species in lower Swift Creek makes this stream a poor long range choice for wastewater assimilation. Please note that the above set of permit limitations are only preliminary and to be used only for planning purposes. Final NPDES permit limitations can only be provided upon approval of an NPDES permit application. If you have any questions concerning this matter,please contact Mr.Juan C.Mangles of my staff at(919)733-5083,ext.515. Since ell ' revor Clements,ASSL Chief —�V ter Quality Section JCM/JTC cc: Tim Donnelly Bobby Blowe Central Files 10/29/92 ver 3.1 T O X I C S R E V I E W Facility: Clayton WWTP y NPDES Permit No.: NCO025453 Status (E, P, or M): M Permitted Flow: 2.5 mgd Actual Average Flow: 0.8 mgd Subbasin: 030402 Receiving Stream: Little Creek 1---------PRETREATMENT DATA--------------I----EFLLUENT DATA---- i Stream Classification: C I ACTUAL PERMITTEDI I 7Q10: 0.1 cfs I Ind. + Ind. + I FREQUENCY I IWC: 97.48 $ I Domestic PERMITTED Domestic I OBSERVED of Chronicl Stn'd / Bkg I Removal Domestic Act.Ind. Total Industrial Total I Eflluent Criteria I Pollutant AL Conc. I Eff. Load Load Load Load Load I Conc. Violationsl (ug/1) (ug/1) I % (#/d) (#/d) (#/d) (#/d) (#/d) I (ug/1) (#vio/#sam) l --------- -- -------- -------- I -------- -------- -------- -------- --------- -------- I -------- --------- I Cadmium S 2.0 I 92% 0.0000 0.0044 0.00 0.0834 0.083 I I Chromium S 50.0 I 76% 0.0000 0.0089 0.01 0.6255 0.626 I l I Copper AL 7.0 I 82% 0.1100 0.0249 0.13 0.1043 0.214 I I N Nickel S 88.0 I 32% 0.0000 0.0107 0.01 0.4170 0.417 I I P Lead S 25.0 l 81% 0.0000 0.0044 0.00 0.6260 0.626 I I U Zinc AL 50.0 I 77% 0.2000 0.1115 0.31 0.2090 0.409 I I T Cyanide S 5.0 I 59% 0.0000 0.0044 0.00 I I Mercury S 0.012 I 0% I I S Silver AL 0.06 I 94% 0.0200 0.2085 0.229 I I E Selenium S 5.00 1 0% I I C Arsenic S 50.00 I 0% I I T Phenols S NA l 08 I I I NH3-N C I 08 I 1 0 T.R.Chlor.AL 17.0 I 08 I I N I I I I I I I I I 1--------------- ALLOWABLE PRDCT'D PRDCT'D PRDCT'D ---------MONITOR/LIMIT--------- 1--ADTN'L RECMMDTN'S-- 1 1 Effluent Effluent Effluent Instream I Recomm'd l l Conc. using using Conc. Based on Based on Based on I FREQUENCY INSTREAM I 1 Allowable CHRONIC ACTUAL PERMIT using ACTUAL PERMITTED OBSERVED I Eff. Mon. Monitor. I Pollutant I Load Criteria Influent Influent OBSERVED Influent Influent Effluent l based on Recomm'd ? 1 I (#/d) (ug/1) (ug/1) (ug/1) (ug/1) Loading Loading Data 1 OBSERVED (YES/NO) 1 --------- -- I --------- -------- --------- -------- -------- -------- -------- ---------I --------- -------- I Cadmium S I 0.18 2.052 0.053 1.000 0.00 Monitor Limit I ( A Chromium S I 1.50 51.290 0.320 22.503 0.00 Limit I i N Copper AL I 0.28 7.181 3.640 5.782 0.00 Monitor Monitor I I A Nickel S I 0.93 90.271 1.091 42.506 0.00 Monitor Limit I I L Lead S I 0.95 25.645 0.125 17.829 0.00 Limit I I Y Zinc AL I 1.57 51.290 10.740 14.101 0.00 Monitor Monitor I I S Cyanide S I 0.09 5.129 0.270 0.000 0.00 Monitor I I I Mercury S I 0.00 0.012 0.000 0.000 0.00 I I S Silver AL I 0.01 0.062 0.000 2.055 0.00 Monitor I I Selenium S I 0.04 5.129 0.000 0.000 0.00 I I R Arsenic S I 0.36 51.290 0.000 0.000 0.00 I I E Phenols S I 0.000 0.000 0.000 0.00 I I S NH3-N C I 0.000 0.00 I I U T.R.Chlor.AL I 17.439 0.00 Limit 1 1 L I I I T I I I S I I I L� dellwood apts. AMMONIA ANALYSIS 7Q10: 0 .1000 cfs NH3 Effl. Conc: 0.0000 mg/l AL (1/1 . 8 mg/1) : 1000 . 00 ug/l Upstream NH3 Conc. : 220 .0000 ug/l Design Flow: 2.5000 MGD Predicted NH3 Downstream: 5.53 ug/l 0. 005534 mg/l NH3 Limit: 1020. 129 ug/l 1. 020129 mg/l AMMONIA ANALYSIS (WINTER) 7Q10 : 0.5400 cfs NH3 Effl. Conc: 0.0000 mg/l AL (1/1. 8 mg/1) : 1800. 00 ug/l Upstream NH3 Conc. : 220.0000 ug/l Design Flow: 2 .5000 MGD Predicted NH3 Downstream: 26. 91 ug/l 0 . 026908 mg/l NH3 Limit: 2020. 180 ug/l 2 .020180 mg/l dellwood apts . AMMONIA ANALYSIS 7Q10 : 0 .1000 cfs NH3 Effl. Conc: 0. 0000 mg/l AL (1/1 . 8 mg/1) : 1000 . 00 ug/l Upstream NH3 Conc. : 220 .0000 ug/l Design Flow: 2.5000 MGD Predicted NH3 Downstream: 5.53 ug/l 0.005534 mg/l NH3 Limit: 1020.129 ug/l 1 .020129 mg/l AMMONIA ANALYSIS (WINTER) 7Q10: 0 .5400 cfs NH3 Effl. Conc: 0. 0000 mg/l AL (1/1 . 8 mg/1) : 1800 . 00 ug/l Upstream NH3 Conc. : 220.0000 ug/l Design Flow: 2.5000 MGD Predicted NH3 Downstream: 26. 91 ug/l 0.026908 mg/l NH3 Limit: 2020. 180 ug/l 2.020180 mg/l