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HomeMy WebLinkAboutNC0050342_Wasteload Allocation_19900302NPDES DOCIMENT SCANNING COVER SHEET NC0050342 Muddy Creek WWTP NPDES Permit: Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Engineering Alternatives (EAA) Correspondence Owner Name Change Instream Assessment (67b) Speculative Limits Environmental Assessment (EA) Document Date: March 2, 1990 'r hba document is printed on realise paper - iartore any content oa the reYeree e�ide NPDES WASTE LOAD ALLOCATION PERMIT NO.: NC0050.314 2- FACILITY NAME: C./ IL) Lanth)r) - .S0 len? ,-)h►1t Facility Status: Permit Status: Major ✓ Pipe No.: dp 2 Minor Design Capacity: NA Domestic (% of Flow): Industrial (% of Flow): .2,(,e Comments: 002- 0 (Arc( ont y cturirt Flood cond. hon5_ ORG Oct/loot- C hoox Itt) C1i5c hct 5e mug / 002 [§ nc� dez,r311 °nit) G.11ow3 dixhak3c. e, o ku'i cIvocc. RECEIVING STREAM: ((k ddk( Creek, Class: C_, Sub -Basin: - Q3c70 Reference USGS Quad: Di 7 N C- (please attach) County: Fot: i`Ho Regional Office: to.5 rap Requested by: Prepared by: Reviewed by: 9° Date: Date: 3J j 190 Date: 3 7_ ' 0 Modeler Date Rec. # C.L 17-As\se .(19 76-L1 Drainage Area (mil ) /a(,¢ , 5- dale Avg. Streamflow (cfs): 7Q10 (cfs) 5 7 Winter 7Q10 (cfs) 30Q2 (cfs) Toxicity Limits: IWC % Acute/Chronic Instream Monitoring: Parameters Upstream Location Downstream Location 9 Effluent Characteristics y r,.'Nound ,BOD:5- (m I .Q) 3O 1\1H3 (m31 !) N!_ <D (1- i ) NL EE Col, roam (AtGaomt) ?OU , 9' Comments: ,q awn! FDrm ruler ks chan863 chhich rhrxjicl he morfe; p.ri char e rra '. ci onki ocoAr Loren Iou. af- (,,fix,S ckas e, oz7(C5oo lc&zl ect af- Hco (0`1/4( on yad iG n ?, v e i' OetA `ad k1 n Coll e.. eixceecto 500U t F3 . cCcommend eFaent mOn'f',mJ fb Cd,Cu, , Pb, zv), Cr. Request No.:4997B Update WASTELOAD ALLOCATION APPROVAL Facility Name: City of Winston NPDES No.: NC0050342 Type of Waste: 74% Domestic Status: Existing Receiving Stream: Muddy Creek Classification: C Subbasin: 030704 County: Forsyth Regional Office: WSRO Requestor: Harris - orig. Date of Request: Quad: RECOMMENDED EFFLUENT Wasteflow (mgd) : BOD5 (mg/1) : NH3N (mg/1) : DO (mg/1) : TSS (mg/1) : Fecal Coliform (/100m1) : pH (su) : Toxicity Testing Req.: Upstream (Y/N) : Y Downstream (Y/N) : Y NL 30 NL NL 30 200 6-9 MONITORING Location: Location: COMMENTS FORM Salem - Outfall 002 Drainage area: Summer 7Q10: Winter 7Q10: Average flow: 30Q2: LIMITS 186.5 55 74 177 95 NtLEIVLO FEB 28 1990 PERMITS & FNGINEFRIIC Approval form reflects changes which should be made to permit. Recommend effluent monitoring for cadmium, chromium, copper, nickel, lead, and zinc. Discharge may only occur when flow at USGS gage 02116500 located at HWY 64 on the Yadkin River near Yadkin College exceeds 5000 cfs. Recommended by: 2UU. (:. S,)(,` 4C. Date: Reviewed by Tech Support Supervisor: - Date: Regional Supervisor: Permits & Engineering: RETURN TO TECHNICAL SERVICES BY: ah /90 2449,6 Date: 2-2G-ic Date: 36(co MAR 15 1990 DIVISION OF ENVIRONMENTAL MANAGEMENT February 12, 1990 MEMORANDUM TO: Winston-Salem WLA File FROM: Ruth Swanek SUBJECT: Modifications to NPDES permit for outfall 002 Lower Muddy Creek WWTP NPDES No. NC0050342 Representatives of the City of Winston-Salem met with DEM on January 10, 1990 to discuss their permit. They brought plans of outfall 002 which indicated that the City cannot choose to dis- charge through outfall 002. When the stream flows reach flood conditions, the discharge automatically occurs through pipe 002. At all other times, the discharge must occur through 001. The City is not able to treat the waste to the levels given for the original permit for pipe 002 (16 mg/1 BOD5, 4 mg/1 NH3-N in summer, and 24 mg/1 BOD5, 10 mg/1 NH3-N in winter). The City contended that it could only treat the waste to secondary levels which are the limits given to outfall 001, and it could not meet a wasteflow limit of 15 mgd during flood conditions. Therefore, the QUAL2E model developed for the Archie Elledge WWTP was run to determine what stream flow is needed to maintain instream dissolved oxygen concentrations at high effluent flows. The Archie Elledge WWTP was input at its existing limits, and an effluent flow of 44 mgd was assumed through outfall 002 since this discharge occurred during Hurricane Hugo. It was determined that a stream flow of approximately 300 cfs was needed at the discharge point to maintain water quality. (Note: the dissolved oxygen concentration was not allowed to fall below 5.5 mg/1 per 15 NCAC 2B.0206 which calls for more stringent limits when a flow other than the 7Q10 is applied). The nearest gage to the outfall is located on the Yadkin River downstream of its confluence with Muddy Creek at Highway 64. The flow at this point is regulated by a dam upstream, and the yields are different from those on Muddy Creek. It was determined that a flow slightly more than twice the drainage area at the gage should correspond to a flow which should protect water quality in Muddy Creek. Therefore, no discharge will be allowed through outfall 002 if the flow at USGS gage 02116500 is less than 5000 cfs. Since metals loading could be high during flood conditions, effluent monitoring for cadmium, chromium, copper, nickel, lead, and zinc were included. The pretreatment headworks analysis did not show sources of any other metals.