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Home My WebLink AboutNC0069841_Long Term Monitoring Plan_20191218 Public Works 4600 Goldmine Rd Monroe NC 28110 Union County —�_— _ . _.. T. 704-289-1434 Government www.unioncountync.gov LS'1. 184.2 December 18, 2019 PECE VED Monti Hassan JAN 0 3 2020 PERCS Unit Pretreatment Coordinator NCDEQ/DWRINPDES 1617 Mail Service Center Raleigh, NC 27699-1617 Subject: Approval of LTMP's & STMP; Union County Dear Mr. Hassan, In the interest in obtaining necessary data prior to requesting the full approval of Union County's Pretreatment Program; Union County would like to request approval of the attached LTMP's for Twelve Mile WRF & Crooked Creek LTMP along with the STMP for Grassy Branch WRF. The additional data required within these plans will allow for a clearer evaluation of our uncontrollable pollutant levels throughout our Collection System & Industrial baselines/contributions. The data collected will allow for more accurate calculations of our Headworks Analysis, and allocation tables. Please contact Katie Fleming 980-425-0735; kate.fleminq a,unioncountvnc.gov , Union County Industrial Pretreatment Program Manager with any questions, concerns, or corrections. Thank you. Sincerely, aUeeA- Andrew Neff, PE Union County Public Works Water/Wastewater Division Director, Union County Public Works CC: Hyong Yi, UCPW Administrator Bart Farmer, WRF Superintendent Kate Fleming, Industrial Pretreatment Program Manager - y N co" AfJ��O 1842 Stijl ( 1 Zoe frr a9TH C pAo`� Long Term Monitoring Plan Union County Public Works Crooked Creek Wastewater Treatment Plant NC0069841 December 2019 Revision 1 : Revision 2: Revision 3: Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP A. Sampling Points(See Figure 1) 1. Influent(sample point 1): prior to mixing with recycle streams a. Regular composite sample collected for NPDES monitoring. 2. Effluent(sample point 2): after all treatment including disinfection a. Regular composite sample collected for NPDES monitoring 3. Activated Sludge Basin(sample point 3): a. Collect grab samples from mixed liquor influent distribution box 4. Sludge to Disposal (sample point 4): sample sludge going to final disposal a. Collect grab sample 5. Significant Industrial Users(SIUs)per locations described in IUPs a. Collect grab samples at each industry 6. Uncontrollable: locations in collection system that serve residential and commercial development a. Collect grab samples at Helmsville Pump Station(MH-5656) b. Collect grab samples at Green Meadows Pump Station(MH-5799) c. Collect grab samples at Suburban Estates 1 (MH-5585) B. Pollutants of Concern (POCs) 1. NPDES permit requirements—biochemical oxygen demand(BOD),total suspended solids(TSS), ammonia(NH3-N),total Kjeldahl nitrogen(TKN),nitrite(NO2),nitrate(NO3),total phosphorus (TP). 2. Headworks analysis required—BOD,TSS,NH3-N,TKN,NO2,NO3,TP,nickel(Ni),copper(Cu), zinc(Zn),cadmium(Cd), chromium(Cr), cyanide(CN), lead(Pb),mercury(Hg), silver(Ag),and arsenic(As). 3. For land application 40 CFR 503 pollutants—As, Cd,Cr,Cu,Pb,Hg,molybdenum(Mo),Ni, Se,Zn, % solids, and sludge to disposal flow. 4. SIU permitted pollutants required with the exception of the organics. 5. EPA required—Cd,Cr, Cu,Ni, Pb and Zn. 6. Additional SIU limited and/or monitored pollutants of concern—chloride,organics(EPA 624/625), pesticides(EPA 608),total oil and grease(HEM),total petroleum hydrocarbon(SGT-HEM),and chemical oxygen demand(COD). C. Detention Times Detention time is not taken into account in this program. The influent and effluent samples are taken on the same day and time for unpaired data for use in the headworks analysis. D. Flow Flow monitoring points are indicated on the attached map. Flow will be monitored during sampling events or calculated. Crooked Creek LTMP Page 2 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP E. SIU Monitoring Significant industrial user monitoring will be conducted per industrial use permits(IUP). The County will conduct once per year SIU sampling will be performed such that all SIUs are sampled for all LTMP POCs at least once per year. Crooked Creek LIMP Page 3 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP F. Sample Frequency and Plan Aeration Basin Sludge to Uncontrollable Pollutant of — _.. Influent(1) and Effluent(2) (3) _ Disposal (4) SIU(5) (6) Concern j Year 1 Year 2,3, 4 Year 5 Years 1-5 Years 1-5 Years 1-5 Years 1-5 Arsenic (As) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Cadmium(Cd) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Chromium(Cr) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Copper(Cu) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Lead(Pb) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Mercury(Hg) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Molybdenum(Mo) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Nickel(Ni) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Selenium (Se) 1/month I Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Silver(Ag) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Zinc(Zn) 1/month Quarterly 1/month 1/6 months Per 503 1/year 1/6 months Cyanide (Cn) 1/month 1/month 1/month 1/6 months ---- ---- 1/6 months Flow Continuous Continuous Continuous Continuous ---- ---- ---- BOD * Daily Daily Daily ---- ---- 1/year 1/6 months TSS * Daily Daily Daily Daily MLSS Weekly ---- 1/6 months (/o solids) NH3-N * 1/month 1/month 1/month 1/6 months ---- 1/year 1/6 months Nitrate and nitrite 1/month Quarterly 1/month 1/6 months ---- 1/year ---- Nitrogen,total Weekly Weekly Weekly 1/6 months ---- 1/year ---- Phosphorus,total 1/month 1/month 1/month 1/6 months I ---- 1/year ---- Crooked Creek LIMP Page 4 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP Aeration Basin Sludge to Uncontrollable Pollutant of Influent(1)and Effluent(2) (3) Disposal(4) SIU(5) (6) Concern Year 1 Year 2,3,4 Year 5 Years 1-5 Years 1-5 Years 1-5 Years 1-5 Organics 1/6 months i 1/6 months 1/6 months 1/6 months ---- ---- ---- Pesticides 1/6 months 1/6 months 1/6 months 1/6 months ---- ---- ---- Chlorides 1/6 months 1/6 months 1/6 months ---- ---- ---- ---- Total oil and grease 1/year 1/year 1/year ---- ---- 1/year Total petroleum hydrocarbon 1/year 1/year 1/year ---- ---- 1/year ---- (SGT-HEM) demand Chemica(COD)oxygen 1/month quarterly 1/month ---- ---- 1/year Industry-specific ---- ---- ---- ---- ---- 1/year ---- pollutants *Daily sampling excludes weekends and holidays Crooked Creek LTMP Page 5 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP G. Detection Level and Sample Method Practical Quantitation Pollutant of Concern Limits(PQLs),mg/L Sample Method Arsenic(As) 0.01 24 hr Composite Cadmium(Cd) 0.002 24 hr Composite Chromium(Cr) 0.005 24 hr Composite Copper(Cu) 0.005 24 hr Composite Lead(Pb) 0.01 24 hr Composite Mercury(Hg) 1.0 ng/L* (Method 1631) Grab* Molybdenum(Mo) 0.01 24 hr Composite Nickel(Ni) 0.01 24 hr Composite Selenium(Se) 0.01 24 hr Composite Zinc(Zn) 0.01 24 hr Composite Silver(Ag) 0.001 24 hr Composite Cyanide(Cn) 0.01 Grab BOD 2.0 24 hr Composite TSS 2.5 24 hr Composite NH3-N 0.1 24 hr Composite TKN 0.50 24 hr Composite Nitrate and nitrite 0.10 24 hr Composite Phosphorus,total 0.10 24 hr Composite Total oil and grease(HEM) 5 mg/L Grab Total petroleum hydrocarbon 5 mg/L Grab (SGT-HEM) Chloride 0.1 mg/L 24 hr Composite Organics ---- Grab Pesticides ---- Grab Chemical oxygen demand(COD) 50 mg/L 24 hr Composite Sampling, preservation, and analytical method must be from 40 CFR 136. * Graphite Furnace Determinations are required to attain the desired detection level for the metals. However,analysis of aeration basin and sludge to disposal samples often cannot meet these detection levels. In this case, analysis of these samples must obtain a detection level at least as stringent as the applicable inhibition criteria or sludge ceiling standard. ** All aeration basin and sludge to disposal samples will be grab. Crooked Creek LIMP Page 6 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP Crooked Creek LIMP Page 7 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP H. WWTP Diagram Legend: FBW =Filter Backwash RAS =Return Activated Sludge WAS =Waste Activated Sludge MLSS =Mixed Liquor Suspended Solids #1 =Sampling Point 3 O O MLSS Influent Coarse Grit Equalization Oxidation Ditch Distribution Pump Station Screens Removal Distribution Box Oxidation Ditches Box \\ -1 Influent c ( -0.A rl id i II. ► ....,.,�.....«. V ♦ ♦ RAS Grit Crooked O , Creek Tertiary Filters Cascade UV Disinfection Aerator FBW 4 ♦ RAS Pump Station Chlorine Contact , (Backup) Pump Station 0 '' 'go Supernatant WAS 0 _ Pump Station Sludge Aerated Aerobic Transfer Digestion Station Solids Holding To Land Tank Application illierpollge Figure 1 WWTP Process Flow Diagram Union County,NC Crooked Creek WWTP NC0069841 30831-052-001 Fig r.et Crooked CIO.cdr Crooked Creek LTMP Page 8 Union County Public Works Long Term Monitoring Plan—Crooked Creek WWTP Crooked Creek LTMP Page 9