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Home My WebLink AboutNC0026689_Compliance Evaluation Inspection_20200228ROY COOPER Governor MICHAEL S. REGAN Secretary S. DANIEL SMITH Director Kenneth W. Gamble Town of Denton PO Box 306 Denton, NC 27239 NORTH CAROLINA Environmental Quality February 28, 2020 Subject: Compliance Evaluation Inspection Report NPDES Permit NCO029246 Linwood Yard WWTP, Davidson County Dear Mr. Gamble: On February 17, 2020, Paul DiMatteo and Jenny Graznak of the Division of Water Resources (Division), Winston-Salem Regional Office met with Troy Branch, Operator in Responsible Charge (ORC), and Steve Abercrombie, backup-ORC, to conduct a Compliance Evaluation Inspection of the above referenced wastewater treatment plant. This inspection consists of (1) a review of the permit and accompanying documentation to determine compliance with permit conditions, and (2) an on -site inspection of several collection system components. The attached inspection form notes the areas that were evaluated for the inspection, with any notable findings outlined as follows. If you have any questions concerning this report please contact Paul DiMatteo at (336) 776-9691 or Lon Snider at (336) 776-9800. Enclosures — Inspection BIMS Report CC: WSRO Laserfiche Files Sincerely, DocuSigned by: OD2D3CE3F161456... for Lon T. Snider, Regional Supervisor Water Quality Regional Operations Section Winston-Salem Regional Office Division of Water Resources, NCDEQ �ATHQARoLI D E Q�� De —.d d E i...mudd Dunl,Ly North Carolina Department of Environmental Quality I Division of Water Resources Winston-Salem Regional Office 1 450 West Hanes Mill Road, Suite 300 1 Winston-Salem, North Carolina 27105 336.776.9800 United States Environmental Protection Agency Form Approved. EPA Washington, D.C. 20460 OMB No. 2040-0057 Water Compliance Inspection Report Approval expires 8-31-98 Section A: National Data System Coding (i.e., PCS) Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type 1 IN 1 2 15 I 3 I NC0026689 111 12 I 20/02/17 I17 18 I S J 19 L G] 201 I 211111 I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I f6 Inspection Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved ------------------- 671 70 I I 71 I I 72 I r I 73 � 74 75I I I I I I I I80 u ty I I Section B: Facility Data Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include Entry Time/Date Permit Effective Date POTW name and NPDES oermit Number) 10:OOAM 20/02/17 16/08/01 Denton WWTP 300 Council Access Rd Exit Time/Date Permit Expiration Date Denton NC 27239 11:30AM 20/02/17 21/02/28 Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data Troy B Branch/ORC/336-859-4460/ Name, Address of Responsible Official/Title/Phone and Fax Number Contacted Kenneth W Gamble,PO Box 306 Denton NC 27239//336-859-4231/ No Section C: Areas Evaluated During Inspection (Check only those areas evaluated) Permit Flow Measurement Operations & Maintenance Records/Reports Self -Monitoring Program Sludge Handling Disposal Facility Site Review Effluent/Receiving Waters Laboratory Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) (See attachment summary) Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date DocuSigned by: Paul DiMatteo DWR/WSRO WQ/336-776-9691/ 2/28/2020 Jennifer F Graznak 10 ; -7M - DWR/WSRO WQ/336-776-9800/ F10C7C2E5BB34D4... Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date ocu by: 2/28/2020 FjDocuSigned EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete. Page# NPDES yr/mo/day Inspection Type (Cont.) NC0026689 I11 12, 20/02/17 117 18 JCJ Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) We discussed the ongoing issues the plant has been having with dichlorobromomethane (DCBM). Operators said they recently consulted with a company that suggested reducing chlorine dosing to decrease disinfection byproduct (DBP) production, while maintaining a level that allowed proper disinfection. Operators said they previously thought that most of the DCBM was introduced when town water was used for dechlorination. They attempted to use less water for dechlorination and reuse its own effluent for dechlorination, but this did not completely solve the issue. DCBM was reportedly around 14 ug/I from the water plant. Operators also said that the cold weather seemed to help with DBP production. We discussed the possibility of doing some timed influent samples (i.e., timing the influent sample to the effluent sample such that approximately the same slug of water is sampled before and after treatment) to determine whether DCBM is actually produced in the treatment process. It didn't seem that such sampling had been conducted in the past. The operators explained that costs prevented them from taking more frequent samples. Page# Permit: NCO026689 Owner - Facility: Denton WWTP Inspection Date: 02/17/2020 Inspection Type: Compliance Evaluation Operations & Maintenance Yes No NA NE Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑ Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑ Solids, pH, DO, Sludge Judge, and other that are applicable? Comment: Permit Yes No NA NE (If the present permit expires in 6 months or less). Has the permittee submitted a new ❑ ❑ ❑ application? Is the facility as described in the permit? 0 ❑ ❑ ❑ # Are there any special conditions for the permit? ❑ 0 ❑ ❑ Is access to the plant site restricted to the general public? 0 ❑ ❑ ❑ Is the inspector granted access to all areas for inspection? 0 ❑ ❑ ❑ Comment: Record Keeping Yes No NA NE Are records kept and maintained as required by the permit? 0 ❑ ❑ ❑ Is all required information readily available, complete and current? 0 ❑ ❑ ❑ Are all records maintained for 3 years (lab. reg. required 5 years)? 0 ❑ ❑ ❑ Are analytical results consistent with data reported on DMRs? 0 ❑ ❑ ❑ Is the chain -of -custody complete? 0 ❑ ❑ ❑ Dates, times and location of sampling Name of individual performing the sampling Results of analysis and calibration Dates of analysis Name of person performing analyses Transported COCs Are DMRs complete: do they include all permit parameters? ❑ ❑ ❑ Has the facility submitted its annual compliance report to users and DWQ? ❑ ❑ ❑ (If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified operator ❑ ❑ ❑ on each shift? Is the ORC visitation log available and current? ❑ ❑ ❑ Is the ORC certified at grade equal to or higher than the facility classification? ❑ ❑ ❑ Is the backup operator certified at one grade less or greater than the facility classification? ❑ ❑ ❑ Is a copy of the current NPDES permit available on site? ❑ ❑ ❑ Page# 3 Permit: NCO026689 Inspection Date: 02/17/2020 Record Keeping Facility has copy of previous year's Annual Report on file for review? Owner - Facility: Denton WWTP Inspection Type: Compliance Evaluation Comment: Reviewed 12/18 and 12/19 DMRs. No issues were noted. Flow Measurement - Effluent # Is flow meter used for reporting? Is flow meter calibrated annually? Is the flow meter operational? (If units are separated) Does the chart recorder match the flow meter? Yes No NA NE ■ ❑ ❑ ❑ Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ Comment: Flow meter was calibrated on 2/14/2020 by Instrument Services. Chart records are kept as required. Bar Screens Type of bar screen a.Manual b.Mechanical Are the bars adequately screening debris? Is the screen free of excessive debris? Is disposal of screening in compliance? Is the unit in good condition? Comment: Helisieve device along with a manual bar screen. Both are in operation. Grit Removal Type of grit removal a.Manual b.Mechanical Is the grit free of excessive organic matter? Is the grit free of excessive odor? # Is disposal of grit in compliance? Yes No NA NE ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ Comment: Grit removal achieved with a velocity drop immediately after the bar screens. Cleaned manually. Pump Station - Influent Yes No NA NE Is the pump wet well free of bypass lines or structures? 0 ❑ ❑ ❑ Is the wet well free of excessive grease? 0 ❑ ❑ ❑ Page# 4 Permit: NCO026689 Inspection Date: 02/17/2020 Pump Station - Influent Are all pumps present? Are all pumps operable? Are float controls operable? Is SCADA telemetry available and operational? Is audible and visual alarm available and operational? Comment: There is an auto dialer installed for the Oxidation Ditches Are the aerators operational? Are the aerators free of excessive solids build up? # Is the foam the proper color for the treatment process? Does the foam cover less than 25% of the basin's surface? Is the DO level acceptable? Are settleometer results acceptable (> 30 minutes)? Is the DO level acceptable?(1.0 to 3.0 mg/1) Owner - Facility: Denton WWTP Inspection Type: Compliance Evaluation level alarm. Are settelometer results acceptable?(400 to 800 ml/I in 30 minutes) Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ❑ ❑ ■ ❑ ■ ❑ ❑ ❑ Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ Comment: Only one of the two oxidation ditches is used due to height differences when built. The other side is used as equalization when needed and otherwise collects rain water. The unused side was covered in duck weed. Operators said they try to keep the DO to —6-8 mq/I Secondary Clarifier Is the clarifier free of black and odorous wastewater? Is the site free of excessive buildup of solids in center well of circular clarifier? Are weirs level? Is the site free of weir blockage? Is the site free of evidence of short-circuiting? Is scum removal adequate? Is the site free of excessive floating sludge? Is the drive unit operational? Is the return rate acceptable (low turbulence)? Is the overflow clear of excessive solids/pin floc? Is the sludge blanket level acceptable? (Approximately'/ of the sidewall depth) Comment: There are 2 center feed and 2 peripheral feed clarifiers. One was down during the inspection. Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ■ ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ■ ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ Page# 5 Permit: NCO026689 Inspection Date: 02/17/2020 Filtration (High Rate Tertiary) Type of operation: Is the filter media present? Is the filter surface free of clogging? Is the filter free of growth? Is the air scour operational? Is the scouring acceptable? Is the clear well free of excessive solids and filter media? Owner - Facility: Denton WWTP Inspection Type: Compliance Evaluation Yes No NA NE Down flow ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ■ ❑ Comment: Operators said they turn off the filtration unit when they hit a flow of 500 qpm because the unit simply won't handle the flow. Disinfection -Gas Yes No NA NE Are cylinders secured adequately? 0 ❑ ❑ ❑ Are cylinders protected from direct sunlight? 0 ❑ ❑ ❑ Is there adequate reserve supply of disinfectant? 0 ❑ ❑ ❑ Is the level of chlorine residual acceptable? ❑ ❑ ❑ Is the contact chamber free of growth, or sludge buildup? 0 ❑ ❑ ❑ Is there chlorine residual prior to de -chlorination? 0 ❑ ❑ ❑ Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No. 7782-50-5)? ❑0 ❑ ❑ If yes, then is there a Risk Management Plan on site? ❑ ❑ 0 ❑ If yes, then what is the EPA twelve digit ID Number? (1000- If yes, then when was the RMP last updated? Comment: Keep up to 10-150 lb cylinders. De -chlorination Yes No NA NE Type of system ? Gas Is the feed ratio proportional to chlorine amount (1 to 1)? 0 ❑ ❑ ❑ Is storage appropriate for cylinders? 0 ❑ ❑ ❑ # Is de -chlorination substance stored away from chlorine containers? 0 ❑ ❑ ❑ Are the tablets the proper size and type? ❑ ❑ 0 ❑ Comment: Kept in a different room. Are tablet de -chlorinators operational? ❑ ❑ 0 ❑ Number of tubes in use? Comment: Page# 6 Permit: NCO026689 Inspection Date: 02/17/2020 Owner - Facility: Denton WWTP Inspection Type: Compliance Evaluation Effluent Pipe Is right of way to the outfall properly maintained? Are the receiving water free of foam other than trace amounts and other debris? If effluent (diffuser pipes are required) are they operating properly? Comment: Didn't observe the outufall today due to flooding/wetness. Aerobic Digester Is the capacity adequate? Is the mixing adequate? Is the site free of excessive foaming in the tank? # Is the odor acceptable? # Is tankage available for properly waste sludge? Yes No NA NE ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ Yes No NA NE ■ ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ■ ❑ ❑ ❑ Comment: Residuals are applied by Southern Soil Builders. 2 aerobic digesters. Haven't applied since October due to wetness. Usually emptied 4-5 times per year. Drying Beds Is there adequate drying bed space? Is the sludge distribution on drying beds appropriate? Are the drying beds free of vegetation? # Is the site free of dry sludge remaining in beds? Is the site free of stockpiled sludge? Is the filtrate from sludge drying beds returned to the front of the plant? # Is the sludge disposed of through county landfill? # Is the sludge land applied? (Vacuum filters) Is polymer mixing adequate? Comment: Drying beds aren't in use. Standby Power Is automatically activated standby power available? Is the generator tested by interrupting primary power source? Is the generator tested under load? Was generator tested & operational during the inspection? Do the generator(s) have adequate capacity to operate the entire wastewater site? Is there an emergency agreement with a fuel vendor for extended run on back-up power? Yes No NA NE ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ❑ ❑ ❑ ■ • ❑ ❑ ❑ • ❑ ❑ ❑ Page# 7 Permit: NCO026689 Owner - Facility: Denton WWTP Inspection Date: 02/17/2020 Inspection Type: Compliance Evaluation Standby Power Yes No NA NE Is the generator fuel level monitored? 0 ❑ ❑ ❑ Comment: Usually tested monthly. Otherwise, operators said it cuts on fairly often. Influent Sampling Yes No NA NE # Is composite sampling flow proportional? ❑ 0 ❑ ❑ Is sample collected above side streams? 0 ❑ ❑ ❑ Is proper volume collected? 0 ❑ ❑ ❑ Is the tubing clean? 0 ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees 0 ❑ ❑ ❑ Celsius)? Is sampling performed according to the permit? 0 ❑ ❑ ❑ Comment: Refrigerator was 5C when observed. Set to take -120 ml every hour. Effluent Sampling Yes No NA NE Is composite sampling flow proportional? 0 ❑ ❑ ❑ Is sample collected below all treatment units? 0 ❑ ❑ ❑ Is proper volume collected? 0 ❑ ❑ ❑ Is the tubing clean? 0 ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees 0 ❑ ❑ ❑ Celsius)? Is the facility sampling performed as required by the permit (frequency, sampling type 0 ❑ ❑ ❑ representative)? Comment: Sampler was 5C when observed. It's programmed to pull 110 ml every 3000 gallons. Laboratory Yes No NA NE Are field parameters performed by certified personnel or laboratory? 0 ❑ ❑ ❑ Are all other parameters(excluding field parameters) performed by a certified lab? 0 ❑ ❑ ❑ # Is the facility using a contract lab? 0 ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees ❑ ❑ 0 ❑ Celsius)? Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ 0 ❑ Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ 0 ❑ Comment: Non -field analysis performed by Meritech. Field lab certification #5455. Calibration logs looked acceDtable. Thermometer calibration was checked in 12/2019. Page# 8