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Home My WebLink AboutNC0021121_Mount_Airy_WWTP_CEI_Letter_20231002ROY COOPER Governor ELIZABETH S. BISER Secretary RICHARD E. ROGERS, JR. Director City of Mount Airy Attn: Stan Farmer, City Manager P.O. Box 70 Mount Airy, NC 27030-0070 NORTH CAROLINA Environmental Quality October 2, 2023 SUBJECT: Compliance Evaluation Inspection City of Mount Airy, Mount Airy Wastewater Treatment Plant NPDES Permit: NCO021121 Surry County Dear Mr. Farmer: On September 28, 2023, Division of Water Resources staff, Ron Boone, conducted a routine compliance evaluation inspection at the Mount Airy Wastewater Treatment Plant, NPDES permit NC0021121. Operator in Responsible Charge (ORC), Chris Marion, was present during the inspection. A review of records, data, treatment components, structures, and the outfall was completed. Please see the attached detailed BIMS inspection report. This inspection reflected compliance with the subject permit. No concerns, deficiencies, or violations were noted during the inspection. If you have any questions or concerns, please contact Ron Boone by phone at 336.776.9690, or by email at ron.boone@deg.nc.gov. Sincerely, DocuSigned by: OD2D3CE3F187456... Jennifer F. Graznak, Assistant Regional Supervisor Water Quality Regional Operations Winston-Salem Regional Office Division of Water Resources, DEQ Attachments: 1. BIMS Inspection Report cc: Chris Marion. Operator in Responsible Charge, via email DffNorth Carolina Department of Environmental Quality I Division of Water Resources oan caaouNn Winston-Salem Regional Office 1 450 W. Hanes Mill Rd, Suite 300 I Winston-Salem, North Carolina 27105 M336.776.9800 oep.m.m or em�nmen� Qualm, 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 u 3 I NCO021121 I11 121 23/09/28 I17 18I � I 19 I s I 201 I 211IIIII 111111III II III III1 I I IIIII IIIIIIIII II r6 Inspection Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved ------------------- 67 I 72 I ni I 71 I 74 79 I I I I I I I80 701 I 71 I LL -1 I I LJ 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 Dermit Number) 10:30AM 23/09/28 20/11/01 Mount Airy WWTP US Hwy 52 S Exit Time/Date Permit Expiration Date Mount Airy NC 27030 12:30PM 23/09/28 25/02/28 Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data Christopher S Marion/ORC/336-786-3597/ Name, Address of Responsible Official/Title/Phone and Fax Number Contacted Ricky George Dean,174 Ashly Ln Mount Airy NC 27030/Utilities Maintenance Supervisor / ORC/336-786-3586/ No Section C: Areas Evaluated During Inspection (Check only those areas evaluated) Permit 0 Flow Measurement Operations & Maintenar Records/Reports Self -Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Compliance Schedules Effluent/Receiving Wate 0 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 Ron Boone Docusigned by: DWR/WSRO WQ/336-776-9690/ 10/2/2023 ana& Boom B20F8DD5F2A3460... Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date F j Docusigned by: -'!�"ee4K DwR/WSRo 336-776-9695 10/2/2023 '—OD2D3CE3F 1 B7456_. EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete. Page# NPDES yr/mo/day Inspection Type NCO021121 I11 12I 23/09/28 117 18 i c i (Cont.) Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) On September 28, 2023, Division of Water Resources staff, Ron Boone, conducted a routine compliance evaluation inspection at the Mount Airy Wastewater Treatment Plant, NPDES permit NC0021121. Operator in Responsible Charge (ORC), Chris Marion, was present during the inspection. A review of records, data, treatment components, structures, and the outfall was completed. This inspection reflected compliance with the subject permit. The permit was last issued in 2020 and expires in February 2025. The plant is currently permitted for a monthly average flow of up to 7.0 million gallons per day (MGD), but the average daily flow is only about 1.5 MGD. Discharge monitoring reports for December 2022 and May 2023 were evaluated along with laboratory records, chains of custody, etc. No transcription or other errors were noted. Operator logs, operation and maintenance records, and required reports and plans were reviewed. All documentation is complete and current, and no concerns, deficiencies, or violations were noted. Laboratory and DMR records are kept for at least five years, and all other records are kept for at least three years. Flow comes into the mechanical bar screen, which is currently inoperable due to a gear malfunction. A manual bar screen is currently in use. Flow then goes to the influent pumpstation, which then carries it through the grit removal process and then through primary treatment. The influent pumpstation is designed for four pumps but two are currently out of service. Other rebuilt pump assemblies are on hand in case either of the remaining two fail. The city is commissioning a project to rebuild the pumpstation. The plant has three primary treatment trains, each consisting of primary clarifiers and trickling filters. Primary sludge is pumped from the primary clarifiers to the sludge holding tanks, which used to be covered anaerobic digesters, but the covers failed and had to be removed so the digesters were transitioned to simple sludge holding tanks. Only two primary treatment trains are needed to treat the current flow, so the third is not in operation. The primary clarifiers appear to be in good condition and are well operated and maintained. Weirs are level and effluent to the trickling filters appears clear with little solids carryover. The trickling filters appear to be operating well. The media has a healthy ubiquitous growth, and no problems or issues were noted. From the trickling filters flow goes to the aeration basins. Only one aeration basin is in operation and needed to treat the current flow. The mixed liquor appears to be of good quality and imparts a healthy pungent earthy odor. Mixed liquor is dark brown and has very little foam. Mr. Marion stated they try to keep mixed liquor suspended solids between 2,500 to 3,000 mg/I. From the aeration basin, flow then goes to one of two secondary clarifiers. The secondary clarifiers also appear to be in good condition. The clarifiers have very little floating solids and effluent appears very clear. The weirs appear level. From the secondary clarifiers, flow goes to the chlorine contact chamber where sodium hypochlorite is injected for disinfection. The contact chamber provides about 37 minutes of contact time. Flow then goes to the effluent channel where it is dechlorinated with sodium bisulfite and reaerated via cascade aeration. Flow then goes to the outfall into the Ararat River, which is about 300' northwest of the reaeration cascade. The right-of-way to the outfall is well maintained, and the effluent appeared clear. Minimal foam was observed on the river at the outfall, and no solids were observed in the effluent at the time of the inspection. This plant appears to be well operated and maintained by the operators. Several units are definitely showing their age, but the operators appear to be maintaining them so that they are running well. Page# Permit: NCO021121 Inspection Date: 09/28/2023 Owner -Facility: Mount Airy WWTP Inspection Type: Compliance Evaluation The plant has not had a limit violation since 2015 or monitoring violation since 2019. No concerns, deficiencies, or violations were noted during the inspection. If you have any questions or concerns, please contact Ron Boone by phone at 336.776.9690, or by email at ron.boone@deq.nc.gov. Page# Permit: NCO021121 Owner -Facility: Mount Airy WWTP Inspection Date: 09/28/2023 Inspection Type: Compliance Evaluation 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? ❑ ■ ❑ ❑ # Are there any special conditions for the permit? ■ ❑ ❑ ❑ Is access to the plant site restricted to the general public? ■ ❑ ❑ ❑ Is the inspector granted access to all areas for inspection? ■ ❑ ❑ ❑ Comment: Several changes should be made to the permit's plant description: 1. Influent pumpstation should be placed between the bar screen and the grit chamber: 2. Intermediate pumpstation should be placed between the trickling filters and activated sludge tank: 3. Return activated sludge pumpstation should be placed after the secondary clarifiers: and 4. The anaerobic digesters should be replaced with sludge holding tanks. Compliance Schedules Is there a compliance schedule for this facility? Is the facility compliant with the permit and conditions for the review period? Yes No NA NE ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ Comment: Special condition A.(4.) Copper - Facility undertook a water effect ratio study for copper limits. The last sample for the study was sent 8/1/2023. Awaiting final report. All is on schedule. Record Keeping Yes No NA NE Are records kept and maintained as required by the permit? ■ ❑ ❑ ❑ Is all required information readily available, complete and current? ■ ❑ ❑ ❑ Are all records maintained for 3 years (lab. reg. required 5 years)? ■ ❑ ❑ ❑ Are analytical results consistent with data reported on DMRs? ■ ❑ ❑ ❑ Is the chain -of -custody complete? ■ ❑ ❑ ❑ 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? Page# 4 Permit: NCO021121 Owner -Facility: Mount Airy WWTP Inspection Date: 09/28/2023 Inspection Type: Compliance Evaluation Record Keeping Yes No NA NE Is the ORC visitation log available and current? 0 ❑ ❑ ❑ Is the ORC certified at grade equal to or higher than the facility classification? 0 ❑ ❑ ❑ 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? 0 ❑ ❑ ❑ Facility has copy of previous year's Annual Report on file for review? 0 ❑ ❑ ❑ Comment: Excellent documentation. Everything present and very well organized. 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? ■ ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 ■ ❑ ❑ ❑ degrees Celsius)? Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ ❑ Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ ❑ Comment: City lab performs field analyses and process control Influent Sampling Yes No NA NE # Is composite sampling flow proportional? 0 ❑ ❑ ❑ Is sample collected above side streams? 0 ❑ ❑ ❑ Is proper volume collected? ■ ❑ ❑ ❑ Is the tubing clean? 0 ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑ degrees Celsius)? Is sampling performed according to the permit? M ❑ ❑ ❑ Comment: Sampler at 1 degree. 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 Celsius)? Page# 5 Permit: NC0021121 Inspection Date: 09/28/2023 Effluent Sampling Owner -Facility: Mount Airy WWTP Inspection Type: Compliance Evaluation Is the facility sampling performed as required by the permit (frequency, sampling type representative)? Comment: Sampler at 4 degrees. Upstream / Downstream Sampling Is the facility sampling performed as required by the permit (frequency, sampling type, and sampling location)? Comment: Sampling is done by the Yadkin Pee Dee River Basin Association. Pump Station - Influent Is the pump wet well free of bypass lines or structures? Is the wet well free of excessive grease? 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? Yes No NA NE ■ ❑ ❑ ❑ Yes No NA NE ■ ❑ ❑ ❑ Yes No NA NE ■ ❑ ❑ ❑ ❑ ❑ ❑ ■ ■ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ■ ❑ ❑ ❑ Comment: Two pumps are currently inoperable but other rebuilt assemblies are in stock in case another breaks down. Pumpstation is under protect for rebuild. Q c,.. --- Type of bar screen Yes No NA NE 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: Mechanical bar screen is inoperable due to a problem with the gears. A manual screen is currently in use until the mechanical screen is repaired. Grit Removal Type of grit removal a.Manual b.Mechanical Yes No NA NE Page# 6 Permit: NC0021121 Owner -Facility: Mount Airy WWTP Inspection Date: 09/28/2023 Inspection Type: Compliance Evaluation Grit Removal Yes No NA NE Is the grit free of excessive organic matter? 0 ❑ ❑ ❑ Is the grit free of excessive odor? ■ ❑ ❑ ❑ # Is disposal of grit in compliance? 0 ❑ ❑ ❑ Comment: None Flow Measurement - Influent Yes No NA NE # Is flow meter used for reporting? ❑ 0 ❑ ❑ Is flow meter calibrated annually? 0 ❑ ❑ ❑ Is the flow meter operational? 0 ❑ ❑ ❑ (If units are separated) Does the chart recorder match the flow meter? ❑ ❑ ❑ Comment: None Primary Clarifier Yes No NA NE 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? 0 ❑ ❑ ❑ Is the site free of weir blockage? 0 ❑ ❑ ❑ Is the site free of evidence of short-circuiting? 0 ❑ ❑ ❑ Is scum removal adequate? ■ ❑ ❑ ❑ Is the site free of excessive floating sludge? 0 ❑ ❑ ❑ Is the drive unit operational? 0 ❑ ❑ ❑ Is the sludge blanket level acceptable? 0 ❑ ❑ ❑ Is the sludge blanket level acceptable? (Approximately'/4 of the sidewall depth) ■ ❑ ❑ ❑ Comment: Two of three trains in use. Trickling Filter Yes No NA NE Is the filter free of ponding? 0 ❑ ❑ ❑ Is the filter free of leaks at the center column of filter's distribution arms? 0 ❑ ❑ ❑ Is the distribution of flow even from the distribution arms? 0 ❑ ❑ ❑ Is the filter free of uneven or discolored growth? 0 ❑ ❑ ❑ Is the filter free of sloughing of excessive growth? ■ ❑ ❑ ❑ Are the filter's distribution arms orifices free of clogging? 0 ❑ ❑ ❑ Is the filter free of excessive filter flies, worms or snails? 0 ❑ ❑ ❑ Page# 7 Permit: NCO021121 Owner -Facility: Mount Airy WWTP Inspection Date: 09/28/2023 Inspection Type: Compliance Evaluation Trickling Filter Yes No NA NE Comment: Two of three trains in use. Secondary Clarifier Yes No NA NE Is the clarifier free of black and odorous wastewater? 0 ❑ ❑ ❑ Is the site free of excessive buildup of solids in center well of circular clarifier? 0 ❑ ❑ ❑ Are weirs level? 0 ❑ ❑ ❑ Is the site free of weir blockage? ■ ❑ ❑ ❑ Is the site free of evidence of short-circuiting? 0 ❑ ❑ ❑ Is scum removal adequate? ■ ❑ ❑ ❑ Is the site free of excessive floating sludge? ■ ❑ ❑ ❑ Is the drive unit operational? 0 ❑ ❑ ❑ Is the return rate acceptable (low turbulence)? 0 ❑ ❑ ❑ Is the overflow clear of excessive solids/pin floc? 0 ❑ ❑ ❑ Is the sludge blanket level acceptable? (Approximately'/4 of the sidewall depth) 0 ❑ ❑ ❑ Comment: None Pumps-RAS-WAS Yes No NA NE Are pumps in place? ■ ❑ ❑ ❑ Are pumps operational? ■ ❑ ❑ ❑ Are there adequate spare parts and supplies on site? 0 ❑ ❑ ❑ Comment: None Aeration Basins Yes No NA NE Mode of operation Ext. Air Type of aeration system Surface Is the basin free of dead spots? 0 ❑ ❑ ❑ Are surface aerators and mixers operational? 0 ❑ ❑ ❑ Are the diffusers operational? 0 ❑ ❑ ❑ Is the foam the proper color for the treatment process? 0 ❑ ❑ ❑ Does the foam cover less than 25% of the basin's surface? 0 ❑ ❑ ❑ Is the DO level acceptable? 0 ❑ ❑ ❑ Is the DO level acceptable?(1.0 to 3.0 mg/1) 0 ❑ ❑ ❑ Page# 8 Permit: NCO021121 Owner -Facility: Mount Airy WWTP Inspection Date: 09/28/2023 Inspection Type: Compliance Evaluation Aeration Basins Yes No NA NE Comment: Only one basin in use. Flow Measurement - Effluent Yes No NA NE # Is flow meter used for reporting? 0 ❑ ❑ ❑ Is flow meter calibrated annually? 0 ❑ ❑ ❑ Is the flow meter operational? 0 ❑ ❑ ❑ (If units are separated) Does the chart recorder match the flow meter? 0 ❑ ❑ ❑ Comment: Calibrated March 2023. Disinfection -Liquid Yes No NA NE Is there adequate reserve supply of disinfectant? ■ ❑ ❑ ❑ (Sodium Hypochlorite) Is pump feed system operational? ■ ❑ ❑ ❑ Is bulk storage tank containment area adequate? (free of leaks/open drains) 0 ❑ ❑ ❑ Is the level of chlorine residual acceptable? 0 ❑ ❑ ❑ Is the contact chamber free of growth, or sludge buildup? ■ ❑ ❑ ❑ Is there chlorine residual prior to de -chlorination? M ❑ ❑ ❑ Comment: None De -chlorination Yes No NA NE Type of system ? Liquid 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? ❑ ❑ ■ ❑ Comment: None Are tablet de -chlorinators operational? ❑ ❑ 0 ❑ Number of tubes in use? Comment: None Effluent Pipe Yes No NA NE Is right of way to the outfall properly maintained? 0 ❑ ❑ ❑ Are the receiving water free of foam other than trace amounts and other debris? 0 ❑ ❑ ❑ If effluent (diffuser pipes are required) are they operating properly? 0 ❑ ❑ ❑ Page# 9 Permit: NCO021121 Inspection Date: 09/28/2023 Effluent Pipe Owner -Facility: Mount Airy WWTP Inspection Type: Compliance Evaluation Comment: Cascade aeration at effluent of contact chamber immedi Anaerobic Digester Type of operation: Is the capacity adequate? # Is gas stored on site? Is the digester(s) free of tilting covers? Is the gas burner operational? Is the digester heated? Is the temperature maintained constantly? Is tankage available for properly waste sludge? after dechlor. Yes No NA NE Yes No NA NE No cover ■ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ■ ❑ ❑ ❑ ❑ ■ ❑ Comment: These were formerly anaerobic digesters but the covers failed and were removed and the tanks are now used only for sludge storage. 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: Only used for sludge holding tank supernate and contact chamber cleanings. Underdrainage goes back to head of plant. Yes No NA NE ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ ❑ ❑ ■ ❑ Chemical Feed Yes No NA NE Is containment adequate? 0 ❑ ❑ ❑ Is storage adequate? 0 ❑ ❑ ❑ Are backup pumps available? ■ ❑ ❑ ❑ Is the site free of excessive leaking? 0 ❑ ❑ ❑ Comment: None Page# 10 Permit: NCO021121 Inspection Date: 09/28/2023 Solids Handling Equipment Is the equipment operational? Is the chemical feed equipment operational? Owner -Facility: Mount Airy WWTP Inspection Type: Compliance Evaluation Is storage adequate? Is the site free of high level of solids in filtrate from filter presses or vacuum filters? Is the site free of sludge buildup on belts and/or rollers of filter press? Is the site free of excessive moisture in belt filter press sludge cake? The facility has an approved sludge management plan? Comment: None Operations & Maintenance Yes No NA NE • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ • ❑ ❑ ❑ ■ ❑ ❑ ❑ ❑ ❑ ❑ 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: MLSS, MLVSS, pH, DO, temperature, setteable solids, etc. Standby Power Yes No NA NE Is automatically activated standby power available? ■ ❑ ❑ ❑ Is the generator tested by interrupting primary power source? 0 ❑ ❑ ❑ Is the generator tested under load? 0 ❑ ❑ ❑ Was generator tested & operational during the inspection? ❑ 0 ❑ ❑ 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 0 ❑ ❑ ❑ power? Is the generator fuel level monitored? ❑ ❑ ❑ Comment: Generator will operate everything except the dewatering building. Page# 11