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Home My WebLink AboutNC0041696_CEI_20231205 SENT VIA ELECTRONIC MAIL ONLY: NO HARD COPY WILL BE MAILED December 05, 2023 Greg A Padgett Town of Valdese Email: gpadgett@valdesenc.gov SUBJECT: Compliance Inspection Report Lake Rhodhiss WWTP NPDES WW Permit No. NC0041696 Burke County Dear Permittee: The North Carolina Division of Water Resources conducted an inspection of the Lake Rhodhiss WWTP on 11/17/2023. This inspection was conducted to verify that the facility is operating in compliance with the conditions and limitations specified in NPDES WW Permit No. NC0041696. The findings and comments noted during this inspection are provided in the enclosed copy of the inspection report entitled "Compliance Inspection Report". There were no significant issues or findings noted during the inspection and therefore, a response to this inspection report is not required. If you should have any questions, please do not hesitate to contact Melanie Kemp with the Water Quality Regional Operations Section in the Asheville Regional Office at 828-296-4500 or via email at melanie.kemp@deq.nc.gov. Sincerely, Melanie Kemp, Environmental Specialist Water Quality Regional Operations Section Asheville Regional Office Division of Water Resources, NCDEQ ATTACHMENTS: Compliance Evaluation Inspection Report Ec: LF, Lonnie Laird (ORC) EPA United States Environmental Protection Agency Washington, D.C. 20460 Water Compliance Inspection Report Form Approved. OMB No. 2040-0057 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 N 52 NC0041696 23/11/17 C S31112171819 20 21 66 Inspection Work Days Facility Self-Monitoring Evaluation Rating B1 QA ----------------------Reserved------------------- 3 N67707172 73 74 75 80 Section B: Facility Data Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include POTW name and NPDES permit Number) Lake Rhodhiss WWTP 2100 Lake Rhodhiss Dr Valdese NC 28690 Entry Time/Date Permit Effective Date Exit Time/Date Permit Expiration Date 10:00AM 23/11/17 21/04/01 Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) /// Christopher John Bortnick/ORC/828-879-2131/ Other Facility Data 11:15AM 23/11/17 26/02/28 Name, Address of Responsible Official/Title/Phone and Fax Number Greg A Padgett,PO Box 339 Valdese NC 286900339/Director/828-879-2131/Contacted 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 Other 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 Melanie Kemp DWR/ARO WQ/ - - / Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete. Page#1 NPDES yr/mo/day 23/11/17 Inspection Type C3111218 1 Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) Melanie Kemp, with the Asheville Regional Office, conducted a Compliance Evaluation Inspection of the Valdese Wastewater Treatment Plant on November 17, 2023. This inspection was conducted to determine if the system is being operated and maintained in compliance with permit no. NC0041696. Lonnie Laird (WWTP Superintendent and ORC) was present and assisted with the inspection. No deficiencies were noted during the inspection. The WWTP is currently being operated under tier one of the three-tiered permit. Tier one allows for a maximum monthly average flow of 3.5 MGD. The flow was 1.8 MGD during the inspection. Most of the flow is comprised of industrial wastewater. Valdese currently has 6 industrial users permitted to discharge into the collection system. The WWTP consists of screen and grit removal equipment, an influent pump station, two primary clarifiers, two aeration basins, two secondary clarifiers, two chlorine contact basins, a de-chlorination structure, two gravity sludge thickeners, two centrifuges, a dewatering structure, and a residuals composting operation. The plant is operated by a SCADA telemetry system. Treated water discharges into the Lake Rhodhiss (Catawba River), classified as WS-IV, B, and CA waters. Aeration Basin: Settleability was 95% at the time of the inspection. This is out of range for what we would typically consider to be normal, however, the clarifiers appear to be adequately settling solids. One of the motor drives for the aeration basin pumps was recently replaced, and they are working on replacing the second. Secondary Clarifier: The splitter box, which was previously accumulating solids, has been regularly cleaned and no buildup of solids and vegetation was noted during the inspection. Disinfection: Currently, the plant is conducting a pilot study to determine whether peracetic acid (PAA) can be used for disinfection, in place of chlorine. Chlorine gas is kept on-site as a back-up disinfectant. The PAA is introduced at the beginning of the chlorine contact chamber, at a rate that is proportional to flow. Solids Handling: The design of this plant is such that return activated sludge is not returned directly to the aeration basin but is first delivered to a holding basin. The holding basin delivers sludge to the aeration basin at the same pace that the holding basin fills. Similarly, sludge is wasted to an adjacent holding tank prior to being pumped to the sludge thickeners. NC0041696 17 (Cont.) Page#2 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP 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? It should be noted that, in coordination with DWR, the facility is currently conducting a study on whether paracetic acid (PAA) can be used to replace chlorine gas for disinfection at the plant. The current permit expires 2/28/2026. Comment: Operations & Maintenance Yes No NA NE Is the plant generally clean with acceptable housekeeping? Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable Solids, pH, DO, Sludge Judge, and other that are applicable? Comment: Influent Sampling Yes No NA NE # Is composite sampling flow proportional? Is sample collected above side streams? Is proper volume collected? Is the tubing clean? # Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees Celsius)? Is sampling performed according to the permit? The tubing is fouled and needs to be replaced and/or cleaned regularly.Comment: Bar Screens Yes No NA NE 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? Page#3 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP Compliance Evaluation Bar Screens Yes No NA NE The facility has two mechnical bar screens and one manual, as backup.Comment: Grit Removal Yes No NA NE 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? Comment: Pump Station - Influent Yes No NA NE 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? Alarms were tested and operational. There is no audible alarm, only visual/SCADA. There are a total of 4 pumps. Pumps 1-2 are smaller and used daily. Pumps 3-4 are larger and only operate during high flow events. Comment: Equalization Basins Yes No NA NE Is the basin aerated? Is the basin free of bypass lines or structures to the natural environment? Is the basin free of excessive grease? Are all pumps present? Are all pumps operable? Are float controls operable? Are audible and visual alarms operable? # Is basin size/volume adequate? Comment: Page#4 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP Compliance Evaluation 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? 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 sludge blanket level acceptable? Is the sludge blanket level acceptable? (Approximately ¼ of the sidewall depth) Prior to the inspection, site personnel measured the sludge blanket at 3 and 4 ft in clarifiers 1 and 2, respectively (total depth 13 ft). During high flows, the plant can run 1 of the primary clarifiers and utilize the 2nd as a backup EQ basin, as needed. Comment: Aeration Basins Yes No NA NE Mode of operation Ext. Air Type of aeration system Surface Is the basin free of dead spots? Are surface aerators and mixers operational? Are the diffusers operational? 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? Is the DO level acceptable?(1.0 to 3.0 mg/l) Aeration basin 1 is still not being used. There are 3 aerators in basin 2. Typically, 2 blowers are running during the day and 1 is running at night. DO is not measured continuously within the basin. Settlability was measured at 95% by staff personnel before the inspection. Comment: Secondary 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? Is the site free of weir blockage? Is the site free of evidence of short-circuiting? Page#5 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP Compliance Evaluation Secondary Clarifier Yes No NA NE 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 ¼ of the sidewall depth) The sludge blanket was measured at 7 and 6 feet in secondary clarifiers 1 and 2, respectively (total depth is 14ft). Some algae growth was observed in the weirs of clarifier 2. The splitter box was being adequately maintained and cleaned out regularly. The weirs on clarifier 3 had some algae buildup and should be cleaned soon. Comment: De-chlorination Yes No NA NE Type of system ?Other Is the feed ratio proportional to chlorine amount (1 to 1)? Is storage appropriate for cylinders? # Is de-chlorination substance stored away from chlorine containers? Are the tablets the proper size and type? The facility is currently utilizing paracetic acid for disinfection. PAA is fed at a rate proportional to flow, at the beginning of the contact chamber. Chlorine gas is kept on hand as back-up disinfection. Comment: Are tablet de-chlorinators operational? Number of tubes in use? De-chlorination not necessary for PAA.Comment: Flow Measurement - Effluent Yes No NA NE # 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? Flow meters are calibrated every 6 months. The meter is due for calibration this month (Nov 2023) and was scheduled to occur the week after the inspection. Comment: Solids Handling Equipment Yes No NA NE Is the equipment operational? Is the chemical feed equipment operational? Page#6 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP Compliance Evaluation Solids Handling Equipment Yes No NA NE 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: Effluent Pipe Yes No NA NE 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? The effluent pipe discharges into the lake, below water surface, and is not visible.Comment: Effluent Sampling Yes No NA NE Is composite sampling flow proportional? Is sample collected below all treatment units? Is proper volume collected? Is the tubing clean? # Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees Celsius)? Is the facility sampling performed as required by the permit (frequency, sampling type representative)? The effluent sampler was recently replaced.Comment: Standby Power Yes No NA NE 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? Is the generator fuel level monitored? Page#7 Permit:NC0041696 Inspection Date:11/17/2023 Owner - Facility: Inspection Type: Lake Rhodhiss WWTP Compliance Evaluation Standby Power Yes No NA NE The facility hires a contractor to maintain and re-fuel the generators. Two diesel generators are present, 1 to power the aeration basin and clarifiers and the other to power everything else. The generators are tested weekly under load. Comment: Other Yes No NA NE Comment: Page#8