Document ZJvzBKjObzngkOr9vm0KROKyY

EPA Inspection Report - Page 1 of 11 Region 6 Compliance Assurance and Enforcement Division INSPECTION REPORT Inspection Date(s): Media: Regulatory Program(s) 07/17/2018 Water CWA - NPDES Company Name: Facility Name: Facility Physical Location: (city, state, zip code) Mailing address: (city, state, zip code) County/Parish: Facility Contact: Belen, City of Belen Wastewater Treatment Plant 1300 Conservancy Road Belen, NM 87002 100 South Main Street Belen, NM 87002 Valencia County Jerah Cordova Mayor, City of Belen jerah.cordova@belen-nm.gov FRS Number: Identification/Permit Number: Media Number: NAICS: SIC: 110001934462 NM0020150 221320 4952 Personnel participating in inspection: Amy Andrews, P.E. USEPA/6EN-WMH Reyes Moreno City of Belen Ben Morrales City of Belen Environmental Engineer Wastewater Operator Wastewater Operator 214-907-0638 505-966-2730 505-966-2730 EPA Lead Inspector Signature/Date Supervisor Signature/Date Digitally signed by AMY ANDREWS AMY ANDREWS DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=AMY ANDREWS, dnQualifier=0000131170 Amy Andrews Date: 2018.09.24 08:55:40 -06'00' CAROL PETERSWAGNON Carol Peters Digitally signed by CAROL PETERS-WAGNON DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=CAROL PETERS-WAGNON, dnQualifier=0000009981 Date: 2018.09.25 10:15:51 -05'00' Date Date 6ENFORM-019-R7 (2/15/2017) 1 EPA Inspection Report - Page 2 of 11 Section I - INTRODUCTION City of Belen Wastewater Treatment Plant Inspection Date 07/17/2018 PURPOSE OF THE INSPECTION Environmental Protection Agency (EPA) Region 6 inspector, Amy Andrews arrived at the City of Belen Wastewater Treatment Plant at 8:50 AM on July 17, 2018 for an unannounced Compliance Evaluation Inspection (CEI). I met with Reyes Moreno, City of Belen Wastewater Treatment Operator, for the Opening Conference. I presented my credentials to Mr. Reyes and explained that this was an EPA inspection to determine compliance with the facility's National Pollutant Discharge Elimination System (NPDES) permit and the Clean Water Act (CWA). The inspection was conducted under the authority of the NPDES permit program, in accordance with the Federal CWA. This report is based on information supplied by City of Belen representatives (the permittee), observations made by the EPA inspector, and records and reports maintained by the permittee and the EPA. FACILITY DESCRIPTION The City of Belen WWTP is located at 1300 Conservancy Road, Belen, in Valencia County, New Mexico. The facility is a non-pretreatment facility classified as a major municipal discharger, permitted for 1.2 million gallons per day (MGD) design flow, with and actual average flow maintained around 0.4 MGD. Discharge is to receiving waters named Bosque Drain and thence to the Rio Grande. The Belen WWTP is an activated sludge facility. The main plant lift station consists of a wetwell and four submersible pumps rated for 880 gpm each. Entrance works include a barscreen and Parshall Flume. All flow from the entrance works goes to the grit tank, where high specific gravity solids are dropped out of the raw wastewater influent in the grit chamber. Slurry from the grit chamber is taken to the grit classifier and de-watered. These solids (grit) are disposed of in a landfill. The wastewater flow from the grit chamber goes to the two aeration basins. The flow is split between the two aeration basins, although either of the basins can handle the entire flow for maintenance, if necessary. Flow from the aeration basins is usually split between two secondary clarifiers, however currently one of the clarifiers is offline. Sludge is drawn from the bottom of the secondary clarifiers and pumped to the sludge thickener unit. The sludge is decanted (thickened) in this unit prior to being pumped to the aerobic digesters. Supernatant from the sludge thickener is piped back the influent wet well and re-introduced to the aeration basins. After digestion, sludge is taken to the sludge drying beds. Drainage from the beds is routed back to the wet well at the Main Plant Lift Station. After drying to approximately 50 percent total solids, the sludge is moved to a sludge composting pad for composting. The sludge is composted after drying without the use of amendment materials. After composting, the sludge is used as a soil conditioner on public and private property. From the clarifier(s), all wastewater flow goes through the chlorine contact chamber, where chlorine contact time is around 30-45 minutes, and then is dechlorinated using sulfur dioxide. Water is then discharged via a rectangular weir into the Bosque Drain. 2 EPA Inspection Report - Page 3 of 11 City of Belen Wastewater Treatment Plant Inspection Date 07/17/2018 Section II - OBSERVATIONS During the opening meeting, I was informed that the Belen WWTP is in the process of working on an assessment to update the whole plant within the next seven years. The facility indicated that the plan is to rehabilitate the aeration basins, to install ultraviolet disinfection instead of the current chlorine contact chamber and dechlorination, and to get rid of the digesters and switch to a belt press for the biosolids management. After the opening meeting, we began the inspection with a tour of the WWTP. The facility was clean with no obvious operational issues, however one of the aeration basins has been down for repair for the last six months but should be back up and running in the next two months. One of the clarifiers has been offline for a while, the other clarifier has algae issues due to humidity problems, and the clarifier weirs are in need of leveling. The laboratory was clean and well maintained, with appropriate Standard Operating Procedure (SOP) documents available, however laboratory bench sheets were difficult to read due to poor copy quality of the blank sheets. A records review showed that the facility's Multi-Sector General Permit (MSGP) Stormwater Pollution Prevention Plan (SWPPP) had not been updated since 2010. Section III - AREAS OF CONCERN Requirement 1 NPDES Permit NM0020150, Part I: Requirements for NPDES Permits, Section A. Limitations and Monitoring Requirements, 1. Final Effluent Limits: Pollutants TSS and BOD, Discharge Limitations in lbs/day (also referred to as "loading"). Concern 1 Permittee is not using actual flow rates in calculations. i.e., for the Month of May 2018, the permittee recorded daily flow rates between 0.334 MGD and 0.486 MGD, however all loading calculations used a daily flow rate value of 0.4 MGD. Permittee is also rounding all concentrations prior to calculating loadings (i.e., using 2.0 mg/L instead of 2.4 mg/L), which results in different calculated values. Requirement 2 NPDES Permit NM0020150, Part I: Requirements for NPDES Permits, Section A. Limitations and Monitoring Requirements, 1. Final Effluent Limits: Pollutants TSS and BOD, Sample Type, 6-Hour Composite Sample. 6-Hour Composite Sample is defined in Part III: Standard Conditions, F.22.e. as consisting of six effluent portions collected no closer together than one hour (with the first portion collected no earlier than 10:00 am) and composited according to flow. Concern 2 Although the facility is collecting six effluent portions at one hour intervals beginning at 10:00 am, they are not composited according to actual flow at the time of portion collection. The facility does not record the actual flow rate at the time of collection, flow rate is only collected once per day, and all samples are composited assuming that the flow is constant at 0.4 MGD, with 500 milliliters for each 3 EPA Inspection Report - Page 4 of 11 City of Belen Wastewater Treatment Plant Inspection Date 07/17/2018 portion of the composite. Composite portions are pre-typed on blank bench sheets, leaving no ability to record flow at each hour and calculate an appropriate flow-weighted volume for each portion. Requirement 3 NPDES Permit NM0020150, Part III: Standard Conditions D.5. Additional Monitoring by the Permittee: If the permittee monitors any pollutant more frequently than required by this permit, using test procedures approved under 40 CFR 136 or as specified in this permit, the results of this monitoring shall be included in the calculation and reporting of the data submitted in the Discharge Monitoring Report (DMR). Such increased monitoring frequency shall also be indicated on the DMR. Concern 3 The permittee sends samples for Biochemical Oxygen Demand (BOD) and total suspended solids (TSS) to Hall Environmental twice a month as a comparison for sample analysis done in-house for the same pollutants. The results of the duplicate sampling are not currently being used to calculate results on the DMR. Requirement 4 NPDES Permit NM0020150, Part III: Standard Conditions C.4 Record Contents: Records of monitoring information shall include: ... b. The individual(s) who performed the sampling or measurements; ... d. The individual(s) who performed the analyses. Concern 4 Hand written bench sheets are typed out at a later date as a quality control procedure, and the initials of the individual who performed the sampling and/or analyses is replaced with the initials of the individual doing the quality control check on the results. The individual who does the actual sampling and actual laboratory analysis needs to be maintained on the final version of the forms. Requirement 5 NPDES Permit NM0020150, Part III: C.2. Representative Sampling: Samples and measurements taken for the purpose of monitoring shall be representative of the monitored activity. Concern 5 Sampling is typically collected on consecutive days each week, instead of spread over the week. It is possible that the samples are not representative of the entire process if there are variations in the wastewater stream throughout the week (i.e., higher residential flow over the weekend vs higher industrial flow during the week). Section IV - FOLLOW UP The following information was received by EPA after exiting the Facility on 7/17/2018: Laboratory Analytical Report sent via email on 7/18/2018 Copy of 2014 NPDES Permit Application sent via email on 7/18/2018 Section V - LIST OF APPENDICES Appendix 1 - Bench sheets showing flow rates and loading calculations for May 2018 4 EPA Inspection Report - Page 5 of 11 City of Belen Wastewater Treatment Plant Inspection Date 07/17/2018 Appendix 1 Bench sheets showing flow rates and loading calculations for May 2018 EPA Inspection Report - Page 6 of 11 EPA Inspection Report - Page 7 of 11 EPA Inspection Report - Page 8 of 11 EPA Inspection Report - Page 9 of 11 EPA Inspection Report - Page 10 of 11 EPA Inspection Report - Page 11 of 11