Document DvD9gkR11k5ZLONNZbBB2mpmQ

EPA Inspection Report - Page 1 of 18 Region 6 Compliance Assurance and Enforcement Division INSPECTION REPORT Inspection Date(s): Media: Regulatory Program(s) 07/24/2018 Water CWA - NPDES Company Name: Facility Name: Facility Physical Location: (city, state, zip code) Mailing address: (city, state, zip code) County/Parish: Facility Contact: City of Socorro Socorro Wastewater Treatment Facility 301 Main Street Socorro, NM 87801 P.O. Drawer K Socorro, NM 87801 Socorro County Jordan Lloyd Martinez Water/Wastewater Department Supervisor lmartinez@socorronm.gov FRS Number: Identification/Permit Number: Media Number: NAICS: SIC: 110000734590 NM0028835 221320 4952 Personnel participating in inspection: Amy Andrews, P.E. USEPA/6EN-WMH Jordan Lloyd Martinez City of Socorro Cody Polston City of Socorro Joe Melendrez City of Socorro Pauline Taylor Jenelle Partridge City of Socorro City of Socorro Environmental Engineer Utility Director Wastewater Treatment Plant Chief Operator Water/Wastewater Superintendent Contract Superintendent Administrative Assistant 214-907-0638 575-838-1606 575-838-1606 575-838-1606 575-838-1606 575-838-1606 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: 2018.08.17 11:39:40 -06'00' Digitally signed by CAROL PETERS-WAGNON CAROL PETERS-WAGNON DN: c=US, o=U.S. Government, ou=USEPA, ou=Staff, cn=CAROL PETERS-WAGNON, dnQualifier=0000009981 Date: 2018.08.17 13:44:27 -05'00' Carol Peters Date Date 6ENFORM-019-R7 (2/15/2017) 1 EPA Inspection Report - Page 2 of 18 Section I - INTRODUCTION City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 PURPOSE OF THE INSPECTION Environmental Protection Agency (EPA) Region 6 inspector, Amy Andrews, arrived at the City of Socorro Wastewater Treatment Plant at approximately 10:00 am on July 24, 2018 for an unannounced Compliance Evaluation Inspection (CEI). I met with Jordan Lloyd Martinez, Utility Director, Cody Polston, Wastewater Treatment Plant Chief Operator, Joe Melendrez, Water/Wastewater Department Superintendent, and Jenelle Partridge, Administrative Assistant, for the Opening Conference. I presented my credentials to Mr. Martinez 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 representatives of the City of Socorro (the permittee), observations made by the EPA inspector, and records and reports maintained by the permittee and/or the EPA. FACILITY DESCRIPTION The City of Socorro WWTP is located on Main Street in Socorro, Socorro County, New Mexico. The facility is a Sequencing Batch Reactor (SBR) with an intermittent cycle extended aeration system (ICEAS) and aerobic sludge digestion classified as a major municipal discharger, permitted for 1.3 million gallons per day (MGD) of discharge, with an average actual flow of around 0.7 MGD. Discharge is into receiving waters named Luis Lopez Drain, thence to Socorro Riverside Drain, thence to the Rio Grande River. Wastewater from the 23 lift stations in the City of Socorro is conveyed to a manhole on Main Street near the treatment facility and flows by gravity to the entrance works of the plant. The entrance works consist of a 5,000 gallon, below-grade septage receiving tank, where the influent wastewater from the last manhole was previously mixed with septage received by the facility (currently received septage goes directly to the digester); mechanical bar screen with bypass channel equipped with a manual bar screen. A lift station with three 20 horsepower submersible pumps then pumps the wastewater past a grit removal unit that has been out of service for a number of years to a splitter box which sends the wastewater to the three ICEAS SBR basins. In the ICEAS process, the wastewater flows continuously into a pre-react zone in the SBR which is separated from the main react zone by a non-hydrostatic baffle wall. The pre-react zone acts as a biological selector to minimize filamentous growth. Wastewater then flows through openings at the bottom of the baffle wall and into the main react zone where treatment occurs by aeration and mixing. At the end of the aeration stage, aeration and mixing are stopped to allow solids separation, at which time the sludge settles to the bottom of the basin, leaving a layer of clear water at the top of the basin. At the end of the settling stage, the clear water is removed from each basin by an automated, time controlled decant mechanism and sludge is wasted using submersible pumps. Chlorine gas is injected into the effluent for disinfection, and then it travels through two baffled 2 EPA Inspection Report - Page 3 of 18 City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 chlorine contact chambers that operate in parallel before being dechlorinated using sulfur dioxide. The effluent then flows through a flow meter before it is discharged over the cascade aeration unit, through an underground pipe, and out of Outfall 001 into the Luis Lopez Drain. The waste biosolids generated at the facility is first sent to a gravity thickener unit. The thickened sludge is then transported to two aerobic digesters that are operated in series. The supernatant from the thickener and the aerobic digesters are sent back to the plant headworks. The digested sludge is sent to the belt filter press to be dewatered. The final dried biosolids are disposed of at the City of Socorro Landfill. Section II - OBSERVATIONS During the opening meeting, I was informed that the Socorro WWTP is due for a major overhaul and they are currently working out the financial details. Prior to the upcoming overhaul, the facility has been actively replacing smaller components, including sludge pumps, chemical induction pumps for chlorine and sulfur dioxide, as well as electrical panels for these pumps. The City of Socorro has been connecting properties near the river over the shallow water table onto the WWTP, but the facility still accepts around 4000 gallons of septage each month. The WWTP has switched from putting the septage into the headworks to putting the septage directly into the digester. The City of Socorro does not have much problem with inflow/infiltration during rain storms except that after especially large rainstorms some of the citizens will pop open the manholes to drain flooding from the streets or their own property. The WWTP alarm system is audio/visual and if the alarm goes off at night, plant personnel get a call from the Socorro police. Standby phone doesn't get called unless there is a power failure. After the opening meeting, we began the inspection with a tour of the laboratory. Samples run by the facility include pH, biochemical oxygen demand (BOD), total suspended solids (TSS), E. coli bacteria, and total residual chlorine. Total and dissolved aluminum is sent to Hall Environmental Laboratory in Albuquerque, NM, and whole effluent toxicity testing is done by Bio Aquatics Laboratory in Carrollton, TX. The laboratory appeared clean and well-maintained. All laboratory procedures were well documented in Standard Operating Procedure (SOP) notebooks with pictures (see Photo 1 of the Photo Log in Appendix 1), and most laboratory data is recorded directly into Excel bench sheets to prevent transcription errors. After the tour of the laboratory was completed, a tour of the WWTP was done. No evidence of operational issues was observed, however due to the ICEAS process, the facility was not actively discharging at the time of the tour, so the clarity of the effluent was not observed. One of the two chlorine contact chambers was in the process of being cleaned for algae, and the other chlorine contact chamber had a visible short circuit at a break in the wall of the contact chamber (see Photo 2 of the Photo Log in Appendix 1). The exterior wall of the SBR basin has a visible deflection, as seen from the walkway around the perimeter of the basin (see Photo 3 of the Photo Log in Appendix 1), as well as significant diagonal cracking that can be seen from the ground looking up at the north wall of the SBR basin (see Photo 4 of the Photo Log in Appendix 1). The SBR basin has not yet been reported to leak any liquid. 3 EPA Inspection Report - Page 4 of 18 City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 A records review, including checking of Excel formulas was completed after leaving the facility. Monthly flow records are missing the reading from the morning of the first day of the following month, thereby missing the flow rate from the last day of the month. Several small typographic errors were noted in the Excel bench sheets, but no errors were found in other mathematical formulas. Section III - AREAS OF CONCERN Requirement 1 NPDES Permit NM0028835, Part III: Standard Conditions B.2. Duty to Mitigate: The permittee shall take all reasonable steps to minimize or prevent any discharge in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. Concern 1 The perimeter wall of the SBR basin is showing stress cracking in the concrete as well as significant deflection of the wall (see Photos 3, 4 and 5 of the Photo Log in Appendix 1). An engineering assessment of the wall has been done by a contracted engineering firm, and monitoring of the cracks via strain gauges is ongoing (see Photo 6 of the Photo Log in Appendix 1). The assessment states that reinforcement of the wall is currently not required, however catastrophic failure is possible. Recommendations from the engineering firm indicate that the cracking in the wall should be repaired with epoxy injection and the wall should be monitored monthly for further movement and increased cracking. Should additional movement or cracking of the wall be observed, the basin should be emptied immediately and the wall shored before the basin is refilled. The Socorro WWTP is located immediately adjacent to a residential area within the city limits of Socorro, and catastrophic failure of the SBR basin would threaten both human health and the environment of the area. Facility personnel stated that they are in the process of attempting to obtain funding for a total overhaul of the facility, but that the funding is not yet available. Requirement 2 NPDES Permit NM0028835, Part III: B.3.a. Proper Operation and Maintenance: The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by permittee as efficiently as possible and in a manner which will minimize upsets and discharges of excessive pollutants and will achieve compliance with the conditions of this permit. Concern 2 There is a crack in one of the walls of the chlorine contact chamber (see Photo 2 of the Photo Log in Appendix 1) which is causing a short circuit in the chlorine contact chamber and potentially shortening the total duration of chlorination. It is possible that this short circuit was caused by the same structural failure that is causing the cracking and deflection in the SBR basin, as the eastern wall of the chlorine contact chamber is in line with the eastern wall of the SBR basin. 4 EPA Inspection Report - Page 5 of 18 City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 Requirement 3 NPDES Permit NM0028835, Part III: B.3.b. Proper Operation and Maintenance: The permittee shall provide an adequate operating staff which is duly qualified to carry out operation, maintenance and testing functions required to insure compliance with the conditions of this permit. Concern 3 The facility is in need of two additional qualified operators. Requirement 4 NPDES Permit NM0028835, Part III: C.5. b. The permittee shall calibrate and perform maintenance procedures on all monitoring and analytical instruments at intervals frequent enough to insure accuracy of measurements and shall maintain appropriate records of such activities. Concern 4 pH buffer solutions had a hand-written date on them, however it wasn't clear if this date was the received-on date, the opened-on date, or the expiration date (see Photo 7 of the Photo Log in Appendix 1). Additionally, pH buffer solutions had been transferred from the original bottles (with the hand-written date) into smaller bottles for ease of use. The smaller bottles did not have specific identifying marks on them, including opened-on and expiration dates. It was therefore not possible to confirm proper calibration of the pH instrument. Section IV - FOLLOW UP Follow-up correspondence emails received from the facility after the close of the inspection were received on 7/25-27/2018, 8/2/2018, and 8/13/2018 regarding information about equipment upgrades and the engineering assessment of the SBR wall cracking and deflection. Section V - LIST OF APPENDICES Appendix 1 - Photo Log: 7 photos taken 7/24/2018 Appendix 2 - Engineering Report: Socorro WWTP; SBR Basin Perimeter Walls, Feb 2, 2018 (report appendices not included - available upon request) 5 EPA Inspection Report - Page 6 of 18 City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 Appendix 1 Photograph Log EPA Inspection Report - Page 7 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 1 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0412.JPG Date of Photo: 7/24/2017 Time of Photo: 10:48 AM Photographer: Amy Andrews Description: Well documented Standard Operating Procedure (SOP) notebook with pictures for Laboratory Procedures EPA Inspection Report - Page 8 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 2 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0421.JPG Date of Photo: 7/24/2017 Time of Photo: 11:24 AM Photographer: Amy Andrews Description: Short circuit in chlorine contact chamber (circled) EPA Inspection Report - Page 9 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 3 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0423.JPG Date of Photo: 7/24/2017 Time of Photo: 11:28 AM Photographer: Amy Andrews Description: Visible deflection of the north wall of the SBR basin, as seen from the walkway around the perimeter of the basin (straight line added for reference). EPA Inspection Report - Page 10 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 4 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0427.JPG Date of Photo: 7/24/2017 Time of Photo: 11:30 AM Photographer: Amy Andrews Description: Significant diagonal cracking that can be seen from the ground looking up at the north wall of the SBR basin. EPA Inspection Report - Page 11 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 5 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0425.JPG Date of Photo: 7/24/2017 Time of Photo: 11:29 AM Photographer: Amy Andrews Description: Cracking at the exterior corner of the SBR basin as seen from the walkway around the top of the basin. EPA Inspection Report - Page 12 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 6 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0428.JPG Date of Photo: 7/24/2017 Time of Photo: 11:31 AM Photographer: Amy Andrews Description: Strain gauge used to monitor changes in cracking. EPA Inspection Report - Page 13 of 18 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Photograph Log Photo No. 7 Location: City of Socorro Wastewater Treatment Plant City: Socorro County/Parish: Socorro State: New Mexico Photo File Name: DSCN0414.JPG Date of Photo: 7/24/2017 Time of Photo: 10:52 AM Photographer: Amy Andrews Description: Larger pH buffer bottles have a single hand-written date with no specific identification as to whether that date is the received-on, opened-on, or expiration date. Smaller pH buffer bottles on the right have no identifying labels or dates. EPA Inspection Report - Page 14 of 18 City of Socorro Wastewater Treatment Plant Inspection Date 07/24/2017 Appendix 2 Engineering Report: Socorro WWTP; SBR Basin Perimeter Walls, Feb 2, 2018 (report appendices not included - available upon request) EPA Inspection Report - Page 15 of 18 EPA Inspection Report - Page 16 of 18 EPA Inspection Report - Page 17 of 18 EPA Inspection Report - Page 18 of 18