Document bOknwMrQOLwROzw2N2owJzr8g

1 ft EA~UnitedStates ~., Environment~! Protection ' Agency Region 6 Compliance Assurance and Enforcement Division INSPECTION REPORT Inspection Date(s): Media: Regulatory Program(s) 06/11/2014 Water CWA .... Company Name: Facility Name: Facility Physical Location: (city, state, zip code) Mailing address: --;-c---------- (city, state, zip code) County/Parish: Facility Contact: _ ~ity of Aztec AztecWWTP 900 South Oliver Street Aztec, New Mexico 87410 201 West Chaco Aztec, New Mexico 87410 San Juan County Josh w. Ray jray@aztecnm.gov FRS Number: Identification/Permit Number: Media Number: NAICS: SIC: N/A N/A NM0020168 221320 4952 Facility Representatives: EPA Inspectors: _,'\ndre\\/_G_~~I/V_'IY Anthony Garcia Jayson Shaw -Juan Ibarra I City Manager -Chief Operator --Op. Responsible in Charge WW Operator I Env. Scientist/6EN-WR State lnspector(s): Other lnspector(s): N/A ~-------- N/A --- -- -- 505-334-6448 505-334-6448 505-334-6448 214-665-8493 Title: ~ "' Author: '"0' ~ "' Subject: OJ ~ Keywords: City of Aztec Aztec WWTP Aztec San Juan County New Mexico US EPA Region 6 Compliance Assurance and Enforcement Division Dallas TX Inspection Report Clean Water Act CWA National Pollutant Discharge Elimination System NPDES -"----- Publically Owned Treatment Works POTW EPA Lead Inspector Signature/Date /)' ( , ~/ci:o/1~0>-Caz:.#A - {lnspecJ;Or name} 06/24/2014 Date Supervisor /) J ( .011/1 ;/)\.~ "' . Signature/Date {Supervisor name} ------------------ ~---~~.-~- ~-- ~I-"' --;/;v --- Date - -------~---- 6ENFORM-019-R5 (2/3/14) 2 City of Aztec/ Aztec WWTP Inspection Date 06/11/2014 Section I -INTRODUCTION PURPOSE OF THE INSPECTION EPA Region 6 inspector Juan Ibarra arrived at the City of Aztec/Actec Wastewater Treatment Plant (WWTP) at 0900 on June 11, 2014 for an unannounced inspection. I met with City of Aztec wastewater representatives Andrew Galloway/Chief Operator, Anthony Garcia/Operator Responsible in Charge, and Jayson Shaw/WW Operator I at the Opening Conference. I presented my credentials and informed them that this was an EPA inspection to determine compliance with the facility's EPA NPDES permit and the Clean Water Act (CWA). The scope of the inspection was to conduct a Compliance Evaluation Inspection (CEI), which included an evaluation of the facility's compliance with their permit discharge limits, operational management of the plant, process control, laboratory data and records management. FACILITY DESCRIPTION Operational Design The City of Aztec operates a 1.2 MGD Aero-Mod activated sludge treatment plant which went on-line in September, 2009. The headworks consists of a fine screen auger followed by a parallel pair of grit removal channels (used one at a time and rotated monthly). Following the headworks, flow enters the lift station (equipped with three 900 gpm pumps that run on a rotational basis) which pumps the wastewater into the Aero-Mod plant. The Aero-Mod plant consists of a Bio Phosphorus Reactor with infrequent diffusers (run six times for four minutes at a time within a 24-hr period), followed by the fermenter that is equipped with mechanical mixers to maintain low anoxic DO and to keep solids suspended. The fermenter is followed by dual train aeration basins that cycle between periods of aeration and anoxic periods for denitrification. Each train has a fine bubble and a coarse air basin. Effluent from the aeration basins flows into two secondary clarifiers. Return Activated Sludge (RAS) from the clarifiers goes back to the fermenter, and decant from the aerobic digesters goes back to the coarse air units of the aeration basins. The clarifiers are followed by the Advanced Nutrient Removal System (ANR) which also operates as a sand filter. Ferric chloride is added prior to the ANR to precipitate phosphorus as it runs thru a "tortuous path" within the ANR. The ANR is followed by UV disinfection and the effluent is discharge into the Animas River thru a 1000' pipe. While the Aero-Mod plant was initially designed to denitrify and remove phosphorus, the City decided to utilize the Aero-Mod plant specifically for denitrification, and use ferric chloride to precipitate phosphorus in the ANR after finding that the plant would not effectively perform both nutrient removal functions within a single treatment unit. Waste Activated Sludge (WAS) comes directly from the aeration basins into the two aerated digesters (there is no solids thickening), followed by belt press dewatering. Dewatered solids are stored in the former drying beds and then shipped to the Bondad Landfill in Colorado for disposal. 2 3 City of Aztec /Aztec WWTP Inspection Date 06/11/2014 Contingency/Emergency Operations The facility has two back-up generators to run the lift station and UV. In the event of a power or unit failure, the plant has an old clarifier and 1 MG oxidation ditch for flow equalization (EQ), and a permanently stationed pump at the plant should a bypass occur to the EQ. Additionally, there is a new SCADA and call-out system, in the event of a power disruption or unit failure, for the entire plant and the Llano Lift Station. Section II- OBSERVATIONS The plant appeared to be well maintained at the time of the inspection. The facility produces a high quality effluent using the Aero-Mod activated sludge wastewater treatment system, followed by the ANR sand filter and UV disinfection. The effluent was very clear, and visually appeared to be of high quality. Solids dewatering was working effectively, using a polymer additive, producing a dump truck load (5 yards) of solids about every 1.5 hours. The belt press is run about six hours during a single day of the week, but it occasionally runs upwards of eighteen hours a week when more digester solids need to be removed. The facility did not have a recent flow meter calibration, and the staff gauge, which was covered with algae and scum, was unreadable. Additionally, I noted that the facility was not running process control testing to evaluate solids settleability, sludge age (or MCRT), and several other standard activated sludge process control parameters. They also needed a new sludge judge. Section Ill- AREAS OF CONCERN Flow Measurement The facility received an "Unsatisfactory" rating for Flow Measurement because the flow meter has not been calibrated since 8/17/2012, nor have any flow measurement checks been performed (recommended at least quarterly). Also, the Parshall flume staff gauge was unreadable. Operations and Maintenance The facility also received a "Marginal" rating for Operations and Maintenance because additional process control testing is required to monitor solids retention time for efficient determination of sludge wasting and return rates. This process control testing must also, include 30 minute settleability, F/M and SVI. The plant needs to develop a tracking system for these and other in-plant operating parameters (such as unit DOs, MLSS, etc.), and it should be performed at a frequency to optimize plant performance (perhaps 3x/week). Additionally, the plant needs a new sludge judge, as the old one is too short for the new units. Effluent The facility received a "Marginal" rating for Effluent due to several permit limit violations for Total Nitrogen and Total Phosphorus. For the DMR review period of January 2012 to present, the effluent exceeded permit limit for Total Nitrogen during two months, and Total Phosphorus during four months. See the table below. Note, that since January, 2013, the facility has only experienced a single DMR violation (for the Total Nitrogen effluent limits). Additionally, the plant had a single minor pH violation of 6.4 (permit limit is 6.6) for the July, 2012 DMR. 3 4 Total Nitrogen Total Phosphorus City of Aztec / Aztec WWTP Inspection Date 06/11/2014 Records Review Additionally, during a records review of effluent data for the month of April, 2014, a few minor errors were discovered. A single pH entry of 7.01 was om itted from the DMR for 4/10/2014. A revised DMR report must include this data point as it was the low pH for t he month. Also, an entry for E. coli was missed for 4/4 and 6/2014. These missing data points do not affect E. coli compliance for the monthly DMR. And, the contract laboratory ana lyzing BOD was contacted during the inspection because all BOD parameters were <2, and the maximum dilution of samp le was 200 mi. The sample volume can be increased to 295 to 300 ml {as the laboratory always uses dilutions of 100-150-200 mls for the City of Aztec wastewater effluent) to help obtain more precise data. Closing Conference Following the inspection, a Closing Conference was held with Josh W. Ray/City Manager, Andrew Galloway/Chief Operator, and Anthony Garcia/Operator Responsible in Charge. The Areas of Concern listed above {with the exception of the Effluent violations which were not obtained until after the completion of the inspection) were discussed during the exit briefing. Section IV- FOLLOW UP A copy of the inspection report will be sent to the facility. Section V - LIST OF APPENDICES Appendix 1- 3560 Cover Sheet 4 5 City of Aztec/ Aztec WWTP Inspection Date 06/11/2014 Appendix 1 3560 Cover Sheet 5 6 rEP A Transaction Code 1~ 2 l2J -- -" ---" -. United States Environmental Protection Agency Washington D.C. 20460 NPDES Compliance Inspection Report Section A: National Data Svstem Codinq NPDES 3 I N I ~ 0 I 0 I 21 ol I I 61 sl 11 yr/mo/day 12 I I I 4 I 0 I 6 I I I I I 17 Inspection Type 18~ Inspector 19~ 211 s I I I c I I c lo I D I E I : 14 I 9 I 5 I 2 I I I L I I I I 66 Fac Type 20 L!J Inspection Work Days 671 I I I 69 w Facility Evaluation Rating 70 Bl 71 ~ QA 72 ~ ~-~--------------------Reserved---------------------------------~ 73 I I I 74 751 I I I I I I 80 Name and Location of Facility Inspected Section B: Facility Data Enhy Time/Date The Aztec WWTP is located at 900 S. Oliver Street, south of Hwy 516, in 0900 /6111/14 Aztec, San Juan County, New Mexico. Name(s) of On-Site Representatives --'l'Ttie(s) - Exit Time/Date 1450/6/11/14 Jayson Shaw WW Operator I Anthony Garcia Operator Responsible in Charge Andrew Galloway Chief Operator Name, Address of Responsible Official Title Josh W. Ray City Manager City of Aztec 201 W. Chaco Phone Number 505-334-7600 Contacted: Aztec, NM 87401 Section C: Areas Evaluated During Inspection (S""' Satisfactory, M =Mar inal, U""' Unsatisfactory, N =Not Evaluated s -s -s M -- Permit Records/Reports Facility Site Review Effluent/Receiving Waters - u Flow Measurement s Self-Monitoring Program N Compliance Schedules s Laboratory s f--- ,s _ N -- M - Storm Water Sludge Handling/Disposal Pretreatment Operations & Maintenance s 1--N f-- N 1--- L__ Section D: Summary of Find in s/Comments (Attach additional sheets if necessary) Permit Effective Date 9/1109 Pennit Expiration Date 8/31/14 Phone ! 505-334-6448 i I " " ---- - YES - X- - NO - - CSO/SSO (Sewer Overflow) Pollution Prevention Multimedia - The facility produces a high quality effluent using an AeroRMod activated sludge treatment plant which went onRiine in September, 2009. The headworks consists of a fine screen auger followed by a parallel pair of grit removal channels (used one at a time and rotated monthly). Followiing the headworks, flow i enters the lift station, (equipped with three 900 gpm pumps that run on a rotational basis) which pumps the wastewater into the Aero-Mod plant. The Aero- I Mod plant consists of a Bio Phosphorus Reactor with infrequent diffusers (run six times for four minutes at a time within a 24Rhr period), followed by the fcnnenter that is equipped with mechanical mixers to maintain low anoxic DO and to keep solids suspended. The fermenter is followed by dual train aeration basins that cycle between periods of aeration and anoxic periods fbr denitrification. Each train has a fine bubble and a coarse air basin. Effluent flom the aeration basins flows into two secondary clarifiers. RAS from the clarifiers goes back to the fermenter, and decant from the aerobic digesters goes back to the coarse air units of the aeration basins. The clarifiers arc followed by the Advanced Nutrient Removal System (ANR) which also operates as a sand filter. Ferric chloride is added prior to the ANR to precipitate phosphorus as it runs thru a "tortuous path" within the ANR. The ANR is followed by UV disinfection and the effluent is discharge into the Animas River thru a 1000' pipe. I While the Aero-Mod plant was initially designed to denitrify (N03 to N2) and remove phosphorus, the facility decided to utilize the AeroRMod plant specifically for denitrification, and usc ferric chloride to precipitate phosphorus in the ANR after finding that the plant would not effectively perform both nutrient removal functions within a single treatment unit. WAS comes directly ffom the aeration basins into the two aerated digesters (there is no solids thickening), followed by belt press dewatering. De\vatered solids arc stored in the former drying beds and then shipped to the Bondad Landfil! in Colorado for disposal. The facility has two back-up generators to run the lift station and UV. In the event of a power or unit failure. the plant has an old clarifier and 1 MG oxidation ditch for flow equalization (EQ), and a permanently stationed pump at the plant should a bypass occur to the EQ. Additionally, there is a new I SCADA and call-out system, in the event of a power disruption or unit failure, for the entire plant and the Llano Lift Station. ' I The facility received an "Unsatisfi1ctory" rating for Flow Measurement because the flow meter has not been calibrated since 8/17/2012, nor have any flow ' measurement checks been performed (needed at least quarterly). Also, the Parshall flume staff gauge was unreadable and either needs to be c!ecmcd or I replaced. ------~~---~-- I ------~--~ - -----..---~-----_j 7 The facil ity received a " Marg inal" rating for Effluent due to several permit limit violations for Total Nitrogen and Total Phosphorus. For the DM R review period of January 20 12 to present, the effluent exceeded permit limit for Total Nitrogen during two months, and Total Phosphorus during four months. See the table below. Note, that since January, 20 13, the faci lity has only experienced a single DMR vio lation (for the Total Nitrogen effluent limits). Additionally, the plant had a s ing le minor pH violation of 6.4 (permit limit is 6.6) for the July, 2012 DMR. The facility received a " Marginal" rating for Operations and Maintenance because additional process control testing is requ ired to mon itor solids retention time for efficient determination of sludge wasting and return rates. This process control testing must also, include 30 minute settability, F/M and SVI. The plant needs to develop a tracking system for these and other in-plant operating parameters (such as unit DOs, MLSS, etc.), and it should be performed at a frequency to optimize plant performance (perhaps 3x/week). Additionally, the plant needs a new sludge judge, as the old one is too short for the new units. The facility has a Multi-Sector storm water permit (NMR051-1529) effective 9/29/08 and expiring 9/29/13. However, a new General Permit has not been issued by the EPA. A brief review of the SWPPP (prepared on 9/ 1511 0) showed that the fac il ity was performing the quarterly inspections and annual reports. When the General Permit is reissued, the facility will have to renew the permit. Name(s) and Signature(s) of Inspector(s) Juan Ibarra Agency/Officeffelephone US EPA/6EN-WR/(214) 665-8493 Date 24 June 2014 Signature of Reviewer Agency/Office Date US EPA/6EN-WR 2