Document Loa2jr4513mj98LR5o3ZQDnK7

Region 9 Enforcement Division 75 Hawthorne Street San Francisco, CA 94105 Inspection Date(s): Time: Media: Regulatory Program(s) June 7, 2023 Entry: 10:00 AM Water Clean Water Act NPDES Exit: 3:00 PM Company Name: Facility or Site Name: Facility/Site Physical Location: Geographic Coordinates: Mailing address: Facility/Site Contact: Arizona Public Service Company Four Corners Power Plant San Juan County, approximately 20 miles southwest of Farmington, New Mexico Latitude: 36 42' 16.5" N Longitude: 108 29' 12" W P.O. Box 53999 Phoenix, AZ 85072-3999 Cameron Corley Title: Sr. Environmental Scientist Phone: 505-860-3619 Email: cameron.corley@aps.com Facility/Site Identifier: NPDES Permit NN0000019 Facility/Site Personnel Participating in Inspection: Name Affiliation Title Pamela Norris APS Environmental Section Leader Cameron Corely APS Sr. Environmental Scientist Email Pamela.norris@aps.com cameron.corley@aps.com EPA Inspector(s): Adam Howell EPA Environmental Engineer howell.adam@epa.gov Federal/State/Tribal/Local Representatives: Patrick Antonio NNEPA NPDES Manager Kayla Chapo NNEPA Senior Environmental Specialist patrickantonio@navajo-nsn.gov kmchapo@navajo-nsn.gov Inspection Report Author: Adam Howell ADAM HOWELL Digitally signed by ADAM HOWELL Date: 2024.02.04 16:39:37 -08'00' 415-947-4248 Date: Supervisor Review: Elizabeth Aubuchon ELIZABETH AUBUCHON Digitally signed by ELIZABETH AUBUCHON Date: 2024.02.06 07:19:18 -08'00' 415-972-3327 Date: 1 APS / Four Corners Power Plant Inspection Date: 06/07/2023 SECTION I - INTRODUCTION I.1 Purpose of the Inspection The purpose of the inspection was to evaluate compliance with the NPDES permit and applicable Federal regulations covering the discharge of wastewaters into waters of the United States. EPA Region 9, issued NPDES Permit NN0000019 to APS Four Corners Power Plant on November 9, 2020 and it became effective December 1, 2020. The permit expires November 30, 2025. The permit was modified on December 1, 2023 to incorporate revised steam electric power generating standards found in 40 CFR 423.13(k)(2)(i)(A) and (B) for Bottom Ash Transport Water (BATW). The modification allows for certain circumstances where APS may discharge a portion of their BATW into the cooling water pond. SECTION II - FACILITY / SITE DESCRIPTION II.1 Facility Description The Four Corners Power Plant is located 20 miles southwest of Farmington, New Mexico. The plant opened in 1962 with 3 coal burning units. Units 4 and 5 were constructed in 1970 to increase power production. On December 30, 2013 Units 1-3 were decommissioned. Only Units 4 and 5 are currently in use. They produce, on average, 650-700 megawatts per unit each day. Coal is transported to the power plant via train from the Navajo Mine, which is the plant's only source. The coal is stored on property adjacent to the power plant. This property is owned and managed by the Navajo Mine. Two different types of coal are mixed before being provided to APS. The coal is then stored in silos for the units. Approximately 6 million tons of coal are burned per year. Water from the San Juan River flows to an intake structure (Photos 1 & 2) located approximately 3.5 miles North of the Power Plant at the "River Station". Water from this structure is pumped to the Plant's recirculated cooling water pond, also known as Morgan Lake (Photo 3). A plan approved by the United States Fish and Wildlife Service (USFWS) governs the pumping of river water to Morgan Lake. The APS Four Corners Power Plant has one NPDES permitted outfall (Outfall 001 in Photos 4 & 5) that discharges to No Name Wash, which is located near the northeast corner of Morgan Lake. A blowdown structure is used to transport water from Morgan Lake out to No Name Wash, which is a tributary to the Chaco River, and then the San Juan River. Additionally, there are three permitted internal outfalls: 01A, 01E, and 01B. Outfall 01A is the canal (photos 6 & 7) that receives wastewater and stormwater from the plant. The sampling point for Outfall 01A is near the end of the canal (Condenser Cooling Water Canal) prior to water entering Morgan Lake, a man-made cooling water pond. Outfall 01E is located in the canal upstream of outfall 2 APS / Four Corners Power Plant Inspection Date: 06/07/2023 01A. Discharge from Outfall 01E consists primarily of low-volume wastewater, with potential for some BATW. Outfall 01B is designed for discharge resulting from the chemical cleaning of the boiler. However, instead of being discharged through outfall 01B, wastewater from the boiler is comingled with BATW and sent throughout the recycle treatment system. The fly ash impoundments, located southeast of the plant, are no longer used for disposal. In the past fly ash from the power plant was placed here. Fly ash is sometimes sold to contractors for cenospheres production. Although material is no longer added to the fly ash impoundments, they are still managed by the facility under a seepage management and monitoring plan. There are a series of ponds that capture the stormwater runoff from the impoundments and an interceptor ditch to prevent below ground seepage from entering the Chaco River. To control dust from these impoundments a chemical dust suppressant is sprayed onto the surface. II.2 Wastewater Sources Water is pumped from Morgan Lake and circulated around the plant to cool machinery, then transported into the canal and sent back into Morgan Lake. Stormwater is captured in grates around the plant area and then sent into a series of settling ponds with the combined wastewater. Stormwater that falls on the other side of the road from the plant (not impacted by plant activities) flows directly into Morgan Lake. Stormwater around the bag houses flows into a sump and is pumped into to the combined wastewater system. Stormwater from the fly ash impoundments is captured in a retention pond and that water is then used for dust suppression. Water used for cleaning the boilers is permitted to be directed to Outfall 01B. However, no cleaning water is currently being discharged since this wastewater is mixed with BATW. II.3 Wastewater Treatment The combined wastewater stream (cooling water and plant stormwater runoff) is sent through an above ground impoundment Suspended solids settle out and oils are skimmed off the surface of the water. This water is then discharged to Morgan Lake through Outfall 01B. Water leaves Morgan Lake via a blowdown structure. At Outfall 001 where water from the blowdown structure enters the No Name Wash there is a grate that prevents fish from entering the wash. Comingled water with fly ash (BATW) is sent through a recycle treatment system and stored in a lined pond for reuse. The modified permit allows for discharge of a small percentage of BATW volumes if necessary for the purposes of maintenance, to adjust the chemistry of the system, or if necessitated by a storm event. 3 APS / Four Corners Power Plant Inspection Date: 06/07/2023 SECTION III - OBSERVATIONS 1. At the time of the inspection, Outfall 001 was not discharging. According to facility personnel, no discharge had occurred since June 2022 due to low water levels in the lake. No Discharge was reported from July 2022 through August 2023. 2. At the time of the inspection, new piping had just been constructed between the river station and Morgan Lake. Facility personnel stated that the construction project would also include repaving the road to the river station. 3. For May 2021, the discharger reported a violation of the daily max limit for residual chlorine of 0.2 mg/L at internal Outfall 01A. The reported value was 0.4 mg/L. This is the only reported violation for the five years leading to the date of the inspection. SECTION IV - AREAS OF CONCERN The presentation of areas of concern does not constitute a formal compliance determination or violation. No areas of concern were identified during this inspection. SECTION V - DOCUMENTS REQUESTED DURING INSPECTION NPDES Permit No. NN0000019; Toxicity Reduction Evaluation Workplan; Seepage Management and Monitoring Plan; USFWS approved Pumping Plan. APPENDICES Appendix 1 - Inspection checklist Appendix 2 - Photograph Log 4 APS / Four Corners Power Plant Inspection Date: 06/07/2023 Appendix 1- INSPECTION CHECKLIST I. GENERAL Facility Type Inspection Type Municipal Industrial Agricultural Compliance Evaluation (non-sampling) Compliance Sampling _____________ Federal Oil & Gas Weather Dry Clear Overcast Rain Recent Rains __________ Was facility notified in advance? Presented credentials? Notes: Yes No Yes No II. RECORDS AND REPORTS REVIEW RECORDS NPDES permit Monitoring and reporting records for past 5 years Maintenance records Operational records/ log books Auxiliary power check logs Employee Training Have any spills been reported since last inspection? Spill records Have any bypasses been reported since last inspection? Bypass records Notes: 5 Available onsite? Not Yes No N/A Inspected APS / Four Corners Power Plant Inspection Date: 06/07/2023 REPORTS Notification of Non-compliance Notification of spills Notification of bypass Pollution Prevention Plan Spill prevention control and countermeasure (SPCC) plan POTW: Biosolids Monitoring/Management Reports POTW: CSO/ I & I Reports POTW: Pretreatment Reports Other: Pumping Plan Other: Seepage Management Monitoring Plan Other: Toxicity Reduction Evaluation Workplan Notes: Completed in time frame and frequency as required by permit? Not Yes No N/A Inspected III. SELF MONITORING PROGRAM SAMPLING RECORDS & DMRS Yes No N/A Not Inspected Are DMRs submitted in timeframe and frequency required by permit? Sampling Records have: Dates, times, location, & name of individual performing sampling: Lab Reports have: Analytical methods, results, dates and time of analyses: Are samples collected and preserved using methods approved in 40 CFR Part 136? Lab Report results are correctly transcribed to DMR: Detection limits are reported for "less than" results: Does discharger monitor effluent more frequently than required by Permit? If Yes, is all data collected reported on DMRs? Notes: Yes No N/A Not 6 SAMPLE MONITORING Are sample locations and methods representative of Effluent? Representative of Influent? Representative of Receiving Waters? What Flow Measurement Device is utilized? Flume Weir Meter Calculation Other___________ Device appears to be functioning properly without obstructions: Is flow meter calibration available onsite? Date of last calibration Calibration performed by Notes: APS / Four Corners Power Plant Inspection Date: 06/07/2023 Inspected ANALYTICAL MONITORING Not Yes No N/A Inspected Does discharger perform on-site analysis for compliance monitoring? List parameters analyzed on-site: Temperature (continuous), Flow rate, pH Are records of equipment calibration available? Is the on-site laboratory certified? Certification Number Expiration Date COMPLIANCE MONITORING RATING CODE Satisfactory Notes: Marginal Unsatisfactory Not Rated IV. SITE REVIEW OPERATIONS AND MAINTENANCE General Not Yes No N/A Inspected Is the facility as described in the permit/fact sheet for the following? Processes Treatment Units Flow and/or Production Rates Outfalls & Monitoring Locations Receiving Waters 7 Have there been significant changes in operation since last inspection or permit reissuance? Plant schematic is up to date Notes: APS / Four Corners Power Plant Inspection Date: 06/07/2023 Treatment Units & Supporting Equipment Not Yes No N/A Inspected Hydraulic and loadings rates appear consistent with the permit and plant design Tanks, floats, pipes, valves, etc. appear in good working condition Equipment appears adequately maintained and functioning correctly There is no visible evidence of hydraulic short-circuiting Process controls appear adequate No safety concerns observed that may interfere with operation, maintenance, monitoring Notes: Operation & Maintenance O &M Manuals are organized and maintained for use: The maintenance activities, spare parts on-hand, and equipment available appear adequate to ensure continuous operation of treatment system: Is a maintenance management program in place? Number of open work orders: Oldest date of open work order: Notes: Not Yes No N/A Inspected Emergencies / Power Outage Alarm systems for power and equipment failure: Auxiliary power available and maintained: Notes: Not Yes No N/A Inspected Stormwater Does facility have exposure and potential to discharge Stormwater ? Is discharger subject to Multi Sector General Permit (MSGP) ? 8 Not Yes No N/A Inspected If Yes Filed Notice of Intent? If Yes Stormwater Pollution Prevention Plan (SWPPP) available Is there evidence of unauthorized (non-stormwater) discharges? Are there signs of spills to soil, groundwater, or surface water ? Is adequate equipment available for spill cleanup and containment? Are the following areas observed to be free of materials to prevent stormwater pollution? Storage areas Fueling areas Maintenance areas Loading and unloading areas Waste disposal areas Chemicals are stored in secondary containment: Notes: APS / Four Corners Power Plant Inspection Date: 06/07/2023 Not Yes No N/A Inspected V. FINAL EFFLUENT AND RECEIVING WATER MONITORING Not EFFLUENT APPEARANCE Yes No N/A Inspected Clear Colorless Free of oil sheen Free of floatables Free of objectionable odor Notes: Facility was not discharging from Outfall 001, the only external outfall, at the time of inspection. RECEIVING WATER APPEARANCE Free of visible plume Free of foam and sheen Free of erosion at the discharge point Free of bottom deposits, algae growth Notes: VI. SINGLE EVENT VIOLATIONS Were any Single Event Violations (SEV) Observed? 9 Yes No If Yes Describe SEV: APS / Four Corners Power Plant Inspection Date: 06/07/2023 SEV CODE 10 APS / Four Corners Power Plant Inspection Date: 06/07/2023 Appendix 2 - Photograph Log The photographs were taken during the inspection by Adam Howell using a Panasonic DMC-TS5.. Original copies of the photos are maintained by EPA Region 9. Photo 1 : River station pump gallery. Photo 2 : Cooling water intake structure in the San Juan River. 11 APS / Four Corners Power Plant Inspection Date: 06/07/2023 Photo 3: Morgan Lake on left and APS Four Corners Power Plant on right. Photo 4 : Outfall 001. 12 APS / Four Corners Power Plant Inspection Date: 06/07/2023 Photo 5 : Looking downstream from Outfall 001 towards No-Name Wash. Photo 6 : Canal. 13 APS / Four Corners Power Plant Inspection Date: 06/07/2023 Photo 7: Discharge of condenser cooling water to the Canal. 14