Document 2jNXB0eM8jn9kGMX4ZZXYe7pL

UST Inspection Report Bighorn Canyon NRA Maintenance Facility Date of Report: Inspection Date & Time: Weather: Facility Owner: August 25, 2025 July 23, 2025, at 10:10 a.m. Mountain Daylight Time (MDT) Overcast, ~59 degrees Fahrenheit National Park Service Facility Owner Address: 5 Avenue B Fort Smith, MT 59035 Facility Address: 5 Avenue B Fort Smith, MT 59035 Facility Representative: EPA Facility ID Number: Reason for Inspection: Inspection Team: 2020032 Routine compliance inspection Marta Grabowski, Inspector, EPA UST Program Roberta Person, Inspector, EPA UST Program UST System Description The Bighorn Canyon NRA Maintenance Facility (Facility) has two federally-owned underground storage tanks (UST) for fueling maintenance vehicles. It is located on the Crow Reservation in Fort Smith, Montana. The Environmental Protection Agency's Facility records indicate the Facility has two, doublewalled, STI-P3 USTs that were installed in January 1998. Piping for the UST is pressurized, doublewalled fiberglass reinforced plastic (FRP). Inspection Narrative On July 23, 2025, the EPA UST program personnel conducted an inspection at Bighorn Canyon NRA Maintenance Facility in Fort Smith, Montana. The EPA last inspected the Facility on October 13, 2022, and they selected it for routine re-inspection. Ms. Grabowski, the EPA inspector, spoke with Facility staff on June 26, 2025, and sent a follow-up email to schedule the inspection and provide inspection details (see Attachment A). The EPA inspection team arrived at the Facility at 10:10 a.m. MDT. The Facility representatives were the same individuals from the previous Facility inspection, as both facilities are part of the National Park Service. Ms. Grabowski proceeded to conduct a physical inspection of the UST system as well as a 2020032-Bighorn Canyon NRA Maintenance Facility Page 1 of 3 7/23/2025 UST Inspection review of Facility records. Photographs of UST system components taken during the inspection are in Attachment B. Copies of operation and maintenance records are in Attachment C. Tank Leak Detection Tank leak detection is conducted by a Veeder Root TLS 300C automatic tank gauge (ATG), which performs static leak tests via probe in the tank. Records of release detection tests were maintained onsite, but did not include passing tests for each of the past 12 months. Both tanks were missing a record from May 2025, and both tanks showed invalid results in March/April 2025. The unleaded tank also showed invalid results for September/October 2024. The invalid tests were caused by low fuel level and/or interruption during the test. A record of passing annual operability testing for the ATG console and probes, dated August 8, 2024, was available onsite. The tanks are also equipped with sensors that monitor the interstitial space. Approximately 1.5 weeks prior to the inspection, the operator was alerted to the presence of fuel in the diesel tank interstice and contacted a service provider. The fuel was pumped out of the interstice and did not return, as of the date of this inspection. The operator indicated via email dated August 22, 2025, that the diesel tank passed a pressure test. Piping Leak Detection Piping leak detection is conducted by mechanical line leak detectors (MLLD) and annual line tightness testing. Line tightness tests were conducted and passed on August 8, 2024. The MLLDs were also tested on August 8, 2024. The diesel MLLD passed, but the unleaded MLLD failed and was replaced according to an email from the service provider. The facility is also equipped with sump sensors, which continuously monitor for leaks in the underground piping. The sensors were tested and passed on August 8, 2024. Additionally, hydrostatic testing of the sumps was conducted and passed on September 27, 2022. Cathodic Protection The last two Cathodic Protection (CP) testing records, dated March 16, 2018, and July 29, 2022, were maintained onsite and showed passing results. Periodic Testing/Inspection of Spill and Overfill Prevention Equipment Records of triennial testing for the spill buckets and overfill prevention devices (high-level alarm) were maintained onsite. The spill buckets were tested and passed on June 15, 2023. The overfill alarm was tested and passed on September 7, 2023. Periodic Operation & Maintenance (O&M) Walkthrough Inspections Monthly walkthrough inspection records for the last 12 months were maintained onsite. The last annual walkthrough inspection occurred on January 27, 2025. 2020032-Bighorn Canyon NRA Maintenance Facility Page 2 of 3 7/23/2025 UST Inspection Operator Training There are designated Class A, Class B, and Class C operators at the facility, and documentation was available onsite. Financial Responsibility Bighorn Canyon NRA maintenance facility is a federally-owned facility (National Park Service) and uses self-insurance as a mechanism of financial responsibility for the UST. Physical Observations The EPA inspector viewed the spill buckets/fill pipes, tank top sumps, dispensers, and the ATG console. The containment sumps and spill buckets were free of liquid and debris. The ATG console indicated all functions normal. Inspection Conclusions and Recommendations At the end of the inspection, the EPA inspector filled out an Onsite Deficiency Identification Form (see Attachment D), which represents initial compliance recommendations at the time of the inspection. Prior to departing the Facility, Ms. Grabowski stated that a full inspection report would be forthcoming, which includes the inspection checklist (see Attachment E). Ms. Grabowski provided the Facility representative with the deficiency form and retained a carbon copy for recordkeeping. Inspection Report Attachments A. Record of communication for scheduling the inspection B. Photo log C. Facility O&M Documents D. Onsite Deficiency Identification Form E. Inspection checklist Signature Lead Inspector MARTA GRABOWSKI Marta Grabowski Digitally signed by MARTA GRABOWSKI Date: 2025.08.25 19:32:54 -06'00' Date of signature 2020032-Bighorn Canyon NRA Maintenance Facility Page 3 of 3 7/23/2025 UST Inspection