Document pe9ao9rZ9MBG0Vg5v1npxkVX7

Compliance Evaluation Inspection Report Locken Oil July 2024 Submitted to: U.S. ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop St. Denver, CO 80202 Submitted by: Eastern Research Group. 14555 Avion Parkway, Suite 200 Chantilly, VA 20151 EPA Contract No. 68HERC21D0007 Task Order 68HERC22F0492 COMPLIANCE EVALUATION INSPECTION REPORT TABLE OF CONTENTS 1. NARRATIVE ..................................................................................................................... 1 2. SUMMARY ........................................................................................................................ 4 ATTACHMENTS Attachment A: Attachment B: Attachment C: Attachment D: Attachment E: Attachment F: Attachment G: EPA Region 8 UST Compliance Checklist Photograph Log Statistical Inventory Reconciliation Results Equipment Testing Records Cathodic Protection Testing Records Monthly and Annual Walkthrough Inspections Notice Of Inspection Locken Oil CEI Report iii July 2024 1. NARRATIVE The Region 8 (R8) office of the Environmental Protection Agency (EPA) requested multiple facilities be inspected on tribal lands. Eastern Research Group (ERG) under EPA's Contract No. 68HERC21D0007, Task Order 68HERC22F0492, provided assistance to EPA in preparing for, conducting the inspection, and preparing this inspection report. ERG inspected Locken Oil located in Isabel, South Dakota on May 15, 2024. The facility was last inspected on June 29, 2021. , contract inspector for EPA, contacted Mr. , the owner and representative of Locken Oil, to notify the facility about the inspection on April 26, 2024 prior to the inspection. The inspection verified compliance with the federal underground storage tank (UST) requirements of Resource Conservation and Recovery Act (RCRA) Subtitle I under 40 CFR Part 280. Upon arrival at the facility, Ms. introduced herself as a contract inspector for EPA, presented her credentials, and provided an in-brief to Mr. , to explain the purpose of the inspection. Following the inspection, Ms. concluded with an exit brief to inform the facility of preliminary observations identified during the inspection and had Mr. sign the Notice of Inspection (NOI). Ms. took photographs during the inspection. UST System Description Locken Oil (facility) is a privately owned gas station with a convenience store located at 301 Main Street, Isabel, SD 57633. The fuel at this facility is sold to the public. The facility is located on the Cheyenne River Indian Reservation. According to the previous EPA inspection report and observations made during the inspection, the facility has three STI-P3 underground storage tanks (USTs) installed in June 1997. Tank 1 has a capacity of 1,000 gallons and contains E10 gasoline. Tank 2 has a capacity of 1,000 gallons and contains unleaded gasoline. Tank 3 has a capacity of 1,000 gallons and contains diesel. The facility piping is fiberglass reinforced plastic (FRP) and is a safe suction system. Ms. completed an EPA Region 8 UST Compliance Inspection Checklist for the USTs while on site which is included in Attachment A. Photograph #1 in Attachment B shows the dispensers and an overview of the UST system. UST System Records The listing of documents reviewed for the Locken Oil inspection included the following: 1. Statistical Reconciliation Inventory records 2. Operator Certification records 3. Monthly and annual walkthrough inspections 4. Cathodic protection tests 5. Insurance Coverage Certification 6. UST Compliance Testing Records Locken Oil CEI Report 1 July 2024 the three USTs. The spill buckets Tank 1 and Tank 2 were dry and in good condition at the time of the inspection. The spill bucket for Tank 3 contained approximately one inch of water. The facility has two double-sided pump dispensers, and both dispensers were opened as part of the inspection. The dispensers are a safe suction system and are not equipped with sumps or liquid sump sensors. Ms. did not observe signs of leaks at the time of the inspection. Photographs #5 through #8 in Attachment B show the safe suction system and the piping for dispenser 1/2 and dispenser 3/4. Monitoring wells were not observed around the UST tank field. Vent lines are located southeast of the USTs against the store. No obstructions or concerns were noted for the vent lines at the time of the inspection. Locken Oil CEI Report 3 July 2024