Public Notice: Intent to Issue Class I UIC Permit to Elk Hills Power LLC, Tupman, CA

Summary

The United States Environmental Protection Agency, Region 9, Groundwater Protection Section, 75 Hawthorne Street, San Francisco, CA 94105 (EPA) is providing an opportunity for the public to comment on its proposal to issue a Class I Underground Injection Control (UIC) Permit for Elk Hills Power (EHP or the Permittee). EHP owns and operates a power plant that includes three existing Class V injection wells, known as 25A-18G, 35A-18G, and 35-18G at 4026 Skyline Road in the Elk Hills Oil Field, City of Tupman, California.

The draft Class I UIC Permit, if issued, would authorize construction of six new wells, named 35EHP-2B, 44EHP-1B, 78EHP-35R, 85EHP-2B, 25EHP-1B, and 82EHP-2B 18G. The application seeks 10-year authorization for the construction and operation of the new Class I injection wells.

Under the proposed permit, EHP’s non-hazardous wastewater would be disposed of in the six injection wells that are proposed to be located about four miles south of the power plant site. The injection fluid consists of wastewater from the following activities and sources: turbine washing; cooling tower blowdown; plant area washing; reverse osmosis regeneration; plant and equipment drains; filter backwash; and non-oil-contaminated storm runoff.

Currently EHP has three (3) active Class V injection wells that dispose of non-hazardous power plant wastewater into the Upper Tulare formation within the Elk Hills oil field. EHP has been operating under their Class V UIC permit (Permit No. R9UIC-CA5-FY20-3), which EPA issued in March 2021. In March 2023, EHP applied for a Class I UIC permit as the new injection wells are proposed to inject into the Lower Tulare Formation, which is below the lowermost USDW. Because of the proposed injection into deeper formations consistent with 40 CFR § 146 Subpart B, EPA has determined that a Class I permit is appropriate for the proposed new wells.

If the UIC permit is authorized, EHP would inject wastewater into the Lower Tulare Formation at an average of 200 gallons per minute with a total daily injection limit of 628,500 gallons. Injection into the new wells would occur at depths ranging between approximately 1,100 and 1250 feet below ground surface.

EPA has made a preliminary determination to issue the proposed Class I UIC Permit to EHP pending this public notice and comment. EPA is taking this action as provided by Part C of the SDWA and pursuant to Title 40 of the Code of Federal Regulations (CFR) Parts 124, 144, 146, and 147.

Supporting Materials

All data submitted by the applicant is available as part of the administrative record for the Draft Permit. This Notice, EPA’s Fact Sheet, the Draft Permit, EHP’s permit application, and other supporting documents are available for public review online at www.regulations.gov under docket number EPA-R09-OW-2024-0605.

• Related Content: Elk Hills Power LLC's current UIC Class V Permit

If you are unable to access these materials on the internet, please contact Mr. Cardona at the telephone number or email address listed above for assistance.

Final Permit Decision and Appeals Process

After the close of the public comment period, EPA will respond to comments and issue a final permit decision pursuant to 40 CFR §124.15(a) and will notify all commenters regarding the Agency’s decision. The final decision shall be to either issue or deny the Permit. If comments are filed which request a change in the Draft Permit, the final decision shall become effective no sooner than thirty (30) days after EPA’s service of the notice of final decision.

Within thirty (30) days after the final permit decision has been issued, any person who filed comments on the Draft Permit, participated in any public hearing on this matter, or takes issue with any changes in the Draft Permit, may petition the Environmental Appeals Board to review any condition of the permit decision. Commenters are referred to 40 CFR §124.19 for procedural requirements of the permit appeal process.

If no comments request a change in the Draft Permit, EPA’s final decision shall become effective immediately upon issuance unless a later date is specified in the notice of final decision.

Applicants or Respondents

Docket Numbers

• EPA-R09-OW-2024-0605