R9UIC-CA1-FY17-4: Chalk Cliff Limited, Maricopa, CA

UIC Class I non-hazardous waste injection well facility with one (1) existing injection well, known as Well Chalk Cliff WD-2, located at the Chalk Cliff Power Plant in Maricopa, California.

• Statement of Basis: Chalk Cliff UIC Permit Termination (pdf) (85.49 KB, October 28, 2025)
  Statement of basis for notice of intent to terminate Underground Injection Control (UIC) Permit No. R9UIC-CA1-FY17-4 at the request of the permittee, Chalk Cliff Limited, Maricopa, CA.
• Major Modification to UIC Permit No. R9UIC-CA1-FY17-4 (pdf) (315.79 KB, June 2, 2022)
  This major modification reflects a revised method for calculating the maximum allowable surface injection pressure for Well Chalk Cliff WD-2 stipulated in Part II, Section D.3.a. of the Permit.
• Minor Modification to UIC Permit No. R9UIC-CA1-FY17-4 (pdf) (224.26 KB, April 23, 2021)
  This minor modification addresses specific financial assurance conditions stipulated in Paragraph II.G of Permit No. R9UIC-CA1-FY17-4 issued to Chalk Cliff Limited, Well Chalk Cliff WD-2, Maricopa, California.
• Notice of Final Permit Decision (pdf) (172.39 KB, September 29, 2020)
  Formal notice of the permit decision, explanation of the appeals process, and the final permit effective date for Class I Non-Hazardous Permit No. R9UIC-CA1-FY17-4 issued to Chalk Cliff Limited.
• Response to Comments (pdf) (141.67 KB, September 28, 2020)
  Provides a summary of the comment received during the public comment period and response to the comments concerning Class I UIC Permit No. R9UIC-CA1-FY17-4 for Chalk Cliff Limited.
• Class I UIC Permit No. R9UIC-CA1-FY17-4 for Chalk Cliff Limited (pdf) (412.97 KB, September 29, 2020)
  Final Class I Non-hazardous Industrial Waste Injection Well Permit No. R9UIC-CA1-FY17-4 for injection operations at Chalk Cliff Limited, Maricopa, CA.
• EPA Fact Sheet: UIC Permit No. R9UIC-CA1-FY17-4 for Chalk Cliff Limited (pdf) (246.8 KB, September 29, 2020)
  This Fact Sheet describes the principal facts and considerations for UIC Permit No. R9UIC-CA1-FY17-4 for Chalk Cliff Limited, including background information, facility description, and information on permit conditions.
• Appendices: UIC Permit No. R9UIC-CA1-FY17-4 for Chalk Cliff Limited (pdf) (2.86 MB, August 13, 2020)
  Appendices A-I to the Final Class I Non-hazardous Industrial Waste Disposal Well Permit No. R9UIC-CA1-FY17-4 for injection operations at Chalk Cliff Limited, Maricopa, CA.