30 Tex. Admin. Code § 331.6
The injection of hazardous fluids or radioactive wastes into or above a formation which within one quarter mile of the well contains an underground source of drinking water is prohibited. Wells used to inject hazardous waste-contaminated ground water that is of acceptable quality to aid remediation and is being reinjected into the same formation from which it was drawn are not prohibited by this section if such injection is approved by the commission pursuant to provisions for cleanup of releases consistent with federal regulations under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), 42 United States Code (USC) 9601-9657, or pursuant to provisions for cleanup of releases consistent with federal regulations under the Resource Conservation and Recovery Act (RCRA), 42 USC 6901 through 6987.
30 Tex. Admin. Code § 331.6