COMPLIANCE INFO_FILE 1 - Laserfiche WebLink

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b. Operation The draft permit requires the permittee to inject only the non-hazardous liquid wastes described in Section 4 of this fact sheet. The injection zone shall be limited to the Domengine Formation in the subsurface interval from ap- proximately 2700 feet to 3200 feet below land surface. c. Maximum injection pressure Pursuant to 40 CFR §146. 13 (a) , EPA Region 9 has determined that the maximum allowable surface injection pressure will be 810 pounds per square inch gage at the wellhead. EPA regulations require that the injection pressure be limited so as to prevent fracturing of the injection and confining zones throughout the operating life of the project. This maximum pressure is based on the fracture gradient of 0.733 psi/ft pursuant to 40 CFR §147 . 253 . The surface injection pressure is related to the fracture gradient through the following equation: Ps = [F.G. - .433 (s.g. ) j (depth) where: Ps is surface injection pressure; F.G. is the fracture gradient for the injection formation interval at the location of the well; s.g. is the specific gravity of the injection fluid; and depth is the depth in feet to the top perfora- tion. For the injection well, the following calculation gives the maximum allowed surface injection pressure. Ps = [0.733 - . 433 (1. 00) ) (2700) 810 psi Additionally, injection between the outermost casing protecting underground sources of drinking water and the well bore is prohibited. The maximum injection rate shall be limited to 195 gallons per minute (gpm) for the injec- tion well. The draft permit requires that the annular space between the tubing and the casing be filled with fresh water con- taining bacteria and corrosion inhibitors or similar non- hazardous corrosion inhibiting fluid. 8