Code of Federal Regulations Title 40. Protection of Environment § 40.147.1803 Existing Class I and III wells authorized by rule—maximum injection pressure

(a) A value which will not exceed the operating requirements of § 144.28(f)(3)(i);  or

(b) A value for well head pressure calculated by using the following formula:

Pm = (0.8—0.433 Sg) d

where:

Pm = injection pressure at the well head in pounds per square inch

Sg = specific gravity of injected fluid (unitless)

d = injection depth in feet.