Code of Federal Regulations Title 40. Protection of Environment § 40.146.9 Criteria for establishing permitting priorities

(a) Injection wells known or suspected to be contaminating underground sources of drinking water;

(b) Injection wells known to be injecting fluids containing hazardous contaminants;

(c) Likelihood of contamination of underground sources of drinking water;

(d) Potentially affected population;

(e) Injection wells violating existing State requirements;

(f) Coordination with the issuance of permits required by other State or Federal permit programs;

(g) Age and depth of the injection well;  and

(h) Expiration dates of existing State permits, if any.