40 CFR § 146.9 - Criteria for establishing permitting priorities.
In determining priorities for setting times for owners or operators to submit applications for authorization to inject under the procedures of § 144.31 (a), (c), (g) or § 144.22(f), the Director shall base these priorities upon consideration of the following factors:
(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.