Criteria For Location And Use Of Class V Wells Requiring Permits

01. General: A Class V injection well requiring a permit may be required to be located a minimum distance, as determined from Table 1, from any point of diversion for beneficial use that could be harmed by bacterial contaminants. The minimum distance shown in Table 1 is also referred to as the zone of influence. This requirement is not applicable to wells injecting fluids of quality that meet adopted Ground Water Quality Standards. In addition, the Director may require a Class V injection well to be located a distance from a point of diversion for beneficial use to minimize or prevent ground water contamination resulting from unauthorized or accidental injection, as determined by the Director. (7-1-25) a. The location requirements in Table 1 may be waived when the applicant can demonstrate that any springs or wells within the minimum distance as determined from Table 1 will not be contaminated by the applicant’s injection well. The applicant may be required to monitor production wells or springs within the minimum distance as determined in Table 1 to demonstrate that they are not being contaminated. (7-1-25) Determined Radii of the Zone of Influence Based on Maximum Average Weekly Injection Rates (cfs) of Class V Injection Wells * Injection (cfs) Radius (ft) 0 - 0.20 800 0.21 - 0.60 1,400 0.61 - 1.00 1,800 1.01 - 2.00 2,500 2.01 - 3.00 3,000 IDAHO ADMINISTRATIVE CODE IDAPA 37.03.03 – Rules & Minimum Standards Department of Water Resources for the Construction & Use of Injection Wells Section 058 Page 19 * Injection rates shall be based on the average volume of fluids injected into the well during the week of greatest injection in an average water year. (7-1-25) b. The Director may reduce separation distance requirements if the quality of injected fluids are improved through additional treatment or BMPs. (7-1-25) c. Heat pump return wells (sub-class 5A7) are exempt from the separation distance requirement of this section. (7-1-25)