(a) All Class V aquifer recharge (AR) injection wells shall be operated in such a manner that injection will not endanger drinking water sources. Underground injection endangers drinking water sources if such injection may result in the presence of any contaminant in underground water which supplies or can reasonably be expected to supply any public water system, and if the presence of such contaminant may result in such system's not complying with any national primary drinking water regulation, or may otherwise adversely affect the health of persons.(b) Injection pressure and volume at the wellhead shall not exceed a maximum which shall be calculated so as to assure the pressure and volume in the injection zone does not cause movement of fluid out of the injection zone.(c) The owner or operator of an AR injection well that has ceased operations for more than two years shall provide verification of the well's mechanical integrity and notification of intent to resume operations to the executive director at least 30 days prior to resuming operation of the well.(d) The owner or operator shall maintain the mechanical integrity of all wells operated under this section.(e) The quality of the water injected at an AR injection well must meet the requirements in §331.267(a)(1) of this title (relating to Additional Requirements).(f) All AR injection wells must be installed with a flow meter for measuring the volume of water injected.