Section Env-Or 305.12 - Interstitial Leak Monitoring for AST Systems(a) Interstitial spaces installed on or after April 25, 1997 in an AST system shall be equipped with interstitial monitoring equipment.(b) The interstitial monitoring equipment shall be:(1) Capable of detecting both a discharge of oil from the inner container and an intrusion of water from the surrounding environment into the interstitial space; and(2) Constructed such that the testing or sampling methods used are not rendered inoperative by groundwater, rainfall, or soil moisture.(c) The requirements of (a) and (b), above, shall not apply to double-walled tanks that: (1) Are not in contact with the soil; and(2) Are completely surrounded by secondary containment as specified in Env-Or 305.08.(d) Interstitial monitoring equipment for double-wall piping shall consist of a continuously operating sump sensor with alarm that is both visible and audible to the AST system operator.N.H. Admin. Code § Env-Or 305.12
(See Revision Note at chapter heading for Env-Or 300) #10487, eff 2-7-14