Section Env-Or 306.14 - Out of Service AST Systems(a) If oil is not introduced to or removed from an AST system designed and intended for the throughput of oil for 36 months, the AST system shall be taken out of service.(b) Those AST systems intended solely for storage, such as back-up tanks for emergency power generation or long-term energy reserves, shall be considered out of service when the contents of such a tank has remained at the lesser of the following for the previous 36 months: (1) One percent of the total system capacity or less; or(2) Less than 3 inches in depth.(c) The owner of an AST system taken out of service shall:(1) Remove all oil from the AST and all piping connected exclusively to that AST;(2) Secure the AST to prevent unauthorized entrance or tampering so that oil is not accidentally or intentionally introduced into the tank, by means such as securely bolting and locking all tank access points and valves and capping or plugging fill lines, gauge openings, or pump lines;(3) Thoroughly clean the interior of the tank and all exclusively connected piping to remove all sludge, solids, and residual oil;(4) Dispose of all oily wastes removed from the AST system in accordance with all applicable state and federal requirements; and(5) Render the tank free of vapors sufficiently to avoid formation of an explosive atmosphere, and vent the tank to ensure the tank remains vapor free.(d) Upon taking an AST system out of service, the owner shall:(1) Comply with Env-Or 304.04 relative to filing an amended registration form;(2) Stencil the words "out of service" on the tank in block letters that are at least 2 inches high and in a color that contrasts with the color of the tank;(3) For tanks that are visible from the fill pipe connection, ensure that the stenciling applied pursuant to (2), above, is readily discernable from the fill pipe connection serving the out-of-service tank; and(4) Securely affix a tag as described in (e), below, at the fill pipe connection serving the out-of-service tank, or, if the fill pipe is also used to fill active tanks, at the first valve after the fill pipe connection used to divert flow to the out-of-service tank.(e) The owner shall obtain a tag used to signify an out-of-service tank system from the department. The tag shall remain affixed to the AST system during the entire time the tank is out of service. The owner shall promptly replace any mutilated, lost, illegible, or destroyed tag by contacting the department to obtain another tag.N.H. Admin. Code § Env-Or 306.14
(See Revision Note at chapter heading for Env-Or 300) #10487, eff 2-7-14