"Compatible" means the ability of 2 or more substances to maintain their respective physical and chemical properties upon contact with one another for the design life of the UST system in which they come in contact, under conditions likely to be encountered in the UST system.
N.H. Admin. Code § Env-Or 402.10
(See Revision Note at chapter heading for Env-Or 400) #10393, eff 9-1-13