"Septic tank" means a watertight unit designed to receive sewage and other wastes for the purpose of removing substantially all settleable solids.
N.H. Admin. Code § Env-Wq 1002.63
(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08; renumbered by #9904-A (from Env-Wq 1002.62)