The septic tank liquid capacity required by Env-Wq 1010.01 or Env-Wq 1010.02, as applicable, may be attained using 2 or more tanks in series, provided that the first tank is large enough to contain at least 2/3 the total required volume.
N.H. Admin. Code § Env-Wq 1010.12
(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08; ss by #9904-A, eff 4-16-11