Section Env-Wq 1010.01 - Liquid Capacity of Septic Tanks: Residential Up To 10 Bedrooms(a) The required minimum liquid capacity of a septic tank for an ISDS serving a residence having up to 10 bedrooms shall be determined in accordance with this section.(b) For a single-family residence having no more than 4 bedrooms, minimum septic tank liquid capacity shall be 1,250 gallons.(c) For a duplex house or a duplex condominium, sometimes also called a condex, each half shall be considered a separate single-family residence for purposes of determining the minimum liquid capacity of the septic tank.(d) For each additional bedroom up to 10, the liquid capacity of the septic tank shall be increased by 250 gallons per bedroom.(e) For residential structures having more than 10 bedrooms, the liquid capacity of the septic tank shall be as specified in Env-Wq 1010.02.(f) If a garbage grinder is or will be used in the structure served by the septic tank, the liquid capacity of the septic tank shall be increased by 50%.(g) Subject to (i), below, where raw sewage is to be pumped into the septic tank, whether or not a garbage grinder is or will be used, then: (1) The liquid capacity of the septic tank shall be twice the liquid capacity otherwise required by this section or Env-Wq 1010.02, as applicable; and(2) The additional capacity shall be provided by using an additional tank or an additional compartment.(h) When raw sewage is pumped only from plumbing fixtures that are below grade to the building's gravity-fed ISDS, no increase in the total liquid capacity of the septic tank shall be required if the sewage from the below-grade plumbing fixtures will be pumped by a sewage pump capable of handling 2-inch or greater solids.(i) When raw sewage is pumped only from plumbing fixtures that are below grade to the building's gravity-fed ISDS and the provisions of (i), above, do not apply, then the total liquid capacity of the septic tank shall be increased by:(1) At least 250 gallons if:a. Only one septic tank is used, regardless of whether it is a single- or multi-compartment tank; orb. A separate septic tank is used that will connect to the main septic tank for the structure; and(2) At least 1,000 gallons if a separate septic tank is used that will connect directly to the EDA.N.H. Code Admin. R. Env-Wq 1010.01
(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08; ss by #9904-A, eff 4-16-11
Amended by Volume XXXVI Number 41, Filed October 13, 2016, Proposed by #11184, Effective 10/1/2016, Expires 10/1/2026.