N.H. Code Admin. R. Env-Wq 1014.04

Current through Register No. 25, June 20, 2024

Section Env-Wq 1014.04 - Receiving Layer

(a) The receiving layer for an effluent disposal area shall meet the following criteria before a site is considered suitable for system design and approval, either as is or with modifications if needed:

(1) If the proposed EDA is within 75 feet of a wetland boundary, then areas delineated as wetlands shall be further classified as having poorly drained or very poorly drained soils, in accordance with Env-Wq 1014.02 or Env-Wq 1014.03, as applicable;

(2) No EDA shall be sited within 75 feet of wetlands that have very poorly drained soils;

(3) No EDA shall be sited within 50 feet of poorly drained jurisdictional wetlands; and

(4) Subject to (e), below, the receiving layer shall:

a. Have at least 2 feet of permeable soil above any impermeable subsoil;

b. Have at least 3 feet of soil above bedrock; and

c. Be under and a minimum of 35 feet down-gradient of the proposed EDA, but no less than the distance required by Env-Wq 1008.05, Table 1008-03 for any side- or down-gradient fill extension.

(b) The 2 feet of permeable soil above any impermeable subsoil required by (a)(4), above, may be created by placing fill onto the subsoil, subject to the following conditions:

(1) The fill shall meet the criteria of (d), below; and

(2) Any state or local permits necessary to place the fill shall be obtained.

(c) The 3 feet of soil above bedrock required by (a)(5), above, for the down-gradient receiving layer may be created by placing fill onto the subsoil, subject to the following conditions:

(1) There shall be an average of 18 inches of natural soil above the bedrock;

(2) The fill shall meet the criteria of (d), below;

(3) Any state or local permits necessary to place the fill shall be obtained; and

(4) Fill shall be placed prior to the department issuing subdivision approval.

(d) Fill used to create a receiving layer in accordance with this section shall:

(1) Contain no tree stumps, sawdust, wood chips, tree bark, bricks, asphalt, concrete, metal, wallboard, construction debris, or other such non-soil materials;

(2) Contain no more than 25% by volume of cobbles larger than 6 inches in diameter or stones larger than 12 inches in diameter;

(3) Have a percolation rate of not greater than 15 minutes per inch after placement and compaction; and

(4) Be homogeneous, and if bedding planes or other discontinuities are present, the applicant shall submit detailed soil analysis from a person or laboratory qualified to perform the analysis with the application to establish that the fill meets the above criteria.

(e) If a technology that has received approval under Env-Wq 1024 with a smaller separation distance to impermeable soil or bedrock will be used on a property, the separation distance(s) specified in the technology approval shall govern the down-slope receiving area requirement.

N.H. Code Admin. R. Env-Wq 1014.04

(See Revision Note at chapter heading for Env-Wq 1000) #9086, eff 2-9-08

Amended by Volume XXXVI Number 41, Filed October 13, 2016, Proposed by #11184, Effective 10/1/2016, Expires 10/1/2026.