N.H. Code Admin. R. Env-Wq 1508.14

Current through Register No. 25, June 20, 2024

Section Env-Wq 1508.14 - Pretreatment Practices: Flow-Through Devices

Flow through devices such as hydrodynamic separators, water quality inlets, and oil/particle separators shall comply with the following:

(a) The devices shall be designed according to the manufacturer's recommendations based on the WQF to remove a minimum of 80% of U.S. Silica grade OK-110 sand at the WQF;

(b) Water quality inlets and oil/particle separators shall have a 4 foot minimum sump;

(c) Water quality inlets shall be a 3-chamber design, with the first and second chambers having a minimum of 400 cubic feet of storage per acre of contributing impervious area;

(d) Each water quality inlet and oil/particle separator chamber shall be accessible by means of a separate manhole;

(e) The contributing area to the oil/particle separator shall not exceed 1.0 acre of impervious area;

(f) Oil/particle separators shall only be used in an off-line configuration to treat the WQF; and

(g) Oil/particle separators shall have a minimum of 400 cubic feet of permanent pool storage per acre of contributing impervious area.

N.H. Code Admin. R. Env-Wq 1508.14

(See Revision Note #1 at chapter heading for Env-Wq 1500) #9343, eff 1-1-09

Amended by Volume XXXVII Number 32, Filed August 10, 2017, Proposed by #12342, Effective 8/15/2017, Expires 8/15/2027.