N.H. Admin. Code § Env-Wq 1508.12

Current through Register No. 44, October 31, 2024
Section Env-Wq 1508.12 - Pretreatment Practices: Sediment Forebays

Sediment forebays shall comply with the following:

(a) Sediment forebays shall not be located in any of the areas identified in Env-Wq 1507.02(c)(1)-(4) unless the practice has an impermeable liner;
(b) Unless otherwise specified, a sediment forebay shall be designed to contain 10% of the WQV;
(c) Sediment forebays for gravel wetland systems shall be designed to drain within 72 hours of storm events;
(d) Forebays shall be no less than 2 feet and no more than 6 feet in depth;
(e) Forebay side slopes shall be no steeper than 3:1;
(f) A fixed vertical sediment marker shall be installed to measure sediment depth; and
(g) Upon completion of maintenance, all disturbed areas shall be re-stabilized in accordance with the approved plans.

N.H. Admin. Code § Env-Wq 1508.12

(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.
Amended by Number 41, Filed October 12, 2023, Proposed by #13758, Effective 9/28/2023, Expires 9/28/2033 (formerly Env-Wq 1508.11) (see Revision Note #4 at chapter heading for Env-Wq 1500).