N.H. Code Admin. R. Env-Wq 1508.11

Current through Register No. 25, June 20, 2024

Section Env-Wq 1508.11 - 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. Code Admin. R. Env-Wq 1508.11

(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.