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).