Section Env-Wq 708.04 - Piping and Flow Distribution Devices(a) Piping and channels throughout the WWTP shall be designed to carry the maximum design flows as follows:(1) Gravity influent sewers shall not be surcharged during normal operating conditions;(2) Bottom channel corners shall be filleted, with the elimination of pockets and corners where solids can accumulate;(3) Suitable gates, stop logs, or plates shall be placed in channels to seal off unused sections that might accumulate solids;(4) Non-corrodible materials shall be used for gates; and(5) Channels that may not be used for considerable periods of time shall have valved drains.(b) Flow distribution devices shall be designed to:(1) Control organic, solids, and hydraulic loading to WWTP process units;(2) Provide distribution to individual treatment units to ensure equal distribution among all units;(3) Provide visible status indication for influent flow to each unit via weirs, sluice gates, slide gates, control valves, or other means;(4) Provide positive scum and foam removal in all channels and distribution structures that have a trapped-free surface; and(5) Not rely on effluent weirs and flow route symmetry for flow control.(c) Underflow shear gates for balancing flows shall not be permitted.N.H. Code Admin. R. Env-Wq 708.04
(See Revision Note at chapter heading for Env-Wq 700) #8590, eff 3-25-06
Amended byVolume XXXIV Number 46, Filed November 13, 2014, Proposed by #10693, Effective 10/15/2014, Expires10/15/2024.