Section Env-Wq 708.07 - Design and Layout of Chemical Feed Equipment: Feed Requirements(a) A separate feeder shall be used for each chemical applied.(b) Chemical feeders shall be manually and automatically controlled with the automatic controls designed to allow override by the manual controls.(c) Chemical feed rates shall be adjustable based on appropriate control parameters.(d) Dry chemical feeders shall measure chemicals volumetrically or gravimetrically and provide adequate solution water and agitation of the chemical in the solution tank.(e) Water supply for chemical feed applications, when needed, shall be sufficient in quantity and pressure for the intended application.(f) A means of measuring supply water shall be provided when preparing specific solution concentrations by dilution.(g) The water supply shall be treated as necessary to ensure compatibility with its intended use.(h) Chemical feed equipment shall be located in a dedicated room or area to reduce hazards and dust problems.(i) The length of feed lines shall be minimized by locating the equipment as close to the application point(s) as practical.(j) The chemical feed equipment shall be accessible for servicing, repair, and observation of operation.(k) Feed lines shall be: (1) As short as possible;(2) Easily accessible along the line's entire length;(3) Protected from freezing;(4) Readily cleanable; and(5) Color coded and labeled.(l) Color coding of WWTP piping and chemical feed lines shall: (1) For upgrades to existing plants, comply with either the existing WWTP color coding system or section 4.4.5 of TR-16, 2011 Edition, available as noted in Appendix B; and(2) For all new WWTPs, comply with color codes specified in section 4.4.5 of TR-16, 2011 Edition, available as noted in Appendix B.(m) When conveying gases, the feed lines shall slope upward from the chemical source to the feeder.(n) Provision shall be made for measuring quantities of chemicals used to prepare feed solutions.N.H. Code Admin. R. Env-Wq 708.07
(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.