Section Env-Ws 380.18 - Monitoring of Residual Disinfectant in the Distribution System for Systems That Do Not Provide Filtration(a) The residual disinfectant concentration shall measure at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in Env-Ws 325.02.(b) A public water system which uses both a SW/GWUDISW, and a ground water source, may take disinfectant residual samples at points other than the total coliform sampling points if the department determines that such points are more representative of disinfected water quality within the distribution system.(c) The department shall make the determination of whether alternate sampling points are more representative of disinfected water quality within the distribution system based on the following criteria:(1) The general hydraulics of the distribution system based on water demand patterns;(2) The relative quantity of water supplied from the various water sources;(3) The scheduling of supply from pumped sources; and(4)Historic disinfectant concentration at various locations in the distribution system as determined from water supply records.(d) Heterotrophic bacteria, measured as heterotrophic plate count may be measured in lieu of residual disinfectant concentration.N.H. Code Admin. R. Env-Ws 380.18
#5098, eff 3-18-91, EXPIRED 3-18-97
New. #6521, eff 6-4-97 (See Revision Note at chapter heading for Env-Ws 300); ss by #8352, eff 5-14-05 (formerly part of Env-Ws 380.22 )