Section Env-Dw 715.06 - Monitoring Requirements(a) The O/O of a PWS subject to this part shall conduct sampling and monitoring as specified in 40 CFR § 141.132 and § 141.133.(b) Multiple wells for which a disinfectant is added at multiple separate points shall be considered as one treatment plant for determining the minimum number of TTHM and HAA5 samples specified in 40 CFR § 141.132, in accordance with the following criteria:(1) Routine monitoring at a frequency specified in 40 CFR § 141.132 shall have been performed for a minimum of one year;(2) Running annual average results shall be less than 0.040 mg/L for TTHM and less than 0.030 mg/L for HAA5;(3) For overburden wells, multiple wells shall be located within the same aquifer as determined using the stratified drift aquifer mapping of the U.S. Geological Survey;(4) For bedrock wells, multiple wells shall be located within an area of less than 4,000 feet in radius; and(5) The water quality of the multiple wells shall be within the following limits: a. pH within 0.5 units, using one of the analytical methods specified in 40 CFR § 141.23(k);b. Total hardness within 10 mg/L, as CaCO3;c. Alkalinity within 10 mg/L, as CaCO3; andd. Conductivity within 50 µmhos/cm2.(c) If running annual average results for multiple wells initially considered as one treatment plant in (b), above, subsequently exceed 0.040 mg/L for TTHM or 0.030 mg/L for HAA5, each well shall then be considered as a separate treatment plant for monitoring purposes, subject to the routine and reduced monitoring frequency requirements specified in 40 CFR § 141.132.N.H. Code Admin. R. Env-Dw 715.06
#9619, eff 1-1-10 (See Revision Note #2 at chapter heading for Env-Dw 700)
Amended by Volume XXXVIII Number 23, Filed June 7, 2018, Proposed by #12532, Effective 6/1/2018, Expires 6/1/2028.