Section Env-Dw 711.19 - Frequency of Monitoring for Nitrate; Confirmation Samples(a) The O/O of a community water system, non-transient non-community water system, or transient non-community water system served by groundwater shall monitor annually for nitrate.(b) The O/O of a community water system, non-transient non-community water system, or transient non-community water system served by surface water shall monitor for nitrate quarterly for the initial 4 quarters of operation and annually thereafter, subject to (h), below, and Env-Dw 711.20.(c) Subject to (d) below, if nitrate sampling results indicate an exceedance of the MCL and the system has no previous detections for nitrate, the O/O shall collect a confirmation sample within 24 hours of the system's receipt of notification of the analytical results of the first sample.(d) Any O/O unable to comply with the 24-hour sampling requirement shall: (1) Immediately notify the consumers served by the system in accordance with Env-Dw 800; and(2) Collect and analyze a confirmation sample within 7 days of notification of the analytical results of the first sample.(e) If nitrate sampling results indicate an exceedance of the MCL and the system has previous detections for nitrate, no confirmation sample shall be necessary.(f) Subject to (h), below, if nitrate results are 50% to 100% of the MCL the O/O shall collect a confirmation sample within 7 days.(g) If a confirmation sample is required pursuant to (c) or (f), above, the results of the initial and confirmation samples shall be averaged to determine compliance.(h) If results from the sampling point or the contributing sources have historically demonstrated the presence of nitrate, then: (1) A confirmation sample shall not be required; and(2) The monitoring frequency for the approved sampling point shall be increased to quarterly for that contaminant.N.H. Admin. Code § Env-Dw 711.19
(See Revision Note #1 at chapter heading for Env-Dw 700) #9700, eff 5-1-10
Amended by Volume XXXV Number 06, Filed February 12, 2015 , Proposed by #10771, Effective 2/1/2015, Expires2/1/2025.Amended by Volume XXXVIII Number 50, Filed December 13, 2018, Proposed by #12668, Effective 1/1/2019, Expires 1/1/2029.