New Hampshire Code of Administrative Rules
Env - Department of Environmental Services
Subtitle Env-Ws - Division of Water
Chapter Env-Ws 300 - NEW HAMPSHIRE DRINKING WATER RULES
Part Env-Ws 382 - DISINFECTANT/DISINFECTION BYPRODUCTS RULE
Section Env-Ws 382.09 - Reduced Monitoring for TTHM and HAA5
Current through Register No. 13, March 27, 2025
(a) After a minimum of one year of routine monitoring, the owner of a SW/GWUDISW system serving at least 10,000 persons may submit a written request to the department to reduce monitoring for TTHM and HAA5.
(b) The written request shall include:
(c) The department shall respond to the request in writing and reduce the monitoring frequency to one sample per treatment plant per quarter at a distribution system location reflecting maximum residence time if:
(d) After a minimum of one year of routine monitoring, the owner of a SW/GWUDISW system serving between 500 and 9,999 persons may submit a written request to the department to reduce monitoring for TTHM and HAA5.
(e) The written request shall include the information specified in (b) above.
(f) The department shall respond to the request in writing and reduce the monitoring frequency to one sample per treatment plant per year at a distribution system location reflecting maximum residence time during the month of warmest water temperature if the system meets the criteria specified in (c)(1) through (c)(4).
(g) A SW/GWUDISW system owner serving fewer than 500 persons shall not reduce monitoring to less than one sample per treatment plant per year.
(h) After a minimum of one year of routine monitoring, a system owner serving at least 10,000 persons using only groundwater not under the direct influence of surface water and using a chemical disinfectant may submit a written request to the department to reduce monitoring for TTHM and HAA5.
(i) The written request shall include:
(j) The department shall respond to the request in writing and reduce the monitoring frequency to one sample per treatment plant per year at a distribution system location reflectingmaximum residence time during the month of warmest water temperature if:
(k) After a minimum of one year of routine monitoring, a system owner serving fewer than 10,000 persons using only groundwater not under the direct influence of surface water and using a chemical disinfectant may submit a written request to the department to reduce monitoring for TTHM and HAA5.
(l) The written request shall include the information specified in (i) above.
(m) The department shall respond to the request in writing and reduce the monitoring frequency to one sample per treatment plant per 3-year monitoring cycle at a distribution system location reflecting maximum residence time during the month of warmest water temperature if:
(n) The 3-year monitoring cycle in (m) above, shall begin on January 1 following the quarter in which the system qualifies for reduced monitoring.
(o) A system in (k) above, on reduced monitoring above shall return to routine monitoring as specified in Env-Ws 382.08(e) if:
(p) A system in (k) above on reduced monitoring shall increase monitoring to a collection frequency of one TTHM sample and one HAA5 sample per treatment plant per quarter at points reflecting maximum residence time in the distribution system if:
(q) After one year of quarterly monitoring, a system owner in (p) above shall be eligible to return to routine monitoring specified in Env-Ws 382.08(e) if:
(r) The owner of a SW/GWUDISW system on reduced monitoring serving greater than 500 persons that exceeds eitherthe TTHM level of 0.060 mg/L or the HAA5 level of 0.045 mg/L shall resume monitoring at the routine monitoring frequency specified in Env-Ws 382.08(a) or (b) in the quarter immediately following the monitoring period in which the system exceeds these TTHM or HAA5 levels.
(s) Theowner of a system on reduced monitoring using only groundwater not under the direct influence of surface water and serving at least 10,000 persons thatexceeds either the TTHM annual average of 0.060 mg/L or the HAA5 annual average of 0.045 mg/L shall resume monitoring at the routine monitoring frequency specified in Env-Ws 382.08(d) in the quarter immediately following the monitoring period in which the systems exceeds these TTHM or HAA5 levels.
(t) Theowner of a system on reduced monitoring using only groundwater not under the direct influence of surface water and serving less than 10,000 persons thatexceeds either the TTHM annual average of 0.080 mg/L or the HAA5 annual average of 0.060 mg/L shall resume monitoring at the routine monitoring frequency specified in Env-Ws 382.08 in the quarter immediately following the monitoring period in which the system exceeds these TTHM or HAA5 levels.
(See third Revision Note at chapter heading Env-Ws 300); #7735, eff 8-2-02; amd by #8351, eff 5-14-05