Section Env-Ws 382.09 - Reduced Monitoring for TTHM and HAA5(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: b. The system EPA number; andc. A summary of TOC, TTHM and HAA5 sample results.(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: (1) The system owner submits the information identified in (b) above;(2) The source water annual average TOC level, before treatment, is less than or equal to 4.0 mg/L;(3) The TTHM annual average is less than or equal to 0.040 mg/L; and(4) The HAA5 annual average is less than or equal to 0.030 mg/L.(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: (2) The system EPA number; and(3) A summary of TTHM and HAA5 sample results.(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:(1) The system owner submits the information identified in (i) above;(2) The TTHM annual average is less than or equal to 0.040 mg/L; and(3) The HAA5 annual average is less than or equal to 0.030 mg/L.(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:(1) The system owner submits the information identified in (i) above;(2) The TTHM annual average is less than or equal to 0.040 mg/L and the HAA5 annual average is less than or equal to 0.030 mg/L for 2 consecutive years; or(3) The TTHM annual average is less than or equal to 0.020 mg/L and the HAA5 annual average is less than or equal to 0.015 mg/L for one year.(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: (1) The TTHM average is greater than 0.060 mg/L and less than or equal to 0.080 mg/L; or(2) The HAA5 average is greater than 0.045 mg/L and less than or equal to 0.060 mg/L.(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: (1) The TTHM average is greater than 0.080 mg/L; or(2) The HAA5 average is greater than 0.060 mg/L.(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: (1) The TTHM annual average is less than or equal to 0.060 mg/L; and(2) The HAA5 average is less than or equal to 0.045 mg/L.(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.N.H. Code Admin. R. Env-Ws 382.09
(See third Revision Note at chapter heading Env-Ws 300); #7735, eff 8-2-02; amd by #8351, eff 5-14-05