Section Env-Ws 381.06 - Definition of Optimized Corrosion Control Treatment(a) A system owner is deemed to have optimized corrosion control and shall not be required to complete the applicable corrosion control steps identified in Env-Ws 381.05 and Env-Ws 381.08 if the system satisfies one of the following: (1) If the water system is small or medium-sized, it shall be deemed to have optimized corrosion control if the system meets the lead and copper action levels during each of 2 consecutive 6-month monitoring periods conducted in accordance with Env-Ws 381.15 through Env-Ws 381.21;(2) Any size water system shall be deemed by the department to have optimized corrosion control treatment if the system owner has conducted activities equivalent to the corrosion control steps applicable to such system in Env-Ws 381.05 through Env-Ws 381.08;(3) The department shall provide the system owner with written notice explaining the basis for its decision and shall specify the treatment control water quality parameters representing optimal corrosion control in accordance with Env-Ws 381.10(e) and (f); or(4) Any size water system shall be deemed to have optimized corrosion control if the system owner submits results of tap water monitoring conducted in accordance with Env-Ws 381.15 through Env-Ws 381.2 l and source water monitoring conducted in accordance with Env-Ws 381.28 through Env-Ws 381.30 that demonstrates for 2 consecutive 6-month monitoring periods that the difference between the 90th percentile tap water lead level computed under Env-Ws 381.03(c), and the highest source water lead concentration is less than the practical quantitation level (PQL) for lead defined in 40 CFR 141.89(a)(1)(ii).(b) A system which is deemed to have optimized corrosion control pursuant to (a) above and which has treatment in place shall continue to operate and maintain optimal corrosion control treatment.(c) A system owner shall provide the department with the following information in order to support a determination under this section: (1) The results of all test samples collected for each of the water quality parameters in Env-Ws 381.09(f);(2) A report explaining: a. The test methods used by the water system to evaluate the corrosion control treatments listed in Env-Ws 381.09(d);b. The results of all tests conducted;c. The basis for the system's selection of optimal corrosion control treatment; andd. How corrosion control has been installed and how it is being maintained to ensure minimal lead and copper concentrations at consumers' taps.(3) The results of tap water samples collected in accordance with Env-Ws 381.15 through Env-Ws 381.21 at least once every 6 months for one year after corrosion control has been installed.(d) The owner of a small or medium-size water system required to complete the corrosion control steps due to its exceedance of the lead or copper action level may cease completing the treatment steps whenever the system meets the lead and copper action levels during each of 2 consecutive monitoring periods conducted pursuant to Env-Ws 381.15 and submits the results to the department.(e) If any water system that ceased completing the treatment steps pursuant to (d) above exceeds the lead or copper action level during any subsequent monitoring period, the system owner shall recommence completion of the applicable treatment steps, beginning with the first treatment step which was not completed. The system shall repeat treatment steps previously completed by the system if the department determines that it is necessary to properly implement the treatment requirements of Env-Ws 381.05 through Env-Ws 381.08. The department shall notify the system owner in writing of such a determination and explain the basis for its decision.(f) The requirements for the owner of any small or medium-size system to implement corrosion control treatment steps in accordance with Env-Ws 381.08, including systems deemed to have optimized corrosion control under Env-Ws 381.06(a)(2), shall be triggered whenever that system exceeds the lead or copper action level.(g) The owner of a water system whose highest source water lead level is below the method detection limit shall be deemed to have optimized corrosion control if the 90th percentile tap water lead level is less than or equal to the practical quantitation level for lead for 2 consecutive 6-month monitoring periods.(h) The owner of a water system deemed to have optimized corrosion control in accordance with this section shall continue to monitor for lead and copper at the tap at least once every 3 calendar years using the reduced number of sites specified in Env-Ws 381.17(b) and collecting the samples at times and locations specified in Env-Ws 381.21.(i) The owner of a water system deemed to have optimized corrosion control pursuant to this part shall notify the department in writing pursuant to Env-Ws 381.33(g) of any change in treatment or the addition of a new source within 60 days.(j) A system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under this section shall implement corrosion control treatment in accordance with the deadlines established in Env-Ws 381.08. A large system owner shall adhere to the schedule specified for medium-size systems, with the time periods for completing each step being triggered by the date the system is no longer deemed to have optimized corrosion control.(k) A water system owner deemed to have optimized corrosion control under this section shall: (1) Operate in compliance with optimal water quality parameters pursuant to Env-Ws 381.10;(2) Conduct lead and copper tap sampling pursuant to Env-Ws 381.18; and(3) Conduct water quality parameter sampling pursuant to Env-Ws 381.20.N.H. Admin. Code § Env-Ws 381.06
#5422 eff 6-22-92 (See Revision Note at chapter heading for Env-Ws 300); #6521, eff 6-4-97, ss by #7734, eff 8-2-02; amd by #9598, eff 11-21-09