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 381 - CORROSION CONTROL TREATMENT, LEAD AND COPPER ACTION LEVELS
Section Env-Ws 381.10 - Department Evaluation, Approval, and Designation of Optimal Corrosion Control Treatment
Current through Register No. 13, March 27, 2025
(a) Having considered available information including, where applicable, studies performed under Env-Ws 381.09(d) through (i) and a system's recommended treatment alternative, the department shall:
(b) When specifying alternative corrosion control treatment, the department shall consider the following:
(c) The department shall notify the system owner of its decision on optimal corrosion control treatment in writing and explain the basis for this determination. When the department requests additional information to aid its review, the water system owner shall provide the information.
(d) Each system owner shall properly install and operate throughout the distribution system the optimal corrosion control treatment specified by the department under (a) through (c) above.
(e) The department shall evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the water system owner and determine whether the system has properly installed and operated the optimal corrosion control treatment specified by the department in (a) through (c) above.
(f) Upon reviewing the results of tap water and water quality parameter monitoring by the system, both before and after the system installs optimal corrosion control treatment, the department shall specify:
(g) The values for the applicable water quality control parameters listed above shall be those that the department determines to reflect optimal corrosion control treatment for the system.
(h) T he department shall specify values for additional water quality control parameters determined by the department to reflect optimal corrosion control for the system and the department shall notify the system owner in writing of these determinations and explain the basis for its decisions.
(i) The owner of a system using corrosion control shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameters at or above minimum values or within ranges specified by the department as specified in (f) above for all samples collected under Env-Ws 381.19 through Env-Ws 381.21.
(j) Compliance with the requirements of this section shall be determined every 6 months pursuant to Env-Ws 381.2 6.
(k) A water system shall be out of compliance with the requirements of this section for a 6-month period if it has excursions for any department-specified parameter on more than 9 days during the period.
(l) The daily value, when determining if a system has an excursion, shall be calculated as follows:
(m) The department shall not use the results in (l) above if the department determines that the data collected is from an obvious sampling error or from known errors in collection, processing, or transcription.
(n) A system owner may submit to the department a written request to modify the department's determination of the optimal corrosion control treatment under (a) through (c) above or optimal water quality control parameters under (e) and (f) above.
(o) The written request for modification pursuant to (n) above shall include:
(p) The department shall respond to the modification request in writing and shall approve the modification if the alternative corrosion control treatment proposed continues to optimize corrosion control treatment.
(q) In approving the request, the department shall:
(See Revision Note at chapter heading for Env-Ws 300) #6521, eff 6-4-97, ss by #7734, eff 8-2-02; amd by #8351, eff 5-14-05; amd by #9598, eff 11-21-09