Section Env-Ws 381.09 - Description of Corrosion Control Treatment Requirements(a) A system owner shall complete the corrosion control treatment requirements described below which are applicable to such system under Env-Ws 381.05 through Env-Ws 381.08.(b) Based upon the results of lead and copper tap monitoring and water quality parameter monitoring, the owner of a small or medium-size water systems exceeding the lead or copper action level shall recommend to the department installation of one or more of the corrosion control treatments listed in (d) below, which the system believes constitutes optimal corrosion control for that system. The system shall conduct additional water quality parameter monitoring in accordance with Env-Ws 381.24 to assist the department in reviewing the system's recommendation.(c) The owner of a small or medium-size system exceeding the lead or copper action level shall perform corrosion control studies under (d) below, to identify optimal corrosion control treatment for the system.(d) A system owner performing corrosion control studies shall evaluate the effectiveness of each of the following treatments, and, if appropriate, combinations of the following treatments to identify the optimal corrosion control treatment for that system: (1) Alkalinity and pH adjustment;(2) Calcium hardness adjustment;(3) The addition of a phosphate or silicate based corrosion inhibitor at a concentration sufficient to maintain an effective residual concentration in all test tap samples; and(4) Any other treatment method identified by the department which will provide optimal corrosion control treatment.(e) The water system owner shall evaluate each of the corrosion control treatments using either pipe rig/loop tests, meta l coupon tests, partial-system tests, or analyses based on documented analogous treatments with other systems of similar size, water chemistry and distribution system configuration.(f) The system owner shall measure the following water quality parameters in any tests conducted under this section before and after evaluating the corrosion control treatments listed above: (7) Orthophosphate, when an inhibitor containing a phosphate compound is used;(8) Silicate, when an inhibitor containing a silicate compound is used;(9) Water temperature; and(10) Any other water quality parameter identified by the department needed to evaluate the corrosivity of the water or the effectiveness of the corrosion control treatment.(g) The system owner shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and document such constraints with at least one of the following: (1) Data and documentation showing that a particular corrosion control treatment has adversely affected other water treatment processes when used by another water system with comparable water quality characteristics; and(2) Data and documentation demonstrating that the water system has previously attempted to evaluate a particular corrosion control treatment and has found that the treatment is ineffective or adversely affects other water quality treatment processes.(h) The system owner shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatment processes.(i) On the basis of an analysis of the data generated during each evaluation, the water system owner shall recommend to the department in writing, the treatment option that the corrosion control studies indicate constitutes optimal corrosion control treatment for that system. The water system owner shall provide a rationale for its recommendation along with all supporting documentation specified in (d) through (h) above.N.H. Admin. Code § Env-Ws 381.09
(See Revision Note at chapter heading for Env-Ws 300) #6521, eff 6-4-97, ss by #7734, eff 8-2-02