Section Env-Ws 382.22 - Treatment Technique for Control of Disinfection Byproduct Precursors(a) The owner of a SW/GWUDISW system using conventional filtration treatment shall use enhanced coagulation or enhanced softening as treatment techniques to control disinfection byproduct precursors in drinking water treatment and distribution systems.(b) A SW/GWUDISW system owner using conventional filtration treatment shall operate with enhanced coagulation or enhanced softening to achieve the TOC percent removal levels specified in Env-Ws 382.23 or Env-Ws 382.24 unless the system achieves at least one of the following criteria:(1) The system's source water TOC level is less than 2.0 mg/L, calculated quarterly as a running annual average;(2) The system's treated water TOC level is less than 2.0 mg/L, calculated quarterly as a running annual average;(3) The system's source water SUVA prior to any treatment and measured pursuant to Env-Ws 382.06 is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average;(4) The system's finished water SUVA measured pursuant to Env-Ws 382.06 is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average;(5) The system meets the following criteria:a. The system uses only chlorine for primary disinfection and for the maintenance of a residual in the distribution system;b. The TTHM running annual averages shall be no greater than 0.040 mg/L; andc. The HAA5 running annual averages shall be no greater than 0.030 mg/L; or(6) The system meets the following criteria: a. Source water TOC level, measured pursuant to Env-Ws 382.06, is less than 4.0 mg/L, calculated quarterly as a running annual average;b. The source water alkalinity is greater than 60 mg/L, as CaCO3, calculated quarterly as a running annual average; andc. Either the TTHM and HAA5 running annual average shall be no greater than 0.040 mg/L and 0.030 mg/L respectively or the system owner submits to the department the following: 1. A clear and irrevocable financial commitment no later than the effective date of compliance specified in Env-Ws 382.04 to use technologies that will limit the levels of TTHMs and HAA5 to no more than 0.040 mg/L and 0.030 mg/L respectively; and2. A schedule containing milestones and periodic progress reports for installation and operation of appropriate technologies no later than the dates specified in Env-Ws 382.04.(7) Systems shall still comply with monitoring requirements in Env-Ws 382.13.(c) The department shall: (1) Review the financial commitment and schedule specified in (6)c. above;(2) Approve the proposed schedule if the monitoring plan conforms to department rules and applicable statutes; and(3) Notify the system owner in writing of its determination.(d) The technologies specified in (6)c. above, shall be installed and operating prior to June 30, 2005.(e) Failure to install and operate these technologies by the date in the department- approved schedule shall constitute a violation of Env-Ws 300.(f) If a system owner practicing enhanced softening cannot achieve the TOC removals specified in Env-Ws 382.23(a), the system owner may achieve compliance with TOC removals by using: (1) Softening that results in lowering the treated water alkalinity to less than 60 mg/L, as CaCO3, measured monthly pursuant to Env-Ws 382.06 and calculated quarterly as a running annual average; or(2) Softening that results in removing at least 10 mg/L of magnesium hardness, as CaCO3 , measured monthly and calculated quarterly as an annual running average.(g) A system owner identified in (f) above, shall comply with the monitoring requirements specified in Env-Ws 382.13.N.H. Code Admin. R. Env-Ws 382.22
(See third Revision Note at chapter heading Env-Ws 300); #7735, eff 8-2-02; amd by #8351, eff 5-14-05