The U.S. Environmental Protection Agency promulgated the Stage 2 Disinfectants and Disinfection Byproducts Rule on January 4, 2006, and the Long Term 2 Enhanced Surface Water Treatment Rule on January 5, 2006. These are national primary drinking water regulations. As a state that has primacy for administering the Safe Drinking Water Act, Idaho must adopt these rules within two years of promulgation. These federal regulations include special primacy requirements that provide limited flexibility to the states. Because the special primacy requirements are the only part of these regulations that allow the states interpretive discretion, the scope of this negotiated rulemaking is limited to the special primacy requirements and how those requirements should be applied in Idaho.
Stage 2 Disinfectants and Disinfection Byproducts Rule, 40 CFR Part 141, Subparts U and V (pdf 2.0 mb, 107 pages): Requires public water systems that add a chemical disinfectant to their water to conduct distribution system evaluations aimed at identifying sites within the system that are subject to high levels of disinfection byproducts (DBP). These byproducts are formed when chemical disinfectants such as chlorine combine with naturally occurring organic matter in the water. Based upon the results of distribution system evaluation, systems are required to prepare and implement a revised DBP monitoring plan that will ensure more equitable protection of customers from these contaminants.
Long Term 2 Enhanced Surface Water Treatment Rule, 40 CFR Part 141, Subpart W (pdf 2.2 mb, 134 pages): Requires systems that use surface water to monitor their source water in order to assess the occurrence of cryptosporidium, an important waterborne pathogen. Systems that find high levels of this organism in their source water will be required to provide additional treatment to ensure adequate removal and/or inactivation of cryptosporidium.
As a primacy agency, DEQ must adopt state rules that are no less stringent than the federal regulations. Under direction from the Idaho Legislature, DEQ must adopt state rules that are no more stringent than the federal regulations. To ensure that Idaho's rules will be neither more nor less stringent than the federal regulations, the preliminary draft rule incorporates by reference the necessary federal regulations and, therefore, is not subject to negotiation. However, DEQ is seeking input regarding the special primacy requirements. Drinking water system owners and operators, developers, consultants, engineers, cities, counties, industry, drinking water professional organizations, and the public at large may be interested in commenting on this proposed rule.
While not part of this rulemaking, DEQ is also seeking public comment on two guidance documents: "Implementation Guidance for the Long Term 2 Enhanced Surface Water Treatment Rule" and "Implementation Guidance for the Stage 2 Disinfectants and Disinfection Byproducts Rule." These documents provide assistance to public water system owners an doperators in understanding and achieving compliance with the requirements of these rules and may be obtained here in pdf format by August 1, 2007 or by contacting Tom John at thomas.john@deq.idaho.gov or (208) 373-0191.
After consideration of public comments, DEQ intends to present the final proposal to the Board of Environmental Quality in October 2007 for adoption of a pending rule. The rule is expected to be final and effective upon adjournment of the 2008 legislative session if adopted by the Board and approved by the Legislature. |
