The U.S. Environmental Protection Agency (EPA) promulgated the Ground Water Rule on November 6, 2006.  This is a national primary drinking water regulation.  As a state that has primacy for administering the Safe Drinking Water Act, Idaho must adopt this rule within two years of promulgation by EPA.

The Ground Water Rule is expected to provide greater protection against microbial pathogens in public water systems that use ground water sources.  The rule attempts to target the subset of ground water systems that are at higher risk of fecal contamination by requiring regular sanitary surveys, establishing a flexible program for identifying higher risk systems through existing bacterial monitoring and state determinations, and providing for ground water source monitoring in systems that do not provide demonstrated virus inactivation through disinfection.  The rule requires that deficiencies detected during sanitary surveys be corrected on a reasonable schedule.  Systems that verify the presence of contamination in a ground water source must remove the source of contamination or provide disinfection treatment.  

As a primacy agency, the Department of Environmental Quality (DEQ) must adopt state rules that are no less stringent than the federal rule. Under direction from the Idaho Legislature, DEQ must adopt state rules that are no more stringent than the federal rule. To ensure that Idaho's rules will be neither more nor less stringent than the federal rule, this proposed rule incorporates the federal rule by reference. The federal rule contains certain special primacy requirements that provide limited flexibility to the state.  The negotiated rulemaking conducted by DEQ was limited to consideration of how the special primacy requirements should be met.  The proposed rule also includes corrections that are typographical and nonsubstantive in nature.

After consideration of public comments, the rule has been adopted as initially proposed.