DEQ proposes broad rewrite of Idaho septic-system rules, including new definitions, riser requirement and reduced setbacks

The Department of Environmental Quality on Wednesday presented a package of proposed changes to Idaho’s septic and subsurface sewage rules that would reorganize definitions, simplify permitting and change several construction and setback requirements.

The update to IDAPA 58.01.03 (docket 580-103-2301) is intended as a 0‑based review, Mary Anne Nelson, Surface and Wastewater Division administrator for DEQ, told the House Environment, Energy and Technology Committee. "This rule follows legislative intent outlined in Idaho code 39102," Nelson said, and DEQ "removed outdated language and cut more than 1,100 words from this rule."

DEQ said the rewrite moves some material out of the Technical Guidance Manual (TGM) and into rule where it belongs, clarifies multiple definitions and reorganizes installation and approval procedures so technical requirements sit in guidance while definitional and enforcement items remain in rule. The agency also described changes intended to encourage service providers for advanced treatment systems while reducing duplicative licensing barriers.

Key changes described by DEQ include adding or consolidating definitions (for example, ‘‘absorption bed,’’ ‘‘bedroom,’’ ‘‘drain field’’ and ‘‘septic tank’’), clarifying that treatment products designed to treat more than…