Committee hears bill to resolve septic "mixing zone" conflict, grandfather existing permits

Representative Courtney Sprunger, sponsor of House Bill 180, told the House Local Government Committee the bill aims to fix a longstanding conflict between two sections of Montana law that can force property owners to remove or replace legally permitted septic systems when they divide land. "This is a common sense bill that will grandfather existing septic system mixing zones that were legally permitted and installed if a property owner wants to divide their property," Sprunger said in opening remarks.

Rachel Clark, engineering bureau chief for the Montana Department of Environmental Quality’s Water Quality Division, described how mixing zones function: wastewater percolates through soil until it reaches groundwater and is diluted within a defined mixing zone. Clark said most mixing zones are site-specific but commonly range on the order of tens to a few hundred feet and that, under the…