Idaho officials are working on rules to provide for septic system setbacks from surface water. The draft model was based on the ability to limit the discharge of phosphorus. According to the Idaho Department of Environmental Quality’s synopsis of the draft regulations, it will use a software tool to account for effluent and groundwater quality, and characteristics of the drainfield, aquifer and surface water bodies to calculate the appropriate setback. The new regulations do not address nitrogen, which continues to be governed by existing rules because systems that reduce nitrogen do nothing to reduce the amount of phosphorus.New MexicoNew state
