Septic-tank/BMAP ordinance prompts debate over scope, cost and exemptions

County engineering staff and the county attorney presented a long, technical draft ordinance intended to reduce nitrogen loadings from on-site wastewater systems in areas covered by Basin Management Action Plans (BMAPs). Staff said the county has an estimated 47,000 septic tanks within BMAP areas and that roughly 9,000 of those would need removal within ten years to meet BMAP goals; they estimated a total conversion cost in the order of $162 million to meet targets at current prices.

Jeff Earhart, the county’s engineering director, said the ordinance would not mandate a single vendor or technology but would require systems that achieve about a 65% reduction in nitrogen for new systems and for certain replacements. "We're looking to achieve a 65% reduction in nitrogen that's coming from our on-site systems," Earhart said. Staff also described the county's distributed wastewater-system (DWTS) option, which the county has been funding for conversions (staff said recent grants covered 100% of installation costs for conversion projects and a $700 annual maintenance fee). Commissioners asked about exemptions for low-income residents and for repairs of failing systems; staff proposed amendments that would narrow the ordinance to apply primarily to new systems and to allow income-based exemptions for repairs.