Salt Savers: Residential Water Softener Efficiency Improvement Incentive Pilot Program

ABSTRACT To meet standards for wastewater treatment plant effluent, Madison Metropolitan Sewerage District in southern Wisconsin has been implementing a wide variety of chloride source reduction actions for nearly 10 years. As part of that work, the district partnered with service-area communities to undertake a pilot project to test the efficacy of an incentive on voluntary home water softener efficiency upgrades. The district offered rebates, administered through municipalities, to incentivize softener evaluations, optimizations, and replacements. In the approximately 2 year pilot, the district demonstrated a feasible method for a municipally administered rebate system, developed cost estimates for such a program, and estimated its impact on chloride levels. While the pilot did have positive outcomes, such as raising community awareness and municipal involvement, development of a standardized softener evaluation method, participation by over 200 customers, and acquisition of other useful data, it did not demonstrate an impact pronounced enough to warrant a recommendation to scale or repeat the incentive. This pilot program both demonstrated limitations of an incentive for reducing softener discharge through voluntary household actions and raised important concerns about cost and sustainability of an efficiency-only–focused household chloride reduction strategy.