No abstract

An evaluation of costs, rate, and environmental impacts of upgrading publically owned treatment works (POTWs) in the State of Utah to four levels of nutrient control allowed a variety of nutrient control policies to be assessed. Upgrade costs and rate impacts indicated that costs would be within a defined range for many POTWs, especially with design capacities greater than 40,000 m3/day (∼10 mgd). However, costs were significantly higher for some POTWs with lower design capacities, and nutrient upgrades to the most stringent levels would not be affordable for these communities, representing about 15 percent of the service population. The resulting equity issues can be addressed through hardship grants program and/or regulations based on a trading scheme. Analysis demonstrated that trading offers advantages, including cost efficiency and flexibility to accommodate further nutrient reductions and population growth, and greater ability to interface with urban and rural nonpoint nutrient control. Currently, the State of Utah is establishing technology‐based nutrient limits that can be affordably implemented at all POTWs in phases. Additionally, a multi‐faceted approach is being evaluated that will consider prioritized watershed‐scale strategies, point and nonpoint sources of pollution, ecological and socioeconomic implications, and stakeholder participation in nutrient reduction programs.

No abstract

An evaluation of the costs, rate impacts, and environmental impacts of upgrading POTWs in the State of Utah to four levels of nutrient control allowed a variety of POTW nutrient control policies to be evaluated. POTW unit upgrade costs and rate impacts indicated that costs would be within a defined range for many POTWs, especially those with design capacities greater than about 40,000 m 3 /day (~10 mgd). However, unit costs were significantly higher for some POTWs with lower design capacities, and nutrient upgrades to the most stringent levels would not be affordable for some communities representing about 15 percent of the service population. Methods for addressing the resulting equity issues include a hardship grants program and/or regulation based on a trading scheme. Analysis demonstrated that trading offers further advantages, including cost efficiency, flexibility to accommodate further nutrient reductions and population growth, and greater ability to interface with urban and rural non-point nutrient control. Consideration of "early movers" is desirable for any POTW nutrient control policy selected. The potential for future, more stringent effluent discharge requirements should be considered during the planning and design of POTW upgrades and expansions.