Socio-economic Implications of Deploying Sustainable Phosphorus Management Systems

Phosphorus causes nutrient pollution in lentic water systems, which act as a reservoir of phosphorus since it is stored within the sediments of these waterbodies. The effects of phosphorus pollution include harmful algal bloom events, hypoxia of waterbodies, and impairment of drinking water sources. Therefore, phosphorus removal or recovery systems must be deployed at point source releases like wastewater treatment plant (WWTP) effluents to mitigate these harmful effects. The economies of scale significantly impact the costs of phosphorus removal, resulting in considerably higher costs in areas where the predominant population structure are small and dispersed towns. Additionally, these areas’ average per capita income is generally lower than significant cities and their metropolitan areas. Therefore, the economic impact of requiring phosphorus removal systems to meet water quality criteria in local communities is crucial information to be considered in designing adequate incentive policies for supporting such water pollution control and prevention efforts. In this work, we assess the costs of preventing and controlling phosphorus releases from WWTP effluents in local communities, accounting for the economies of scale and income distribution throughout the contiguous United States by considering open data sources. The fraction of the average annual income the users would need to allocate to cover the cost of phosphorus removal in the absence of potential governmental incentives ranges from 0.002% to 2.5%. In terms of annual costs per household, the cost of phosphorus removal is strongly influenced by the economies of scale, ranging from 10$/year for the more populated counties favored by the economies of scale to thousands of dollars for those WWTPs serving less populated areas. The results obtained constitute a valuable source of information for designing fair policies that promote an equitable contribution of each community to the control and prevention of nutrient pollution.