The costs of direct and indirect potable water reuse in a medium-sized arid inland community

Abstract

Planned potable water reuse can improve the reliability of water supplies by providing drinking water from wastewater. While the US government predicts near-term conflict over water in numerous small-to-medium-sized arid inland communities, knowledge gaps exist regarding the cost of potable reuse for this context, making it difficult for water managers to understand the feasibility of options. This research aims to inform decision-making about potable reuse in small-to-medium-sized arid inland communities by estimating the total present worth of several indirect and direct potable reuse treatment scenarios. We find that the present worth for indirect potable reuse that uses an aquifer as an environmental buffer is only slightly higher than for direct potable reuse that includes drinking water treatment; the present worth of both of these scenarios is higher than for direct potable reuse that does not include drinking water treatment due to the additional pumping and piping requirements. Further, scenarios including reverse osmosis for advanced treatment have significantly higher present worth values than those including ozone/biological activated carbon. All reuse scenarios considered cost far less than purchased water. Costs aside, any scenario must also be acceptable to regulators and the public and approvable from a water rights perspective.