Triple bottom line costs for multiple potable reuse treatment schemes

As populations around the world continue to grow and communities appreciate the difficulty in securing new water supplies, water reuse is expected to expand in the coming years. Other factors, such as localized drought severity and increased community and regulatory pressure may also increase the application of water reuse. The level of treatment provided in water reuse projects varies significantly throughout the world depending on numerous factors, such as regulations, water quality, end uses of the treated water, and public influence. Selecting the appropriate treatment technology and level of treatment can be a complex decision. Recent experiences within the water reuse industry have demonstrated that governmental and nongovernmental organizations and advocacy groups can influence selection of a higher or more costly level of treatment than is fit for the water purpose. This is partially because of a failure to consider the full financial, environmental, and social elements of the triple bottom line (TBL). The focus of this report was to develop and apply a TBL framework to help guide sound selection of the treatment process. The objective is to match the treatment to the intended use without expending unnecessary funds or energy or emitting excess greenhouse gas (GHG) and other air emissions, while minimizing other environmental and social costs. Although the present research addresses water reuse only, the TBL approach is equally applicable toward evaluating the full suite of water supply and demand alternatives. Select appropriate potable reuse treatment technologies to meet the need while minimizing the sum of financial, environmental and social costs.