The report outlines wastewater treatment technologies for mitigating chemical and microbial contaminants, including both engineered and natural treatment systems. These processes can be used to tailor wastewater reclamation plants to meet the quality requirements of intended reuse applications. The concentrations of chemicals and microbial contaminants in reuse projects designed to augment drinking water supplies can be comparable to or lower than those commonly present in many drinking water supplies. The committee emphasized the need for process reliability and careful monitoring to ensure that all reclaimed water meets the appropriate quality objectives for its use.
Costs of water reuse for potable and non-potable applications vary widely because they depend on site-specific factors, the committee said. Water reuse projects tend to be more expensive than most water conservation options and less expensive than seawater desalination and other new supply alternatives. Although the costs of reclaimed water are often higher than current water sources, the report urges water authorities to consider other costs and benefits in addition to monetary expenditures when assessing reuse projects. For example, water reuse systems used in conjunction with a water conservation program could be effective in reducing seasonal peak demands on the drinking water system. Depending on the specific designs and pumping requirements, reuse projects could also have a larger or smaller carbon footprint than existing supply alternatives or reduce water flows to downstream users and ecosystems.
Water reuse regulations differ by state and are not based on risk-assessment methods, the report says. Adjustments to the federal regulatory framework could help ensure a high level of public health protection, provide a consistent minimum level of protection across the nation, and increase public confidence in potable and non
|Contact: Jennifer Walsh|
National Academy of Sciences