Report Evaluates Grey Water and Storm Water Use: More Research and Regulations Needed

As water scarcity becomes a real issue for state and local water officials, some water managers and property owners are exploring the option of using greywater and stormwater for non-potable uses. While this solution to augmenting an area’s water supply holds promise, further research and guidelines are necessary according to the National Academies of Science, Medicine, and Engineering.

The Colorado River May Run Dry by 2050. Source: The Ecologist

While California’s drought emergency has grabbed headlines in the media, state and local official across the country face the challenging of coping with water scarcity issues. According to a 2014 GAO report, state water management official in 40 states anticipate shortages of fresh water during the next decade. Major areas of concern are the states dependent on the Colorado River for their water supply. For example, the water level in Lake Mead, a reservoir created by the Hoover Dam located 24 miles southeast of Las Vegas, reached a historic low in June 2014, which put the drinking water supply for 40 million people at risk. Lake Powell, which is also dependent on the Colorado River, is currently at 50 percent capacity, which is an increase from a low of 39 percent capacity. A significant drop in water levels at this lake means a shut down the hydroelectric generators that provide enough electricity to meet the needs of 350,000 homes, according to the New York Times. While rationing is a part of water management plans in the states dependent on the Colorado River, officials are exploring other options for conserving fresh water supplies. Many are looking at the options of using greywater and stormwater to augment their fresh water supplies. What are the cost, benefits, and risks of using these sources for non-potable water?

In-Depth Report Evaluating the Potential Uses of Greywater and Stormwater

In December 2015, the National Academies of Science, Engineering and Medicine announced the release of a report analyzing various aspects of the potential use of stormwater and greywater as a source of water for non-potable applications. The report authors explored the availability of these water sources, their possible use, the potential risks of using these sources, and various best practices. One of the significant findings in their research review is that there is little to no scientific investigation into the public health and environmental impacts of greywater and stormwater use. Another issue raised by the authors is that given the diversity of potential uses and sources of this reclaimed water, generalizing the cost and benefits of this means of water supply augmentation.

Recommendations for Research to Use in Formulating Guidelines and Regulations

Based on research backed by National Academies of Science, Engineering and Medicine, the authors of the report recommended further study and investigation in these five broad areas related to the use of stormwater and greywater:

• Health Risks and Water Quality Issues
• Water Treatment Technology
• Infrastructure Requirements
• Social Science and Decision Making Analysis
• Policy and Regulatory Issues

The report suggests that the Environmental Protection Agency, in collaboration with private water organizations and state government water management officials, conduct the recommended research and analysis.