From Channel to Tap - Stormwater as a Potable Water Supply
Prolonged droughts, the fragility of the Delta ecosystem and other factors have made sustainable and reliable water supplies increasingly scarce in California. Based on these conditions, there is a clear need to more effectively use our water resources to provide reliable high-quality potable supplies to our communities. Most of California’s existing stormwater capture is accomplished through surface water reservoirs that collect runoff to supply potable water and while also providing flood protection. However, more work can be done to utilize this important resource. Several agencies are implementing programs to reclaim wastewater for potable supply using advanced treatment. Opportunities existing to augment wastewater supplies with stormwater to capture and use stormwater for potable supply.
Connectivity of stormwater to potable reuse programs may provide multiple benefits, such as:
• Diversification of local water supplies
• Improved water quality
• MS4 permit compliance
• Use of existing infrastructure
• Partnerships can offer cost sharing opportunities that provide multiple benefits such as local environment enhancement and potable water use offsets
Understanding the potential applications of stormwater as a potable water supply and the associated treatment needs requires characterization of stormwater quality and an understanding of the impact of introducing stormwater to potable reuse systems. Stormwater quality is highly variable and could contain elevated levels of bacteria, metals, organics and sediment, potentially needing treatment for various beneficial uses. Other challenges include institutional and regulatory constraints (potable reuse regulations, NPDES permits/pretreatment programs), technical challenges and dealing with stormwater uncertainty and timing.
Although connecting stormwater to potable reuse systems presents several challenges, the stormwater-potable reuse nexus is well worth exploring. This presentation will provide a framework for agencies to evaluate the stormwater-potable reuse nexus.
Brown and Caldwell promotes a One Water approach for helping agencies evaluate this opportunity. This approach considers the water cycle as an integrated system, acknowledging the interconnectedness of surface water, groundwater supply, stormwater, wastewater, and energy.
To engage the audience, we will seek their participation by having the audience discuss opportunities and challenges with using stormwater as a potable water supply.
Lisa Skutecki, P.E., CPESC, QSD/P is Brown and Caldwell's Southern California Water Resources Leader and has 19 years of environmental engineering consulting experience, including watershed guidance and planning, storm water quality assessment and monitoring, and Best Management Practice assessment and design. Lisa received her B.S. in Civil and Environmental Engineering at Arizona State University and participated in the Water Leaders Class through the Water Education Foundation. When it rains in Southern California, you can expect to find her assisting with the storm event and then heading to Mammoth to enjoy the fresh powder.