Steps Toward a Sustainable Water Future: A Case Study from a STORMS POTW Pilot Project and Stormwater Master Planning Effort
The most recent drought again highlighted the weakness of southern California’s water situation due to reliance on imported sources. As our population continues to grow, and our climate continues to change, so to must our approach to water supply. Many agencies are looking for ways to become less water dependent on imported sources and remove water as a limiting factor for growth. This session will explore action Orange County Sanitation District (OCSD) has taken, along with their partners, to exploit wastewater and stormwater as potable water sources. Connecting the drops is a daily occurrence and nexus point at OCSD; join us as we talk about how.
In an ongoing partnership, OCSD works with the Orange County Water District (OCWD) to develop a new source of potable water by recycling both wastewater and stormwater. The Groundwater Recharge System (GWRS) treats these otherwise wasted sources of water and stores the product in an aquifer through recharge basins. It is the largest indirect potable reuse project in America and just received a Guinness World Record for recycling the most water in a 24-hour period. This system reduces OCWD’s reliance on water from State resources by taking advantage of OCSD’s ability to capture and prepare a water resource that would typically be lost to the marine environment. This helps OCSD in its mission to protect the environment, succeed in its goal to recycle as many resources as possible, and provide TMDL support to neighboring communities to help with regional water quality issues.
OCSD recently partnered with the State Water Resources Control Board, the County of Orange, and OCWD to facilitate a STORMS related pilot study to quantity the amount of stormwater captured and used within a specific geographic area. This presentation will focus on the lessons learned from OCSD’s effort to quantify their facility stormwater capture and use as part of the study. These lessons will translate to other Publicly Owned Treatment Works (POTWs), counties, cities, and others who will need to understand what data gaps may exist in capturing this information. The study includes stormwater and urban runoff through dry weather diversions and explains how much water from each source stream was measured and captured. Wastewater agencies are built to effectively measure wastewater, and even dry weather diversion flows, however, there has typically been little to no measurement of true stormwater. As the State looks to POTWs and other entities to measure additional flows, these lessons learned will really shine.
In addition, OCSD is currently updating their Stormwater Master Plan (SWMP). OCSD is partnering with Michael Baker International to produce 1D-2D models of their facilities to account for onsite stormwater and process flows to demonstrate compliance with the NPDES permit. OCSD facilities have always been designed to capture and treat all the stormwater that falls on its property. Now the agency will be looking towards the future and trying to ascertain what limitations and opportunities might exist to maximize stormwater use efforts. OCSD is already providing millions of gallons of treated wastewater for the GWRS reuse project. Through the SWMP, OCSD wants to quantify how much urban runoff and captured stormwater is used and what opportunities there may be to increase this water resource.
This is truly an exercise in not only connecting the drops from summit to sea but capturing and using every single drop along the way.