David Pedersen, PE – Wastewater for Potable Re-Use Now Has High Value In California

David Pedersen is the General Manager of the Las Virgenes Municipal Water District and the Administrating Agent for the Las Virgenes – Triunfo Joint Powers Authority. These two agencies are developing the PURE Water Project and are building a $466 million facility that will take wastewater and purify it for re-use as potable water.

Given his municipal water agency’s dependence on State Water Project allocations from Northern California four hundred miles away, under his leadership, Las Virgenes is diversifying the water sources that it delivers to 100,000 customers.

The conversation starts with the big picture: Fully 71% of the Earth’s surface is covered with water. But 95% of this water is saltwater. Only 5% is freshwater and of this, 68% is locked up in ice caps. Clearly access to fresh water is problematic around the world, and especially so in Southern California where the effects of climate change are causing more severe droughts and shortages, followed by flooding. Given this reality, water agencies have been exploring alternative sources… from the low-hanging fruit of water conservation, to far-out ideas like tapping and piping waters from Alaskan Rivers proposed in 1991.

The discussion turns to desalination, a logical pursuit given the Las Virgenes service territory and its proximity to the Pacific Ocean. During water shortages in 1922, hundreds of concerned residents and businesses questioned asked about this opportunity… especially as it has been employed worldwide. While its costs of approximately a half penny per gallon compares to the PURE project — Dave explains that there are environmental factors that hinder such desalination developments… from the need for a coastal footprint to industrial desalination plants, to water intakes sucking in fish and other marine life, to concentrated brine being discharged into the ocean. But paramount is the reality that it is energy intensive… exacerbating climate change.

The PURE Water Project builds on Las Virgenes’s work to diversity its water supply, taking its use of recycled water for watering grass, irrigation, golf courses, school grounds, and highway medians to the next level. Now these agencies are purifying recycled water so that it is potable. Recycled water will be drawn from the Tapia Water Reclamation facilities, then will be advanced through three purification steps – microfiltration, reverse osmosis, and ultraviolet light oxidation, before being stored in a reservoir to be treated once again for human consumption.

Similar purification projects are being done around the country in states including Nevada, Texas, Virginia, North Carolina, and Florida. Los Angeles County has a similar project albeit a much larger scale. The Warren Water Resource facilities in Carson, California are being adapted to clean and produce up to 150 million gallons of potable water each day. That $8 billion project will send potable water through pipelines to recharge local groundwater basins in different parts of the county.

Dave summarizes that he is fulfilled in his career. He is proud to be making a difference pioneering with recycled water and turning it into a viable resource for the future and future generations. He is educating his constituents, many of whom need special attention and time to get comfortable with drinking wastewater. Dave explains that the PURE Water Project, and the quest for potable re-use of wastewater, is all part of the water cycle that replenishes the Earth. Water is not created or destroyed, it is just turned from one form or another to sustain healthy life on the planet.