San Diego To Recycle Sewer Water Into Tap Water

Treated sewer water will make up one-third of the city's drinking water supply by 2035.

San Diego sewer water could enter tap water system
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Treated sewer water will make up one-third of the city's drinking water supply by 2035.

In May 2017, San Diego city officials made an important announcement regarding the future of the city’s water supply. According to the San Diego Union-Tribune, the city planned to blend treated sewer water with the regular drinking water supply.

Fast forward to 2018 and the project is moving right along. On March 6, the State Water Board announced the approval of new regulations. These detail the use and quality of recycled sewer water that will later blend with surface water reservoirs.

The board noted that independent scientific reviews and an expert panel worked together for two years to verify the validity of the new regulations. For San Diego’s water recycling project, Pure Water San Diego, the regulation approval was just another step in their multi-year plan.

According to the Pure Water San Diego website, the goal is to provide one-third of the city’s water supply with recycled water by 2035. The water purification process will utilize ozonation, biologically activated carbon, and membrane filtration. Also, it will use reverse osmosis and UV/advanced oxidation. Additionally, the water treatment process will use calcium and carbonate.

In the first phase of the project, the soon-to-be-built North City Pure Water Facility will first treat the sewer water. From there, the water will be sent to the Miramar Reservoir for a holding period. At this point, the filtered water is blended with regular tap water. Finally, a facility treats the water once more before it’s released as tap water. In addition to the North City Pure Water Facility, the city is planning additional locations in Central Area and South Bay.

The future of California tap water involves sewer water
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Even if you’re not a San Diego resident, all Californians should take note. Fox News reported that other cities in the state are likely to follow San Diego’s example. The newly announced regulations can be applied to any of the 36 water reservoirs in the state. It may just be a matter of time until all California tap water is partially comprised of treated sewer water.

If you’re wondering what sewer water tastes like, ask some breweries. In fact, beer brewers have already experimented with using recycled water. Water Deeply described how Half Moon Bay Brewing used gray water for a test batch. Taking it a step further, Stone Brewing made five barrels of its pale ale with treated sewer water.

Colorado breweries also followed suit and produced craft beers with recycled water. In addition, an Oregon competition in 2017 hosted by Pure Water Brew challenged participants to brew the best beer with treated sewer water.