In the future human water is derived from recycled human wastes is predicted by more than a few dystopian fantasies. While no climate model predicts a future without rain on Earth, severe disturbances in hydrology are visible. In some regions, excessive rain and flooding are expected and intensifying drought in others. California has become a leading example of the last one.
Know in the industry known as recycled wastewater and in common person terms tap to water. In some consumers, this water source understandably triggers a gag reflex, but it shouldn’t. Recycled wastewater is quickly becoming an essential element of a drought-proof water supply in the climate-change era.
Some south California has already been drinking recycled wastewater for years, and this because of the pilot project in the Orange Country. $5.1 billion drought-response package Governor Gavin Newsom announced last week focuses mainly on making these resources more readily available.
Infrastructure spending on wastewater recycling facilities the federal government should prioritize as many places are facing water shortages. No state faces more economic danger from an unstable water supply than California. About 80% of the water developed for urban and agriculture use flows to California farms. California produces more than half of the US vegetables, nuts, and fruits. The dairy cows that graze in California pastures produce 20% of the national milk supply.
California farmers have faced water insecurity for a long, but the stresses are now increasingly severe. In the next 30 years, the summer drought will be triple more severe. Southern California depends entirely on Northern California and on the Colorado River to hydrate its 24 million inhabitants and lands.
One option that has been explored is desalination, a filtration method that separates salt from ocean water. A $1.5 billion desalination plant was built in Carlsbad, California, in 2015, which now supplies 10% of San Diego’s water. Since then, many more desalination plants have been set up in central and southern California. Yet recycling wastewater is much cheaper.
Both the water is treated mechanically, pumped through a multi-setup filtration process that culminates with reverse-osmosis membranes that pull out impurities. The most challenging thing to remove is salt. Sewage is easier and cheaper to filter because it contains lower salts.