The entire state of California is suffering from moderate to extreme drought for the first time in 15 years. The economic loss to the state — partly due to 800,000 acres of farmland being idled because of a lack of irrigation — is estimated to be at least $7.48 billion in direct and indirect costs.
What is projected to be the worst drought in 500 years has brought many communities to the brink. According to the State Water Project, California’s primary municipal water distribution system, the organization does not have enough water to supplement local water agencies’ reserves, meaning that 17 communities risk running out of drinking water within 60 to 120 days.
The state is moving to put emergency measures into place, including plans to truck in water to the most-endangered communities, drilling additional groundwater wells, continuing bans on fishing and camping, and imposing mandatory water conservation measures.
“Every day this drought goes on we are going to have to tighten the screws on what people are doing,” said Gov. Jerry Brown.
One controversial measure being considered by a number of California communities is the reclamation of sewage water. Under typical circumstances, sewage water is collected in treatment plants, where dissolved solids are filtered out and the remaining water is chemically purified, subjected to organic cleaning agents, and released. For most of California, the treated wastewater is dumped into the Pacific Ocean. Under the proposed wastewater recycling scheme, instead of being re-integrated into the water table, the treated water would be pumped back to the community’s businesses and households either by dumping it into the ground, allowing the water to be filtered naturally before it returns to the water table, or directly returned into a community’s water system.
The use of recycled water is not a new phenomenon. To reduce the weight of supplies needed during long space operations, the space agencies have developed a closed-circuit urine distillation system capable of producing clean water. As humans urinate 50 percent more water than they consume due to the extraction of water from food, in theory, such a system would produce an inexhaustible supply of water for non-agricultural uses.
In 2000, Los Angeles completed a sewage reclamation plant capable of providing water to 120,000 homes. The plant was closed after public outrage, and attempts to bring the reclamation plant back to full operation are not expected to be completed until 2022. Nearby Orange County currently runs the world’s largest “toilet to tap” system. The system purifies sewage water via microfiltration, reverse osmosis and an ultraviolet light/hydrogen peroxide treatment, yielding 70 million gallons of drinkable water every day. The county is currently carrying out a $150 million expansion of its reclamation facility to increase the water yield to 100 million gallons per day. San Diego County is also currently operating a wastewater reclamation system.
With wastewater reclamation requiring only a third of the power consumed in sea water desalination, toilet to tap systems may be the lifeline California needs to survive this drought. This thinking is reflected in California’s allocation of $1 billion in direct funding and low-interest loans toward developing more reclamation systems.
However, the psychological hang-ups associated with even purified sewage water may still mean the state will have a hard time selling this idea to Californians.