Irrigating with wastewater

With the western part of the United States experiencing increasing droughts, California’s CoCo San Sustainable Farm is working to find sustainable solutions to irrigate the land and sustain the local community.

According to an article on www.foodtank.com, CoCo San Sustainable Farm has redesigned its conventional irrigation methods, and the farm no longer relies on rainfall and snowmelt to ensure a fruitful harvest. CoCo San Sustainable Farm uses treated wastewater from the neighboring Central Contra Costa Sanitation District plant to grow crops. According to Carolyn Phinney, founder of CoCo San Sustainable Farm, the farm is able to prevent between 190 and 760 million liters of water per day from being expelled into nearby Suisun Bay.

“The Greater San Francisco Bay Area threw away about 4 trillion liters of wastewater that could have been recycled and reused at the height of the California drought,” Phinney tells Food Tank, referring to the five-year drought from 2012 through 2016.

According to Phinney, recycled water is better for farmers than rain or potable water because of its high nutrient levels, including nitrogen, phosphorus and potassium. But the water also contains contaminants, such as E.Coli bacteria and pharmaceutical residue. Central Contra Costa Sanitation District — and all water sanitation plants—monitors the levels of these impurities closely, to determine they remain low enough and are deemed safe for use on edible crops.

This year, CoCo San Sustainable Farm plans to use recycled wastewater to help grow and donate approximately 230,000 kilograms of fresh produce, which they will share with local food banks and school districts.

Collectively, California grows 13% of all produce purchased in the United States, according to the California Department of Food and Agriculture. The majority of the state is under some degree of drought warning, threatening the water reserves necessary to maintain current crop production.