News Feature | August 30, 2016

Analysts See Role For Waste Plants In Beating California's Nitrates Problem

Sara Jerome

By Sara Jerome
@sarmje

sanjoaquinvalley reg new

In California’s top farming regions, up to 250,000 consumers are highly susceptible to encountering nitrate contamination in their drinking water.

That’s according to a new report from analysts at the University of California-Davis. The writers envisioned a role for wastewater treatment plants in reducing the amount of nitrogen in the state:

Wastewater nitrogen management could be transformed to expand nitrogen removal where appropriate and stimulate recycling whenever possible. Technologies for wastewater nitrogen management include creating conditions to support microbial nitrification and denitrification (with nitrogen released harmlessly into the atmosphere as non-reactive N2) and separation of solid and liquid portions of the waste stream for reuse as fertilizers. A conservative increase in nitrogen treatment at wastewater treatment plants would reduce nitrogen discharged into the environment by 17,000 tons/year. And depending on the extent of retrofits and operations, nitrogen discharged could be reduced by an additional 1,400–12,000 tons/year.

Nevertheless, the biggest source of nitrate contamination is clear, according to the report. The agriculture industry is the top source of this contaminant: “Agriculture is the largest source of nitrogen in California. Synthetic fertilizer accounts for 32 percent (514,000 tons) new nitrogen entering CA each year, and animal feed accounts for another 12 percent (220,000 tons).”

The report tallied up the far-reaching and long-lasting consequences of nitrate contamination, which has been linked to cancer.

“Even if the pollution source could be stopped tomorrow, these communities — representing a population more than twice as large as that of Flint, Michigan — would endure the effects of past practices for decades,” according to Mother Jones, which cited the University of California-Davis analysis.

In California, nitrate-contaminated water disproportionately affects low-income residents, according to a report by the Pacific Institute analyzing health risks in the San Joaquin Valley, a pivotal agricultural region for the U.S:

The eight-county San Joaquin Valley has some of the most contaminated aquifers in the nation: 92 drinking water systems in the San Joaquin Valley had a well with nitrate levels above the legal limit from 2005-2008, potentially affecting the water quality of approximately 1.3 million residents. In addition to public water systems, the State Water Board sampled 181 domestic wells in Tulare County in 2006 and found that 40 percent of those tested had nitrate levels above the legal limit.

To read more about nitrogen removal visit Water Online’s Nutrient Removal Solutions Center.

Image credit: "Straight Lines," Dave Parker © 2006, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/