The Human Costs of Nitrate-contaminated Drinking Water in the San Joaquin Valley

Published: March 2011
Authors: Eli Moore, Eyal Matalon, Carolina Balazs, Jennifer Clary, Laurel Firestone, Susan De Anda, Martha Guzman
Pages: 72

While most Californians take for granted that safe water is readily available at the turn of a tap, a growing number of communities, primarily in the San Joaquin Valley and other agricultural areas of the state, face very real impacts from nitrate contamination of the drinking water sources serving their homes and schools. New research led by the Pacific Institute, The Human Costs of Nitrate-Contaminated Drinking Water in the San Joaquin Valley, finds that nitrate contamination of groundwater has wide-reaching effects on California’s health, economic vitality, and environmental well being, disproportionately affecting low-income households and Spanish-speaking residents.

Nitrate Contamination in the San Joaquin Valley

The analysis brings a stark reality check to the fore as the Central Valley Water Board considers a new regulatory program for irrigated lands, the primary source of nitrate contamination in the San Joaquin Valley. There have never been any regulatory requirements on irrigated agriculture to protect groundwater from fertilizers, which are the primary source of nitrate in the valley. Nitrate levels have increased dramatically in drinking water supplies over the last few decades.

The new study, The Human Costs of Nitrate-Contaminated Drinking Water in the San Joaquin Valley, a collaboration of the Pacific Institute, Community Water Center, Clean Water Fund, and California Rural Legal Assistance Foundation, focuses on the household costs of avoiding nitrate-contaminated drinking water connected to community water systems and the costs to these systems of removing or avoiding nitrates, and it points to key policies and further research needed to better understand and resolve this entrenched challenge.

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% of those tested had nitrate levels above the legal limit.

The report delineates critical steps necessary in California to protect health in nitrate-impacted communities:

-Ensure residents are well-informed about their water quality and appropriate measures to protect their health.
-Provide sufficient funding for short and long-term solutions to ensure safe drinking water.
-Remove political barriers to consolidating small community water systems.
-Prioritize source control to reduce current and prevent new nitrate contamination.

Researchers conducted surveys to characterize how households in nitrate-impacted communities perceive the quality and safety of their water, the types of avoidance measures they undertake, and the financial burden of these avoidance costs, particularly to low-income families. They found a significant number of people at high risk of health problems resulting from nitrate exposure and the expense of having to purchase drinking water pushing water costs well above affordable levels for low-income households.


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