Monterey County Farm Bureau

Nitrates in Groundwater

A 2014 report published by University of California, Davis, has publicized the on-going issue of nitrates in our groundwater.  This report specifically focused on the Salinas Valley and Tulare Lake basins, areas where high amounts of fertilizer applications have occurred in past decades, or on-going cattle/dairy operations produced large amounts of manure.

Nitrogen is required by all crops to produce a healthy, safe result: fresh fruits and vegetables that are marketed in our local grocery stores and farmers markets, produced either conventionally or organically.  Improvements in nitrogen management have reduced the amount of fertilizer applied to crops in the past decades; in fact, studies show that, while yields have increased exponentially in the past two decades, the actual use of nitrogen has leveled off and has remained constant for many years now.

But we can all do better.  New science and research is developing improved ways to manage and apply nitrogen to crops.  Salinas Valley farmers and ranchers have been early adopters of these new methods and remain vigilant in their search for better ways to manage nitrogen when growing fruits and vegetables.  Nitrogen is an input cost, and in recent years that cost has increased considerably and farmers won’t apply fertilizer they don’t need.

Studies show it has taken decades for the nitrogen applied generations ago to reach the groundwater as nitrates.  And it will take decades to make improvements; cleansing groundwater is a long, expensive process.  Today’s farming practices are much improved over those of even one generation ago, and the contributions to the problem in groundwater should be viewed as a legacy issue, not as a punitive action to those currently farming responsibly.  With all things in our society, science and research have improved our knowledge base.

The UC Davis report will be peer-reviewed to validate the study findings; much data previously collected was not included in the report and needs to be validated to show that groundwater quality in the Salinas Valley is not impaired to the degree that the report determines.  Until then, we maintain that the groundwater in Monterey County is being improved through the pro-active solutions growers have adopted in recent years.


To address nitrates in drinkng water wells of the Salinas Valley area, landowners and growers came together in 2017 to form the Salinas Basin Agricultural Stewardship Group.  This organization has developed a new program that provides drinking water to residents who have nitrate-impacted wells, a collection of less than 30 wells and small water systems.  The membership of the Stewardship Group encompasses a major porition of the irrigated lands of the Salinas Valley area.

But this solution is not sustainable in the long-term; more premanent water supply solutions need to be put into place to ensure that all residents receive clean drinking water.  Salinas Valley Agriculture, along with Monterey County Farm Bureau, support a statewide solution to funding replacement drinking water systems for all areas impacted by contaminates.  Well contamination is not just an agricultural issue, as only about  30% of well contamination in California can be linked to the use of fertilizers on agricutlural fields.  Thus, a shared responsibility must be put in place to fund these permanent water supply solutions, not just relying on landowners and growers to fund these projects.