The California Watch nitrates project was a yearlong effort to highlight a critical public health issue that affects millions of Californians.
This story began in February 2009, when we started hearing stories about ordinary Californians who couldn’t drink their water because it was contaminated with nitrates and had no alternative to pay for bottled water. Often, these same individuals also continued to pay an expensive, monthly water bill.
We knew it would be challenging to characterize the extent of the water supply contamination because statewide drinking-water data pertaining to nitrates is often fragmented and out-of-date. There are also at least one million private well owners in California who likely have no idea what they’re drinking, because the state does not oversee domestic wells and maintains no record of them. Scientists have done local and regional studies on nitrate contamination focusing on a particular groundwater basin or dairy, but the state has no estimate of how deeply or widely nitrates have sunk into our soil.
Sasha KhokhaChristopher Beaver films Camelia Lopez.
The state keeps no record of nitrate concentrations under farms or vineyards, making it impossible for nearby communities to figure out whether their nitrate problems could be attributable to agricultural sources. California’s dairies only recently started reporting nitrate concentrations in their domestic wells to the State Water Resources Control Board, so the one year of data on record is 2007.
California Watch decided to illustrate the human toll of nitrates by testing the groundwater supply of a group of nine communities, schools and private family wells, and then sharing the results with the well owners. The nine wells were spread out across Tulare County, a part of the southern San Joaquin Valley where one in three wells have exceeded the public health limit for nitrates. Most of the participants had tested their wells in the past, with nitrate results above the limit.
The testing was conducted by California Watch in late October and analyzed by BSK Laboratories of Fresno. Three wells tested high for nitrates, for which the maximum contamination limit is 45 milligrams per liter. Those tested included Citrus South Tule Elementary School in Porterville (70 mg/L); a private well belonging to the family of Camelia Lopez of East Orosi (72 mg/L); and the private well of Ericka Carmona, also of East Orosi (46 mg/L).
Julia ScottSasha Khokha records the sound of contaminated water.
Three other nitrate-contaminated well sites tested very close to the limit, but not above it: the tap water of Eunice Martinez, who is on a community water system in Tooleville (42 mg/L); the home of Becky Quintana in Seville (43 mg/L); and the drinking water fountains across the road at Stone Corral Elementary School in Seville (42 mg/L). Seville’s drinking water has had nitrate problems in the past, as has Tooleville’s.
Three other participants’ wells tested below the nitrate limit: a household well owned by Ducor resident Anna Vargas and her family (31 mg/L); Olivia Sierra’s tap water, also in Ducor but supplied by the town’s community water system (1.5 mg/L); and water taken from a tap at Ducor Elementary School (no detectable level).
We determined how to gather uncompromised water samples by following careful instructions from lab technicians at BSK Laboratories, as well as consulting with scientists from within the Chemical Sciences Division of Lawrence Livermore National Laboratory.
Sasha KhokhaReporter Julia Scott tests water for nitrates.
We also used an emerging technology called isotope testing on a few of our samples, and had the samples analyzed by the Lawrence Livermore National Laboratory. The test acts like a DNA fingerprint to tell us a little bit about where the nitrates might be coming from. The results illustrated how diverse nitrate sources can be. One sample suggested the nitrates were coming from either cow manure or a leaky septic tank, or both. At another location, the potential source was natural nitrates in the soil. A third site had an issue related to agricultural fertilizer in the area.
We read through hundreds of pages of documents and used several databases, including lists of communities and schools that have exceeded the public health limit, to capture a larger picture of the nitrate problem in California. Using printouts from the Central Valley Regional Water Quality Control Board, we found hundreds of dairies and food processors that have had nitrate problems and checked them against an online state database to see whether officials had followed up with them. Annual enforcement reports provided a taste of the priorities and staffing levels at the state and regional water boards.
We crisscrossed the state with visits to dairies and a multimillion-dollar nitrate treatment plant in San Bernardino County. And we dove into stacks of documents at regional water board offices to find examples of local facilities struggling with nitrate problems.