Nitrate Contamination Spreading in California Communities

The water supply of more than two million Californians has been exposed to harmful levels of nitrates over the past 15 years – a time marked by lax regulatory efforts to contain the colorless and odorless contaminant, a California Watch investigation has found.

Nitrates are now the most common groundwater contaminant in California and across the country. A byproduct of nitrogen-based farm fertilizer, animal manure, wastewater treatment plants and leaky septic tanks, nitrates leach into the ground and can be expensive to extract.

The problem affects both rural Californians and wealthier big-city water systems. State law requires public water systems to remove nitrates. Many rural communities, however, don’t have access to the type of treatment systems available in metropolitan areas.

Nitrates have been linked to “blue baby syndrome,” which cuts off an infant’s oxygen supply. Some studies have found connections to certain cancers in lab animals.

The State Water Resources Control Board acknowledges that nitrates are a problem affecting vast regions of California. And the situation is worsening, especially in the Central Valley, Central Coast, and the Los Angeles and Imperial Valley regions. High nitrate levels have already impacted public water system wells in many areas, and the contaminants continue to migrate toward groundwater supplies that could ultimately impact the water supply for millions of additional Californians.

Statewide, the number of wells that exceeded the health limit for nitrates jumped from nine in 1980 to 648 in 2007. Scientists anticipate a growing wave of nitrate problems in some parts of the state if remedial steps aren’t taken.

And yet the state’s patchwork regulatory efforts remain riddled with gaps that have allowed nitrate contamination to spread virtually unchecked. Consider:

  • Nothing is being done to regulate the use of the leading source of nitrate pollution in many regions of the state – nitrogen fertilizer. A lettuce farmer can apply as much fertilizer as he wants, within feet of the nearest water supply well, without having to worry how much of it might contaminate the groundwater with nitrates. Officials aren’t even equipped to determine the sources of contamination, meaning no one is held accountable.
  • Sixty-five percent of domestic wells at Central Valley dairies test over the public health limit for nitrates, putting local residents at risk of potential exposure. Yet, according to records obtained from the State Water Resources Control Board, none of the dairies were fined for a nitrate problem identified by the state.
  • When polluters are found responsible for nitrate contamination, the state rarely does anything to correct it. California has issued 248 enforcement actions against 44 polluters for nitrate contamination in the past six years. But only once has the state ordered a polluter to clean up contaminated groundwater.

In one of life’s ultimate ironies, families in poorer, rural communities typically pay more for tainted water than ratepayers hooked up to clean water systems.

Residents in the tiny town of Seville in eastern Tulare County, for instance, pay a flat monthly fee of $60 for nitrate-laden water they have been warned by local health officials not to drink. By comparison, the average metered bill is just $26.50 a month for San Francisco residents, who consume water from the pristine Hetch Hetchy water system.

“The people who are polluting the water, they don’t pay for that cleanup – the ratepayer does,” said Debbie Davis, a legislative analyst with the Oakland-based Environmental Justice Coalition for Water, a statewide network of grassroots groups that advocates for clean, safe water. “If California is going to meet the water challenges of the future, we have to figure out how to deal with nitrates.”

State officials, meanwhile, say that efforts to regulate and clean up nitrates have taken a backseat because the state has too many other environmental dangers to worry about. California finds itself grappling with a host of difficult water issues – ranging from the logistics of delivery and supply to basic safety and health concerns. Nitrate contamination is just one challenge facing regulators.

Darrin Polhemus, deputy director of the State Water Resources Control Board’s division of water quality, said his agency has chosen to spend more time and resources dealing with chemicals such as perchlorate and dry cleaning solvents, which cause more acute health effects when leached into groundwater.

“On the scale of things we deal with, while nitrates is certainly a concern and we’re managing for it, I don’t rank it high up there as something that makes me stay awake at night,” he said.

It’s unclear how often nitrate exposure has led to serious health consequences, because the dots aren’t always connected. For instance, more than 2,000 cases of acute “blue baby syndrome” have been tied to excessive nitrate consumption around the world since the mid-1950s, but scientists say many cases go undiagnosed. Bottle-fed infants whose formula was prepared using water are at greatest risk if the water exceeds public health limits for nitrates. Pregnant women are also at risk.

Many of the state’s fastest-growing regions overlie vast stores of nitrate-polluted groundwater. In the Eastern San Joaquin Valley, one of every three domestic wells has nitrate levels that exceed public health limits.

One of those wells is located on property owned by Camelia and Manuel Lopez in East Orosi, a small Central Valley town in Tulare County.

The Lopez family volunteered to have their family’s private well tested by the state last winter. The water contained nearly three times the federal health limit for nitrates. Follow-up testing of the family’s tap water by California Watch confirmed these results.

“You would never imagine in this country, that someone would have this problem,” said Camelia Lopez, who emigrated from Mexico as a young woman and moved to the countryside from the Bay Area.

Now the family buys bottled water for drinking and cooking at a cost of $60 a month – a real hardship since Manuel Lopez, a contractor, is unemployed.

Their three boys, age 6, 16 and 18, take the bottles to school as a precaution. A local high school has had nitrate problems for years. Camelia Lopez has taught them how to brush their teeth with bottled water and keep their mouths closed when they’re in the shower. Putting filters on all the taps in the house would cost at least $750.

Boiling water isn’t an option. It can actually make matters worse, scientists say, because it concentrates the water without eliminating the nitrates, making the dose of contaminants even more potent.

The U.S. Environmental Protection Agency has estimated that as many as 52 percent of community water wells and 57 percent of domestic water wells in the United States are contaminated by nitrates. And 15 percent of contaminated wells in agricultural and urban areas have been found to exceed levels considered safe, according to the U.S. Geological Survey.

Much of the nitrates are only deep enough to affect private wells, which are shallower than their public counterparts. But the contaminant is starting to sink further into aquifers, deep enough to affect towns and cities, according to Karen Burow, a Sacramento-based scientist with the USGS.

“In the absence of some sort of mitigation, it’s likely that the water that’s at the domestic wells now is going to move downward and eventually reach the public supply wells,” Burow said.

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This story was produced in collaboration with KQED Central Valley Bureau Chief Sasha Khokha and Christopher Beaver of CB Films. It was edited by Mark Katches. It was copy edited by William Cooley.