The UC Davis study found that less than 40 percent of the nitrogen applied to farmlands is used by crops. The rest escapes into the air, waterways and ground water.
Nitrate contamination has been a concern for regulators for decades, said Kenneth Landau, assistant executive officer for the Central Valley water board. Although state law requires “reasonable practices” to prevent pollution of surface and ground water, he said, “it left a whole lot of freedom of choice up to the dairies.”
The regional board has long struggled with scant resources to monitor compliance. “We were down to one half of a person for the whole Central Valley in the early '90s,” Landau said.
The board started regulating agricultural waste discharges into surface water in 2003, but applied those rules to ground water only last year. The program requires growers in areas where nitrates pose a high risk to develop nutrient plans and monitor the underground water.
Still, said UC Davis' Harter, “you can’t regulate the problem away overnight.” Once contaminants get into ground water, it’s extremely difficult to remove them. Levels can increase when chemicals move downstream or if aquifers drop after a drought.
Action on nitrate pollution has taken so long in part because the board had to demonstrate threats to public health or water quality before it could impose regulations, Landau said. “There’s been a lot of resistance to acknowledging that irrigated agriculture and dairies are causing the ground water problem.”
Dave Kranz, a spokesman for the California Farm Bureau Federation, calls nitrate contamination a legacy issue, stemming from outdated fertilizing practices.
Last spring, after the proposed regulations were announced, Jack Hamm, a vice president of the San Joaquin Farm Bureau Federation, said that the new rules would be “extremely onerous” for farmers due to requirements for evaluations, record-keeping and water monitoring.
Long-term solutions would cost $36 million a year to bring everyone’s water in the Tulare Lake Basin and Salinas Valley into compliance with federal safety standards, according to the UC Davis report.
The report identified 85 public water systems, serving about 220,000 people, with high vulnerability to nitrate contamination, and 34,000 people with private wells, which the state doesn’t regulate.
Depending on the severity of contamination, treating nitrates at a single well head can range from $135,000 to $1,090,000 per year.
“The poorest communities in the state are paying the highest price for water and there aren’t any mechanisms to fix that,” said Clean Water Action’s Clary.
Funding is available from California’s Proposition 84, which allocated $60 million in 2006 to fund new wells, treatment systems and other projects. But many communities have yet to receive a penny. Most small systems are run by volunteers and can’t afford to hire experts to help them navigate the funding process, Clary said.
“If, on top of that, the community is very small, very poor and has a large number of non-English-speaking ratepayers, those barriers become astronomical,” she said.
Many people in these farming communities have been living with nitrate contamination for most of their lives, De Anda said.
“They think it’s normal not to drink water from your tap, that it’s normal to have to go buy bottled water. Part of our job is telling people, ‘This is not normal.’ ”
By law, water system managers must notify customers when contaminants exceed safety standards. But the notices are confusing, even to proficient English speakers. Complicating matters, Tulare County tests just one contaminant at a time.