Nitrate problems prohibitively expensive to treat
- May 20, 2010
Most small communities with serious nitrate problems can't afford expensive water treatment plants. That means the communities, made up largely of low-income families who work the fields, end up drinking whatever comes out of the tap, even if the water violates public health standards for nitrates.
At least 1 million Californians rely on private wells that have no public health oversight. These residents are at high risk for nitrate contamination because their wells are shallower than municipal wells. Nitrates are colorless and odorless, making them hard to detect without lab testing.
At the other end of the spectrum, cities in Southern California have spent millions of dollars on nitrate treatment plants because they have no other choice -- dirty or not, the groundwater is crucial to meet population growth while access to imported water shrinks.
Other California communities will be facing the same tough choices in the coming years. California's population is projected to increase 53 percent by 2050. Of the 50 million people who will one day call the state home, many will settle in the greater Los Angeles area, Inland Empire, and parts of the Central Valley -- areas that overlie some of the most nitrate-contaminated groundwater in the state.
City planners are looking to groundwater to supply one-third of the water needed to accommodate California's coming population boom, or 1.1 trillion gallons per year -- more than any other source, according
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to the Public Policy Institute of California.
Experts say the slow spread of nitrates underground has already affected millions of Californians, mostly due to a legacy of leaky septic tanks and intensive nitrogen fertilizer-based farming over the last 60 years. Nitrates are the leading cause of well closures in California. Scientists say that if nitrate concentrations don't taper off, the pollution will eventually sink deep enough to affect the well water that millions of Californians depend upon.
Studies have shown that although only 3.5 percent of public water supply wells in the Central Valley exceed the public health limit for nitrates today, an additional 13 percent of wells are at substantial risk of contamination.
Solving the groundwater problem will take imagination -- and a lot more money than the state is spending. California voters have passed two water bonds since 2002, worth more than $8 billion. Roughly $2 billion was allocated for clean, safe drinking water.
No estimate exists for what it would cost to clean up the nitrates in our groundwater basins, in part because the state has limited knowledge about where the pollutants are and where they go when they reach the water table.
The Environmental Protection Agency has estimated that the cost of treating all the polluted groundwater in California over the next 20 years, including nitrates, would amount to $7.5 billion.
It's too late to prevent nitrate contamination in many Southern California groundwater basins, especially in heavily urbanized portions of Los Angeles, Orange, Riverside and San Bernardino counties.
It's a problem that harkens back to the region's agricultural legacy. Land now covered with suburban neighborhoods once sprouted with citrus trees and vegetable fields where farmers used nitrogen fertilizer. Until recently, the Chino Basin was home to more dairies than anywhere in the world.
Nitrate problems were detected as early as the 1970s in the Chino Basin, one of the largest groundwater basins in the state. Nitrate concentrations in the worst-hit parts of the basin were double the EPA threshold in the 1980s and quadruple the limit by 2000, according to records.
Today, residents pay high water bills to bankroll multimillion-dollar nitrate treatment plants in places like Pomona and Riverside.
The most common technologies to remove nitrates, ionic exchange and reverse osmosis, can be expensive and cumbersome.
"We do this crazy thing now and take pristine, beautiful water and put it on our farms, and the minute it soaks into the ground it's filled with nitrate, and then we ask cities to clean up marginal water and use it as drinking water," said Jean Moran, professor of earth and environmental science at CSU East Bay and a former groundwater research scientist at Lawrence Livermore National Laboratory.
In the Central Valley, farmers may soon face regulation of their fertilizer use similar to an order imposed on dairies in 2007. The agricultural industry wants those rules to remain voluntary and says it would be unfair for regulators to require farmers to comply with strict statewide water quality standards.
Nitrogen fertilizer use in California has stabilized at an average 700,000 tons each year, but it's unclear whether voluntary strategies have made a difference for nitrate levels so far. It took 50 years to detect nitrate problems in many areas and it will take decades to see changes, experts say.
One option would be to require farmers to limit the amount of fertilizer they apply to their fields. That would require new legislation. The State Water Resources Control Board does not have the authority to impose those limits.
Lawmakers have directed hundreds of thousands of dollars of aid to small communities struggling with nitrates, and established demonstration projects for good farming practices through the University of California. But when it comes to tackling fertilizer itself, results have been mixed.
State Senate Majority Leader Dean Florez, D-Shafter, calls nitrates "a backwater issue in Sacramento."
"These are the kinds of things public policy makers need to hear," he said. "It's always difficult to get any of these things on the radar screen. ... We've got to get our farmers to recognize the long-term impact of these materials on water systems. People say it's the end of a major, multi-billion dollar industry without these fertilizers."