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Where Fields of Green Lead to Dirty Rivers

Agriculture: As more pesticides are found in Central Valley waters, the state is poised to finally crack down on the use of chemicals.


CROWS LANDING, Calif. — The Central Valley's Holy Trinity of sun, dirt and water embraced Tom Maring's baby tomato plants.

Irrigation water snaked across the field, giving the transplants their first drink of the season. The overflow spilled into a drainage ditch and then on to the San Joaquin River a few miles away.

The watering started in early May and will be repeated every week or so until the mid-September harvest.

As the irrigation runoff leaves the brown clay fields of the valley's west side, it will carry the residue of the herbicides and pesticides Maring sprays on his tomato plants to ward off weeds, bugs and fungus. Ultimately, the chemicals will wind up in the chocolate brown waters of the San Joaquin.

Most of the river is contaminated with pesticides, as are hundreds of miles of streams, sloughs and drainage canals in the Central Valley's intricate plumbing system. Beyond, the chemicals foul parts of the Sacramento-San Joaquin Delta.

The government has long looked the other way--or didn't look at all. Preoccupied with industrial and municipal polluters, state and federal laws for decades have exempted agriculture from water discharge controls. Aside from making sure their topsoil didn't wash away, most valley farmers haven't had to worry much about what rolled off their fields.

That is about to change. Some, like Maring, are already starting to pay heed. Soon, thousands of other farmers may be following his lead--whether they want to or not.

Pressured by the Legislature, environmental lawsuits and mounting evidence of pesticide pollution, the state is poised to crack down on farm runoff, sending clouds of anxiety floating across the valley's 7 million acres of irrigated cropland.

"It just makes you want to pull your hair out," said Paul Wenger, a ruddy-faced almond grower, pesticide applicator and vice president of the California Farm Bureau Federation. Wenger worries that runoff controls will mean more paperwork and higher production costs--"with nothing out the other side."

California farmers applied 170 million pounds of pesticides to crops in 2000. More than half of that was used on the fruit and nut trees and vegetable rows that make the Central Valley one of the nation's most productive food factories.

When rain pounds the orchards in winter storms, pulses of dormant season pesticides roll with it into the river systems that feed the delta. When irrigation water runs off the slow-draining fields of the valley's west side, the residue of summer sprays goes with it.

Rivers Full of Chemicals

Scientists for the Central Valley Regional Water Quality Control Board have been studying runoff for more than a decade, collecting and testing water samples. Researchers at the UC Davis aquatic toxicology lab and the U.S. Geological Survey have conducted similar surveys.

All have found pesticides. A federal study of the San Joaquin-Tulare river basins, for instance, reported as many as 22 different pesticides in a single water sample.

Concentrations of the chemicals are potent enough to kill aquatic life.

The findings prompted the state in 1998 to list hundreds of miles of Central Valley waterways and parts of the delta as violating clean water standards.

Included were sections of such rivers as the San Joaquin, Sacramento, Merced and Stanislaus, as well as the sloughs and drains that are the workhorses of the valley's elaborate water grid. Late last year, the regional water board staff recommended declaring eight more pesticide-laden bodies of water in violation of clean water standards.

The problem extends beyond the boundaries of the huge Central Valley. "Almost any agricultural watershed we go into, we see the same thing," said Victor de Vlaming, director of the UC Davis aquatic lab.

Two parallel currents are forcing action on the issue. When a waterway is listed as polluted, the Clean Water Act demands contaminants be reduced until water quality standards are met. Additionally, legislation passed in 1999 ended agriculture's exemption from the state's clean water law as of January 2003. Regional water quality boards could, in theory, renew the waiver, but environmental litigation and the pollution listing make it highly unlikely that a wholesale exemption from clean water standards will continue.

"[Agriculture is] being dragged kicking and screaming under the regulatory umbrella," said Bill Jennings, whose Santa Claus-like appearance and folksy Tennessee accent belie the intensity with which his group, DeltaKeeper, has hammered the state to end the farm exemption. "They're not happy about it. But I think the writing is on the wall. Essentially, they're being asked to do the same things as municipalities, business and industry. They're not being asked anything special."

Indeed, a key researcher at the Central Valley water board said that if industry put into the state's waters what farmers are, it would be ordered to stop. "It's a double standard," said Chris Foe, senior staff scientist at the board.

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