Rice runoff fouling water
Cities want limits on herbicide use
Marysville Appeal Democrat - 3/15/03
By Harold Kruger, staff writer

Herbicide levels in the water supplies of Sacramento and West Sacramento continue to bedevil the rice industry.

Last year, the cities reported "an increased number of detections and higher concentrations" of thiobencarb and molinate in the Sacramento River, a trend that began in 1998 and "has not been reversed," according to their submittals to the Central Valley Regional Water Quality Board.

The board, which met Friday in Sacramento, implemented a new array of measures to address the herbicide situation.

For the rice industry, cutting herbicide releases into waters that go to urban areas is key to keeping in the regional board's good graces.

"There are two ways to skin the cat," said Tim Johnson, president of the California Rice Commission. "One way is through a well-managed, self-regulated system. The other way is through the heavy hand (of government regulation), such as waste discharge requirements.

"We think that the first model provides us with the best opportunity to manage our business as well as the water quality requirements of the state. It's been successful for over 12 years. Last year was an anomaly."

Said board Chair Robert Schneider, "I really appreciate the rice industry stepping up and trying to address this in a proactive manner."

But board member Christopher Cabaldon, West Sacramento's mayor, said he was "not that optimistic. This is our showcase, our marquee program for a collaborative approach as an alternative to a strict regulatory mechanism."

If this bit of self-regulation fails, he warned, other efforts may never get a chance.

West Sacramento, in its letter to the board, said it spent $500,000 to install a granular activated carbon filtration system at its water intake "to remove breakdown products of rice pesticides from our water."

Thiobencarb affects how water tastes. Molinate also is a concern for the cities. Both cited "possible health effects" in their letters to the board.

The rice industry, herbicide manufacturers, the state Department of Pesticide Regulation and county agricultural commissioners all work together to control herbicide releases.

"We have not seen an evaluation that demonstrates that these efforts are sufficient to reduce the trend of increased detections and higher concentrations of the pesticides in the Sacramento River," West Sacramento said in its letter.

Based on what happened last year, the city said, "These efforts have been insufficient and ... better control measures should be considered for implementation."

About 544,000 rice acres were planted last year in the Sacramento Valley. Thiobencarb was applied on nearly 204,000 of those acres. Molinate was applied to about 214,000 acres.

Rice acreage this year may be down 10 percent to 15 percent as some farmers fallow land as part of water sales to Southern California.

Thiobencarb was detected on eight days at Sacramento's sensors, while molinate was found on nine days, according to the Department of Pesticide Regulation. In West Sacramento, the detections were eight days for thiobencarb and 10 days for molinate.

Both pesticides were detected in higher concentrations in 2002 than they were in 2001.

A staff report to the board acknowledged that "current management practices are not sufficiently protective of drinking water quality."

A strong mid-May storm exacerbated the problem, officials said, as the Natomas Mutual Water District released about 1,400 acre-feet of water from their closed tailwater recovery system. At the time, about 4,200 acres of farmed land in the district was under treatment with thiobencarb.

Herbicide drift and seepage from fields also are continuing problems, the board said.

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