Clearing the Air : Tests Show Cows Pollute Less Than Thought, so Dairy Farms May Escape New Smog Rules

Dairy farmers have a message for Los Angeles Mayor Richard Riordan: You can blame us till the cows come home, but the facts are now on our side.

New tests show that dairy cows in the Inland Empire are a much smaller source of air pollution than previously thought.

Cow pollution is serious business in Southern California. It has pitted Los Angeles against two neighboring counties in a debate over how to reduce airborne particles. Riordan caused a big stink in 1994 by trying to shift some of the focus from city sources to the Chino area’s dairy farms.

In an effort to settle the issue, air quality experts spent 12 days surrounded by manure, sampling the air in the corrals of four dairies. They calculated that each cow emits 20 pounds of ammonia into the air per year--about 73% less than previously estimated.

Figuring out the pollution power of cows is helping the South Coast Air Quality Management District craft a strategy this year for cleaning up particulates--the microscopic pieces of soot, dust, nitrates, ammonia and other materials that turn the sky a gritty gray and can lodge in people’s lungs, triggering respiratory disease. A plan for reducing the particles to healthful levels must, under federal law, be adopted by next February.

In August 1994, as the AQMD board was a few days from approving a 15-year clean air plan, Riordan persuaded the panel to drop aggressive and costly proposals targeting diesel trucks, buses, trains, ships and airliners so that other sources of particulates--dairies and rural roads--could be explored.

The mayor’s move upset many elected officials in San Bernardino and Riverside counties, who accused him of trying to ease the burden on urban industries at the expense of rural businesses. Environmentalists called it a delaying tactic.

The AQMD’s tests leave no doubt that, in total tons of pollutants spewed, the smelly four-legged creatures are far outweighed by smoky big-wheeled rigs.

With about 312,000 cows in the Inland Empire, the ammonia released amounts to a hefty 8.5 tons per day. But in comparison, heavy-duty trucks in the Los Angeles Basin emit 239 daily tons of nitrogen oxides and particulates, while ships contribute 35 tons and trains emit 34 tons, according to the state Air Resources Board.

Just comparing raw tonnage doesn’t necessarily show which sources are most to blame for particulates. Various chemicals react differently in the air, so the AQMD is conducting a computerized analysis to detail how the role of cow ammonia compares to other sources.

Still, dairy farms will probably escape major rules in the new plan--which will be unveiled in June--while diesel engines will not.

Essentially, cows are off the hook for at least eight years, said Mel Zeldin, who is coordinating the drafting of the AQMD’s particulates plan.

Since the Inland Empire’s dairy industry is shrinking, Zeldin said the agency might not require reductions in cows’ ammonia. The Chino Valley’s dairy farms, numbering 350 in 1984, have dropped to 260, and many more are contemplating moves.

“If the targeted reductions are met through relocation, we may not need any rules,” Zeldin said. “But if they aren’t met, those that have not left the basin might be required to put on some suggested controls by 2004.”

If some pollution controls are needed, Zeldin said, farmers could remove and recycle manure several times weekly or switch their cows to new feed.

The dairy farmers, already hard-hit by high grain prices and water pollution laws in Southern California, are encouraged.

“If they put any controls on us in this area, it may put us out of business, so this is great news for our industry,” said Wendy Vander Dussen of the Milk Producers Council in Ontario.

Dairy farmers had found Los Angeles’ proposal to increase the burden on them “sort of hard to swallow,” Vander Dussen said.

“Buffalo were here before cows and we didn’t have the particulate problem,” she said. “It’s not the cows. It’s the people. We know we are not pure, but what do you do? Put diapers on a cow?”

Lillian Kawasaki, environmental affairs manager for the city of Los Angeles, said much of the cow debate was a “big misunderstanding” of the mayor’s intentions.

Worried about the economic impact on the city’s port and airport, Riordan asked the AQMD to delay putting measures in its plan that would have required steep reductions in diesel emissions after 2004. Kawasaki said the city, after further analysis, had quickly dropped its dairy proposal as impractical, and since then has focused on helping the AQMD refine its data on vehicle exhaust to develop fair and cost-effective rules.

“We looked at a lot of different scenarios and did a lot of ‘what if’ studies, and way back early . . . we decided it didn’t make sense to do much on the ammonia side,” she said.

The AQMD has long eyed the dairy industry because of its location--upwind of the Riverside-Rubidoux area, which has the worst particulate pollution in the United States. A state study estimates that 275 people die per year in Riverside and San Bernardino counties because the particles aggravate their heart and lung ailments.

Also, as those who reside near Chino know, manure odors are a big nuisance for miles around. Ironically, the stink often descends on the AQMD headquarters about 10 miles away in Diamond Bar.

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Dairy or Diesel?

Dairy farms and diesel engines are sources of particulates- the tiny particles that foul the LosAngeles region’s skies and lodge in lungs. But new data has determined that the role played by cows is smaller than expected.

Cow manure emits ammonia, which can form particulates, while diesel trucks emit particulates as well as nitrogen oxides, which can react in the air to form the particles. Figures are for the four- county Los Angeles Basin.

Emissions per cow: 20 pounds per year.

Number of cows: 312,000.

Total emissions from cows: 8.5 tons per day.

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Emissions per truck: 2,303 pounds per year.

Number of diesel trucks: 75,774.

Total emissions from trucks: 239 tons per day.

Sources: South Coast Air Quality Management District and California Air Resources Board