Concentration of Cow Byproduct Leaves a Stink With No Easy Remedy

In its endless struggle to clear skies of smog, Southern California has long targeted cars and trucks. Now, it's cracking down on cows.

The region has the most polluted air in the country. It also has 300 dairies. Corrals there contain about 250,000 cows -- and more manure than you might want to imagine.

Barry Wallerstein, executive director of the South Coast Air Quality Management District, has to keep track of it. "Our region's dairies generate more than 1 million tons of manure every year,'' he says.

The waste does more than stink. It emits ammonia and other chemicals that foul the atmosphere. Air quality authorities say it's time to clean it up.

Most of the dairies are in San Bernardino and Riverside counties. They do not have much land on which to spread cow manure as fertilizer, so they have to scrape up and stockpile much of it, then haul the mess off to composts twice a year.

Southern California regulators recently proposed that dairies in the region be required to empty corrals of decomposing dung at least four times a year and take an assortment of environmentally conscious steps to dispose of it.

Dairies that have 50 cows or fewer would be exempt from the tougher rules, which may be adopted in a few weeks. But some dairy farmers are grumbling about the proposed changes, which they say would cost too much and force them into the corrals during the region's rainy season, when the waste is slippery and wet.

-- Rene Sanchez

Bob DeJager's dairy farm in Chino, Calif., could be contributing to pollution. Regulators want manure to be disposed of more often.