DIAMOND BAR, Calif. – A California air quality agency may adopt the nation’s first regulation to reduce odor from the waste generated by more than 250,000 dairy cows, primarily concentrated in the Chino area.
The region’s dairies generate more than 1 million tons of manure every year, according to Barry Wallerstein, executive officer of the South Coast Air Quality Management District.
The district is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.
Air quality. Wallerstein said emissions from that manure contribute to ozone and fine particulate pollution, which must be reduced to meet federal health-based air quality standards.
The proposed rule requires dairies to clear manure more frequently and send the manure to an emissions-controlled compost facility, an anaerobic digester or to agricultural land where manure is approved for spreading as fertilizer.
The rule also contains other provisions to minimize dust.
Compliance is expected to cost the dairy industry a total of about $3.5 million a year or about $15,000 per dairy annually.
Phased in. The measure would be phased in, starting Dec. 1, 2004, and apply to the more than 300 dairies in the region, which is considered to have the highest concentration of dairy cows in the nation.
Dairies with fewer than 50 cows would be exempt from the rule.
Concentration. Unlike dairies in many other parts of the country, the region’s milk cow operations have evolved into densely populated facilities with little land for spreading manure as fertilizer.
Instead, manure is stockpiled in corrals, where it decomposes and emits ammonia and volatile organic compounds (VOCs).
Wallerstein said ammonia emissions in the atmosphere readily combine with nitrogen oxides and sulfur oxides – both byproducts of fuel combustion – to form ammonium nitrate and ammonium sulfate particles.
VOCs combine with nitrogen oxides to form ozone smog.
Federal mandate. Southern California’s smog is so severe that the district is mandated to adopt all feasible measures, including the dairy rule, as quickly as possible to meet health-based standards for ozone and fine particulates.
“Inland Empire dairies are directly downwind of large amounts of nitrogen oxide emissions generated in Los Angeles and Orange counties,” Wallerstein said.
Proposed strategies. Currently, most dairy manure is sent to agricultural land in the Los Angeles Basin for spreading as fertilizer, or trucked out of the region to agricultural fields in areas such as the San Joaquin and Imperial valleys.
Dairies send some of their manure to an open-air composting facility in Chino, which is planning to close in 2006.
Some manure also is sent to an anaerobic digester operated by the Inland Empire Utilities Agency. The digester creates biogas (mostly natural gas) from fresh manure, dramatically reducing emissions from the manure while producing energy.
By 2010, Wallerstein said, the measure is expected reduce more than 3 tons per day of ammonia emissions and more than 1 ton per day of volatile organic compounds.
That is in addition to emission reductions resulting from the relocation of dairies outside of the Los Angeles Basin.
California emission proposal
The proposed rule would require dairies to: