The Simplot Feeders cattle feedlot at Wallula has been fined $50,000 by the Washington Department of Ecology for air pollution violations.
The company has not made a decision on whether to appeal. It has 30 days.
The feedlot allowed small particles, including dust and dried manure, to pollute the air, Ecology said. Fine particles can cause health problems for people who are exposed frequently at high enough levels.
The state is accusing Simplot of a knowing or willful violation of regulations.
Inspections have found broken sprinklers and too few water trucks to control dust from cattle and feedlot roadways, the state said.
Simplot submitted a plan to control dust at the feedlot in July 2014, but the state continued to receive complaints of excessive dust created by feedlot operations, the state said in its penalty notice.
The plan called for Simplot to start up a sprinkler system to control dust in pens on April 1, 2015. But when the system started up, it had several problems, and the state received complaints about dust bothering people outside the feedlot from April 2-4.
Not only did state officials observe excess dust on site and leaving the property during the next few months, but on 50 days between April and September, Simplot staff observed excess dust, the state said.
In response to continuing complaints to the state, Ecology officials met with the feedlot manager in early June.
State officials were told that Simplot did not have a way to adjust sprinklers and other controls at night, even during dry, hot periods, the penalty notice said. No trained staff is working then to operate sprinklers or water trucks, the state was told.
Simplot instead has a night watchman observe the feedlot from five vantage points and leave a report on the level of dust for the site maintenance manager on duty the next day.
The state reviewed 10 reports, finding that dust was observed but that no record or information showed that the dust releases were addressed the next day with water trucks or by adjusting sprinklers.
The lot had about 45,000 head of cattle in June and has a permit for up to 80,000 head.
The company received a formal notice from the state in July for failing to manage air pollution. Some improvements have been made since then, including to reduce dust in the feed preparation area, according to the state.
Simplot has spent about $1 million on improvements to reduce dust, said Ken Dey, a Simplot spokesman.
“We are also committed to meeting the environmental, social and economic needs of our customers and communities,” he said.