ROCK SPRINGS — A chemical leak at Simplot Tuesday morning dissipated into the air and doesn’t pose a threat to area residents according to the Air Quality Division of the Wyoming Department of Environmental Quality.
Kimberly Mazza, the public information supervisor for Wyoming DEQ, said the leak was reported to the department by both Simplot itself and the National Response Center (NRC). The center is an organization within the Environmental Protection Agency serving as a federal point of contact for reports of chemical discharges into the environment.
According to Mazza and documents received through a public records request, an unknown amount of sulfur dioxide was released Tuesday. SweetwaterNOW initially reported the chemical released was sulfur trioxide – that article has since been corrected. Mazza said the release doesn’t pose any harm to residents or Simplot employees.
Mazza said companies are required to notify DEQ of a discharge after one occurs and to keep the department informed of what they discover as they investigate the cause.
According to NRC documents, the incident occurred at 10:20 a.m. Tuesday and was caused by a valve leak at the sulfuric acid plant. The source of the sulfur dioxide was also listed as unknown in the report, though it notes the leak was secured and Simplot evacuated 300 employees during the incident.
Sulfur dioxide emissions were the focus of a settlement reached between Simplot and the U.S. Department of Justice a decade ago. In 2015, the company agreed to spend approximately $42 million to cut sulfur dioxide emissions from its sulfuric acid plants, including the plant in Rock Springs. The settlement also called for Simplot to develop a plan to monitor sulfur dioxide emissions and pay a $899,000 civil penalty. The settlement was the result of allegations that the company violated the Clean Air Act.
