J.R. Simplot Settlement Information Sheet

On July 11, 2023, the U.S. Environmental Protection Agency and U.S. Department of Justice announced a settlement agreement with J.R. Simplot that resolved alleged violations of hazardous waste and air regulations (among others) at its plant in Pocatello, Idaho. Under the settlement, Simplot will ensure that the financial resources to close the facility are available when needed, pay a civil penalty of $1.5 million, and implement specific wastewater management measures valued at approximately $150 million.

On June 30, 2025, EPA and DOJ reached an agreement with Simplot regarding the modification of Appendix 9 filed with the 2023 consent decree. The modification sets forth the interim compliance measures relating to the routing of liquid effluent from the absorbers (wet scrubbing devices) and fluoride emissions from the cooling towers at the Don Plant.  

• Overview of J.R. Simplot and Don Plant
• Summary of Violations
• Overview of Settlement Agreement
• Environmental Benefits
• Contact Information

Overview of Simplot’s Don Plant

J.R. Simplot, headquartered in Boise, Idaho, is an international food and agriculture company. Simplot’s Don Plant facility, located near Pocatello, Idaho, manufactures phosphate products for agriculture and industry, including phosphoric acid and phosphate fertilizer, through processes that generate large quantities of acidic wastewater and a solid material called phosphogypsum. The phosphogypsum is deposited in a large pile known as a gypstack, and acidic wastewater is also discharged to the gypstack. The gypstack, which has a capacity to hold several billion gallons of acidic wastewater, was fully lined in 2017 under a previous settlement agreement with the United States and the State of Idaho.

Summary of the Violations 

Overview of Settlement Agreement

The settlement agreement requires Simplot to implement process modifications to enable greater recovery and reuse of phosphate and requires the company to ensure that financial resources will be available during facility closure. 

Under the settlement, Simplot agreed to implement specific waste management measures it has valued at nearly $150 million. Significantly, these measures include extensive new efforts to recover and reuse the phosphate content within these wastes and avoid their disposal in the gypstack. Simplot will implement requirements that ensure gypstack stability and containment that will protect the environment during severe weather events.

The settlement also includes a detailed plan setting the terms for the future closure and long-term care of the gypstack. The settlement requires Simplot to immediately secure and maintain approximately $108 million in dedicated financing to ensure that funding will be available when the facility is eventually closed.

Simplot also agreed to cease operation of the facility’s cooling towers no later than June 27, 2026, and replace them with one or more newly constructed cooling ponds, which will significantly reduce fluoride emissions to the air. 

Additionally, Simplot agreed to submit revised Toxic Release Inventory forms for 2004-2013 that include estimates of certain metal compounds manufactured, processed, or otherwise used at the facility.

Simplot is providing $200,000 in funding for environmental mitigation work that will be administered by the Idaho Department of Environmental Quality in conjunction with the city of Pocatello and the Shoshone-Bannock Tribes. The mitigation work will address habitat degradation on the Portneuf River that has resulted in part from excess phosphorus releases, especially from the facility’s formerly unlined gypstack.

Environmental Benefits

The settlement requires Simplot to: 

• Treat over 1 billion pounds of hazardous process wastewater over the several years; 
• Properly store and contain acidic wastewaters;
• Install and expand the synthetic geomembrane liner for the proposed expansion of the facility’s gypstack;
• Monitor groundwater to prevent releases;
• Close the facility in an environmentally sound manner; and
• Replace the cooling towers with cooling ponds resulting in a reduction of roughly 84% of all fluoride emissions from the plant. 

The mitigation project will restore native vegetation and ultimately improve the water quality and overall natural habitat to support a healthy fish population, which will benefit the tribal members for those that rely on fishing and the use of the water for traditional and ceremonial activities.

Contact Information

For more information, contact:  

Gregory Sullivan, Director 
OECA/WCED 
U.S. Environmental Protection Agency 
Washington, DC 20460 
sullivan.greg@epa.gov