POCATELLO — Air and water quality near the J.R. Simplot Don Plant will continue to improve at an accelerated pace thanks to a new agreement between the company and the Idaho Department of Environmental Quality.

A new agreement between Simplot and the DEQ signed this summer will reduce fluoride and particulate emissions by more than 50 percent in the coming years. In addition, a 2008 agreement signed by Simplot to reduce phosphates from leaking into the Portneuf River by lining the gypsum stacks near the plant is bringing a steep drop in phosphate levels in the groundwater that seeps into the river.

“Our goal is to clean up the air and water as much as possible,” said regional administrator for the DEQ Bruce Olenick. “I think it will improve this community profusely.”

Olenick said the DEQ has been working with J.R. Simplot for the past eight years to come to an agreement on timelines and procedures to cut air emissions. Simplot immediately began procedures to line the massive gypsum piles located on the hill above the Don Plant so phosphate seepage could be controlled before it entered the groundwater.

“Within the next nine years, Simplot will get a system on line,” Olenick said about replacing the existing cooling towers at the Don Plant that produce 80 percent of the emissions from the plant.

The cooling towers are chiefly responsible for the distinctive odor that is often recognized in the Chubbuck/Pocatello area, particularly during winter inversions, according to Olenick. This new agreement, called a consent order, was created to resolve excessive levels of fluoride detected in vegetation samples collected around the facility.

Fluoride is listed by the US Environmental Protection Agency as a hazardous air pollutant and the state of Idaho has set standards for fluoride in forage. This standard is used to protect grazing animals near airborne sources of fluorides from ingesting too much of the compound which can cause sickness.

Details of the new consent order include a plan to replace the cooling towers with a low-emission alternative or incorporate other measures that reduce fluoride emissions by greater than 50 percent to meet the existing Idaho standard while simultaneously reducing particulate emissions. Simplot will be required to also install an air monitor and associated meteorological equipment downwind of the plant and revise their facility’s air operating permit to be consistent with the reduction in emissions.

Simplot will also submit a “Remedial Action Plan” for approval to the DEQ that will coordinate all the pollution abatement activities. The agricultural company that manufactures fertilizer at the Don Plant has agreed to pay a penalty for exceeding accepted state levels for fluoride emissions in the past and help support other air pollution reduction initiatives in the Portneuf Valley.

Simplot funding was responsible for the wood stove change-out program that is currently in effect for residents of Pocatello and Chubbuck. Under the guidelines of the wood stove program, people who own older wood burning stoves can receive a $500 rebate to help purchase a new unit that will have an additional 10 percent discount from the participating vendors. The four vendors participating in the program are Mr. Mower, Nick’s Fireplace Outfitters, Rocky Mountain Supply and Webbco.

“All of the actions required under this agreement may take up to 10 years to complete due to the sweeping changes required to reduce emissions at the plant,” Olenick said.

As far as water quality in the Portneuf, Olenick said efforts to line the gypsum stacks has paid huge dividends.

In 2008, phosphorus inputs to the river attributed to the Don Plant because of contaminated ground water averaged around 2,500 pounds per day, which equates to a maximum concentration in the river of approximately 1.60 milligrams per liter. In 2016, phosphorus inputs to the river have dropped to about 750 pounds per day.

“Ideally we’d like to see that reach zero,” Olenick said.

In working out the pollution control agreements with Simplot, Olenick said it was the DEQ’s goal to improve air and water quality while still allowing the fertilizer plant to maintain sustainable operations well into the future.

“These two agreements have charted a path forward to address many complex, long-standing issues that exist as a result of Don Plant operations,” Olenick said.