Mosaic seeks permit for deep wastewater wells in Riverview

Mosaic has filed a permit application to drill two exploratory wells at its phosphate processing facility in Riverview. The wells are designed to send treated wastewater approximately 3,500 feet underground. This depth places the injection point far below the local aquifer that supplies drinking water. The company intends to use the wells during emergencies such as major storms or hurricanes.

The facility is located along the shore of Hillsborough Bay. Mosaic spokeswoman Jackie Barron stated that the wells are not for daily use. She described them as a backup system for times when the plant must remove water faster than usual. Barron noted that similar injection wells are already in operation at a few of Mosaic’s other processing plants.

“This is not a go-to. It is not like we're going to automatically put water down it, but it will be nice to have in the event we have historic storms or we run into a situation where we need to dispose of water faster,” Barron said during a recent public meeting in Riverview. She added that the water entering the wells must meet the same quality standards as water released through the plant's current outfalls.

The Florida Department of Environmental Protection is currently reviewing the draft permit. Richard Lobinske, an environmental administrator with the department, explained that the primary goal of the exploratory phase is to map the geology beneath the site. The tests will identify the depth of the underground source of drinking water and locate the natural confinement layers that protect that water.

“It's really designed to identify the subsurface geology,” Lobinske said. “How it is made up, layers of confinement, where the underground source of drinking water is, and that's really the purpose of it to just see the subsurface conditions.” He confirmed that hazardous waste or toxic substances would not be allowed in these specific wells.

Lobinske pointed out that Florida already operates more than 200 Class I injection wells. Many of these are used by water and wastewater treatment facilities to dispose of brine from purification processes. Several of these existing wells are already located in Hillsborough County. Mosaic’s proposed wells would be part of this existing statewide infrastructure.

Barron emphasized that the project relies on established science and technology. “We do not believe that there are any safety concerns,” she said. “Not just based on what we believe, but based on the science and technology and extensive studies. Remember, this would be one of a couple of 100 across the state. So this is not a new concept.” She also noted that any future injection of wastewater would require a separate permit distinct from the current exploratory application.

Environmental advocates have voiced strong opposition to the plan. They argue that most injection wells leak over time. Critics say that if groundwater becomes contaminated, the damage is often detected too late to prevent harm to the aquifer. They view the potential threat to the water supply as a significant risk.

The state is accepting public comments on the draft permit through Nov. 5. Residents can submit feedback by email to app@dep.state.fl.us. Additional details about the permit are available from the DEP Underground Injection Control Program. The office is located at 2600 Blair Stone Road, MS 3520, Tallahassee, Florida 32399. Inquiries can also be sent to APP@FloridaDEP.gov.