A receiver in charge of closing the troubled Piney Point phosphate plant in Manatee County has presented a plan to the state.

It's now up to the Florida Department of Environmental Protection to determine whether the plan meets state regulations. It would permanently close four gypsum stacks formerly used to store toxic wastewater from the production of fertilizer.

The report says as of Jan. 1, the four stacks held approximately 397 million gallons of water. More than half of that is in the pond that last year released about 215 million gallons of nutrient-rich wastewater into Tampa Bay.

Most of the water from the ponds would be injected far into the ground below the drinking water aquifer. That process is expected to begin in November. The report says all four stacks would be closed for good by the spring of 2024.

The leaky stack would be closed by placing a liner over the existing sediments, covered by two feet of compacted soil.

Several environmental groups have sued the plant's operators and the state. They are seeking accountability and want to beef up state regulation of the two dozen other gypsum stacks around the state, so another Piney Point spill doesn't happen again.