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Sulphuric acid unit, seen Tuesday, Jan. 29, 2019, at Mosaic's Uncle Sam plant in Convent. A byproduct of Mosaic's operations is phosphogypsum. The waste is stored in an enormous white pile on the company's site.  

Fertilizer maker The Mosaic Co. said it will cut phosphate production by 300,000 tons for the spring season, a move that will affect its Louisiana and Florida facilities. 

The company said it is cutting production because of "continued weather concerns across key U.S. growing regions," as well as higher than normal inventory levels carried over from the fall. 

The move will not affect employment levels at Mosaic's Faustina and Uncle Sam plants in St. James Parish, a company spokesman said. The plants have about 400 workers combined.

Mosaic processes phosphate rock into fertilizer for sale to farmers at the Louisiana plants. 

In recent weeks, the company has scrambled to prevent an endangered lake of acidic process water from breaking through a barrier and flooding nearby waterways.

That lake is on top of a mountainous pile of waste gypsum at the Uncle Sam plant near Convent. The gypsum, which encases the lake, is a byproduct of Mosaic's production process and has little ability to be reused.

The northern face of the pile has been slowly moving, potentially for months, and Mosaic has been trying to pump down the amount of process water inside the lake to reduce weight on the wall, slow its movement and avoid a failure.

Company officials have maintained that continued production — and its consumption of process water — was another way to reduce the water in the lake.

But Callie Neslund, a Mosaic spokeswoman, said the production slowdown isn't related to the company's response to the gypsum pile. 

Neslund said two of five production units for either sulfuric acid or phosphoric acid at the Uncle Sam plant will be shut for previously scheduled maintenance. 

A sulfuric acid production unit will be shut for 30 days, starting this weekend, and a phosphoric acid production unit will be shut for 16 days, starting next week, Neslund said.

The slowdown is expected to have mixed effects on the waste pile and its lake. It will reduce the deposition of process water and gypsum into the endangered lake, but also cut the amount of process water drawn from the lake and consumed by the Mosaic plant.

Mosaic is based in Minnesota and has operated the Louisiana plants since the 1960s.