Picketers in Polk County, protesting tens of millions of gallons of radioactive water pouring into the Floridan Aquifer.

"They say they have it fixed or are working on fixing the problem, but where's the proof," said protester Lee Cole.

"How can we trust them," said protester Heidi Strickland.

A handful of protesters gathered outside of Mulberry City Hall Saturday morning.

Mosaic says it has contained contamination from a sinkhole that opened at one of its Gypsum stacks late last month.

But several people who live nearby and depend entirely upon the aquifer for their water supply are skeptical.

It's not the first time a sinkhole has threatened their neighborhood.

Mosaic says it has strong pumps all around the property at its New Wales plant pulling that now-contaminated water up out of the ground and storing it. Keeping it from spreading.

You'd think for a guy like Rob Bentley that would be a huge relief. But it's not.

“I'm a little more concerned now, what did they say? Radioactivity possibly? Slightly? Yeah - I'm concerned.” said Bentley.

In 1994, another massive sinkhole at the New Wales plant threatened the drinking supply there. In 1997 and 2004, acid spills made it to local rivers. Again, people in Pine Dale were told there was no problem.

Mosaic says so far tests show they've been able to keep this latest incident contained too.

“We are monitoring extensively to make sure nothing gets past us and certainly nothing will get to the property line,” said David Jellerson, Mosaic’s Senior Environmental Director.

As part of it's response plan, Mosaic says it's making free well-testing available to anyone who lives around the area who may share those concerns.