Piney Point holds millions of gallons of wastewater from a former phosphate plant and forms part of a system of ponds from a phosphate mining operation.
Although phosphate forms part of a healthy diet, excess amounts of the chemical in the body have been linked to kidney disease and cell stress.
Processing phosphate ore into fertiliser also creates a type of radioactive waste known as phosphogypsum – an element found at the site.
However, Florida’s authorities have claimed the water is not radioactive but rather “primarily saltwater”.
Last week, when the leak was first detected, the reservoir held an estimated 480 million gallons of water.
As of Sunday morning local time, the water has dropped to about 306 million gallons.