The Everglades Forever Act, introduced by Governor Lawton Chiles in 1994, was an attempt to legislate the lowering of phosphorus in Everglades waterways. The act put the South Florida Water Management District (SFWMD) and the Florida Department of Environmental Protection (DEP) in charge of testing and enforcing low phosphorus levels: 10 parts per billion (ppb) (down from 500 ppb in the 1980s).[154] The SFWMD built Stormwater Treatment Areas (STAs) near sugarcane fields where water leaving the EAA flows into ponds lined with lime rock and layers of peat and calcareous periphyton. Testing has shown this method to be more effective than previously anticipated, bringing levels from 80 ppb to 10 ppb.[155]