Crews have begun dredging Onondaga Lake as part of a five-year, $450 million project to clean up what was once considered one of the nation's most polluted bodies of water.
Dredging machinery began scooping sediment from the lake bottom on Monday. The work will go on 24 hours a day, six days a week, and will only stop during the winter months. In addition to dredging 185 acres of lake bottom, another 400 acres will be capped.
The goal: To bring the lake's water quality up to federal standards. What it will take is dredging out about six percent of the lake, 185 of the 3,000 acres of lake bottom.
Diane Carlton, with the State Department of Environmental Conservation in Syracuse, says they're mostly after mercury, but also PCBs and some hydrocarbons. Most of the pollution was dumped, or seeped into the lake from the old Allied Chemical plant in Solvay.
Onondaga Lake qualified for federal Superfund money in 1994, and the cleanup is now being done by Honeywell, the corporate successor to Allied Chemical.
The dredging will go down through about 30 feet of silt, then remove another five to ten feet of the soil on the lake bottom. That's for the pollution 'hotspots' that have been targeted. For areas that have higher, but not toxic chemical levels, they plan to cap the area with a thick level of clay and soil. There's another boat that will head up that effort.
The DEC says that during the project there will be continuous monitoring of water quality, of the soundness of pipes and other equipment being used for the toxics's removal, and also of the air quality around the lake.
Here's the link to a DEC fact sheet on frequently asked questions about the Onondaga Lake Dredging Project.