A historic step, the start of Onondaga Lake dredging operations later this summer, was the focus of a special event Thursday with the New York State Department of Environmental Conservation (DEC), the U.S. Environmental Protection Agency (EPA), the New York State Department of Health (DOH), Honeywell, elected officials, and community leaders.
More than 500 Central New York scientists, engineers, and skilled craft laborers have been working with Honeywell, achieving significant progress implementing lake improvement plans under the jurisdiction of DEC. Significant upgrades made by Onondaga County to its municipal wastewater treatment system plus the construction of Honeywell’s underground barrier wall, which prevents contaminated groundwater from reaching the lake, have improved lake water quality to the best it has been in decades.
“The commitment, energy, and talent of the Syracuse community, including our 500 local workers, have helped shape the progress we have achieved so far,” said Honeywell Senior Vice President and General Counsel Kate Adams. “Honeywell is committed to remaining on schedule to complete a sustainable Onondaga Lake remedy that protects health and the environment, diversifies and enhances habitat, and helps restore a valuable recreation and ecological resource for this community.”
Hydraulic dredges will operate on the lake 24 hours a day, six to seven days a week (except during winter months) for approximately four years to remove about 2 million cubic yards of material from the bottom of the lake.
In the upcoming weeks, construction necessary for lake operations will be completed. The removal of underwater debris, such as wood pilings and concrete blocks, will also begin.
Once this work is done, the entire system will be tested, including the dredges, pipeline, and water treatment plant. We will first use water and then a limited amount of material before increasing operations to full capacity sometime this summer.
Using a “closed system,” the lake material will be transported through a four-mile double-walled pipeline through non-residential areas to a lined consolidation area, where it will be pumped into geotextile tubes for drying and safe isolation long-term. This system prevents lake material from being exposed to the open environment. Extensive efforts are being taken to minimize odors, including the use of geotextile tubes, the “closed system” from lake to consolidation area, use of thickeners to reduce the volume of water, plus a system to capture and treat vapors in the initial processing stage.
A high-strength plastic liner and a low-permeability natural clay layer form the bottom of the consolidation area to safely seal the material inside. Once the lake cleanup is complete, an additional high-strength liner will be placed over the geotextile tubes, sealing the liners together to keep out rain water. Above the liner, layers of clean soil will be added and vegetation will be planted on top.
Water leaving the geotextile tubes will be collected, treated on-site, and then sent to the Metropolitan Syracuse Wastewater Treatment Plant for further treatment to meet DEC standards before being returned to the lake.
Protection of the public’s health and safety is an important part of every stage of the work to restore Onondaga Lake. For example, the air quality is continuously monitored at the perimeter of the work zone to protect surrounding areas. Air and odor monitoring results are available at www.lakecleanup.com.
In locations where dredging occurs and adjacent areas, a new lake bottom “cap” will be added to permanently isolate any remaining contaminants. Extensive modeling and testing by national experts were part of the design process. The top portion of the cap will function as a habitat layer where fish and other organisms will interact with the new, clean lake bottom, improving lake habitat and fish spawning.
In addition, substantial progress has been made in cleaning upland sites such as the former Linden Chemical and Plastics site in the Town of Geddes, a former Allied Chemical property, which was the major source of mercury contamination to Onondaga Lake. Today, native species and wildlife populate the nine-acre area.
The cleanup plan is based on sound science and incorporates input from top national and local scientists, engineers, experts in the field, and community members, who participated in a series of public meetings that have been held since 2004.
Individuals interested in more information should contact Honeywell at 315-552-9784. For more information on the Onondaga Lake cleanup, visit www.lakecleanup.com.