Proposal Includes One of the Largest Environmental Dredging Projects Ever Undertaken in the United States
In a major step toward the cleanup of Onondaga Lake, the New York State Department of Environmental Conservation (DEC) announced progress on a plan for the lake’s full-scale environmental remediation.
The DEC informed Honeywell that, after submission and review of additional information, it would “propose a cleanup plan for public consideration late this fall.” Following a 60-day public comment period, the final version of the DEC plan would be issued in the spring of 2005, permitting the lake cleanup program to begin.
Honeywell will carry out a responsible cleanup of the contamination in and around the lake through a program of good science, thorough regulatory reviews and extensive public participation. The DEC’s decision to move forward is good news.
In May 2004, in response to the DEC’s request, Honeywell submitted a comprehensive study of the lake cleanup called a “Feasibility Study” (FS). This study, presented in three volumes, follows the strict requirements and timetables under federal law and state regulations for thorough environmental, engineering and scientific analyses of various options for cleaning up the lake. Today’s environmental conditions in the lake are the result of more than 200 years of industrial activity, urban development and population growth. The lake was named as a federal Superfund site in 1994.
The FS evaluates a full range of potential remedies and alternatives to clean up Onondaga Lake. It recommends an extensive dredging and capping cleanup that will protect human health and the environment; meet the performance criteria established by the EPA; significantly improve the habitat for fish and wildlife; improve recreational opportunities and expand public access to the lake; and create the conditions allowing, over time, for the lake’s natural recovery. Moreover, the recommended alternative could be completed within a reasonable timeframe, supporting the community’s future goals for the lake and its surroundings.
Steps Already Taken at the Upland Sites
Honeywell has already made strong progress to address environmental contamination resulting from the old Allied Chemical sites, spending more than $50 million so far. At the old LCP Bridge Street site, Honeywell has removed 19,000 gallons of contaminated liquids (enough to fill four oil tankers) and 280,000 pounds of sludge and 3,380 cubic yards of debris and contaminated soil (enough to fill a football field two feet high).
In 1995, Honeywell installed a large contaminant recovery system that has removed over 25,000 gallons of chlorobenzene and other contaminants from the soil and groundwater. The company also will build a 7,800-foot barrier wall in the southwest corner of the lake to prevent contaminated groundwater from entering the lake. A state-of-the-art facility will treat the groundwater.
Honeywell is also developing cleanup plans for Nine Mile Creek, Geddes Brook, Harbor Brook and the East Flume.
A Rigorous Study Process
Deciding on an environmentally sound course of action was a highly complex process, requiring more than 50,000 hours of analysis. Over 100 national and local experts worked on the plan.
The Feasibility Study summarized 12 years’ worth of scientific investigation, including the analysis of thousands of data points from extensive sampling of the lake water, tributary waters, shoreline groundwater, sediment, wetlands, fish and plants, as well as engineering data for a wide range of options for cleaning up the lake.
The study team included independent technical experts consisting of environmental engineers, civil engineers, geotechnical engineers, marine biologists, toxicologists, environmental scientists, habitat biologists, geologists, and nationally recognized experts from the University of California, the University of Utah, Louisiana State University and the U.S. Army Corps of Engineers (retired).
Cleanup Steps Proposed for the Lake
The FS offers a comprehensive analysis of various alternatives to address the most significant contaminants in the lake sediments. The recommended alternative would use a combination of capping and dredging – both proven technologies – to remediate the contamination in the lake’s sediment and water. Implementation of the remedy would not cause any delay in completing the planned walking and biking trail around the lake, and it would cause no long-term restrictions on canoeing, fishing, boating or other recreational uses of the lake.
The cleanup recommendation includes a step-by-step plan to remove more than 500,000 cubic yards of contaminated sediment from the lake, which would make this project one of the largest environmental dredging programs ever undertaken in the United States. The plan would not dredge the entire lake bottom – a step that would do more harm than good by stirring up and dispersing the pollutants that are now settled within the sediment. In addition to making the water quality worse, this approach would significantly prolong the timeframe for cleaning up the lake. Instead, the proposed dredging would remove the shallow sediments within the lake that are heavily affected by pollutants.
In combination with the removal of contaminated sediments, there are two kinds of protective caps that will be installed. In the shallow parts of the lake, an isolation cap would be installed to ensure any remaining contaminants are permanently isolated from the lake ecosystem. This cap will be placed over an estimated 335 acres in the lake. In the deeper parts of the lake, a thin layer cap — covering about 20 acres — would be installed to enhance the natural recovery of the deeper sediments.
Capping is a well-recognized environmental technique that has been successfully used in many cleanup efforts at other sites. The isolation cap, engineered to be stable, will effectively isolate the sediments from human contact and from organisms that live in the lake, providing long-term, permanent isolation of contaminants. Extensive testing of models of the proposed caps for the lake has strengthened scientists’ confidence in their effectiveness. A long-term monitoring program will ensure that the caps remain effective. Samples will be collected periodically to make sure the contamination doesn’t penetrate the cap and there will be physical inspections to make sure there is no movement or erosion of the caps from wind, wave action or ice.
The highly engineered isolation cap will, in effect, create a new lake bottom in the areas where it will be installed. The cap will consist of several layers and will be anywhere from two feet to three-and-one-half feet thick. The surface characteristics of the isolation cap will be carefully designed in such a way as to enhance the growth of aquatic plants, increase fish spawning, improve aquatic habitat, and resist erosive forces. For example, in some areas of the lake, grasses and other plants favored by fish will be planted. In these areas, the cap would include a layer of gravel that creates fish spawning habitat.
The thin layer cap, composed of approximately six inches of clean sand, will encourage a faster natural recovery of contaminated sediments in the deep parts of the lake.
The Results: A Cleaner Lake, Improved Fish Habitat and Increased Public Access
Together, the steps already taken on the upland sites, the further cleanup of the upland sites and the lake cleanup program will result in a cleaner lake. The contaminants now within the lake will be removed or permanently sealed. As a result, over time, mercury in fish tissue should decrease, water quality will improve, and fish and wildlife habitat will be restored. This process of “natural recovery” will, over time, renew the health of the lake.
In addition, the proposed cleanup plan will enhance the positive impact of Onondaga County’s upgrades to the Metro Waste Water Treatment Plant.
Next Steps in the Process
As the DEC requested, Honeywell will submit additional information. Once that information is submitted, the DEC will analyze the data and generate a Proposed Remedial Action Plan (PRAP) sometime in the fall of 2004. There will then be a 60-day public comment period. The final cleanup plan will be selected and documented in a Record of Decision (ROD) to be released sometime in the spring of 2005.
The recent news from DEC marks a dramatic step forward in the cleanup process for Onondaga Lake, offering residents of the Central New York region the prospect of regaining an important environmental, recreational and social resource that can be enjoyed for generations to come.