GOVERNMENT
Cleanup Agreed on for Niagara Landfill The U.S., New York state, and Occidental Chemical finally have reached agreement on how to clean up toxic liquid wastes at the Hyde Park landfill in Niagara, N.Y. It comes six years after the U.S. and New York filed suit against Occidental, formerly Hooker Chemical, the firm that used the site for waste disposal for nearly 22 years. The agreement takes effect after a public comment period of at least two months, and after federal court Judge John T. Curtin approves it. Environmental Protection Agency regional administrator Christopher J. Daggett says the agreement is "a far-reaching effort to curb exposure to chemicals that have migrated from the site and that continue to migrate." The cleanup program is a multifaceted scheme designed to remove and destroy the most concentrated of the hazardous liquids buried in the landfill. Hyde Park, a 15-acre site in the town of Niagara, was used as a landfill from 1953 to 1975. During that period, Occidental disposed of nearly 80,000 tons of hazardous waste, including up to 2 tons of 2,3,7,8tetrachlorodibenzo-p-dioxin. In 1982, three years after the federal and state governments filed suit, Occidental agreed to an out-of-court settlement under which it would clean up Hyde Park. Then, a year-
and-a-half survey to assess the extent of contamination and to develop a cleanup scheme revealed "that chemicals had spread much further than had previously been known," explains the state's Attorney General Robert Abrams. Chemicals were found to have migrated through the soil and into the bedrock near the landfill, threatening to contaminate the Niagara River and Lake Ontario. The unexpected extent of chemical migration forced the development of a more complex and expensive cleanup. Today, Occidental's Hyde Park project coordinator John Nichter expects the remedial effort to take five years and cost about $17 million. The agreed-upon remedial plan calls for the construction of a deeper tile drain system than now exists around the landfill. This second drain system will collect contaminated groundwater and the so-called nonaqueous-phase liquids (NAPL) trapped under the clay cap. The groundwater will be treated with activated carbon to remove the soluble contaminants. Treated groundwater will be flushed into the municipal sewage treatment system. The NAPL will be collected and incinerated at an Occidental facility in Niagara. Extraction wells in the landfill will withdraw additional NAPL.
Hyde Park landfill at a glance Owner: Occidental Chemical, formerly Hooker Chemical & Plastics
nyls (PCBs), dioxins including 2,3,7,8tetrachlorodibenzo-p-dioxin
Size: 15 acres
Amount of TCDD disposed: 0.6 to 1.6 tons
Location: town of Niagara, northwest of Niagara Falls, N.Y.
Amount disposed: about 80,000 tons of hazardous waste
Cleanup plan: community monitoring program, extraction wells, deeper tile drain system, bedrock purge & recirculation well system, groundwater studies, study of dioxin accumulation in Lake Ontario fish
Chemicals disposed: phenol, toluene trichloroethylene, polychforinated biphe-
Cost of cleanup: $17 million plus $1.5 million yearly for operating, monitoring
Used as landfill: between 1953 and 1975
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December 16, 1985 C&EN
These liquids also will be incinerated. In addition, a so-called bedrock purge and recirculation system will be used "to reclaim the NAPL already migrating offsite," says James R. Marshall, spokesman for EPA's regional office. This system essentially flushes the nonaqueous-phase liquids from the bedrock, and collects these liquids for incineration. Yet another purge system will collect the faster moving but less hazardous chemicals that are migrating with the groundwater to and out the Niagara Gorge face. Marshall says the nonaqueousphase liquids are viscous, heavier than groundwater and so have not migrated so far offsite as the watersoluble contaminants. But, he says, 90% of the contaminants that have moved offsite are nonaqueous-phase liquids. Dioxins will be found in this fraction. Neither EPA nor Occidental knows just how much of the contamination will be removed by this cleanup scheme. Some residual contamination is expected. So the company will have to monitor and maintain the site for 35 years. Occidental is obliged to take additional corrective steps should monitoring detect the concentration of residual contamination above certain set action levels. Annual operating and maintenance costs are estimated at $1.5 million, but Nichter expects this to decline as his company gains experience over the years. In addition, Occidental will monitor the community and signal a warning should chemicals migrate into residential areas. "I am confident the cleanup program . . . will protect the public health and the environment, including the Niagara River," says Attorney General Abrams. The community may not be so sanguine. EPA's Marshall expects the comment period to be extended and judicial approval, if it is granted, to come no sooner than late winter. Lois Ember, Washington
