or 2B and also has the greatest potential for ehort-term exposures due to dust and volitilization of organics during excalration of the waste. Alternative 1 is the easiest to implement and the lowest in cost since no action would be taken. Alternative 2 is the easiest "action alternative" to implement and least cost followed by Alternatives 2B and 3 regpectively. 2. C m t o n Narsh Eastern chainel ~edireitAlternative. Alternative 4A is more protective than Alternative 4B in the long-term due to the removal of sediments which have elevated metal concent/rations. However, the remova.1 of sediments in Alternative 4A also poses a potential short-term ecological threat due to physical disturbance of the adjacent areas and the potential for suspended sediments to escape from twe containment dams needed to excavate this area. However, a releade of sediments from a containment dam would only be expected during a severe storm event. The only ARARs for sediments'would be administrative, i.e., dredging permits. Alternative 4A would comply with this ARAR by obtaining necessary permits while no permit would be required for Alternative 4B. The channel is a demsitional area and as such will beain to reaccumulate Hudson ~ i v & sediments immediately after remo;al of the siltation control devices associated with Alternative 4A. The amarent lower quality of the eastern channel may be due in part to the dGaimilarity of this channel to the others present. The eastern channel is th/e only channel studied that completely dewaters during periods of low tide, whereas the others maintain some standing waters. Once the landfill is capped and proper leachate and stormwater control systems begin operating, the eastern channel should experience a eignificant change in hydraulic and chemical loading. NYSDEC expects that only clean precipitation-induced surface water discharges will be occurring in the eastern channel in the future. The stormwater management system includes settling basins which have been designed to eliminate any detrime~tal transport of sediments to the Hudson River. These stormwater distharge points will be monitored under the County's general stormwater diecharge permit. The chemical loading from landfill leachates should decrease relatively rapidly (90 percent in 8 years) based upon the groundw ter modeling performed during the RI/FS. Since the migration pathway #rom the landfill to the marsh has existed for over 60 years the driving fcbrces behind these conditions are expected to be remedied by Alternative 2. The Department has determined that remediation of the aedimerlts was impracticable since the cost was considered to be excessive for tlie expected benefits that would be realized by the biotic community. Alternatrive 4A's estimated cost would be a minimum of $2,650,000 for on-site disposal up to a maximum of $8,935,000 for off-site disposal. I HIGHLIGHTS OF COMMUNITY PARTICIPATION Residents and environmental groups in the immediate vicinity of the site have shown very strong interest in the Croton Point Landfill site throughout the remedial process. Public maetings and other events have been held to update the community on remedial activities, as summarized in the following chronology: September, 1989: A public informational meeting concerning the remedial program and the Title 3 State Assistance Program was held at the CrOton Village Municipal Building. September, IYYV: A public informational meeting was held at the Croton Village Municipal Building to present the results of the RI work to date and to present the preliminary plans for the early cap. October, 1991: Westchester County held a public hearing in the Village on their Draft Environmental Impacts Statement: ."Propoped Dredging for Materials Delivery: CPSL." Due to several.issues incltading community concerns, the County did not pursue the dredging option. November 25, 1992: The Department of Environmental Conservation (DEC) announced the availability of its Proposed Remedial Action Plan (PRAP) to the general public. December 14, 1992: A public meeting was held at the Croton Village Municipal Building to present the PRAP.' December 24, 1992s In response to community requests, DEC extends the formal public comment period on the PRAP to January 15, 1993. A Citizen Participation Plan for this site was devqloped and implemented jointly by Westchester County and DEC. Allmajor reports were placed in document repositories in the vicinity of the site and made available for public review. A public contact list was developed, expanded as needed throughout the project, and used to distribute information and meeting announcements. Comments received regarding the Proposed Remedial fiction Plan [PRAP) have been addressed and are documented in the Responsiveness Summary (Exhibit D). I VIII. SELECTED REMEDY The selected remedy consists of Source Alternative 2 and Marsh Alternative 48 which would incorporate the final design plans for the leachate transfer system and the Cap System. The major elements of the proposed remedial program can be summarized as follows: o Construction of an engineered capping system to isolate the landfilled wastes from rainfall and human contact. This cap system