Site Name: JOHNSTOWN CITY LANDFILL
EPA ID: NYD980506927 EPA Region: 02 Metro Statistical Area:
W FULTON S EXT, JOHNSTOWN, NY 12095
Operable Unit: 01
ROD ID: EPA/ROD/R02-93/197 ROD Date: 03/31/93
Contaminant: VOCs, Other Organics Metals, Inorganics
Keys: Air Monitoring; Alternate Water Supply; Arsenic; Benzene; Capping; Carbon Adsorption (GAC); Carcinogenic Compounds; Chromium; Clean Water Act; Contingent Remedy; Debris; Direct Contact; Drinking Water Contaminants; Excavation; Filling; Ground Water; Ground Water Monitoring; Ground Water Treatment; Inorganics; Institutional Controls; Landfill Closure; Lead; MCLs; Metals; O&M; Onsite Containment; Onsite Discharge; Onsite Disposal; Onsite Treatment; Organics; PAHs; PCBs; PCE; RCRA; Safe Drinking Water Act; Sediment; Soil; State Standards/Regulations; Surface Water Monitoring; TCE; Toluene; VOCs; Xylenes
Abstract:
The 68-acre Johnstown City Landfill site is a municipally-operated, unlined landfill situated in the LaGrange Gravel pit located in Johnstown, Fulton County, New York. Land use in the area is predominately mixed residential, agricultural, and recreational. The site overlies both an overburdened and bedrock aquifer, which appear to be hydraulically connected downgradient from the site. The primary surface water in the immediate vicinity of the landfill is Mathews Creek, which along with the associated wetlands, appears to be affected by contamination from the site. The estimated 1,000 people who reside within one mile of the site use private wells to obtain their drinking water supply. The site consists of two flat terraces filled into former borrow pits, and a remnant of a pit along the western side of the landfill, which was used previously to dispose of demolition debris and metals. From 1947 until 1960, 34 acres of the site were used as an open refuse disposal facility, which subsequently was converted into a sanitary landfill. Until 1979, the landfill accepted industrial wastes, which included chromium-treated hides, trimmings, and other materials from local tanneries and textile plants. From 1973 to 1979, sewage sludge containing concentrations of chromium, iron, and lead was accepted from the nearby treatment plant and disposed of onsite in open piles. All onsite landfilling operations ceased in 1989. Routine storm water runoff and drainage have created ponded areas on the landfill surface, which have eventually infiltrated into landfill wastes. The associated leachate seeps and occasional ephemeral runoff from the landfill then flowed into, and contaminated, the adjacent LaGrange Gravel pit. This ROD addresses both onsite source and ground water contamination, as the first and final remedial action for this site. The primary contaminants of concern affecting the soil, sediment, debris, and ground water are VOCs, including benzene, PCE, TCE, toluene, and xylenes; other organics, including PAHs, PCBs, pesticides, and phenols; metals, including arsenic, chromium, and lead; and inorganics, including cyanide. SELECTED REMEDIAL ACTION: The selected remedial action for this site includes excavating contaminated LaGrange Pit sediment, and placing the excavated material on the existing landfill; regrading and constructing a multi-layer cap over the landfill and excavated sediment; filling any excavated areas with clean fill; allowing ground water to naturally attenuate; expanding the city's municipal water supply to provide potable water to all residences potentially affected by the site; performing a cultural resource survey for onsite and offsite areas to determine sensitivity of the site for cultural resources; monitoring ground water, surface water, and air; maintaining the cap and monitoring and controlling landfill gas emissions, as needed; implementing institutional controls, including deed restrictions, and site access restrictions, including fencing; and providing for a contingency in the event that monitoring indicates that the ground water is not being restored to acceptable levels through natural attenuation. The contingency remedy involves extraction and onsite treatment of ground water using physical/chemical processes such as pH adjustment, chemical precipitation, and carbon adsorption, with discharge of the treated water to the aquifer through percolation ponds, injection wells, or direct discharge to surface water. The estimated present worth cost for this remedial action is $16,454,000, which includes an estimated annual O&M cost of $174,000 for 30 years. The estimated present worth cost for the contingency remedy is $32,580,000, which includes an estimated annual O&M cost of $936,000 for 30 years. PERFORMANCE STANDARDS OR GOALS: Not provided. INSTITUTIONAL CONTROLS: Deed restrictions will be implemented to restrict activities that could affect the integrity of the cap and to prevent installation of drinking water wells at the site.
Remedy:
This operable unit represents the entire remedial action for the Site. It addresses the principal threats to human health and the environment at the Site by controlling the source of contamination and the generation of leachate.
The major components of the selected remedy include:
* Excavation of the LaGrange Gravel Pit sediments and placing the excavated materials on the existing landfill. The pit will be filled with clean fill, so that it may be used as an infiltration basin and/or stormwater collection basin;
* Regrading and compacting the landfill mound to provide a stable foundation for placement of the various layers of the cap and to promote rapid runoff;
* Construction of a multi-layer closure cap over the landfill mound and excavated sediments as per New York State 6 NYCRR Part 360 regulations. The cap, by reducing leachate generation, will act to improve the ground-water quality in the upper (overburden) and lower (bedrock) aquifers and surface-water quality in Mathew Creek through natural attenuation of contaminants;
* Expansion of the Johnstown City water-supply system to provide potable water to all private water supplies potentially impacted by the landfill. Providing city water will require the extension of the City's water lines and construction of a booster pump station; and
* Erection of approximately 6,800 feet of conventional chain-link fencing surrounding the entire landfill mound, with placement of appropriate warning signs.
The effectiveness of the landfill cap will be evaluated through post-construction monitoring of ground-water and surface-water quality. The evaluation will be conducted within 5 years following initiation of construction of the landfill cap, and at any time as needed thereafter, during the long-term monitoring of the Site. Should the monitoring results indicate that either ground-water quality in the upper (overburden) aquifer or the lower (bedrock) aquifer, or surface-water quality in Mathew Creek, is not being restored to acceptable levels through natural attenuation as a result of reduced leachate generation, the following will be implemented:
* Extraction of contaminated ground water from either of the aquifers, as necessary. The extraction system would utilize extraction wells which would induce flow to the wells through drawdown of the ground-water table. Operation of the ground-water extraction system would reduce the migration of contaminants away from the Site; . Treatment of ground water by a treatment system located permanently on-Site that would use physical/chemical processes such as pH adjustment, chemical precipitation, and carbon adsorption, to remove inorganic and volatile organic contaminants; and
* Discharge of treated ground water by returning it to the aquifer via percolation ponds or injection wells, or by discharging it to a stream, the nearest being Mathew Creek. The discharge standards would be established by NYSDEC.