Record of Decision System (RODS)
KEYSTONE SANITATION LANDFILL
|Site Name:||KEYSTONE SANITATION LANDFILL|
|City & State:||UNION TOWNSHIP PA 17331|
|NPL Status:||Currently on the Final NPL|
In 1982, in accordance with State permitting requirements, groundwater monitoring for volatile organic compounds (VOCs) was conducted. VOC contamination was detected in on-site monitoring wells and in a nearby spring, Mundorff Spring, which is located east of the Site.
In April 1984, an EPA Field Investigation Team performed a site investigation in response to citizens' complaints of groundwater contamination in residential wells. Sampling results from the Pennsylvania Department of Environmental Resources (PADER), the predecessor to the Pennsylvania Department of Environmental Protection (PADEP), and the Environmental Protection Agency (EPA) confirmed the presence of low levels of VOC contamination in some of the residential wells.
In August 1984, the owner of the landfill installed a spray irrigation system in the most contaminated groundwater area to prevent the migration of contaminants off-site and to remove VOC from the groundwater. Spray irrigation is a practice consisting of spraying contaminated groundwater on a field and allowing VOCs to evaporate into the air. The spray irrigation system was opened until 1992. In addition, leachate collection was attempted on the southern side of the landfill along Line Road. Two perforated pipes were located at the base of the landfill. The pipe ran parallel to Line Road and discharged into a storage tank. The storage tank was pumped periodically, and the contents were disposed off-site.
In the spring of 1985, the State of Maryland installed monitoring wells at the Maryland border to monitor potential contaminant migration. Low levels of VOC contamination have been consistently detected in at least one of these wells.
The Keystone Sanitation Landfill Site was placed on the Superfund National Priorities List (NPL) in July 1987. This list includes sites where uncontrolled hazardous substance releases present the most significant potential threats to human health and the environment.
In 1987, EPA began a Remedial Investigation (RI) and Feasibility Study (FS) at the Site. The RI field activities began in the spring of 1989. The RI/FS reports were issued in July 1990 and finalized in September 1990. EPA issued the OU-1 ROD on September 30, 1990. The remedy selected in the OU-1 ROD included:
- Installation and maintenance of an impermeable cap and gas collection system over the 40-acre landfill
- Installation and maintenance of on-site groundwater extraction wells and a treatment plant to capture, contain and
reduce the concentrations of VOCs and metals in groundwater
- Provision of a point-of-use groundwater treatment system to on-site residents
- Installation and maintenance of a fence around the Site
- Monitoring of the groundwater in monitoring and residential wells
- Monitoring of surface water and sediments
- Initiation of institutional controls regarding present and future activities on the landfill property
To date, the fence and the on-site point-of-use groundwater treatment system have been completed. Construction of the extraction wells and groundwater treatment plant has recently been completed. EPA expects the plant will begin operating later this year.
In addition, the 1990-ROD included a requirement to perform another RI to further study the groundwater contamination in the off-site residential wells and off-site monitoring wells. This RI was completed in January 1998. During the second investigation, EPA collected groundwater samples from 72 monitoring wells, sampled 74 residential wells, and sampled surface water and sediment at numerous locations. Based on the results of the second RI, the ROD was amended on June 25, 1999 to address groundwater contamination outside the boundaries of the landfill. As required by the June 25, 1999 Amendment, carbon filtration units have been offered to residents within 3/4 miles of the landfill. To date, filters have been installed to all eligible residents who accepted the offer.
Following review and consideration of the information in the Administrative Record File, the requirements ofComprehensive Environmental Response, Compensation and Liability Act (CERCLA), the National Contingency Plan (NCP), and public comment, the Environmental Protection Agency (EPA) has selected the following remedial response action to be implemented at this Site in conjunction with the groundwater remedy selected in the Operable Unit (OU)-1 Record of Decision (ROD) of September 1990 and amended on June 25, 1999. The response action will be incorporated as an amendment to the OU-1 ROD of September 1990. The main components of the selected amendment (hereafter the selected amendment to the OU-1 ROD will be referred to as the "Alternate Source Control Remedy") are described below:
Based on new methods of characterizing landfill permeability and gas concentrations, since the 1990 ROD was signed, the owners/operators, under the oversight of EPA and in consultation with the Commonwealth of Pennsylvania Department of Environmental Protection (PADEP), developed an Alternate Source Control Remedy,that meets the remedial action objectives presented in the 1990 ROD and provides protection of human health and the environment.
A. General Description of the Selected Alternate Source Control Remedy
The primary components of the Alternate Source Control Remedy are described below.
- Upgrades to the existing landfill soil cover
- Installation and operation of an ELGE system to actively remove VOCs and methane from the landfill waste
- Monitoring to ensure proper functioning of the ELGE system and to evaluate VOC removal from the landfill
- Monitoring to determine the impact of the ELGE system on the quality of the leachate within the landfill
- Use of surface water management controls to minimize soil erosion and sedimentation
- Maintenance of the existing fence
- Use of institutional controls on the landfill property
1. Upgrades to the Existing Soil Cover
- Addition of low permeability cover soil to maintain a minimum 2-foot thick soil cover across the landfill
- Regrading of the landfill surface to repair minor erosion gullies, improve drainage, and ensure adequate slope
- Removal of woody vegetation
A comprehensive investigation of the landfill cover thickness will be performed. Areas of the landfill soil cover having a thickness of less than 2 feet will be increased to at least 2 feet using compacted soils. The cover will then be revegetated. A waste investigation will be performed to verify the boundaries of the landfill. The cover upgrades will also address waste discovered outside the boundaries of the landfill.
Areas of the landfill where surface water ponding has occurred will be regraded to promote positive drainage of surface water off the landfill. Areas where erosion has occurred will be repaired with cover soil, which will be revegetated to prevent future erosion. These areas will be inspected and evaluated to determine whether specific additional surface water management controls are needed. Woody plants from the small tree-covered portion
View full-text ROD [
To download a full-text ROD, right click on the above link and select Save Link As. A full-text ROD is in PDF format. Please note that download time may be extended given the size of the full-text document. File size is noted in kilobytes (K) or megabytes (M) next to the download link.
Return to Search Results Return to RODS List