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EPA Region 3 (Mid-Atlantic)
EPA ID# PAD009862939
7th Congressional District
Last Update: January 2015
Current Site Status
The U.S. Environmental Protection Agency just completed the 4th five year review of the Henderson Road site in December 2013. Current site work for the injection well remediation involves: on-going vapor extraction system operation and maintenance, light non-aqueous phase liquid (LNAPL) removal, vapor intrusion inside the on-site garage, quarterly sub-surface water sampling program and an in-situ bio-augmentation pilot program.
- The vapor extraction system has been repaired to improve the vacuum. The system is still effective in reducing concentrations of contaminants of concern (CoC) and will continue to be used in the remedy process.
- LNAPL was detected in the injection well during sampling in 2013. Since the discovery, passive absorbent socks have been used to remove LNAPL from the sub-surface water.
- Vapor Intrusion sampling inside the garage is on-going. Results have shown that levels are below OSHA Permissible Screening Levels but above EPA Screening Levels. As a result, the injection well vault has been sealed and a vapor extraction system will be installed inside the garage. Continued indoor air sampling will be conducted to determine if the remedy is working.
- Quarterly sub-surface water sampling results have shown that concentrations of CoC are primarily found in and around the injection well. CoC above ARAR have not been detected north of the Pennsylvania Turnpike.
- EPA approved a pilot study to determine what conditions in the sub-surface would accelerate bio-remediation. The bio-remediation could be used as an alternative remedy then ground-water extraction and treatment should it prove effective. The pilot study conclusions showed that an oxygen enriched environment had the greatest benefit for a bio-remediation removal method. Currently, the ground water extraction and treatment system is not operating. Decision to restart the ground water extraction system will be made after results of the bio-remediation efforts are analyzed.
Operation and maintenance for the landfill includes vegetation maintenance and erosion repair, leachate monitoring, and methane monitoring. While the ultimate clean-up objective for the aquifer restoration has not been met, the remedy remains effective in protecting human health and the environment by controlling the off-site migration of contaminants. Pumping concentrated around the major contamination source, the injection well, creates a cone of depression which draws water from the highly contaminated sub-surface areas. The landfill cap prevents off-site release of contamination due to wind or water erosion, prevents shallow leachate seeps into the adjacent intermittent stream (Frog Run) and limits leachate generation contributing to ground water pollution.
Site DescriptionThe Henderson Road site occupies 7 acres in a commercial business area of Upper Merion Township, Pennsylvania. Since 1975, O'Hara Sanitation has used the site for waste storage, waste recycling, vehicle maintenance and parking, and office facilities. A former industrial water supply well was used to dispose of industrial liquid wastes during the 1970s. The injection well lies beneath the floor of the O'Hara Sanitation maintenance garage. Contaminants include volatile organic compounds such as benzene, toluene, perchloroethene, and trichloroethene, and polyaromatic hydrocarbons. Other areas of concern include an area of previously ponded water and a landfill located 200 feet east of the well, containing approximately 158,000 cubic yards of landfill material. Additionally, about 21,000 cubic yards of trash and cinder fill were disposed of on adjacent properties. The landfill did not have a permit and contains a mixture of construction demolition debris and other commercial wastes, cinders, a former trenching area, and four underground storage tanks. Liquid waste, sludge, and drums also may have been disposed of at the landfill. The site is located approximately 2,000 feet upgradient of the Upper Merion Reservoir, a source of drinking water owned and operated by Aqua America, Inc that services over 200,000 people. Apartment complexes and private homes are situated beyond the neighboring industrial facilities of the site. The population residing within one-mile of the site is over 5,000 people. A school is located 3,000 feet south of the site.
- Site Responsibility
- This site is being addressed through federal and potentially responsible parties' actions.
- NPL Listing History
- Our country's most serious, uncontrolled, or abandoned hazardous waste sites can be cleaned using federal money. To be eligible for federal cleanup money, a site must be put on the National Priorities List. This site was proposed to the list on September 8, 1983 and formally added to the list on September 21, 1984.
Threats and ContaminantsPrincipal on-site threats to ground water are volatile organic compounds (VOCs) such as benzene, chlorobenzene, vinyl chloride, chloroform, xylenes, and trichloroethylene (TCE). The major potential health risk is drinking contaminated ground water. Site workers could be exposed to site-related contaminants from inhalation of vapors generated by the injection well located in an operating truck repair shop on-site although this property is sampled on a regular basis with favorable results to date.
Contaminant descriptions and risk factors are available from the Agency for Toxic Substances and Disease Registry, an arm of the CDC.
In November, 1985, an Administrative Order on Consent was signed by EPA and nine potentially responsible parties (PRPs); Smithkline Beckman Corp., Alumax, Inc., Congoleum Corp., Sanduik, Inc., Scott Paper Co., Childers Products Co., and the site owners and operators to perform a study to determine the extent of the contamination.
A Consent Decree (CD) was entered into in June 1989 in which the PRPs agreed to clean up the injection well and the ground water contamination caused by the injection of hazardous substances into an on-site well before 1977. Construction of the ground water treatment plant is complete and the plant has been in operation since late 1991 (currently shut down). In addition, a vapor extraction system to remove contaminants from the ground water has been installed within the garage.
An Administrative Order was issued by EPA in August 1990 to the PRPs for the cleanup of the landfill. The selected cleanup remedy included capping of the landfill, leachate collection and storm water management. The PRPs have removed debris from an adjacent property and the western portion of the site has been paved. In addition, land use has been restricted to prevent unauthorized use. Construction of the landfill cap and the leachate collection system has been completed. Leachate has not been generated from the landfill for more than ten years.