On this page:
- What Has Been Done to Clean Up the Site?
- What Is the Current Site Status?
- Activity and Use Limitations
- Sampling and Monitoring
- Emergency Response and Removal
On related pages:
From 1947 to 1991, National Wood Preservers ran a wood treatment operation on this site in Delaware County, Pennsylvania. The company reportedly disposed of liquid waste in a well leading to groundwater under the plant. The wastes where mostly oil contaminated with pentachlorophenol (PCP). The liquid wastes leaked into nearby Naylor’s Run, a small stream that flows through a residential area and then empties into the Delaware River. Liquid wastes were also spilled on the surface, contaminating soil in the area. Approximately 26,000 people live within a mile of the site and there are no known users of the groundwater within a one mile radius of the site. The nearby population is on the public water supply. The Site was added to the National Priorities List (NPL) on September 8, 1983. Operations and maintenance activities are ongoing.
What Has Been Done to Clean Up the Site?
The cleanup work completed to date included:
- Installing an additional deep extraction well to withdraw contaminated groundwater from deep below the ground surface for treatment.
- Excavating soil in a 50-by-50-foot area and in a narrow zone along a nearby abandoned sewer line in the Residential Open Space (ROS), an open area located behind Rittenhouse circle.
- Removing a portion of the sewer that is not sealed with grout.
- Backfilling both excavated areas with clean soil and revegetating them.
- Installing new monitoring wells and three new extraction wells to withdraw groundwater and pump it through an underground pipe back to the treatment plant in the ROS area.
- Conducting ecological sampling to demonstrate habitat and fish recovery.
- The Site reached construction completion on September 16, 2010. The groundwater continues to be extracted and treated on a continuous basis.
- Operation and maintenance of the Site was transferred from EPA to the Pennsylvania Department of Environmental Protection on June 24, 2013.
- EPA established institutional controls site-wide to ensure the environmental cleanup is not compromised. The groundwater continues to be extracted and treated on a continuous basis, and operation and maintenance of the site is ongoing.
What Is the Current Site Status?
Operation and maintenance of the Site was transferred from EPA to the Pennsylvania Department of Environmental Protection (PADEP) on June 24, 2013.
The new Haverford YMCA (aka Freedom Valley YMCA) opened in the fall of 2013 across the street from the Site’s groundwater treatment system. As a precaution, vapor intrusion sampling was conducted at the new YMCA to evaluate if contaminants from the groundwater plume are accumulating beneath and/or entering the building. The first round of sampling was conducted in the YMCA during the 2013-2014 winter heating season and the second round of sampling was conducted ruing the 2014-2015 winter heating season. Vapor intrusion did not appear to be occurring and no unacceptable risks were identified.
The YMCA also installed a state-of-the-art vapor intrusion venting system beneath the building slab during construction. Currently this system is passively vented but can be converted to an active system if vapors are detected in the future.
EPA has conducted several five-year reviews of the Site’s remedy. These reviews ensure that the remedies put in place protect public health and the environment, and function as intended by Site decision documents. The most recent 2015 Five-Year Review (PDF), concluded that the remedy continues to be protective of human health and the environmentin the short-term because the groundwater extraction and treatment facility is operating as intended, the multi-layer geotextile cap prevents contact with contaminated soil in the Source area and the excavation and off-site disposal of the soils from the Recreation and Open Space area prevent exposure to contaminated soil in that portion of the Site. The next five-year review is scheduled for 2020.
In early 2019, residents along Rittenhouse Circle in Havertown contacted EPA and PADEP reporting wetter than normal conditions in their backyards and flooding in their basements. They expressed concerns to both Agencies about potential contamination. PADEP began taking samples on residential properties in February 2019. Additional sampling was conducted by EPA in April 2019. .
As part of the additional investigations, EPA also conducted a dye tracer study in April 2019. EPA injected brightly colored, non-toxic dyes into the ground at various points and monitored the discharge locations to help determine the cause of the elevated ground water table. EPA and PADEP asked that residents notify the Agencies if they saw the brightly colored dyes coming to the surface.
The sampling results identified one or more Site contaminants in the soil and/or sump water (where present) for most of the residential properties that were tested. The contamination appears to have been transported from the groundwater into residential yards and structures between the YMCA and Rittenhouse Circle. This likely occurred when the water table was elevated and seeping out of the ground in 2018-2019.
The contaminants that were detected are not present in amounts that pose an emergency situation or immediate health threat. However, some of the contaminants are high enough to exceed EPA's cleanup standards for the Site and they can pose a health risk if people are in frequent contact with the contaminants over long periods of time (several decades).
Based on the investigations, EPA will use its Superfund authority to conduct a short term response to reduce the potential for exposure to the Site contaminants. This action will address residential property contamination and modify the groundwater collection system to capture increased water table conditions. Additonal testing of more residential properties will be conducted to determine the extent of the contamination. More information can be found in this Community Update - November 2019.
Activity and Use Limitations
At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.
For more background, see Institutional Controls.
Institutional controls are in place to prevent the use of groundwater wells and protect the integrity of the capped area of the site.
Additional information about the institutional controls are available in the 2015 Five-Year Review (PDF) (page 12).
Sampling and Monitoring
Annual Groundwater Monitoring Reports
Emergency Response and Removal
Cleanup has also included several removal actions, or short-term cleanups, to address immediate threats to human health and the environment. These actions included installation of a catch basin in Naylor’s Run to contain chemicals; removal of contaminated tanks and drums; securing of on-site buildings; and capping of contaminated soil.