Four inactive quarries in Upper Merion Township, Pennsylvania make up this 50-acre Superfund site. Waste from a nearby coking facility was dumped into the quarries starting in 1919, and operations continued until 1980. EPA added the site to the National Priorities List in October 1992. Today it sits in the late stages of cleanup, with most work done and long-term monitoring underway.
The site holds 51 identified contaminants across soil, sediment, and groundwater. Metals found on-site include arsenic, lead, mercury, chromium, and cadmium, among others. Polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene and fluoranthene are present in soil and sediment. Volatile organic compounds (VOCs), including benzene, are in the groundwater, along with phenol, cyanide, ammonia, and naphthalene. The main health risks come from drinking contaminated groundwater or direct contact with contaminated sediment.
EPA selected the cleanup remedy in a September 2000 Record of Decision. The plan covers ten separate operable units and includes dewatering and on-site treatment of water in Quarry 3 ponds, excavation and off-site disposal of contaminated soil and sediment, permanent caps over Quarries 1, 2, and 4, and monitored natural attenuation for groundwater. Modifications to the remedy were issued in 2009, 2016, and 2017. Caps are now installed on all quarries to block human contact with contamination. EPA tested five private drinking water wells near the site in 2019 and confirmed they are not affected by site contamination. Human exposure is under control, and groundwater migration is stabilized with no unacceptable discharge to surface water. Full construction is expected to be complete between September and November 2026.
The fourth five-year review, completed in July 2021, found the remedy is working as designed and protecting human health and the environment. The next five-year review is scheduled for July through September 2026. Institutional controls restrict soil disturbance and land uses that are inconsistent with cleanup levels. The site currently hosts Renaissance Park, a commercial office park. Portions of the Gulph Mills Golf Club occupy the far southern part of the property. A commuter rail station is also located nearby.
Community members who want to get involved can contact the EPA's Community Involvement Coordinator. Administrative records are available for review online or in person at the Upper Merion Township Building in King of Prussia or the U.S. EPA Region 3 office in Philadelphia. Appointments should be scheduled before visiting either location.
