From 1956 to 1998, Mercury Refining Company, Inc. ran an industrial oven on the border of Guilderland and Colonie, New York, to recover mercury from batteries, thermometers, pressure regulators, and dental amalgams. That process left soil and sediment contaminated with mercury and polychlorinated biphenyls (PCBs). Contaminated stormwater also drained into an unnamed tributary of Patroon Creek. The EPA placed the site on the National Priorities List (NPL) in September 1983 after the New York State Department of Environmental Conservation found PCBs and mercury in soil near the southern edge of the property and along creek banks.
Contaminants of concern span soil, sediment, and groundwater. Mercury is present across all three. Sediment also contains Aroclor 1260 (a specific PCB product), methyl mercury, polycyclic aromatic hydrocarbons (PAHs), benzo(k)fluoranthene, benzo(a)pyrene, and vanadium. Cleanup began under state oversight and shifted to EPA leadership in 1999. Workers excavated and removed about 5,700 tons of mercury-contaminated soil and sediment for off-site disposal. For deeper contamination, contractors used in-situ solidification and stabilization, mixing Portland cement and a sulfur compound directly into the soil to stop mercury from migrating. Construction was complete by April 2015.
Human exposure at the site is under control, with no unacceptable exposure pathways identified. Groundwater contamination is stabilized, with no unacceptable discharge to surface water. The site reached "sitewide ready for anticipated use" status on September 30, 2020, meaning all cleanup goals for current and future land uses have been met and required land-use controls are in place. EPA deleted the site from the NPL on March 5, 2025. Long-term monitoring continues, with periodic groundwater and ecological sampling. The next five-year review is due on or before February 2029.
The site is still active in a limited way. A company called MERECO operates an on-site building as an office and processes materials containing precious metals. As of December 2024, one on-site business employed six people and generated an estimated $684,000 in annual sales revenue.
Community members who want more information can contact the EPA staff assigned to the site. Documents are available online through EPA's database and in person at the EPA Superfund Records Center at 290 Broadway, 18th floor, New York City, or at the William K. Sanford Town Library at 629 Albany Shaker Road in Albany.
