Zschiegner Refining is a 6.1-acre Superfund site in Howell Township, New Jersey. It operated as a precious metals recovery facility from 1964 to 1992. A 1992 federal Drug Enforcement Administration raid found roughly 3,000 different chemicals stored improperly on the property, including peroxide, cyanide, caustics, and acids. EPA placed the site on the National Priorities List in March 1988 and has been overseeing cleanup ever since.
EPA identified 34 contaminants of concern across soil, sediment, and groundwater. Soil contaminants include metals such as arsenic, cadmium, lead, and mercury, as well as pesticides like aldrin, chlordane, and dieldrin, and polychlorinated biphenyls (PCBs). Sediment contains a similar mix, adding cyanide and p,p'-DDT. Groundwater is affected by chloroform, chromium(VI), and iron. EPA determined these substances pose unacceptable risk to human health and the environment.
Cleanup moved through several phases. Starting in 1988, EPA removed over 5,000 gallons of hazardous solutions and 1,400 containers of hazardous substances. A second removal action wrapped up in April 2000. After a remedial investigation and feasibility study, EPA issued a Record of Decision in September 2004 selecting demolition, excavation, and monitoring as the cleanup approach. Workers demolished the on-site building in February 2007, then excavated about 10,425 cubic yards of contaminated upland soil and 15,351 cubic yards of contaminated wetland soil, disposing of all of it at an approved off-site facility. Excavated areas were backfilled with clean fill and restored. Wetland restoration monitoring wrapped up in 2016, and overall construction was completed in August 2016.
Today, human exposure to contaminants is under control and groundwater contamination migration is also under control, with no unacceptable discharge to surface water. Slightly elevated concentrations of site-related metals remain in shallow groundwater on the former property but are declining naturally. Groundwater monitoring continues at a reduced frequency. As of August 2023, the site achieved sitewide ready for anticipated reuse status, meaning all cleanup goals have been met and the property is suitable for future use. The site has not yet been deleted from the National Priorities List, so it remains under EPA oversight. The most recent five-year review was completed in April 2021, and the next is estimated between April and June 2026.
Community members or property stakeholders with questions can contact the EPA staff assigned to the site. EPA's Superfund Redevelopment program also works with communities to support the site's return to productive use. Documents related to the site are available for review in person at EPA's Superfund Records Center at 290 Broadway, 18th floor, in New York, New York.
