The Nepera Chemical Co., Inc. site covers 29 acres in Hamptonburgh, New York, near Maybrook. From 1953 to 1967, lagoons on the property received about 50,000 gallons of wastewater per day from a chemical plant in Harriman, roughly 25 miles away. That plant made pharmaceutical and industrial chemicals. State inspectors found lagoon leaks in 1958 and 1960. Disposal ended in December 1967, and the lagoons were backfilled with clean soil by 1974. EPA placed the site on the Superfund National Priorities List in June 1986.
Contamination affects both soil and groundwater. EPA identified 16 contaminants of concern, including benzene, toluene, chlorobenzene, ethylbenzene, xylene, pyridine, aniline, 2-aminopyridine, and acetone. These substances were detected in both soil and groundwater and pose unacceptable risks to human health or the environment.
EPA selected a cleanup remedy in September 2007 and updated it in July 2011. The updated plan required excavating all contaminated soils for off-site treatment and disposal. About 83,000 tons of contaminated soil have been removed. Soil cleanup took place in 2011 and 2012, with a brief pause in winter before resuming in late spring 2012. Groundwater remediation uses oxygen-releasing compounds to encourage natural breakdown of contaminants. Construction of the cleanup was completed in September 2013. Long-term response action for soil and groundwater ran from October 2013 through October 2023, followed by ongoing operation and maintenance starting in October 2023.
Human exposure is under control across the entire site, with no unacceptable exposure pathways identified. Groundwater migration is also under control, with no unacceptable discharge to surface water. The site achieved sitewide readiness for anticipated reuse on March 31, 2023, meaning all cleanup goals for current and reasonably anticipated future land uses have been met and required land-use controls are in place. EPA's most recent five-year review, completed in May 2023, confirms that cleanup actions continue to protect people's health and the environment. The next five-year review is estimated between May and July 2028. The site remains on the National Priorities List.
Community members with questions can contact EPA's Community Involvement Coordinator or the Remedial Project Manager. Site documents can be reviewed in person at the EPA Superfund Records Center at 290 Broadway, 18th floor, in New York City, or at Hamptonburgh Town Hall in Campbell Hall, New York.
