The Bethpage Plume: Sixty Years of Grumman’s Groundwater Legacy on Long Island
By Paul E. Rosenfeld, M.S., Ph.D., Principal Environmental Chemist, RoseyFields LLC, Santa Monica, California
An aerospace giant’s sixty-year footprint
From the 1930s through the 1990s, Grumman Aerospace, later Northrop Grumman, manufactured and tested military and civilian aircraft at its roughly 600-acre Bethpage, New York facility, using trichloroethylene (TCE), tetrachloroethylene (PCE), and other chlorinated solvents extensively for degreasing aircraft parts, along with plane-painting and metal-finishing operations that released additional volatile organic compounds and heavy metals into the ground. Dr. Paul E. Rosenfeld, M.S., Ph.D. of RoseyFields LLC addressed the resulting groundwater contamination and community exposure in the associated personal-injury litigation (Romano, 2022).
One of the largest groundwater plumes in the region
The resulting contamination plume, now recognized as one of the largest groundwater contamination sites on Long Island, has migrated for miles from the original Bethpage facility, contaminating drinking-water supply wells serving both the Bethpage and South Farmingdale Water Districts and continuing to spread southward beneath residential neighborhoods.
Decades of underestimated plume growth
Historical agency records show that a 1990 model developed to characterize the plume’s extent substantially underestimated its actual growth, contributing to remediation planning that lagged behind the contamination’s real spread for years, a documented history directly relevant to any historical exposure reconstruction addressing what area residents were actually exposed to during that period.
Multiple contaminants, multiple health endpoints
In addition to TCE and PCE, the site has released 1,4-dioxane, PCBs, and metals including arsenic, cadmium, chromium, and lead into groundwater and residential soil, requiring an exposure assessment that addresses each contaminant’s distinct toxicological profile and pathway rather than treating the plume as a single undifferentiated hazard.
The regulatory basis for TCE and PCE concern
TCE and PCE are each regulated under the Safe Drinking Water Act at a Maximum Contaminant Level of 5 parts per billion, and IARC classifies TCE as carcinogenic to humans while identifying PCE as probably carcinogenic to humans, providing the toxicological and regulatory framework against which reconstructed historical groundwater concentrations at Bethpage are evaluated (IARC, Vol 106; US EPA, 40 CFR § 141.61).
1,4-dioxane as a comparatively recent regulatory concern
New York established a state drinking-water standard for 1,4-dioxane specifically because levels detected in Bethpage-area wells were found at concentrations many times higher than health-protective guidance, illustrating how a plume can present evolving regulatory significance decades after the original contamination occurred, as testing methods and toxicological understanding advance.
Both cost-recovery and personal-injury claims arising from one plume
The Bethpage contamination has generated two distinct categories of litigation: water district lawsuits recovering the substantial capital costs of installing advanced treatment systems, and separate personal-injury lawsuits brought by residents alleging health harm from decades of exposure, each requiring a different, though related, exposure and damages analysis.
Vapor intrusion as an additional exposure pathway
Beyond drinking-water ingestion, the same volatile solvents implicated at Bethpage are capable of vapor intrusion into homes overlying the contaminated groundwater, requiring the exposure assessment to address indoor air alongside drinking water, consistent with the multi-pathway analysis applied at other chlorinated-solvent sites (US EPA, OSWER Vapor Intrusion Technical Guide).
Why a fifty-year-old plume remains an active exposure question
Because the plume continues to migrate southward at an estimated rate of roughly one foot per day and complete remediation has been projected to take over a century under current cleanup plans, the Bethpage matter illustrates that historical exposure reconstruction for a legacy contamination site is not purely retrospective; it must also inform an understanding of ongoing and future exposure for residents who remain in the plume’s path.
Why large aerospace and defense manufacturing sites recur in this litigation category
Bethpage’s contamination profile, chlorinated solvent degreasing combined with metal finishing and coatings operations sustained over many decades, is characteristic of numerous other legacy aerospace and defense manufacturing sites nationally, making the exposure reconstruction and multi-pathway assessment methodology developed at Bethpage broadly transferable. RoseyFields.com has additional background on Dr. Rosenfeld’s chlorinated solvent and groundwater exposure assessment work.
References
1. Romano R, et al. v Northrop Grumman Corporation. Case No. 16-cv-5760, US District Court for the Eastern District of New York.
2. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Trichloroethylene, Tetrachloroethylene, and Some Other Chlorinated Agents. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol 106. Lyon, France: International Agency for Research on Cancer; 2014.
3. US Environmental Protection Agency. National Primary Drinking Water Regulations: Volatile Organic Chemicals. 40 CFR § 141.61.
4. New York State Department of Health. Maximum Contaminant Level for 1,4-Dioxane in Drinking Water. Albany, NY: NYSDOH; 2020.
5. New York State Department of Environmental Conservation. Bethpage/Grumman Site Remediation Program. Albany, NY: NYSDEC.
6. Bethpage Water District v United States, et al. Case No. 2:22-cv-02050, US District Court for the Eastern District of New York; consent decree 2022.
7. South Farmingdale Water District v United States, et al. Case No. 2:22-cv-02051, US District Court for the Eastern District of New York; consent decree 2022.
8. US Environmental Protection Agency. OSWER Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor Air. Washington, DC: US EPA; 2015.
9. US Environmental Protection Agency. Toxicological Review of Trichloroethylene. Integrated Risk Information System (IRIS). Washington, DC: US EPA.
10. US Environmental Protection Agency. Toxicological Review of Tetrachloroethylene (Perchloroethylene). Integrated Risk Information System (IRIS). Washington, DC: US EPA.
11. Agency for Toxic Substances and Disease Registry. Toxicological Profile for 1,4-Dioxane. Atlanta, GA: US Department of Health and Human Services; 2012.
12. Gonzalez J, Feng L, Sutherland A, Waller C, Sok H, Hesse R, Rosenfeld P. PCBs and dioxins/furans in attic dust collected near former PCB production and secondary copper facilities in Sauget, IL. Procedia Environ Sci. 2010:113-125.
13. Rosenfeld PE. RoseyFields LLC: Chlorinated Solvent Groundwater and Vapor Intrusion Assessment. Santa Monica, CA: RoseyFields LLC; 2026.
14. US Environmental Protection Agency. Revisions to the Guideline on Air Quality Models. 40 CFR Part 51, Appendix W. Fed Regist. 2017;82(10):5182-5235.