Contamination at the Landfill
More than two decades of investigations have documented contamination and environmental concerns at the landfill. A 2004 investigation by Sadat Associates reported benzene and chlorobenzene exceedances in groundwater, identified conditions consistent with landfill leachate, and noted that the landfill lacked engineered systems to manage leachate and landfill gas.
A 2010 investigation by Excel identified contaminants in groundwater at concentrations about New Jersey groundwater quality standards, including benzene, arsenic, lead, vinyl chloride, and PCBs.
The investigation also identified potential pathways for contaminants to migrate from the site into Raritan Bay and Chingarora Creek. While the report considered ecological exposure from groundwater impacts to be negligible, it documented the presence of hazardous substances and recommended additional investigation in several areas.
New testing in 2026 found many of the same contaminants still present. SESI's testing of groundwater at the landfill detected metals including arsenic, lead, aluminum, cobalt, iron, manganese, and sodium at levels above standards. Benzene, vinyl chloride, and PFAS were also detected above standards.
Contamination Outside the Landfill
Independent testing has identified contaminants beyond the landfill itself. A study commissioned by NJ.com found elevated levels of toxic and carcinogenic metals including arsenic, cobalt, lead, nickel, antimony, and vanadium in the surrounding community, including areas near playgrounds and a baseball field.
Testing by environmental scientist Scott Smith also detected dioxins in soil collected at the landfill and at a nearby residence. The reported concentration was approximately 6.5 times the EPA's trigger threshold for human health concern and follow-up testing. Dioxins are highly toxic, persistent chemicals associated with cancer and other serious health effects.
A second round of residential testing by Scott Smith echoed NJ.com's findings of elevated arsenic and lead. He also found benzo(a)pyrene and dioxins above the EPA's residential screening levels. Due to these exceedances, additional follow-up testing was recommended.
Potential Exposure Pathways
At the August 13 council meeting, Commissioner Ed Potosnak said that NJDEP had not found evidence of a pathway exposing people to contamination at levels that would require action:
“When there is a pathway to expose humans at levels that will affect their health, regulations require immediate action. 2010, if that were the case, immediate action would have been taken. If any of these test results that are coming out today show that, immediate action will be taken. To date, that has not been the case in Keyport."
The 2010 landfill investigation detected volatile chemicals in soil gas at concentrations exceeding NJDEP Soil Gas Screening Levels (SGSLs), which are used to evaluate potential vapor intrusion risks.
Vapor intrusion occurs when chemicals in groundwater or soil gas move through the ground and enter buildings through cracks or openings in foundations.
In 2010, benzene was detected at concentrations up to 1,086 µg/m³, approximately 68 times higher than NJDEP's residential SGSL of 16 µg/m³.
NJDEP vapor intrusion guidance states that exceedances of these screening levels require further evaluation of the vapor intrusion exposure pathway. No vapor intrusion investigation was conducted following these findings. NJDEP is currently conducting groundwater and soil gas testing in surrounding neighborhoods to evaluate potential vapor intrusion.
Testing and Investigations
State & Township
NJDEP
In June 2026, NJDEP sampled groundwater from monitoring wells on the landfill and surface water in Raritan Bay, Chingarora Creek, and other tributaries adjacent to the site.
In August, NJDEP expanded its testing beyond the landfill, collecting soil-gas and groundwater samples in surrounding neighborhoods to investigate whether contamination could have migrated off-site and created a potential vapor intrusion pathway.
NJDEP will hold a town hall on September 22 to present their findings. They released a video on August 26, outlining their efforts.
Excel Environmental Resources
In July 2026, Excel conducted a Focused Site Investigation Report on behalf of the Borough of Keyport. The investigation examined the shallow groundwater in the landfill area, as well as soil and groundwater quality in Lot 14, an undeveloped parcel in the southwest portion of the site.
In 2010, Excel conducted a Site Investigation/Remedial Investigation that identified contaminants above groundwater quality standards, potential pathways for exposure, and confirmed inadequate site closure. As part of the investigation, Princeton Hydro, LLC performed a Baseline Ecological Evaluation to assess potential ecological impacts associated with the site.
Property & Due Dilligence
SESI Environmental Consultants
Between October 2025 and July 2026, SESI conducted environmental testing on behalf of Pacer Group Holdings, the company currently under contract to purchase the property. The testing was conducted as part of the company's due dilligence to evaluate existing environmental conditions and potential risks associated with the property.
SESI/Pacer's Keyport Website: keyportlandfillclosure.com
Sadat Associates
In 2003 and 2004, Sadat Associates conducted environmental due dilligence on behalf of Century Land Group, a prospective purchaser exploring redevelopment. The investigation included test pits, soil borings, groundwater monitoring, and landfill gas testing.
Independent
Scott Smith
Scott Smith is an environmental scientist and EPA whistleblower who has independently tested the Aeromarine site and nearby properties.
[Town Hall 8/7 - Preliminary Results for Dioxins, Metals, PFAs]
[Town Hall 9/16 - Preliminary Results for Dioxins, Metals, SVOC/PAHs]
NJ.com
NJ.com conducted independent testing at locations outside the landfill, including public parks. Its investigation also documented more than 400 cancer cases reported by residents in the area.
[NJ.com's independent testing report]