HERCULES IN KENVIL REMAINS A POLLUTED HOTSPOT

HERCULES KENVIL, NJ, PHASE II REMEDIATION INVESTIGATION REPORT SUMMARY
 

by Brian T. Lynch, MSW

After decades of wondering, we now can be sure that the 900+ acre former Hercules Powder Company property in Kenvil, NJ, would still qualify as a superfund site. After twenty years of study, the final Phase II Remedial Investigation Report was released six years ago to the N.J. Department of Environmental Protection (DEP) with little fanfare. The DEP decided years earlier not to list the abandoned Hercules Powder property as a State Superfund site. Instead, the agency chose to assign the investigation and clean up of the property under a new law at the time that permitted Ashland Chemical, the corporation that purchased the property, to self-fund environmental studies and cleanup operations on land where explosives were manufactured for over 150 years. 

Under the supervision of a Licensed Site Remediation Specialist (LSRP) indirectly employed by the Ashland Corporation, privately hired subcontractors specializing in environmental assessment and remediation services conducted the investigation of soil, sediment, groundwater, and surface water contamination. Concurrently, an LSRP has overseen the most critical remediation actions taken over the past 30 years, including work to safely demolish buildings on the site, remove and destroy chemicals stored there, and other measures required to limit the further release of toxic chemicals.

Under this legal arrangement with the State, an LSRP (there have been several over the years) prepares periodic reports and submits all study materials and documents to the DEP for review and approval. It has been estimated that the number of documents submitted to the DEP over the years exceeds thirty-thousand pages. 

While all documents are public records, accessing them is not easy. Many older documents are only now being digitalized. Interested parties have to request a review of older documents from the DEP. This involves a trip to the DEP's Trenton headquarters, where boxes of paper documents are brought into a reviewing area from a nearby warehouse. Many reports are highly technical and incomprehensible to non-scientists. 

For most residents, the former Hercules property has been a black box of potential health risks for everyone downwind or downstream. The general public is unaware of the extent or severity of the pollution. 

Last month, the Raritan Headwaters Association obtained about 30,000 pages of more recent, digitally accessible records, including the complete copy of the Hercules Phase II Remedial Investigation Report summary (RIR).  The RIR summary reveals that many significant contaminants remain in the site's soil, sediments, groundwater, and surface water. Some contaminants are at unsafe levels, and the site must remain off-limits to the general public. The good news is that the natural, undisturbed conditions at the site have so far confined the most toxic substances within its boundaries.  The summary report is over 900 pages long and difficult to synthesize further. What follows are snippets of the report (in bold) to support some of the report's general conclusions.  


From the Report as regards just the surface waters and sediments at the facility:

“• SVOCs were detected in sediment, but not in surface water at five of the seven co-located
sample points.

• Beryllium, selenium, and silver were detected in sediment and not in surface water,
indicating these constituents are not partitioning from sediment to surface water.

• Arsenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, vanadium, and zinc
were detected in surface water and sediment.

• Aluminum, barium, calcium, iron, magnesium, potassium, and manganese were detected in both surface water and sediment samples from each co-location. Per the United States
Geological Survey (1984), these metals are commonly found in surficial geologic material in the vicinity of the Facility.”

And this:

“In certain instances, constituents were present at concentrations that exceeded their aqueous solubility limits by two to four orders of magnitude, indicating that these constituents were associated with suspended sediment entrained in the surface water sample.”

Different contaminants are found in different areas on the property according to the manufacturing activity that took place at those locations. In addition, many contaminants were spread throughout the site as a result of drainage ditches, construction work, burn pits, and explosions. This created mixed layering and cross-contamination in many areas. For example, soil samples in the TNT manufacturing area, which took place closest to the Great Springs wetlands on the southern end of the property, contain the highest levels of toxic chemicals related to TNT manufacturing but also contain various contaminants from different manufacturing locations on the property.

From the Report: [4-13, pdf pg 35]

“TNT in soil exceeds its IGWSSL [Impact to Groundwater Soil Screening Levels] in the TNT Area, the PETN [Pentaerythritol Tetranitrate] Area, and the western portion of the Dynamite Area. TNT and related breakdown constituents (4-Amino-2,6-dinitrotoluene, 2,4/2,6-Dinitrotoluene, and 2-Amino-4,6-Dinitrotoluene) exceed their respective GWQS[Groundwater Quality Standards] in… [12]… monitoring wells… located downgradient of soil sample results exceeding the IGWSSL for TNT."

And this: 

"RDX [1,3,5-Trinitroperhydro-1,3,5-triazine, Hexahydro-1,3,5-Trinitro-1,3,5-Triazine] exceeds its GWQS in a monitoring well (MW-36) co-located with and/or downgradient of soil samples with RDX detections that exceed its IGWSSL.”

As a result of different contaminants at various toxicity levels in different areas, anyone authorized to be on the property must first receive special training. Note that the word “receptor” is used throughout the report to refer to any living thing that can potentially be harmed by the contaminants, including “human receptors.”

From the Report:

“Facility-related influences in environmental media result in unacceptable levels of [the] potential risk to ecological receptors based on the screening and conservative exposure modeling conducted in the EE/ERA… Current Facility use precludes human health exposure risks, as personnel permitted to access the Facility are trained in the identification and control/mitigation of potential exposures.”

The report states that hunters are brought into the facility to hunt deer and wildlife that graze on potentially toxic vegetation, presumably so they don’t carry pollution off-site. It’s possible that deer contaminated from grazing on toxic plants could end up in another hunter's venison. Also, trappers are brought in to control the beaver population. Perhaps this is to keep the hydrology on the property from becoming dangerously altered by damn buildings or other bever activities. The report doesn’t specify why the need to control wildlife populations.

From the Report:

5.3.3.1.2 Hunters/Trappers
“Hunters and trappers occasionally enter the Facility under Hercules direction to facilitate control wildlife populations using the Facility (e.g., deer and beaver). Access is limited to weekends during approved hunting/trapping seasons, and their activities are non-intrusive in nature. These individuals receive hazard communication training and are restricted from entering areas where constituents [i.e. contaminants] are likely to be present on the surface.”

We also learned some good news. To date, the most concerning contaminants on the property haven’t migrated off-site to residential areas. For example, toxic chemicals on the property have not been detected in nearby residential wells. The Black River flowing out of the wetlands at the site's southern end isn’t picking up the toxins detected in the surrounding soils or sediments. Note that the report refers to the Black River as a “drainage ditch.” That ditch is actually thousands of years old.

From the Report:

“Surface water leaves the Facility in a single location, via a drainage ditch beneath Route 46 in the southeastern corner of the Facility. SI/RI data at this location indicate that constituents are not leaving the Facility via surface water transport.”

There is a caveat that increases in the flow rate could cause contaminates embedded in the surrounding soil or sediments to become suspended in the water and carried downstream. This fact should be of immediate concern when assessing the adequacy of safeguards to prevent this from happening during the current bioremediation activity.

From the Report:

“Beyond the direct transport of dissolved phase constituents in surface water, surface water may transport constituents adsorbed to suspended sediment offsite during high flow conditions… As previously discussed, flowrates influence the transport of suspended sediment.”

Trees and vegetation that have grown back over time seem to be keeping the wind and rain from carrying off potentially polluted soil. However, high levels of soil contamination in some areas have caused those areas to remain barren.

From the Report:

“It is believed soil erosion was much more prominent historically (estimated to
be from the late 1800s until approximately 1950) when the Facility intentionally removed
vegetation to prevent the spread of fires. The removal of vegetation destabilizes the surficial
soils allowing erosion to occur more freely. From the 1950s through Facility closure in 1996, low-growing groundcover (e.g., turf) was maintained, reducing the potential for erosion. Following Facility closure, maintenance activities ceased and vegetation now covers much of the Facility.

And this from the Report:

"Areas devoid of vegetation do exist and are attributed to constituent concentrations in soil (e.g., over-nitrification of soil where TNT is present)."

Now, however, there has been a recent change of status. Earlier this year, soil remediation activity has begun for the first time. Trees have been cut down; vegetation has been removed. Soil contaminated with PCB was excavated for transport to a special landfill. Other polluted soil was excavated and taken to a bioremediation facility that was built on the edge of the Black River wetlands. This is the area that Lenape natives called “the Great Spring” and is the headwaters of the North Branch of the Raritan River.

Nevertheless, according to the investigation report, the surface water discharge to the Black River from the Great Spring is not carrying contaminants off-site. That’s good news so long as the current excavations underway don’t accidentally release dangerous chemicals that could turn the Black River into a conduit carrying pollution downstream. All is well so long as newly exposed soil doesn’t get carried away by the wind or severe rainstorms. All is well so long a stable plume of contaminated groundwater discovered under the property's southwest corner doesn't migrate into residential areas.

From the Report:

“A small well defined RDX [groundwater] plume exists within the area bounded by monitoring wells MWs 25, 33, 35, 37, J2, and J3 located immediately southwest of the Development Area.”

We trust that all conceivable safeguards are in place and that the stream flowing from that land is frequently and rigorously tested. We must trust the NJDEP, the LSRP, and the Ashland Corporation because we don’t have all the data or information necessary to independently verify the adequacy of the current remediation plans.