Posted on April 1, 2019
PLYMOUTH – According to the Department of Environmental Protection, groundwater contamination from the Cedarville landfill discharged into Cape Cod Bay some time ago.
“The contaminants detected in the landfill plume in the 1980s and 1990s, volatile organic compounds, are no longer present in groundwater samples collected from downgradient of the landfill and thus the Cedarville landfill is not a continuing source of volatile organic compound groundwater contamination based on data submitted,” DEP spokesman Ed Coletta wrote in an email.
Located off Hedges Pond Road, the Cedarville landfill resurfaced in the news recently when town officials discussed the possibility of depositing a portion of material from the Plymouth Harbor dredging project in the landfill. While the federal government finishes up a $14 million project of dredging 400,000 cubic yards of sediment from the harbor, in a separate project the town is on the hook to remove 96,000 more cubic yards of sediment from town-controlled harbor areas that hug the coastline, like around State Pier where the Mayflower II is berthed.
The state has deemed that some of this 96,000 cubic yards of material contains the pesticide DDT and is, therefore, too toxic to be buried at sea, so it must be deposited in a landfill. Marine and Environmental Affairs Director David Gould said the town investigated the possibility of depositing the DDT-laden sediment in the “valley area” of the Cedarville landfill. However, Cedarville residents objected to this plan, saying it would add contamination to an already contaminated site, which harbors thousands of barrels of toxic solvents like methyl chlorine. Town officials abandoned the proposal in light of the protest, but the story unearthed the facts surrounding this unlined landfill, leaving some with lingering concerns about its safety and possible impact to the village.
It came to light that approximately 2,000 barrels of toxic waste had been illegally dumped in the landfill decades ago, causing groundwater contamination and the need to connect town water to a number of affected Cedarville homes during the 1980s.
Some residents want to know where the contaminated plume is now, how the landfill is being monitored and what should be done about those 2,000 barrels containing toxic solvents that remain festering underground.
Dredging the inner harbor is important so that vessels like the Mayflower II and other boats docked in the harbor are able to travel freely; the sediment in these areas is so thick, some vessels are grounded by it during low tide. It’s not clear what the alternate plan for disposal of this dredged material will be used.
The Department of Environmental Protection has weighed in on the issue, noting that, according to a Final Screening Report performed by NUS Corporation dated Jan. 25, 1989, several thousand gallons of hazardous waste were buried in the landfill and, in 1982, a community well was closed as a result of contamination from the landfill, which is unlined.
The DEP states: “Groundwater monitoring data from the early 1980s indicates that the aquifer below the landfill was contaminated with several Volatile Organic Compounds (VOCs), including 1,1-dichloroethane, 1,2-dichloroethane, vinyl chloride, and bis(2-ethylhexyl)phthalate.”
According to the DEP, by the 1990s, groundwater data indicated that the plume had decreased in concentration to the point of negligible. The state agency notes that the landfill was capped in 1995, to prevent water from continuing to percolate through the toxic site and into groundwater, thus impacting area wells. The capped landfill was then monitored with test wells for the next 30 years. The DEP report also notes that it currently requires landfills to be lined to prevent leachate and contaminants from getting into the groundwater.
In 2008, the DEP approved a revised monitoring network, with six monitoring well locations monitored twice a year.
Coletta summed up the DEPs report on the landfill: “In other words, the landfill plume was barely detectable back in the 1990s and, based on our understanding of groundwater flow direction and speed of groundwater flow, the contaminants detected in groundwater in 1992 discharged to Cape Cod Bay some time ago.”
While that may be reassuring to some, others say the presence of this toxic waste site in their village is continuing reason for concern since exposure to the solvents therein is deadly and linked to cancer. Ideas that have been pitched of possibly creating a recreational field on this 12-acre site worry these residents, since the clay cap that was installed on the landfill is nearly 25 years old and suffering from wear and tear. Gases from these toxins can be dangerous, and Gould said during his visit to the Cedarville Steering Committee two weeks ago that residents should be more concerned about what’s currently in the landfill than a plan to deposit DDT-laden sediment in a lined middle portion of it.
Source: plymouth.wickedlocal.com
