RI: DEM approves modified closure plan for former Portsmouth town dump site

DEM APPROVES MODIFIED CLOSURE PLAN FOR FORMER PORTSMOUTH TOWN
DUMP SITE

Department Will Oversee Cleanup Efforts and Conduct Unannounced
Inspections of Site

PROVIDENCE – Following a thorough review of a proposal to modify an
existing “Beneficial Use Determination” for closing the Portsmouth
Town Dump, the Department of Environmental Management has approved
a plan that is protective of the environment and human health. The
approval will allow for soils with elevated levels of
naturally-occurring arsenic to be used as sub-grade fill beneath
two feet of clean soil to bring the site to the correct elevations
so that a permanent, protective cap can be installed. The
privately-owned 18-acre site, 14 acres of which were leased as a
landfill by the Town of Portsmouth, is contaminated with hazardous
substances and needs to be cleaned up and capped.

The former landfill in the Island Park neighborhood was operated
by the Town of Portsmouth for the disposal of waste from 1954 to
1974. Since then, the property has been dormant. When the landfill
operations ceased, the site was not properly closed, and as a
result, solid waste has remained at the surface, and chemical
contamination has been found. The site was purchased in 2003 by AP
Enterprise LLC which performed a comprehensive environmental
investigation of the property and proposed a clean up and closure
plan to address environmental issues. Site investigation reports
from 2003 and 2006 indicate existing soils at the site exceed DEM
direct exposure criteria for arsenic, lead, benzo (a) pyrene, benzo
(b) fluoranthene, and chrysene, and groundwater protection
standards for trichloroethene, tetrachloroethene, and other
contaminants. These reports make clear the current condition is
unsafe, and must be cleaned up.

The cleanup proposed by AP Enterprise LLC complies with current
environmental laws and regulations and includes installation of a
protective cap. In order to construct such a cap properly, fill is
needed to be brought in to grade and contour the land so that the
cap will stay in place and remain protective for the long term.
DEM’s approval will allow AP Enterprise LLC to accept soils
containing naturally-occurring arsenic above the DEM Direct
Exposure Criteria of 7 mg/kg, with an average arsenic level below
20 mg/kg and a maximum level of 40 mg/kg, to contour and grade the
site. The use of shaping and grading soils under the final cap will
minimize stormwater infiltration and better protect the
groundwater. Once these contours are established, the site will be
capped using clean soil – soil that is suitable and protective for
unrestrictive use – to cover the site. Grass seed will be applied
to keep this in place.

“The Department shares the concerns of citizens that the
landfill be capped and maintained in a manner that supports
environmental quality and human health,” said DEM Director Janet
Coit. “DEM will closely monitor the project and conduct frequent,
unannounced site visits and inspections on a regular basis, based
on the progress taking place at the site and the amount of soils
that are being brought to the site.” Director Coit also said that
DEM is willing to work with the Town, and/or any other responsible
party, should they want to work with the developer and go above and
beyond the current requirements for cleaning up the former landfill
site.

“HEALTH believes that the clean fill cap over the contaminated
soil is an appropriate solution to prevent health risks in the
community,” said Interim Director of Health, Michael Fine, MD.

Last year AP Enterprise LLC received final approvals of its
closure plans for the town dump from DEM, the Coastal Resources
Management Council, and the Town of Portsmouth. In December 2010 AP
Enterprise LLC submitted a request to modify an aspect of a prior
DEM approval, in order to accept materials from another location on
Aquidneck Island that have elevated levels of naturally-occurring
arsenic to be used below the final cap. These naturally-occurring
elevated arsenic concentrations are typically identified by the
absence of any other contaminants.

The Department held a public meeting at Portsmouth Town Hall on
this modification on January 18, 2011. This proposal is consistent
with the management of these types of arsenic soils recommended by
a legislative commission that looked at the issue in detail over a
year-long process. The RI House of Representatives’ Special
Legislative Commission to Study Naturally Occurring Arsenic in
Soil, as reported in May 2008, dealt with the issue of
naturally-occurring arsenic, particularly on Aquidneck Island. The
commission found that the cleanup standard of 7 mg/kg had a
negative economic, environmental and quality of life impact that
disproportionately affected the residents of Aquidneck Island.

As a result of the Commission’s findings, DEM proposed revised
standards in its Remediation Regulations that were released for
public comment in December 2010. These allow for the presence of
arsenic in residential soils at a level of 43 mg/kg with 6 inches
of cover and some notification. Levels above 43 mg/kg are
considered acceptable with two feet of cover and an Environmental
Land Use Restriction. The approval issued to AP Enterprise LLC will
allow the use of soils containing naturally occurring arsenic above
the DEM Direct Exposure Criteria of 7 mg/kg, with an average
arsenic level below 20 mg/kg and a maximum level of 40 mg/kg. These
levels are similar to naturally-occurring levels on Aquidneck
Island.

 

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