SURE RFUND
Cleaning Up New England SITE UPDATE
JULY 2011
Centredale Manor
Restoration Project Superfund Site
North Providence/Johnston, RI
U.S. EPA | HAZARDOUS WASTE PROGRAM AT EPA NEW ENGLAND
THE SUPERFUND PROGRAM protects human health
and the environment by investigating and cleaning up often-abandoned
hazardous waste sites and engaging communities throughout the process.
Many of these sites are complex and need long-term cleanup actions.
Those responsible for contamination are held liable for cleanup costs.
EPA strives to return previously contaminated land and groundwoter
to productive use.
SITE DESCRIPTION:
The Woonasquaiucket River, which forms the border between Johnston and North Providence, Rhode Island, has wide-
spread dioxin contamination resulting from the former operations of a chemical company and a drum recycler from the
early 1940s to the early 1970s. The main part of the Centredale Manor Site, called the Source Area, is approximately
9 acres and is currently occupied by the Centredale Manor and Brook Village apartment complexes on Smith Street,
North Providence. The site also includes free-flowing reaches and ponds of the Woonasquatucket River next to and
downstream from the Source Area. Contamination was first found in fish in 1996. EPA has since documented elevated
levels of contaminants including dioxin, PCBs, Volatile Organic Compounds (VOCs), semi-VOCs, and metals In soil,
sediment, wetlands and surface water at the site. The Rhode Island Department of Health recommends that the public
not eat fish caught from the Woonasquatucket below the Johnston/Smithfield town line.
The Superfund process, conducted in several steps over multiple years, leads to the ultimate goal of protecting
the environment and health of those people living and working around the Centredale Manor site and using the
Woonasquatucket River. Since becoming a federal Superfund site in 2000, EPA and the Potentially Responsible Parties
have taken several short-term actions to control current exposure of residents and visitors to contaminants. These
actions included capping of contaminated soil in the Source Area, installation of a fence to control access, removal of
contaminated soil from residential properties along the river, reconstruction of the breached Allendale Dam, and the
removal of contaminated soil to limit the movement of contamination through groundwater into the river.
CLEANUP AREAS:
The site is organized into five cleanup areas:
1. Source Area Soil
The nearly 9 acre Source Area is the main part of the
site where the contamination originally occurred and
now includes two apartment buildings, paved and land-
scaped surfaces, and three temporary capped areas.
These three temporary soil covers were constructed
from the 1990s through mid-2000s in the area not occu-
pied by buildings, parking lots, or roadways; soil was also
removed under one of the parking lots in the late 2000s
as part of the groundwater short-term cleanup. Most of
the Source Area is located within the floodplain. and also
includes riverbank wetlands.
2. Groundwater
Groundwater is the water that is found beneath the
surface of the ground, The groundwater area contami-
nated in excess of cleanup levels is located underneath
the Source Area that is bound by the river and streams.
The 2009 short-term cleanup action addressed about
0,13 acres on the west side of the Brook Village parking
lot where contaminated groundwater was flowing into
the river.
3. Allendale Pond and Lyman Mill Pond Sediment
This area includes all contaminated sediment in AHendale
Pond and Lyman Mill Pond and monitoring further down-
stream.
continued >
KEY CONTACTS:
ANNA KRASKO
EPA New England
Project Manager
(617) 918-1232
krasko.anna@epa.gov
STACY GREENDLINGER
EPA New England, Community
Involvement Coordinator
(617) 918-1403
greendlinger.stacy@epa.gov
GENERAL INFO:
EPA NEW ENGLAND
5 Post Office Square
Suite 100
Boston, MA 02109-3912
(617)918-1111
www.epa.gov/ region 1 /
EPA TOLL-FREE
CUSTOMER SERVICE
1-888-EPA-7341
LEARN MORE AT:
www.epa.gov/region1/
superfund/sites/centredale
£EPAi
United States
Environmental Protection
k Agency
© printed on 100% recycled paper, wilh a minimum of 50% post-consumer wasle, using vegetable-based inks
July 2011
SDMSDocID 486558
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SUPERFUND | HAZARDOUS WASTE PROGRAM AT EPA NEW ENGLAND
SITE UPDATE
SITE CONTAMINANTS WHICH
WARRANT ACTION
Dioxins are a class of chemical contaminants that are formed during some industrial pro-
cesses such as disinfectant (anti-bacterial) or herbicide manufacturing as well as combustion
such as waste incineration.
Furans are by-products usually created when herbicides or other products are made or burned.
PCBs, or Pol/chlorinated Biphenyls, are man-made chemicals that were used in electrical
manufacturing and were banned in 1979,
Pesticides are substances used to destroy or repel insects, weeds, or other animal life that
are considered to be pests.
VOCs, or Volatile Organic Compounds, include a variety of chemicals that are used in glue,
paint, solvents, and other products and easily evaporate. Common VOCs include TCE, or
Trichloroethylene, and PCE, or Tetrachloroethylene.
SVOCs, or Semivolatile Organic Compounds, are chemicals that may vaporize when ex-
posed to temperatures above room temperature. SVOCs include phenols found in coal and
wood tar, and polynuclear aromatic hydrocarbons (PAHs), a widespread pollutant from
petroleum production and fuel emissions.
Metals, including lead, cadmium, copper, arsenic, zinc and others, occur naturally in the
environment but high concentrations result from man-made activities such as smelting, fuel
manufacturing, and electroplating.
4. Allendale Fioodplain Soil
A floodplain is the flat or nearly flat land next to a
river that floods easily. This cleanup area includes
riverbank and floodplain areas next to the Woon-
asquatucket River along the Source Area and Allen-
dale Pond.
5. Lyman Mill Stream Sediment and Flood-
plain Soil (including the Oxbow Area)
This cleanup area includes the stream channel and
old mill raceway connecting Allendale Pond and
Lyman Mill Pond, the Oxbow Area, and riverbank
and floodplain areas along Lyman Mill Pond. The
Oxbow Area is a large forested wetland area below
the Allendale Dam.
REMEDIAL INVESTIGATION
FINDINGS:
EPA conducted a detailed study, the Remedial Inves-
tigation, to better understand the site's contamina-
tion and collect the kind and amount of information
needed to identify any potential human health and
ecological risks. It is used to make decisions regard-
ing the long-term cleanup of the site. The Remedial
Investigation concluded that past industrial opera-
tions resulted in the contamination of the site's sedi-
ment, soil, surface water, groundwater, and animal
life. EPA's investigations have found:
• Source Area Soil contaminants include
dioxin/furans, polychlorinated biphenyls
(PCBs), selected pesticides, semi-volatile
organic compounds (SVOCs), metals, and
volatile organic compounds (VOCs);
• Fish and Birds, Sediment and Floodplain
Soil contaminants include dioxin/furans,
PCBs, selected pesticides, SVOCs, and
metals;
• Surface Water contaminants include dioxin.
PCBs, pesticides, VOCs, SVOCs and metals; and
• Groundwater contaminants at the Source
Area include dioxm, PCBs. pesticides,
SVOCs. VOCs [such as tetrachloroethylene
(PCE) and trichloroethylene (TCE)], and
metals.
Source Area Soil sampling data indicates wide-
spread contamination above the state's residen-
tial direct exposure criteria for PCBs/pesticides,
VOCs. SVOCs. and metals; the state's leachability
(movement of contaminants from soil into water)
criteria for PCBs, pesticides, VOCs, and SVOCs;
and EPA's recommended residential levels for
dioxin and PCBs.
Groundwater sampling data at the Source Area
indicates contamination is above federal deanup levels
at 25 out of 37 monitoring wells tested. The most
common contaminant detected is tetrachloroethyl-
ene, followed by trichloroethylene. Dioxin has also
been detected in groundwater.
The Allendale Pond and Lyman Mill Pond Sedi-
ment area data showed widespread sediment
contamination. Dioxin levels were above cleanup
levels in more than 90% of the surface sediment
(top 1 foot) at Allendale Pond and Lyman Mill
Pond. Contamination in sediment at depths of 2 to
2.5 feet was typically above cleanup levels. Other
contaminants like PCBs, pesticides, SVOCs, and
metals, were also present at levels above cleanup
levels in surface and subsurface sediment.
In the Allendale Floodplain Soil area, dioxin
contamination was above cleanup levels in approxi-
mately 40% of the floodplain areas sampled. This
suggests that low-lying areas next to the Woon-
asquatucket River and Allendale Pond have been
impacted by contamination from the Source Area,
especially during flooding and times of high water.
SVOCs and lead at concentrations above the state
residential direct exposure criteria were also found
in this cleanup area.
Lyman Mill Stream & Floodplain Soil (including
the Oxbow Area) data showed dioxin contamination
above deanup levels in more than 90% of the surface
sediment and approximately 30% of the floodplain soil
locations sampled. Other contaminants, including PCBs,
pesticides, SVOCs, and metals, were also frequent-
ly measured at levels above cleanup levels. EPA
investigations indicate that the low-lying areas
in the Oxbow forested wetland area have been
impacted by high water flow and by contamination
from the Source Area. Based on sampling which
occurred in 2010 and is still being analyzed, the above
numbers and condusions may change.
EXPOSURE PATHWAYS &
POTENTIAL RISK:
Just because contamination exists does not mean
the environment or people are at risk. One has to
have exposure to the contaminant to have a poten-
tial risk. Exposure occurs when people or other
living organisms eat, drink, breathe or have direct
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Cleanup Action Areas
Centredale Manor Restoration Project Superfund Site
Source Area
Ground v/dter
Action Area
Centredale- •'
Cap Area 2
-Cimit
' S^ourc^^J
.•*.Tfl
Allendale and Lyman
Mill Reach Sedlmenl
Action Area
AJIendale Reach
Roodplaln Soil
Action Area
Lyman Mill Reach
Stream Sediment and
Roodplaln Soil
Action Area
Source Area Soil and
Groundwater Action Area
(see inset map!
:•-'•••:' V
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SUPERFUND | HAZARDOUS WASTE PROGRAM AT EPA NEW ENGLAND
SITE UPDATE
skin contact with a substance or waste material.
Based on existing or reasonably anticipated future
land use at a site, EPA develops different possible
exposure scenarios to determine potential risk,
appropriate cleanup levels for contaminants, and
potential cleanup approaches.
Site human health and ecological risk assessments
use a number of contamination exposure scenarios
to determine if and where there are current or
potential future unacceptable risks.
THREATS TO
HUMAN HEALTH:
People have the potential for exposure to the site's
contaminants through eating fish from the river and
having contact with site sediment and floodplain
soil. Overall, the risk assessment determined that
the following exposure pathways pose an unaccept-
able risk:
Allendale Pond:
• Eating contaminated fish may pose a 5 in
1,000 chance of causing cancer and may
pose non-cancer health effects 30 times
greater than the acceptable level of 1 for
residents along the river and visiting
recreational anglers;
• Having direct skin contact with or accidently
ingesting contaminated sediment may
pose a 2 in 10,000 chance of causing
cancer for residents along the river.
Lyman Mill Pond:
• Eating contaminated fish may pose a 6 in
1,000 chance of causing cancer and may
pose non-cancer health effects 30 times
greater than the acceptable level of 1 for
residents along the river and visiting
recreational anglers;
• Having direct skin contact with or
accidently ingesting contaminated sediment
may pose a 3 in 10,000 chance of causing
cancer for residents along the river.
Site Exposure Assumptions
EPA used the following exposure assumptions to
figure out its risk results for the site:
• For eating fish, it is assumed that residents
along the river and visiting recreational
anglers would eat 14 grams per day
(adult), 9.3 grams per day (older child), or
4.7 grams per day (young child) for 350
days a year for a total of 30 years;
For having direct skin contact with or
accidently ingesting contaminated
sediment, it is assumed that a resident
along the river would wade and swim 4
days a week between June and August for
a total of 30 years.
THREATS TO
THE ENVIRONMENT:
Fish and wildlife are exposed to site contaminants in
sediment on the bottom of the Woonasquatucket
River and its ponds, or floodplain soil associated
with wetlands immediately downstream of the
site. Site contaminants are also in the tissue and
organs of animals living in the contaminated river
and its wetlands. Predatory fish and wildlife feed on
contaminated animals or organisms such as forage
fish, crayfish or larval stages of aquatic insects
that live in the mud bottom (benthic macroinver-
tebrates) or small mammals, birds, amphibians or
benthic macroinvertebrates in wetlands, and are
at risk from their foraging activities (direct contact
with contaminated sediment or floodplain soil) and
feeding upon contaminated prey.
A high-level of exposure to site contaminants
and a significant negative reproductive effect was
measured in tree swallow populations (reduced
egg hatchability) in ponds downstream of the site
as this bird species preys upon emergent, flying
aquatic insects that develop from benthic macroin-
vertebrates.
Threats to the environment from greater to lesser
amounts exist for:
• Birds and mammals that use Allendale
Pond aquatic and wetland habitats to
forage for food (1,000 times greater than
the acceptable level of 1):
• Birds and mammals that use Oxbow Area
aquatic habitat in between Allendale Pond
and Lyman Mill Pond to forage for food
(100 times greater than the acceptable
level of 1);
Birds and mammals that use Lyman Mill
Pond wetland habitats to forage for food
(100 times greater than the acceptable
level of 1).
POTENTIAL CLEANUP
APPROACHES:
Once possible exposure pathways and potential
risk have been identified at a site, cleanup alterna-
tives are developed to address the identified risks
and achieve the site's cleanup objectives. A detailed
description and analysis of each alternative devel-
oped to reduce risks from contaminated soil, sedi-
ment, and groundwater is presented in the 2010
Centredale Manor Restoration Project Superfund
Site Feasibility Study (which EPA is in the process
of amending).
The cleanup approaches for each action area
detailed in the Feasibility Study can be generalized
as follows.
For Source Area Soil the general options are:
I. Take no action (an alternative that we are
legally required to evaluate);
II. Maintain existing caps or upgrade or
reconstruct them.
For Groundwater, a cleanup action was performed
in 2009/2010 while the Feasibility Study was near-
ing completion. At that time, EPA determined that
a short-term cleanup was necessary to prevent
contamination from this soil and groundwater
moving into the Woonasquatucket River. This
action included removal of nearly 2.300 tons of
contaminated soil to limit the movement of contam-
ination through groundwater into the river. Future
long-term monitoring will be done to check that this
action has been successful by confirming contami-
nated groundwater is not leaving the Source Area,
For sediment and floodplain soil (cleanup areas
J-5) the general options are:
I. Take no action (an alternative that we are
legally required to evaluate);
II. Cap or cover contaminated soil and
sediment in place;
III. Excavate and dispose of contaminated
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SUPERFUND | HAZARDOUS WASTE PROGRAM AT EPA NEW ENGLAND
SITE UPDATE
ENVIRONMENTAL ACTIONS
1943 - 1970s Source Area used for chemical manufacturing activities. Metro
Atlantic Chemical Company manufactured hexachlorophene around
1965 in a building on the eastern bank (current!/ Brook Village parking
lot). Dioxin associated with process. Other manufacturing activities
resulted in additional contamination.
1952-1970s New England Container Company, Inc. operated incinerator-based
drum reconditioning facility at Source Area. Chemical residues dumped
or burned prior to and during drum reconditioning and are source of
site dioxins, furans and other chemicals.
1972 Fire destroyed most structures.
1977 Brook Village apartment complex constructed.
1982 Centerdaie Manor apartment complex constructed and approximately
400 drums and 6,000 cubic yards of contaminated soil removed and
disposed of off-site under RIDEM supervision.
1991 Floodwaters breached Allendale Dam reducing pond surface water
level and exposing bottom sediment. Dam breached again in 2001.
1996 EPA found dioxin and other contaminants in fish.
1998 RIDOH issued fish advisories for dioxin, mercury and PCBs.
1996 to 2004 EPA conducted numerous investigations to characterize nature and
extent of site contamination.
1999 to 2000 First Source Area short-term cleanup to reduce immediate health
threat to residents included: construction of two interim soil caps and
installation of fencing to restrict access to potentially contaminated
areas in Source Area and Allendale Pond. Repairs to fence were
performed in 2005.
2000 to 2003 Second short-term cleanup included reconstruction of breached
Allendale Darn, restoration of Allendale Pond to pre-1991 levels, and
excavation and off-site disposal of contaminated floodplain soil from 11
residential properties ana recreational access points along Allendale
Pond and Lyman Mill Pond.
2000 Added to Superfund Program's National Priorities List.
2003 to 2004 Third short-term cleanup covered contaminated soil and sediment in
Source Area's former tailrace (a narrow channel that moved away
industrially used water).
2005 Remedial Investigation identifies extensive contamination in site soil,
sediment, surface water, plants and animals and localized groundwater
contamination at Source Area.
2004 to 2005 Baseline Human Health and Ecological Risk Assessments concluded
current and future exposures pose elevated risks.
2009 to 2010 Fourth short-term cleanup addressed Source Area groundwater
contamination by excavating and disposing off-site contaminated soil
and installing a cap made to cover hazardous waste over the excavated
area next to river.
2010 Feasibility Study identified long-term cleanup options for contaminated
soil, groundwater, surface water and sediment.
2010 Additional investigations conducted in the Oxbow Area.
2011 Addendum to Feasibility Study to be issued.
soil and sediment using the following
disposal approaches (with dams in place or
replacing dams with smaller weirs):
a. Consolidate and cap contamination
within river or floodplain along
shore;
b. Consolidate and cap contamination
in upland area next to river;
c. Ship contamination off site to
permitted facility;
d. Incinerate contaminated soil and
sediment using temporary facility at
the site.
NEXT STEPS:
Based upon the Feasibility Study and Addendum.
EPA will issue a Proposed Plan that will include
the agency's preferred cleanup approach as well
as other alternatives. The public will be invited to
comment on the Proposed Plan and the preferred
alternative during a 60-day comment period. Once
the comment period closes, EPA will consider public
comments received in making its cleanup decision.
The cleanup plan ultimately selected is formalized
in a Record of Decision and includes a Responsive-
ness Summary that reflects the public's input and
the agency's response. EPA expects to issue the
Proposed Plan in fall 2011.
COMMUNITY INVOLVEMENT:
Over the years, EPA and the Rhode Island Depart-
ment of Environmental Management have held
Dialogue Group meetings with interested stake-
holders, including the Towns of North Providence
and Johnston, the Woonasquatucket River Water-
shed Council, the Audubon Society, the Natural
Resources Trustees, and the Potentially Responsi-
ble Parties. These meetings have provided a forum
to exchange ideas and give stakeholders input into
EPA's investigation and cleanup selection process.
Since January 2005, EPA has awarded $125,000
to the Woonasquatucket River Watershed Council
through a Superfund Technical Assistance Grant.
This grant has been used to hire an independent
expert to help the impacted communities better
understand technical data and site hazards.
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SUPERFUND | HAZARDOUS WASTE PROGRAM AT EPA NEW ENGLAND SITE UPDATE
ADDITIONAL CONTACT:
Louis Maccarone
Senior Engineer
Rl Dept. of Environmental Management
(401) 222-2797 ext,7142
louis.maccarone@dem.ri.gov
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