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Dewey Loeffel Landfill

Superfund Site

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Town of Nassau, Rensselaer County, NY

U.S. Environmental Protection Agency * Region 2 * August 2014 * Community Update

If you have any questions or
would like additional
information, please contact:

Larisa Romanowski

EPA Community Involvement
Coordinator

(518) 747-4389
romanowski.larisa@epa.gov

Ben Conetta

EPA Remedial Project Manager

(212) 637-3030
conetta.benny@epa.gov

If you would like information on
general environmental concerns
or the federal Superfund
hazardous waste program,
have concerns or complaints
about the Superfund program,
or if you seek assistance in
resolving site-specific issues that
were not fully addressed by the
EPA, please contact:

George Zachos

EPA Regional Public Liaison

(732) 321-6621
zachos.george@epa.gov

Or toll free at (888) 283-7626

Water Treatment Plant Operations

In 201 2 the EPA reached an agreement to perform a removal action at
the Dewey Loeffel Landfill Superfund site with two of the parties
responsible for the contamination at the site, General Electric Company
(GE) and SI Group. This agreement required the companies to construct a
water treatment plant adjacent to the landfill and install five additional
groundwater extraction wells along the western edge of the landfill. The
new extraction wells will collect additional contaminated groundwater
and are located closer to the landfill than the three existing extraction
wells.

The construction of the treatment plant began in May 201 3 and was
completed in November 201 3. The plant, which began operating in
January 2014, was designed to remove contaminants from the liquids
seeping from the landfill, called leachate, and groundwater (being drawn
from three existing extraction wells). Since the treatment plant began
operating, the EPA has required that the treated water from the plant be
stored in a series of three on-site storage tanks and thoroughly tested
before each individual tank is discharged to the Valatie Kill. The slow
startup phase was intended to ensure that the plant is working effectively
and is capable of meeting the strict discharge limits set by the New York
State Department of Environmental Conservation (NYSDEC). To date, 32
tanks have been sampled, analyzed and individually discharged to the
Valatie Kill. This comprehensive sampling program has demonstrated that
the plant is operating very well. Sampling data from the treated water at
the plant is available on the EPA's Dewey Loeffel Landfill Superfund site
webpage: http: / /www.epa.aov/reaion2 /superfund /npl/dewev /.

Treatment Building February 20 14

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(continued)


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Water Treatment Plant Operations (cont.)

In July 201 4 the EPA reached another agreement with
GE and SI Group to add an additional treatment
technology to the existing treatment plant at the site. The
new treatment system is being added to further address
the long-term treatment of the chemical 1,4-dioxane, a
stabilizer and solvent that is also a component of some
cosmetics, detergents and shampoos. The new treatment
technology should be delivered by November 2014 and
installed before the end of November. The carbon
filtration system, which is a component of the existing
treatment plant, has been effectively removing 1,4-
dioxane and will continue to be the primary treatment
method until the new technology is in place this fall.

Treatment Building Inferior

In order for the new treatment system to be installed, the storage tanks at the site wili need to be removed so
that the system can be physically brought into the water treatment plant. As a result, the tank-by-tank sampling
and discharge process will end 7 to 1 0 days prior to delivery of the new treatment system and direct discharge
of the treated water from the plant to the Valatie Kill will be approved at that time, provided the sampling data
continue to meet the stringent discharge limits set by the NYSDEC.

Out of an abundance of caution, the rate of groundwater and leachate coming into the plant for treatment,
called the flow rate, will also be reduced to as low as possible while the additional treatment technology is being
installed. The plant needs to be kept running during the two to three week installation period to ensure that one
of the treatment technologies in the plant that relies on microorganisms to treat the wastewater can continue to
operate effectively. The wastewater and leachate coming into the plant provide the nutrients these microorgan-
isms need to survive. After the new system is installed, the flow rate will slowly be increased to normal operating
flow rates.

Regular sampling of the treated water will continue after
direct discharge begins and surface water will also be
sampled at least three times after direct discharge is
approved. The EPA will have sampling data from
approximately 40 individual tanks by the time it allows
any direct discharges from the treatment plant. The plant,
as constructed, is effectively treating 1,4-dioxane and
will continue to treat 1,4-dioxane until the additional
system is added.

The construction of the treatment plant was an action that
was taken to address potential risks to human health and
the environment, but does not represent the final cleanup
decision for the site. This treatment plant may be
modified in the future based on the findings of the long
term investigation of the site, called the Remedial
Investigation, and the final cleanup remedy chosen. All of
the work being performed by GE and SI Group under
the removal action agreement is being done under EPA
oversight.

Surface Water Sampling

During the public availability sessions held in March
2014, the EPA committed to collecting surface
water samples near the site and in Kinderhook
Lake. Samples were collected by EPA staff in May
2014 at locations above (north) and below (south)
of the water treatment plant on the Valatie Kill, on
the Valatie Kill between Nassau Lake and
Kinderhook Lake, and in Kinderhook Lake. The final
data summary report for this data has not yet been
completed. The report is expected to be available
by fall 201 4 and will be posted on the EPA's
Dewey Loeffel Landfill Superfund site webpage. As
mentioned previously, additional surface water
sampling will be conducted after direct discharge is
approved.


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LEACHATE

COLLECTION

TAHK

Legend:

Construction of New Extraction Wells

m POLE BARN
1JJ WITH
, FRAC TANKS

The construction of the five new groundwater extraction wells began in March 2014 and is expected to be
completed by the end of 2014. During the drilling of the extraction wells to their approximate depths of
200 to 250 feet, bedrock cores (from the rock below the surface) were collected and are being tested to
determine whether site-related contaminants have become concentrated in the bedrock. Groundwater
samples were also collected from different water bearing zones In the bedrock to test for site-related
contaminants. Each
extraction well had
multiple water bearing
zones sampled.

The information gathered
will help inform and guide
additional investigations
that will be conducted as
part of the Remedial
Investigation. As part of
these continuing investiga-
tions, the extraction wells
will be sampled quarterly
and the leachate collection
tank will be sampled semi-
annually.

TREATMENT

Discharge to > BUILDING W/
Valatie Kill S	PERIMETER

,/	FENCE

( Existing Extraction Well
A Proposed Extraction Wei

Residential and Monitoring Well Sampling Programs

A volatile organic compounds (VOC) groundwater contamination plume has been traced to extend south of the
landfill to the vicinity of Central Nassau Road, approximately Vi mile from the site. Monitoring of residential
drinking water wells around the site is done periodically (quarterly, semi-annually, annually, or biennially) by
GE. Five drinking water wells near the landfill have been impacted by VOCs from the site. The water from
these wells is treated by point-of-use treatment systems installed, maintained, and routinely monitored by GE.
Residents with wells impacted by the VOC plume, as well as additional residents beyond the edge of the
VOC plume, are provided with bottled water by GE.

All residential wells in the sampling program were sampled in late April/May 2014 (including those sampled
quarterly, semi-annually, annually, and biennially). Sampling included analysis for VOCs and 1,4-dioxane.
Sampling results are communicated to the individual landowners.

Groundwater monitoring wells in and around the landfill were also sampled in May. All the information
collected as part of the sampling program will be evaluated as part of the Remedial Investigation of the site.

www.epa.gov/region2/superfund/npl/dewey/

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EPA Agreement with Companies to Conduct Comprehensive Studies of
Contamination at the Site

While a removal action is sometimes conducted to address immediate threats to the environment or to the
people that live or work around a hazardous waste site, the Remedial Investigation/Feasibility Study (RI/FS) is
the first step in the long-term cleanup of a site. The primary objective of a RI/FS is to determine the nature
and extent of contamination, identify potential threats and evaluate options for cleaning up a site. On
September 30, 201 3, EPA, GE and SI Group finalized an agreement which requires GE and SI Group to
perform the RI/FS for the landfill and groundwater components of the site. Under EPA oversight, GE and the SI
Group will investigate and evaluate cleanup options for the landfill and the groundwater portions of the site.
On October 30, 201 3, the EPA and GE finalized an additional agreement which requires GE to perform the
RI/FS for the drainageways (surface waters and sediments) component of the site. Under EPA oversight, GE will
investigate and evaluate cleanup options for the ponds, streams and other water bodies that have been
impacted by contamination from the site, including Nassau Lake. Together the two agreements will result in a
comprehensive RI/FS for the site.

Landfill—Groundwater Investigation

GE and the SI Group have submitted the Site Characterization Summary Report to the EPA. The Report is a
compilation, to the extent possible, of all the existing data collected at the site by GE/SI Group, NYSDEC,
and the EPA, to date. The EPA has completed its review and provided comments on the Report. The Report
will be used to develop the Work Plan for the Remedial Investigation of the landfill—groundwater. Based on
the EPA's review and comments, the Report is expected to be updated and re-submitted by the beginning of
September 2014. The Remedial Investigation Work Plan is expected to be submitted by the beginning of
October 2014.

The Remedial Investigation will include, but will not be limited to, the installation of additional monitoring
wells, soil sampling, the collection of landfill soil borings, an evaluation of the existing slurry wall surrounding
the landfill, and an evaluation of groundwater impacts to surface water.

All work being performed by GE and SI Group under the Removal and RI/FS agreements is being done
under EPA oversight.

Surface Drainageways Investigation

GE submitted, and the EPA has reviewed, the Phase 1 Remedial Investigation Work Plan, Health and Safety
Plan (HASP), and Quality Assurance Project Plan (QAPP) for the investigation of surface drainageways. The
EPA expects to receive revised versions of these documents from GE by the beginning of September 2014.

The investigation of the surface drainageways will include, but will not be limited to, surface water and
sediment sampling in the Valatie Kill and Nassau Lake, floodplain evaluations, and bathymetric (water depth)
evaluations in Nassau Lake.

The annual fish sampling in the Valatie Kill and Nassau Lake was also conducted by GE, with NYSDEC and
EPA oversight, in June and July 2014. A summary report is expected by the end of the year.

For more information: www.epa.gov/region2/superfund/npl/dewey/

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