Smithtown Ground Water Contamination

Smithtown, New York

Site Description

The Smithtown Ground Water Contamination site is an area of contaminated
groundwater which has impacted drinking water in the Town of Smithtown in a
location that includes the Villages of Nissequogue and Head of the Harbor and
the Hamlet of St. James. There are approximately 500 homes in the immediate
vicinity of the Site. Many homes in Smithtown use private wells for a potable
water supply and septic systems for sanitary waste disposal. The Site is situated
south of Stony Brook Harbor and east of the Nissequogue River. While the Site
is located in a residential area, active commercial areas are located within one
mile to the east and south.

Current Site Status and Cleanup Actions to Date

•	In April 1998, EPA collected samples from 295 private wells to delineate
the extent of perchloroethylene (PCE) contamination. Based on the
analytical data, a total of 35 residential wells were identified as
contaminated with PCE (or its breakdown products) at concentrations
above the federal maximum contaminant level (MCL) of 5 parts per
billion (ppb). The Removal Action Level (RAL) of 70 ppb for PCE was
exceeded in six homes.

•	Based on the results of well water samples, EPA initiated a Superfund
Removal Action to supply bottled water to homes with wells
contaminated above the MCLs. These actions were taken to protect the
health of the public until a more permanent solution can be
implemented.

•	In the fall and winter of 1998 - 1999 EPA took further action. Where a
public water supply was available, the impacted residences were
connected. At homes where water mains were not available, EPA
installed individual carbon treatment systems or upgraded existing
household treatment systems to EPA specifications.

•	EPA conducted a Remedial Investigation/Feasibility Study (RI/FS) to
determine the nature and extent of the contamination at the Site and
develop remedial alternatives to address the contamination. EPA
observed sporadic and isolated pockets of groundwater contaminated
with volatile organic compounds (VOCs), particularly PCE. No
contiguous groundwater plume was detected. The Rl was not able to
determine the source(s) of the VOC contamination detected in the
groundwater. During the Remedial Investigation (Rl), four additional
residential wells were identified as contaminated above the MCL.

Those homes were connected to the public water supply.

•	EPA signed a Record of Decision (ROD) in September 2004 which
selected a remedy of providing an alternate water supply to homes
currently and potentially impacted by groundwater contaminated by
VOCs, particularly PCE, by connecting these homes to the municipal
water supply. Approximately 200 homes are within the area of potential
contamination designated in the ROD. In addition, the remedy includes
long-term groundwater and surface water monitoring and the

	implementation of institutional controls to restrict use of contaminated

Key

Accomplishments

•	EPA has
addressed 39
private wells with
PCE levels above
or equal to the
EPA MCL by
connecting the
well owners to the
public water
supply or installing
a water treatment
system in
individual
properties where
public water mains
are not available.

•	A ROD was signed
in September 2004
to address
approximately 200
homes within the
area of potential
contamination
designated in the
ROD.

For more information
on the projects at this
site, please read the
Smithtown Ground
Water Contamination
Site Fact Sheet on the
Region 2 Superfund
Web site.

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groundwater.

•	The work to connect residences within the area designated in the ROD
to water mains began in November 2005.

Current Funding Status

•	To date, EPA has spent approximately $3.7 million for RI/FS work
conducted at this site.

•	EPA has funded the Region 2 ERRS contract with $2,.9 million to
perform the remedy selected in the 2005 ROD.

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