Jump to main content.


Sole Source Aquifer Designation of Conanicut Island, Narragansett Bay, RI

PDF Version (2 pp, 75K, About PDF)


[Federal Register: August 14, 2008 (Volume 73, Number 158)]
[Notices]
[Page 47599-47600]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14au08-36]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

[FRL-8704-7]

Sole Source Aquifer Designation of Conanicut Island, Narragansett
Bay, RI

AGENCY: Environmental Protection Agency.

ACTION: Notice of determination.

-----------------------------------------------------------------------

SUMMARY: The Regional Administrator of Region I of the Environmental
Protection Agency (EPA) has determined, pursuant to section 1424(e) of
the Safe Drinking Water Act, that the aquifer system that underlies
Conanicut Island, Rhode Island is the sole or principal source of
drinking water for this area and if the aquifer system were
contaminated would create a significant hazard to public health. As a
result of Sole Source Aquifer (SSA) designation, federal financially-
assisted projects over the designated aquifer area will be subject to
EPA review to ensure that these projects are designed and constructed
so that they do not contaminate this aquifer so as to create a
significant hazard to public health.

DATES: Effective Date: This determination shall become effective on
August 14, 2008.

ADDRESSES: The data and record upon which these findings are based are
available to the public and may be inspected during normal business
hours at the U.S. Environmental Protection Agency--Region I, Office of
Ecosystem Protection, One Congress Street, Suite 1100, Boston, MA
02114-2023.

FOR FURTHER INFORMATION CONTACT: Douglas Heath, U.S. EPA--Region I at
the address above or at (617) 918-1585, e-mail: heath.doug@epa.gov.

SUPPLEMENTARY INFORMATION:

I. Background

    Section 1424(e) of the Safe Drinking Water Act, 42 U.S.C. 300h-
3(e), states: ``If the Administrator determines, on his own initiative
or petition, that an area has an aquifer which is the sole or principal
drinking water source for the area and which, if contaminated, would
create a significant hazard to public health, he shall publish notice
of that determination in the Federal Register. After the publication of
any such notice, no commitment for federal financial assistance
(through a grant, contract, loan guarantee, or otherwise) may be
entered into for any project which the Administrator determines may
contaminate such aquifer through a recharge zone so as to create a
significant hazard to public health, but a commitment for federal
financial assistance may, if authorized under another provision of law,
be entered into to plan or design the project to assure that it will
not so contaminate the aquifer.''
    On February 1, 2006, EPA Region I received a petition from the
North End Concerned Citizens (NECC) requesting the designation of the
aquifer system underlying Conanicut Island as a SSA. NECC subsequently
submitted a revised petition. Among other things, the revised petition
removed references to an original request that EPA review closure plans
for a landfill and the location of a proposed Town Garage. On August
17, 2007, EPA completed its technical review of the completeness and
adequacy of the petition. On February 13, 2008, EPA held a public
meeting in Jamestown and invited public comment on the petition. The
public comment period closed on March 19, 2008.

II. Basis for Determination

    Among the factors considered by the Regional Administrator as part
of the review and technical verification process for designating an
area under section 1424(e) were:
    1. The aquifer system underlying Conanicut Island supplies the
service area population with 50% or more of its drinking water needs.
Approximately 57% of the island's residents rely solely on residential
supply wells. The remaining 43% of residents rely on municipal water
provided by the Jamestown Water District (a portion of which is also
ground water extracted by bedrock wells) with a peak flow of 400,000
gallons per day.
    2. There is no physical, legal and/or economical alternative
drinking water source or combination of sources to meet all of the
needs of the designated service area.
    3. The EPA finds that the petition appropriately delineates the
boundaries of the aquifer project review and service area. For purposes
of this designation, EPA finds the Conanicut Island Aquifer System
boundary is based on the mean high tide line since this marks the
freshwater-saltwater boundary.
    4. While the quality of the area's ground water is considered to be
good, it is vulnerable to contamination due to the relatively thin soil
cover and rapid movement of ground water in fractured rock, coupled
with increasing development and other land uses. Recharge of the water
supply is by infiltration of precipitation over the entire island. The
designated area is underlain primarily by a fractured bedrock aquifer
system. The aquifer system is overlain by areas of glacial till and
soil deposits. Freshwater in bedrock fractures under the island forms a
lens-shaped body that floats on saltwater as its density is less than
that of saltwater. According to a 1997 study by the University of Rhode
Island, the thickness of the freshwater lens is estimated to range from
a few tens of feet near the shoreline to more than 500 feet in the
central part of the island under non-pumping conditions.

III. Description of the Conanicut Island Aquifer System That Underlies
Conanicut Island

    The Conanicut Island Aquifer System is a nine-square-mile island
located in Narragansett Bay, Rhode Island. The island is divided into
three land masses: North Island, Central Island, and Beavertail
Peninsula. North Island rises to an elevation of about 140 feet above
sea level and is characterized by parallel ridges running north-south
which create

[[Page 47600]]

the Jamestown Brook Watershed. To the south, separated by Great Creek
and extensive wetlands, is the Central Town area. The Central Island
area is comprised of gently rolling hills up to 100 feet elevation with
bedrock outcrops in the Dumplings and Fort Wetherill area. To the
southwest is the Beavertail Peninsula rising to an elevation of 125
feet. The peninsula is connected to the rest of the island by a sandy
isthmus called Mackerel Cove Beach.
    The average annual precipitation is approximately 43 inches. The
island's climate is moderated by the waters of Narragansett Bay and the
Atlantic Ocean.
    Conanicut Island's bedrock is terrestrial metasedimentary rock of
Pennsylvanian age (approximately 300 million years old) in the north
and the Cambrian-age Conanicut group in the center of the island and on
Beavertail. Originally deposited as sediments ranging from coarse-
grained gravel to fine-grained silt, these materials hardened over time
into metamorphic rocks. Fort Wetherill on the southeastern portion of
the island is underlain by Proterozoic Newport Formation granites.
These are overlain by poorly-sorted glacial till ranging from 0 to
about 45 feet in thickness. Because the rock and till transmit water
very slowly, seasonally-high water table conditions occur throughout
much of the island.

IV. Information Utilized in Determination

    The information utilized in this determination includes: The
petition and supporting documents submitted by the NECC, letters
received before and during the public comment period, and public
comments received during the public hearing. In addition, much of the
information has been derived from published literature on the
hydrogeology and water resources of the region. This information is
available to the public and may be inspected at the EPA Region I office
in Boston, Massachusetts (address listed above). The petition and
support document and EPA's response summary to public comment are also
available at the Jamestown Public Library in Jamestown, Rhode Island.

V. Summary and Discussion of Public Comments

    Most comments received were in favor of the designation. Written
comments in support were received from the Honorable Lincoln Chaffee,
U.S. Senate; Senate Majority Leader M. Teresa Paiva Weed and House
Deputy Minority Whip Bruce J. Long of the Rhode Island General
Assembly; the Rhode Island Department of Health; the Rhode Island
Department of Environmental Management; and 36 residents/households of
Jamestown. On March 11, 2008, a majority of the Jamestown Conservation
Commission voted to support the petition. On March 17, 2008, a majority
of the Town Council approved a motion to support SSA designation. EPA
received five written comments expressing opposition to the
designation. Among these were letters from two members of the Town
Council.
    EPA has addressed the written comments received in a Responsiveness
Summary, which is part of the record of this decision. The
Responsiveness Summary is available at the EPA Region I offices and at
the Jamestown Public Library.

VI. Project Review

    After the effective date of this designation, EPA will evaluate
projects within the designation area that include federal financial
assistance to determine whether the project may contaminate the aquifer
so as to create a significant hazard to public health. Where
practicable, EPA will offer comments as to how the project may be
designed to protect the aquifer. EPA anticipates that few future
projects will trigger SSA review. Where review is required, EPA will
coordinate with state and local agencies and the project's developers.
EPA will give their comments full consideration. Through its review,
EPA will attempt to complement and support state and local ground water
protection measures. Although the project review process cannot be
delegated, EPA will rely to the maximum extent possible on any existing
or future state and/or local control measures to protect the quality of
ground water in the review area. EPA also will work to integrate any
review with related reviews required pursuant to other federal laws,
such as the National Environmental Policy Act (NEPA) as amended 42
U.S.C. 4321, et seq., to avoid delay or duplication of effort.

    Authority: This action is issued under the authority of section
1427 of the Safe Drinking Water Act as amended 42 U.S.C. 300h-3(e).

    Dated: July 30, 2008.
Ira Leighton,
Acting Regional Administrator, USEPA Region I.
[FR Doc. E8-18836 Filed 8-13-08; 8:45 am]

BILLING CODE 6560-50-P

 
 


Local Navigation


Jump to main content.