[Federal Register: September 6, 2006 (Volume 71, Number 172)]
[Notices]
[Page 52541-52544]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06se06-62]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
[FRL-8217-2]
Sole Source Aquifer Designation of the Troutdale Aquifer System;
Clark County, WA
AGENCY: Environmental Protection Agency.
ACTION: Notice of Final Determination.
-----------------------------------------------------------------------
SUMMARY: Notice is hereby given that pursuant to Section 1424(e) of the
Safe Drinking Water Act (42 U.S.C. 300h-3(e), Pub. L. 93-523), and in
response to a petition from a group of Clark County residents (two
private groups and 8 individuals), the U.S. Environmental Protection
Agency (EPA) Region 10 Administrator has determined that the Troutdale
aquifer system, in Clark County, Washington, is a sole or principal
source of drinking water, and that if contaminated, would create a
significant hazard to public health. As a result of this action, all
Federal financially-assisted projects proposed over the designated
aquifer system will be subject to EPA review to ensure that they do not
create a significant hazard to public health.
DATES: This determination shall be promulgated for purposes of judicial
review at 1 p.m. eastern time on September 20, 2006.
ADDRESSES: The information upon which this determination is based is
available to the public and may be inspected during normal business
hours at the EPA Region 10 Library, 1200 Sixth Avenue, Seattle,
Washington 98101, or on the EPA Web site at: http://yosemite.epa.gov/r10/water.nsf/Sole+Source+Aquifers/Program
.
FOR FURTHER INFORMATION CONTACT: Martha Lentz, Hydrogeologist, Office
of Environmental Assessment, OEA-095, Environmental Protection Agency,
Region 10, 1200 Sixth Avenue, Seattle, Washington 98101, 206-553-1593.
SUPPLEMENTARY INFORMATION:
I. Background
Section 1424(e) of the Safe Drinking Water Act states:
If the Administrator determines, on his own initiative or upon
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 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.
The EPA Region 10 Drinking Water Section received a draft sole
source aquifer (SSA) petition in early November 2005 from a group of
Clark County residents, who represent both individuals and private
public interest groups. The petitioners were:
The Columbia Riverkeeper,
The Rosemere Neighborhood Association,
Dvija Michael Bertish,
Dennis Dykes,
Thom McConathy,
Nathan Reynolds,
Karen Kingston,
Coleen Broad,
Richard Dyrland,
Dean Swanson.
A final petition was presented to EPA on November 29, 2005. On
December 28, 2005, EPA sent a letter to the petitioners acknowledging
that the agency considered the petition complete, and that the
technical review process would begin.
In January 2006 EPA met with the petitioners to discuss expanding
the aquifer system boundary to include more of the geologic formations.
There was agreement to extend the boundary, and the petitioners agreed
to provide updated values for population and drinking water use data.
On January 17, 2006 the petitioners provided the adjusted water use and
population data to EPA.
In February of 2006, the Troutdale aquifer system review was
completed and the area appeared to meet all criteria for SSA
designation. The legal and technical basis for the proposal was
outlined in an EPA publication titled: ``Draft Support Document for the
Sole Source Aquifer Designation of the Troutdale Aquifer System''.
After a technical peer review and public
[[Page 52542]]
comment period, a final publication was compiled titled: ``Final
Support Document for the Sole Source Aquifer Designation of the
Troutdale Aquifer System''.
II. Basis for Determination
Among the factors to be considered by EPA in connection with the
designation of an area under Section 1424(e) are: (1) Whether the
aquifer is the area's sole or principal source of drinking water, and
(2) whether contamination of the aquifer would create a significant
hazard to public health.
EPA Region 10 follows EPA guidance which interprets the statutory
language of ``sole or principal'' as meaning that the aquifer must
supply at least 50 percent of the drinking water for the area.
Furthermore, there should be no alternate drinking water source(s)
which can physically, legally, and economically supply all those who
depend upon the aquifer for drinking water, should it become
contaminated. In addition, aquifer boundaries should be delineated
based on sound hydrogeologic principles and the best available
scientific information.
Although designation determinations are largely based on science-
based criteria, the Regional Administrator may also consider the
overall public interest and net environmental and public health
benefits in making a sole source aquifer determination.
On the basis of information available to this Agency, the Region 10
Administrator has made the following findings:
(1) The aquifer system is the principal source of drinking water
(approximately 99.4%) for the people in the Troutdale aquifer system
area and there are no alternate sources which can physically, legally,
and economically supply all those who depend upon the aquifer for
drinking water, should it become contaminated. Potential alternate
sources considered include surface water, alternative aquifers, and an
intertie with the Portland Water Bureau. None of these drinking water
sources are considered by EPA to be feasible replacements for the
entire aquifer system due to economic barriers or because these sources
are not consumed or utilized for domestic purposes in significant
quantities.
(2) Contamination of the aquifer system would create a significant
hazard to public health. The aquifer system is vulnerable to
contamination because recharge occurs essentially over the entire area,
the aquifer is highly permeable, and there are many human activities
that have released, or have the potential to release, contaminants to
the aquifers. The Washington Department of Ecology (WDOE) currently
lists 204 active cleanup and 12 Federal Superfund sites in the proposed
aquifer service area. These sites are known to have been contaminated
and are undergoing cleanup. Many of these sites include plumes of
groundwater contamination. WDOE also lists 625 hazardous waste
generators, and 609 underground storage tanks in this area.
Superfund sites--12
Active state cleanup sites--90
Active voluntary and independent cleanup sites--114
LUST sites--185
Hazardous waste sites--625
UST sites--609
Other sources of contamination include untreated or poorly treated
storm water and septic systems. There are about 7,000 septic systems
within the City of Vancouver's sewer service area. There are tens of
thousands of additional septic systems outside the city discharging to
the aquifer. The county is experiencing rapid growth which increases
the threat to the quality of the aquifer as well as increases the
demand for potable water.
Because the aquifer system is vulnerable to contamination and
restoring groundwater quality can be difficult or even impossible; and
because the aquifer system is the principal source of drinking water
for the area and there are no other sources which can economically
supply all those who depend upon it for drinking water; EPA believes
that contamination of the aquifer system would pose a significant
hazard to public health.
These findings are based on information from various sources
including the petition, EPA guidance, U.S. Geological Survey reports,
and public comments.
III. Description of the Troutdale Aquifer System
The following is a summary of information from the Support Document
available upon request from EPA Region 10, or from the EPA Web site.
Much of the hydrogeological information in the Support Document is
taken from the petition and from ``Description of the Groundwater Flow
System in the Portland Basin, Oregon and Washington'', U.S. Geological
Survey (USGS) Water Supply Paper 2470-A, by McFarland, William D. and
David S. Morgan, 1996A.
The petitioned area is within Clark County, Washington, which is a
part of the southernmost boundary of the state, along the Columbia
River. The geography is characterized by flat-lying alluvial lands
along the Columbia River and its tributaries. These alluvial lands are
interrupted by low, rolling hills and/or buttes with benches and hilly
areas that rise to meet the foothills of the Cascade Range to the east
and the northeast. The altitude of the land surface ranges from
approximately 10 feet along the Columbia River to about 3,000 feet in
the foothill of the Cascade Range. The Columbia River flows westward
out of the Columbia River Gorge, past the City of Vancouver,
Washington, where it flows northward. The tributaries to the Columbia
River that drain Clark County include the North and East Forks of the
Lewis, Little Washougal, Washougal, and Lake Rivers. Major creeks are
Cedar, Salmon, Burnt Bridge, and Lacamas Creeks.
The geologic units of the Troutdale aquifer system are all
lacustrine and fluvial sediments of the upper and lower members of the
Troutdale Formation, other consolidated sand and gravel aquifer units,
and overlying unconsolidated alluvium and flood deposits. These aquifer
system units overlie volcanic and marine sedimentary rocks that are
commonly known as the ``older rocks'' unit. The older rocks unit is
minimally productive as an aquifer and is therefore not included in the
aquifer system being considered for sole source designation.
Sedimentary units of the aquifer system include eight hydrogeologic
units comprising the Portland Basin aquifer system. From youngest to
oldest, these hydrogeologic units are (1) The unconsolidated
sedimentary aquifer, (2) the Troutdale gravel aquifer in the Troutdale
Formation, (3) confining unit 1, (4) the Troutdale sandstone aquifer in
the Troutdale Formation, (5) confining unit 2, (6) the sand and gravel
aquifer, and (7) older rocks. The eighth unit is an undifferentiated
fine-grained sediment deposit that occurs in the basin where the
Troutdale sandstone and the sand and gravel aquifer are absent or where
there is insufficient information to characterize the aquifer units
within the lower Troutdale member.
The quality of groundwater in the proposed aquifer service area is
generally good with some exceptions. Dissolved-solids concentrations
ranged from 12 to 245 milligrams per liter, with a median concentration
of 132 milligrams per liter. Most waters can be characterized as soft
to moderately hard. Concentrations of nitrate as nitrogen exceeded 1.0
milligram per liter throughout the Vancouver urban area, and were as
large as 6.7 milligrams per liter (Maximum Contaminant Level (MCL) is
10 milligrams per liter). Potential nitrate sources are septic
[[Page 52543]]
systems and fertilizers. According to the 1990 Census, there are more
than 31,000 septic systems in Clark County. An analysis of limited
historical data indicates that nitrate concentrations may be decreasing
in the southwestern part of the county around the Vancouver urban area.
A slight increase in nitrate concentrations was noted in rural areas.
Nitrate concentrations correlated with sulfate concentrations (r =
0.61), indicating similar sources for the two. Volatile organic
compounds have been detected in wells in the Vancouver urban area.
Compounds identified included tetrachloroethene, 1,1,1-trichloroethane,
and other solvents. Atrazine and 2,4-D have also been detected in well
water. Trace elements and radiochemical constituents were present only
at small levels, indicating natural sources for these constituents.
The Troutdale aquifer system boundaries are represented by rivers
and the geologic boundary between the aquifer system units and the
older rocks unit. The Columbia River forms the southern and western
boundaries of the proposed Troutdale aquifer system. The northern
boundary follows the North Fork of the Lewis River from its confluence
with the Columbia River, east to the confluence of Cedar Creek. Cedar
Creek is used as the northeast boundary because its location is the
closest geographic representation of the geologic boundary between the
Troutdale unit and the older rocks unit, and the creek also most likely
acts as a local ground water divide for the upper parts of the aquifer
system. The aquifer boundary follows Cedar Creek east where the
boundary turns southeast and follows the mapped geologic contact
between the Troutdale Formation and the older rocks unit. The eastern
boundary follows the geologic contact south to the Little Washougal
River, and then follows the Little Washougal River to its confluence
with the Washougal River. The boundary then follows the Washougal River
south to Woodburn Hill, where it turns northwest and follows the
geologic contact along a small outcrop of the older rocks unit. The
boundary follows the geologic contact through the City of Camas, and
meets the Columbia River. In the northern part of the area, the aquifer
system boundary is drawn around Bald Mountain, which is excluded from
the aquifer system because it is composed of the older rocks unit.
Please see the Support Document for a more detailed hydrogeologic
description.
IV. Project Reviews
The Safe Drinking Water Act authorizes EPA to review proposed
Federal financially-assisted projects which have the potential to
contaminate a designated SSA. Federal assistance may be denied if EPA
determines that a project may contaminate the SSA through its recharge
zone so as to create a significant hazard to public health. Outright
denial of Federal funding is rare as most projects pose limited risk to
ground water quality or can be feasibly modified to prevent ground
water contamination. Proposed projects that are funded entirely by
state, local, or private concerns are not subject to SSA review by EPA.
EPA does not review all possible Federal financially-assisted
projects, but tries to focus on those projects which pose the greatest
risk to public health. Memorandums of Understanding have been developed
between EPA and various Federal funding agencies to help identify,
coordinate, and evaluate projects. EPA relies to the maximum extent
possible on existing local and state mechanisms to protect SSAs from
contamination. Whenever feasible, EPA coordinates project reviews with
local and state agencies that have a responsibility for ground water
protection. Their comments are given full consideration in the Federal
review process.
V. Public Participation and Response to Comments
The following is a summary of the information from the ``EPA
Response to Public Comments Submitted on the Draft Support Document for
the Sole Source Aquifer Designation of the Troutdale Aquifer System'',
which is available on the EPA Region 10 Sole Source Aquifer Web site.
EPA used various methods to notify and involve the public and
others in the Troutdale Aquifer System SSA designation process. The
outreach effort included briefings to local and State government,
distribution of EPA facts sheets, placing information in local
libraries, a public advertisement in the local newspaper, and posting
all designation information on the EPA Region 10 Sole Source Aquifer
Web site.
A public comment period was in effect from March 1, 2006 to May 1,
2006. EPA received 26 letters of support for the designation from a
combination of individuals, public interest groups, Indian tribes, and
public utilities. A letter from the City of Portland Bureau of Water
Works suggested corrections to the Support Document regarding accurate
wording of information about the Bureau of Water Works. A letter from
the Board of Clark County Commissioners listed 7 questions for EPA to
answer. In a follow-up letter, the Board questions the need for the
designation and requests a written guarantee that EPA will only address
technical aspects of federally-funded projects in the area, and not
involve itself in local land use issues. A letter from the City of
Vancouver questioned the need for the designation, and questioned the
validity of the alternative source evaluation. There were no letters
expressing strong opposition to the designation.
The primary reason given for supporting the proposed action was a
belief that designation would increase protection of the area's ground
water. Many people cited concerns regarding historical and current
ground water contamination of the aquifer system, indicating the high
degree of aquifer vulnerability. Many cited the educational benefit
that SSA status would have on the area's residents and on Clark County
government on the source of the area's drinking water, and its value
and the need for protection and conservation. Some people commented
that protection of the area's ground water was important because there
are no feasible alternate sources of drinking water.
Two local governmental agencies questioned the need for the sole
source, citing other ground water protection laws that are currently in
effect. In response, there is no program in the State of Washington
that designates an entire aquifer boundary for protection efforts. EPA
has authority to review, and recommend mitigating measures to any
federally-financially assisted project that is determined to be a risk
to the ground water. No such review exists through any other program.
One governmental agency expressed concern that special interests
would exploit the designation which would lead to unnecessary project
delays and the advancement of other agendas. In response, EPA's role,
after designation, is to review federally-financially assisted projects
proposed in the area, to make sure that they will not contaminate the
aquifer. Project delays would only occur if it became necessary to
incorporate mitigating measures to assure that the public's drinking
water would be protected.
One government agency believes that there are feasible alternative
sources of drinking water for the area. In response, EPA considered and
evaluated the potential costs of supplying the aquifer population with
water from various rivers, Lake Vancouver, etc. * * * individually. We
did not consider them collectively because if they were not feasible
individually, then they would certainly not be economically feasible
[[Page 52544]]
collectively. It would cost considerably more to hook up everyone to
not only a river source, but also to a lake source. When evaluating
economic feasibility, the costs of supply lines running to every single
household in the area must be included * * * this includes every
household up in the foothills, out in the middle of the woods, and not
just in the metropolitan areas. Although there may be a collection of
alternative water supplies that could serve the City of Vancouver, this
still does not meet the EPA guidance criteria for alternative sources,
which states that it has to be shown that the alternative source could
supply the entire population that lives over the aquifer. We requested
information from the public that would show us if any such alternatives
exist, but none were supplied to us.
One government agency requested the EPA provide the technical basis
for listing Salmon Creek and Lacamas Creek as losing stream reaches. In
response, both creeks were measured as losing reaches by the U.S.
Geological Survey in stream measurements made in 1996.
One government agency expressed concern that EPA is unwilling to
guarantee in writing that Federal agency Memorandums of Understanding
(MOU's) will only address technical project elements and not diverge
into non-technical issues such as land use or other local jurisdiction
decisional concerns. In response, EPA creates MOU's with other Federal
agencies to ensure that that EPA receives project information on all
federally-financially assisted projects that are located in a Sole
Source Aquifer and which have the potential to contaminate such
aquifer. EPA's role is to review the projects and either approve as-is,
or recommend changes in the project design that offer aquifer
protection. Such recommended changes in project designs could have an
indirect impact on local land use. EPA's direct role in local projects
is solely the technical review of federally-financially assisted
projects.
VI. Summary
This determination affects only the Troutdale Aquifer System
located in Clark County, Washington. As a result of this determination,
all Federal financially-assisted projects proposed in the designated
area will be subject to EPA review to ensure that they do not create a
significant hazard to public health.
Dated: August 14, 2006.
Ron Kreizenbeck,
Acting Regional Administrator, Region 10.
[FR Doc. E6-14710 Filed 9-5-06; 8:45 am]
BILLING CODE 6560-50-P