VvX
PROJECT
Cal/EPA
Pete Wilson
Governor
Los Angeles Regional Water Quality Control Board
U.S. Environmental Protection Agency -Region 9 • July 1998
Santa Monica, CA
This fact sheet is being distributed in the City
of Santa Monica and nearby sections of the City of
Los Angeles and Culver City to provide informa-
tion on the gasoline additive MtBE and its impact
on Santa Monica's and Southern California Water
Company's drinking water wellfields. It summa-
rizes the efforts being made to address the MtBE
problem in these areas. Developed by the Los
Angeles Regional Water Quality Control Board
(Regional Board) and the U.S. Environmental
Protection Agency (EPA), this informational fact
sheet was designed to give a brief overview of the
current situation and future activities as well as
provide a list of people who can be contacted for
further information.
What is MtBE?
Methyl tertiary butyl ether (MtBE) is a gaso-
line additive that boosts the oxygen content in fuel
(an oxygenate), resulting in less air-polluting car-
bon monoxide being released from vehicle exhaust
systems. It has been used as an octane booster in
the United States since the late 1970s. However,
usage increased in the 1990s as a result of federal
Clean Air Act Amendment requirements for refor-
mulated gasoline. Reformulated gasoline was de-
signed to not only reduce carbon monoxide but
also lower ozone and smog by reducing compo-
nents such as benzene (a known human carcino-
gen) and sulfur. Federal law requires that reformu-
lated gasoline, which includes oxygenates such as
MtBE, be sold throughout the year in regions with
high smog levels such as Southern California. In
recognition of the clean air benefits derived from
its use, reformulated gasoline has been in use year-
round throughout the State since 1996.
t UNIVERSITY
i OF
'CALIFORNIA AT
/ LOS ANGELES
Charnock
Wellfield
2
Southern California
Water Company Wells
CHARNOCK SUB-BASIN
INVESTIGATION AREA
Location map showing Arcadia Wellfield and Charnock Sub-basin
Investigation Area
Why is MtBE used?
Although federal requirements for oxygenates do not specify
the use of MtBE, it has become the additive of choice in most
regions of the country requiring oxygenated fuel. Some of the
reasons for MtBE's preferred usage are: it is relatively inexpensive
to produce, it has a high octane rating, it has a low evaporation rate
-------
and it can readily mix with other gasoline
components. Additionally, MtBE has a
dilution effect on undesirable components
(benzene and other aromatics, sulfur and
olefins) and can be pumped through existing
gasoline distribution lines.
However, the chemical properties of
MtBE, an ether, are significantly different
from those of other typically-investigated
constituents found in gasoline (benzene,
toluene, ethylbenzene and xylenes—
otherwise known as BTEX). One main
difference is that MtBE travels much
faster and farther through soil and
groundwater than other components of
gasoline. And, although quite volatile in
its pure form (it vaporizes easily), MtBE,
unlike BTEX, is not very volatile once mixed
with groundwater. Another difference from
other gasoline components is that MtBE does
not biodegrade readily. These are some of the
reasons MtBE has become a problem in the
groundwater of the West Los Angeles/Culver
City areas.
How did MtBE get into Santa
Monica's drinking water and
other California water supplies?
Drinking water in California comes from
either groundwater or surface water. The
primary source of MtBE contamination in
groundwater is from leaking underground
storage tanks (USTs). Other sources of pollu-
tion include above-ground storage tanks and
pipelines. Recreational boating is thought to
be the primary source of MtBE in surface
water (rivers, lakes or reservoirs).
Where does Santa Monica's water
supply come from?
A major portion of Santa Monica's water
has come from groundwater supplies. Seven
production wells in two of the City's wellfields
have been contaminated with MtBE (see map
front page). Water from these two wellfields is
not currently being served as drinking water
to residents. Drinking water for Santa Monica
is coming from other Santa Monica wells and
the Metropolitan Water District of Southern
California (MWD). MWD's water comes
from the Colorado River and/or Sierra Nevada
snowmelt. All drinking water presently being
supplied to Santa Monica is clean and safe.
Some of the companies who may be respon-
sible for the MtBE pollution are currently
paying for all of Santa Monica's replacement
water.
What is being done to solve the
MtBE problem in the Santa
Monica area?
There are two distinct areas affected by
MtBE that are being addressed on a site-
specific basis. These are the Arcadia Wellfield
and the Charnock Sub-basin.
Arcadia Wellfield Area
The Arcadia Wellfield, located in West
Los Angeles, has two domestic supply produc-
tion wells. This wellfield has been affected by
MtBE from underground gasoline storage
tank system leaks at a former gas station at
Wilshire Boulevard and Bundy Drive. MtBE
has been found in shallow groundwater
monitoring wells near the drinking water
production wells at concentrations up to
100,000 micrograms per liter (parts per billion
or ppb). During August 1995, MtBE pollu-
tion was detected by the City in water samples
obtained from production wells in the Arcadia
Wellfield at concentrations less than 20 ppb.
Arcadia Well No. 5 was shut down by the City
on August 27, 1996; the highest concentration
of MtBE detected in this well was 86.5 ppb.
Arcadia Well No. 4 was shut down by the City
on October 17, 1996; the highest concentra-
tion of MtBE detected in this well was 19.6
ppb. The City previously operated the Arcadia
Wellfield with an average pumping rate of
approximately 250 gallons per minute (gpm)
but has since ceased all production as a result
of the MtBE pollution. The reported maxi-
mum capacity of the Arcadia Wellfield
(Arcadia Wells No. 4 and 5) is approximately
600 gpm.
PAGE•2
ARCADIA WELLFIELD/CHARNOCK SUB-BASIN MTBE PROJECTS
-------
Under the regulatory authority of the
Regional Board and with assistance from EPA,
the responsible party, Mobil Oil, was directed
to investigate and clean up this area. However,
due to compliance issues, the Regional Board
issued a Cleanup and Abatement Order
directing Mobil to conduct additional investi-
gations and cleanup on an expedited schedule.
These activities have been ongoing since late
1996. Following demolition of the former gas
station, excavation of approximately 2,000
cubic yards of gasoline-containing soils and
the removal of all underground storage tanks
and lines, cleanup crews are now working to
control and remove the remaining sources of
contaminated soil and groundwater from the
surrounding area. A low-flow groundwater
pump and treat system was installed in Octo-
ber 1997 to control further migration of
contaminated groundwater. This interim
cleanup system extracts contaminated ground-
water and filters it through three carbon beds
which remove the MtBE before the water is
discharged into the sanitary sewer. A final
technical report containing the results of all
assessment work completed at the Arcadia
Wellfield was submitted to the Regional Board
and EPA on June 18, 1998. A Remedial
Action Plan and Treatment Feasibility Study is
due by July 21, 1998. It is expected that
complete cleanup of this area will take several
years.
Charnock Sub-basin Investigation Area
The second area affected by MtBE is
known as the Charnock Sub-basin, located in
the Mar Vista area of West Los Angeles. The
Charnock Sub-basin Investigation Area
includes two municipal production wellfields.
The Charnock Wellfield is operated by the
City of Santa Monica and includes five
production wells; a second wellfield, operated
by the Southern California Water Company,
has two production wells. MtBE has been
found in drinking water wells at the Charnock
Wellfield at concentrations up to 610 ppb
(Well No. 19 on March 25, 1996). MtBE has
not been detected in production wells oper-
ated by the Southern California Water Com-
pany. However, both wellfields were shut
down to control the potential spread of MtBE
in the Charnock Sub-basin.
A thorough area-wide investigation is
currently underway in the Charnock Sub-
basin to determine the sources contributing to
the groundwater contamination. Potential
sources include 26 underground storage tank
sites and two intrastate gasoline pipelines. Sites
of current and former gasoline service stations
within the Charnock Investigation Area are
being investigated for leaking underground
tank systems that would result in contamina-
tion of soil and/or groundwater. Oil compa-
nies that operate intrastate petroleum pipelines
(Shell and Chevron) are checking them to
determine if they are leaking and possibly
contributing to the groundwater contamina-
tion problem. Pipeline testing completed to
date does not show that this is the case.
Monitoring wells and borings have been
installed to characterize the multi-aquifer
groundwater basin in certain parts of
this area. As information becomes avail-
able on where MtBE gasoline leaks have
occurred, the Regional Board and EPA (who
are overseeing the investigation) will
then direct the responsible
parties to remove and/or
repair any problem tank
systems or petroleum
pipelines; they will also be
directed to clean up any
contaminated soil and
groundwater that may be
affecting the drinking water wells.
While there are many companies that may
be responsible for the MtBE contamination in
the Charnock area, three of them (Shell,
Chevron and Exxon) have voluntarily been
conducting pilot tests of treatment technolo-
gies which may be capable of removing the
contamination from the groundwater. These
companies have proposed constructing a
treatment plant so that the wellfield may
resume providing drinking water as soon as
possible. However, the companies must first
SANTA MONICA, CALIFORNIA
PAGE•3
-------
propose a specific plan to be reviewed by the
agencies and other interested parties. In
addition, water will only be served to the
public if a permit is granted by the California
Department of Health Services. Permitting,
design, construction and testing processes are
likely to take one to two years.
What is California doing about
underground storage tanks?
The State of California has developed an
aggressive underground storage tank replace-
ment program to avoid future fuel leaks. State
regulations require that all underground
storage tanks installed before 1984 be re-
moved, replaced or upgraded to meet current
standards by December 22, 1998. About 52%
of the approximately 60,000 active USTs in
California now meet State upgrade require-
ments.
At what level is MtBE harmful in
drinking water?
A Maximum Contaminant Level (the
maximum level allowable for a contaminant in
drinking water) has not been set by either EPA
or the State of California Department of
Health Services (DHS) for MtBE. There are
no studies of effects to humans from long-
term exposure to MtBE. Studies available for
hazard assessment have primarily involved
laboratory animals.
EPA's current Drinking Water Advisory
recommends a level of 20 to 40 ppb or below.
These levels are thought to provide a large
margin of safety from potential toxic effects of
MtBE and minimize concerns related to taste
and odor of drinking water for the average
consumer. The 20 to 40 ppb range is 20,000
to 100,000 times lower than concentrations
associated with observed cancer and noncancer
effects in animals. However, existing data do
not allow for accurate estimation of cancer risk
at low levels of exposure. When adequate data
become available, EPA's Office of Water will
publish another Advisory that will include
such quantitative estimates for health risks.
The State of California Office of Environ-
mental Health Hazard Assessment (OEHHA)
has issued an Interim Action Level for MtBE
in drinking water at 35 ppb. This is similar to
a "health advisory" level which, if exceeded,
advises the water supplier to find another
source of drinking water or provide public
notification. Recently, OEHHA released for
public review and comment a Public Health
Goal (PHG) of 14 ppb for MtBE in drinking
water. If adopted, this health-based number
would form the basis for a primary drinking
water standard in California. The taste and
odor threshold, or point of sensory detection,
for MtBE in water is variable and reportedly
ranges from 2.5 ppb to 134 ppb.
On October 8, 1997, Governor Pete
Wilson signed two MtBE-related bills. Assem-
bly Bill 592 (Kuehl), in part, requires DHS to
adopt primary and secondary drinking water
standards for MtBE. The secondary standard
will be adopted by DHS this Fall and must
not exceed what is termed a "consumer
acceptance level" for MtBE. The primary
drinking water standard for MtBE must be
established by DHS by July 1, 1999.
Senate Bill 521 (Mountjoy) enacted the
MtBE and Environmental Protection Act of
1997. This bill, in part, requires collection and
reporting of MtBE data (and other oxygen-
ates) to water purveyors throughout the state
on a quarterly basis. It also requires a study by
the University of California to assess the health
effects and environmental risk and benefit of
MtBE and other oxygenates. The bill also
prohibits UST closures without MtBE testing
data. In addition, no public water systems or
their customers will be responsible for
remediation or treatment costs.
Research
Additional research on the health effects of
MtBE and related environmental issues is
necessary, and this is being conducted by EPA,
other federal and state agencies and private
entities. Research projects include work on
environmental monitoring/occurrence, source
characterization, fate and transport, exposure,
PAGE•4
ARCADIA WELLFIELD/CHARNOCK SUB-BASIN MTBE PROJECTS
-------
toxicity and remediation. EPA's Office
of Water issued the Drinking Water
Advisory on MtBE to provide infor-
mation and guidance because no
national regulations currently exist.
To obtain a copy of the Advisory
(EPA-822-F-97-009), call the Na-
tional Center for Environmental
Publications and Information at
(800) 490-9198.
Regulatory Authority
The Regional Board and EPA
are using separate authorities to
address the MtBE pollution prob-
lems impacting the Arcadia
Wellfield and the Charnock Sub-
basin. The Regional Board is using
authority under the Porter-Cologne
Water Quality Control Act, Section
13267. EPA is using authority under
the Safe Drinking Water Act,
Section 1431, 42 U.S.C. 300i and
the Resource Conservation and
Recovery Act, Section 7003, 42
U.S.C. Section 6973.
The Regional Board and EPA
entered into a Memorandum of
Understanding on April 24, 1997 to
address the impact of MtBE contami-
nation on Santa Monica's drinking
water wellfields. The goal of this
cooperative effort between both
agencies is to promptly restore and
protect the use of the valuable water
resources at both wellfields. •
FOR MORE INFORMATION
The following agencies and personnel are directly involved in the Santa Monica MtBE project.
If you have questions or concerns about the situation, please do not hesitate to contact any of us:
Los Angeles Regional Water Quality Control Board
101 Centre Plaza Drive, Monterey Park, CA 91754
Project Manager:
Project Geologist:
Public Relations:
David Bacharowski (213)266-7546
DBACHARO@rb4.swrcb.ca.gov
RickVergets (213)266-7556
RVERGETS@rb4.swrcb.ca.gov
Karen Caesar (213)266-7569
KCAESAR@rb4.swrcb.ca.gov
City of Santa Monica
Rey Rodriquez
1212 Fifth Street
Santa Monica, CA 90401
(310) 458-8286
Southern California Water
Company
Denise Kruger
P.O. Box 9016
SanDimas, CA91773
(909) 394-3600
U.S. Environmental Protection Agency, Region 9
75 Hawthorne St., San Francisco, CA 94105
Project Manager: Steven C. Under, P.E. (415) 744-2036
Linder.Steven@epamail.epa.gov
Community Involvement
Coordinator: Vicki Rosen (415)744-2187
Rosen. Vicki@epamail .epa.gov
You may also call the above EPA staff on EPA's
toll-free line: (800)231-3075
Additional Information Available on the Internet at these WEB Sites
Regional Board: http://www.swrcb.ca.gov/-rwqcb4/ust.htm
State Board: http://swrcb.ca.gov
Calif. Dept. of Health Services: http://www.dhs.cahwnet.gov/org/ps/ddwem/ddwemindex.htm
MtBE Risk Assessment: http://www.calepa.cahwnet.gov/oehha
EPA: http://www.epa.gov
Health Advisory: http://www.epa.gov/ost/tools/MtBEaa.pdf
Research Strategy: http://www.epa.gov/ncea/oxywater.htm
Air Research: http://www.epa.gov/omswww/omsfuels.htm
SANTA MONICA, CALIFORNIA
PAGE•5
-------
Printed on Recycled ^ A Recyclable Paper
I I
I I
I I
I I
I I
I I
------- |