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2007 Consumer Confidence Report of Water Quality |
To Our Water Customers,
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The City
of Daly City is pleased to present to you,
our customers, the 2007 Consumer Confidence
Report. It is important for you to know about
the City’s water supply; where it comes from,
how it is handled to insure public health
and safety, future changes to the system and
the results of ongoing water quality monitoring.
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Top Quality Water Resource |
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drinking water is the highest quality and
undergoes a rigorous monitoring program to
comply with prescribed regulations, as mandated
by the State Department of Public Health and
the United States Environmental Protection
Agency standards. The water delivered to your
home, business and/or school is of the safest
quality. Only under rare circumstances specifically
involving persons with identified health concerns,
such as people on dialysis or those with significantly
compromised immune systems, is there a need
for specially treated, filtered or prepared
water. Additional technical information regarding
monitoring and water quality results can be
found later in this report.
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Contacts for your Questions |
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If you have any questions regarding your water
bill, water quality, or this Report, please
use the numbers below for answers to your
inquiries. |
For questions concerning your bill, starting
or stopping service, contact Utility Billing
at: (650)
991-8082.
To report a leak or other service problems,
obtain water quality information or other
technical data, or to ask any water related
questions, please call the Water and Wastewater
Resources Department at: (650)
991-8200.
For questions regarding this report contact
Patrick Sweetland, Director of the Department
of Water and Wastewater Resources, at: (650)
991-8200. |
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| Free
Water Conservation Devices |
The Daly City Water Department offers free
water-saving devices, publications, rebates
and school programs for residents, commercial
users and students. Call or email Daly City’s
Ward Donnelly for more information: wdonnelly@dalycity.org
or (650) 991-8208.
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| How
The Public Can Be Involved |
Meetings
of the Daly City City Council begin at 7:00
p.m. on the second and fourth Monday of each
month and are open to the public. Meeting
are held in the City Council Chambers located
on the second floor of the Daly City Civic
Center, 333-90th Street.
The City welcomes your comments and suggestions
on how to improve the municipal water system
or methods to better preserve our resources.
Important consumer information is also available
on Daly City’s website at: www.dalycity.org.
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Chloramine
Conversion and the Disinfection Byproducts Rule |
Conversion
to chloramine enabled the City to provide
water to meet the stringent drinking water
standards for disinfection byproducts, specifically
the Federal and State Disinfectant/Disinfection
Byproducts Rule. Chloramine, a drinking
water disinfectant, is a combination of
five parts chlorine and one part ammonia.
It is a more stable disinfectant than chlorine,
lasts longer in water, and produces lower
levels of disinfection byproducts called
trihalomethanes and halacetic acids, which
are suspected carcinogens. While the current
standard is a maximum trihalomethane level
of 80 parts per billion, Daly City water
currently tests at 30.2 parts per billion.
Halacetic acids currently test at 17 parts
per billion, well below the standard of
60 parts per billion.
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| Daly
City Completes Drinking Water Source Assessment |
An
assessment of local municipal groundwater
production wells of the drinking water source
for the City of Daly City was completed in
March 2003.
Five of Daly City’s six municipal production
wells assessed (“A” Street, Vale, Jefferson,
Junipero Serra and Westlake) were noted as
being highly protected from potential pathways
of contamination. Well #4 was noted as being
moderately protected. The City’s municipal
wells are considered most vulnerable to automotive
repair activities, roadway contaminants and
railways.
A copy of the complete assessment is available
from the Department of Public Health (DPH)
Drinking Water Field Operations Branch, 850
Marina Bay Parkway, Building P, 2nd Floor,
Richmond, CA 94804. You may also obtain a
summary of the assessment by contacting either
DPH District Engineer Eric Lacy at (510) 620-3453,
or Daly City’s Director of Water and Wastewater
Resources Patrick Sweetland at (650) 991-8200.
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| Weekly
Water Sampling by Certified City Water Operators
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Daly City maintains 35 sampling sites
located throughout the community which
are tested weekly for microbiological
contaminants.
Coliforms
Coliforms are bacteria that are naturally
present in the environment and are
used as an indicator that other, potentially
harmful, bacteria may be present.
In
2007, certified water operators collected
1,312 samples. Of these samples, four
tested positive for coliform. This
equates to just 0.3 percent of all
samples taken. Upon re-sampling of
the locations, all tests came back
negative for total coliform and on
no occasion did a test detect the
presence of fecal coliform or E. Coli.
Lead and Copper
Lead in amounts in excess of established
notification levels in drinking water
can cause delayed physical and/or
mental development in infants and
attention span and learning deficits
in children. In adults, it can cause
kidney problems and possible high
blood pressure.
Because of these concerns, in 1993
the United States Environmental Protection
Agency mandated that lead and copper
monitoring be conducted by all water
systems. Daly City completed the required
monitoring and corrosion study in
1994.
Since Daly City had previously conducted
this study, an agreement was reached
with the Department of Public Health
to do a special water quality study
to determine the corrosivity of our
well water. The study was performed
in September 1999.
The results of the second Daly City
study were again under any notification
levels and met all quality standards.
In December 2001, lead and copper
samples were again collected and results
remained under any notification levels.
The results of the second and third
Daly City studies indicate that the
well water blend with Hetch Hetchy
supply provided a buffering effect,
which lowered the corrosiveness of
the water. A forth round of testing
occurred in August 2004 and were again
below notification levels. A fifth
round of testing took place in August
2007. None of the 66 homes tested
at or above notification levels. Testing
will take place again in 2010.
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| Fluoridation
Program |
The
San Francisco Public Utilities Commission
has fluoridated treated drinking water for
more than 50 years. Since June 2004, Daly
City fluoridated the blended water supply
throughout the entire community, in keeping
with the optimum level of 1.0 milligrams per
liter established by the California Department
of Public Health.
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| Daly
City’s Wells (Groundwater) |
Daly
City’s municipal drinking water wells comprise
what is termed "groundwater",
or water that is stored below the earth's
surface. About half the water distributed
by the Daly City Water System is from local
wells that is blended with San Francisco
Water and provided throughout the community.
Daly City completed a source water assessment
of its local groundwater sources in 2003.
Groundwater in many ways is a much more
protected source than surface water. We
draw water from an average depth of 300
feet below ground from a large aquifer known
as the Westside Basin that serves a large
portion of the northern San Mateo Peninsula
and extends north to Golden Gate Park in
San Francisco. Because of its protected
environment and the consistency of our monitoring
results, our well water is only required
to have a disinfectant added to it prior
to being served in our system.
The City wells are checked regularly for
bacteriological levels and nonchlorinated/untreated
well water is consistently determined to
have a rating of "non-detect"
for any coliform organisms.
Results from nitrate testing showed detected
amounts of nitrate in excess of the maximum
contaminant level of 45 milligrams per liter
at Well #4 and A Street Well, but the blended
average in the distribution system was 5.41
milligrams per liter.
Nitrate in drinking water at levels above
45 mg/L is a health risk for infants of
less than six months of age. High nitrate
levels in drinking water can interfere with
the capacity of an infant’s blood to carry
oxygen, resulting in serious illness; symptoms
include shortness of breath and blueness
of the skin. High nitrate levels may also
affect the ability of the blood to carry
oxygen in other individuals, such as pregnant
women and those with certain specific enzyme
deficiencies. Nitrate levels may rise quickly
for short periods of time because of rainfall
or agricultural activity. If you are caring
for an infant, or you are pregnant, you
should seek advice from your health care
provider.
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| Other
Health Related Information |
Arsenic:
New regulations for reporting arsenic levels
have been established at less than 10 parts
per billion. Staff has completed preliminary
testing of its groundwater at five local wells.
Current testing standards detect arsenic at
1 part per billion, andJunipero Serra Well
test results were 1.4 parts per billion, while
all other wells tested were non-detect. While
results are below the standard, Daly City
will provide an informational statement if
for any reason sampling exceeds 5 parts per
billion as this testing program continues.
Chromium-6: Chromium is currently
regulated under the 50 parts per billion maximum
contaminant level for total chromium. There
is no minimum contaminant level established
at this time for Chromium-6; however, testing
from three Daly City wells were as follows:
Well#4 - 19 parts per billion; Jefferson Well
- 9.7 parts per billion and Vale Well - 16
parts per billion
For additional information, please refer to
the California Department of Health Services
website at: http:/www.dhs.ca.gov/ps/ddwem/chemicals/Chromium6/Cr+6index.htm
Cryptosporidium and Giardia:
Cryptosporidium and Giardia are found in most
surface water supplies and can pose a potential
health threat. If ingested, either may produce
symptoms of diarrhea, stomach cramps, upset
stomach, and slight fever. Some people are
more vulnerable to Cryptosporidium than others
and should seek advice about types of drinking
water from their health care providers. The
SFPUC tests regularly for Cryptosporidium
and Giardia in both source and treated water
supplies. Drinking water, including bottled
water, may reasonably be expected to contain
at least minute amounts of some contaminants
including Cryptosporidium and Giardia. The
presence of small amounts of contaminants
does not necessarily indicate that water poses
a health risk. More information about contaminants
and potential health effects can be obtained
by calling the Environmental Protection Agency’s
Safe Drinking Water Hotline at (800) 426-4791.
Please note that Cryptosporidium and Giardia
are associated with surface water supplies
and are not commonly detected in groundwater.
Daly City's wells in previous years have never
had a detected level of either of these microbes.
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| State
Certification |
All
water operators possess water treatment certifications
issued by the California Department of Public
Health. Additionally, all water operators
and water distribution personnel possess water
distribution certifications.
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Drinking Water Sources Become Polluted |
The
sources of drinking water include rivers,
lakes, streams, ponds, reservoirs, springs
and wells. As water travels over the surface
of the land or through the ground, it dissolves
naturally occurring minerals and in some cases
even radioactive material. Surface waters
in particular can be susceptible to substances
resulting from the presence of animals or
human activity.
Drinking Water, including bottled water, may
reasonably expected to contain at least small
amounts of some contaminants. The presence
of contaminants does not necessarily indicate
that water poses a health risk. Some people
may be more venerable to contaminants in drinking
water than the general population. Imnuno-compromised
persons, such as persons with cancer undergoing
chemotherapy, persons who have undergone organ
transplants, people with HIV/AIDS or other
immune system disorders, some elderly, and
infants can be particularly at risk from infections
. These people should seek advise about drinking
water from their health care providers. EPA/Centers
for Disease Control guidelines on appropriate
means to lessen the risk of infection by Cryptosporidium
and other microbial contaminants are available
from the Safe Drinking Water Hotline (800)
426-4791 or on the U.S. EPA’s website: www.epa.gov/safewater/hfacts.html.
Contaminants that may be present in source
waters include:
Microbial
Contaminants such as viruses and
bacteria that may come from septic systems,
agricultural livestock operations and wildlife.
Inorganic Contaminants such
as salts and minerals which can be naturally
occurring or result from urban stormwater
runoff, industrial or domestic wastewater
discharges, oil and gas production, mining
or farming.
Organic Chemical Contaminants
including synthetic and volatile organics
which are by-products of industrial processes
and petroleum production and can also come
from septic systems, urban stormwater runoff,
agricultural chemicals such as chemical fertilizers
and gas stations.
MTBE, a gasoline additive,
has become a recent water quality concern.
This organic contaminant has rapidly been
made a primary contaminant by DHS and is regularly
monitored. All test results for MTBE in the
City's wells and distribution system have
been rated "non-detect".
Radioactive Contaminants
which can be naturally occurring, or the result
of oil and gas production and mining activities.
Pesticides and Herbicides
may come from a variety of sources such as
agriculture, urban stormwater runoff and residential
uses.
Unregulated Contaminant Monitoring
Helps the U.S. EPA and the California Department
of Health Services (DHS) to determine where
certain contaminants occur and whether the
contaminants need to be regulated. During
2000, the SFPUC monitored for twelve unregulated
contaminants including MTBE, perchlorate,
herbicides, and pesticides. These contaminants
were not detected in any of Daly City's or
SFPUC’s supplies.
Source
Protection is the primary barrier
to water pollution. A contaminant that does
not get into the water source does not need
to be removed. SFPUC maintains a comprehensive
watershed control and management program to
protect source water.
The water from Hetch Hetchy Reservoir in Yosemite
National Park is so well protected that the
Hetch Hetchy water supply is one of only six
major water supplies in the country exempt
from filtration.
Water Treatment is the next
protective barrier. Water from the remote
Hetch Hetchy reservoir and local wells are
unfiltered because it meets all state and
federal requirements without filtration. Water
from the other Bay Area watersheds near populated
areas is filtered to meet standards for clarity.
All of Daly City’s water is disinfected in
order to retain distribution system residuals
that meet state and federal quality standards.
Effective Operation & Maintenance
of the distribution system assures that the
water maintains its quality as it travels
through the system to your tap. Minimal chlorine
residual is maintained in the distribution
system to prevent any regrowth of organisms
during storage and transmission of the water
as it travels to you. Active flushing of water
mains and rotation of stored water supplies
also keep the water fresh and limits growth
of organisms.
Daly City conducts continuous water quality
monitoring and testing to assure your drinking
water is safe and healthy. Daly City, working
with the San Mateo County Health Department,
maintains an active cross-connection control
program to prevent the intrusion of potentially
harmful materials into the drinking water
system.
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| Where
Your Water Comes From
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The
Daly City water system is supplied by two
sources, the San Francisco Water Department
and local Daly City wells. San Francisco Water
Department is supplied exclusively by their
surface water system which is mostly reliant
on the Hetch Hetchy Watershed, and to a lesser
degree local reservoirs.
Hetch
Hetchy Watershed
The Hetch Hetchy watershed provides approximately
80 percent of the San Francisco Public Utilities
Commission (SFPUC) supply. The Hetch Hetchy
system captures water inflows from the watershed
in the Hetch Hetchy Reservoir. This reservoir,
the primary source for the system, is filled
by spring snowmelt, runoff and the Tuolumne
River. Water in the Hetch Hetchy Reservoir
is treated but not filtered because it is
of such high quality.
Alameda
and Peninsula Watersheds
The Alameda and Peninsula watersheds provide
the remaining 20 percent of the SFPUC water
system. The Alameda watershed is located in
the East Bay, and represents about 10 percent
of the total water supply, with water captured
and stored in two reservoirs: Calaveras and
San Antonio. The Peninsula watershed, representing
the remaining ten percent of the SFPUC supply,
captures runoff in four reservoirs: Crystal
Springs, San Andreas and the smaller Pilarcitos
and Stone Dam reservoirs.
The six reservoirs in the Alameda and Peninsula
watersheds capture rain and local runoff.
Some also store Hetch Hetchy water for use
by the SFPUC. Water from the Hetch Hetchy
Reservoir that is stored locally is treated
and filtered, as are all local water sources.
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Water
Quality Data Table |
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