> City of Daly City > City Hall > Departments > Water and Wastewater Resources > Consumer Confidence Reports of Water Quality > 2007 Consumer Confidence Report Of Water Quality

2007 Consumer Confidence Report Of Water Quality

2007 Consumer Confidence Report of Water Quality

To Our Water Customers,
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.

Top Quality Water Resource
Your 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.


Contacts for your Questions
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.

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.
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.
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.

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.
Weekly Water Sampling by Certified City Water Operators

Daly City maintains 35 sampling sites located throughout the community which are tested weekly for microbiological contaminants.

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.

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.
Back to the list of Contents | Back to top
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.

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.
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.
How 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.
Where Your Water Comes From

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.

Water Quality Data Table





































If English is Not Your Primary Language