PHG Report Final_Sunnyvale_2025 — Sunnyvale City Council, August 26, 2025

City of Sunnyvale – Public Health Goals Report 2025 1
CITY OF SUNNYVALE – 2025 PUBLIC HEALTH GOALS REPORT

BACKGROUND
The California Health and Safety Code, section 116470(b) requires public water systems serving more than 10,000 service connections to prepare a report if water quality monitoring results over the past three years exceed any California Public Health Goals (PHGs) and/or federal Maximum Contaminant Level Goals (MCLGs). PHGs are non-enforceable goals established by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA). MCLGs are goals that are adopted by USEPA, and only come into play if there is no California PHG. PHGs may not be more lenient that MCLGs.

Only constituents that have a California primary drinking water standard and for which either a PHG or MCLG has been set are to be addressed in the Report. Attachment 1 contains a list of the regulated constituents and their respective PHGs or MCLGs.

If a constituent was detected by a water supplier between January 1, 2022 and December 31, 2024 at a level exceeding an applicable PHG or MCLG, the Report shall contain the following information as required by the law:
 Numerical public health risk associated with the enforced Maximum Contaminant Level (MCL) and the PHG or MCLG;
 Category or type of risk to health that could be associated with each constituent;  Best treatment technology available, if any, that could be used to remove or reduce the constituent to a level at or below the PHG or MCLG;
 Estimate of the cost to install that treatment and if it is appropriate and feasible; and  Description of the actions, if any, the City intends to take to reduce the level of the constituent.

The City of Sunnyvale conducts weekly, quarterly, annual, triennial, and 9-year monitoring on a continuous basis and is pleased to report that water quality meets all state and federal standards.

However, chromium VI (hexavalent chromium) was detected above the PHG of 0.02 parts per billion (ppb) in the water supplied to the City by a water wholesaler and is discussed for the purpose of this report.

PHG/MCLG vs. MCL
PHGs are set by OEHHA (and MCLGs by USEPA) based solely on public health risk considerations. MCLs are set by USEPA or the California State Water Resources Control Board (SWRCB) Division of Drinking Water (DDW) as the contaminants maximum level which public water systems must not exceed. Violations of MCLs can result in fines, abatement orders, or closure of facilities. When the USEPA, or the DDW, adopts an MCL, they take into account such factors as (1) analytical methodologies, (2) effectiveness of available treatment technologies, and (3) health benefits versus costs. PHGs (and MCLGs) are not enforceable and are not required to be met by any public water system.

Attachment 1

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City of Sunnyvale – Public Health Goals Report 2025 2
Water Quality Data Review for this Report
Water quality data collected by the City of Sunnyvale during the calendar years of 2022, 2023 and 2024 for purposes of determining compliance with drinking water standards were reviewed in order to prepare this Report. The City of Sunnyvale also purchases water from two water retailers: the San Francisco Public Utilities Commission (SFPUC) and the Santa Clara Valley Water District (Valley Water) and results of that monitoring is also considered in the report review.

This data was summarized in the 2022, 2023 and 2024 annual Water Quality Reports, also known as Consumer Confidence Reports, which were distributed to all of our customers by July of each of the following year and is also available online (see Attachment 2 for copies of the 2022, 2023, and 2024 City of Sunnyvale Water Quality Reports).

Guidelines Followed for Preparation of this Report
The Association of California Water Agencies (ACWA) formed a workgroup that prepared guidelines for water utilities to use in preparing required PHG Reports. These guidelines, titled “Public Health Goals Report Guidelines: Ensuring Compliance with California Health and Safety Code Section 116470(b)” dated April 2025 were used in the preparation of this report.

Best Available Treatment Technology and Cost Estimates
Both USEPA and DDW adopt Best Available Technologies (BATs), which are the best known methods of reducing contaminant levels below the MCL. This report also considers, where appropriate, other commercially available BATs that may have the ability to further reduce constituent levels beyond the MCL to the PHG/MCLG level or below. While a BAT may identify a process that can reduce the presence of a constituent, the cost of implementation can be a major factor in deciding whether or not to adopt the process. For a system that is in compliance with MCL levels, striving to keep constituents at or below PHG/MCLG levels must be evaluated with costs in mind. Thus, while the City is meeting all water quality MCLs, the intent of this exercise is to re-evaluate the value of a technology to remove or reduce a constituent to the level at which the USEPA or OEHHA has determined that there is no associated health risk (i.e. at or below the PHG/MCLG), if possible, and whether the cost to the ratepayers to provide advanced treatment could be justified.

The PHGs/MCLGs are set much lower than the MCL, and it is not always possible or feasible to determine what treatment technology is able to further reduce a constituent to a level at or below the PHG/MCLG. In some cases, such as when the MCLG is set at zero, there may not be commercially available technology to reach that level. The issue is further complicated because it is often not possible to verify by analytical means that the constituent has been totally eliminated, as some laboratory analyses can detect constituents down to a DDW approved level with certainty and are unable to definitively identify the constituent at lower levels. In some cases, installing treatment to try and further reduce very low levels of one constituent may have adverse effects on other aspects of water quality

CONSTITUENTS DETECTED THAT EXCEED A PHG OR MCLG
In reviewing water quality monitoring data collected during 2022, 2023 and 2024, it is concluded that a PHG Report is required that addresses chromium VI (hexavalent chromium).

Attachment 1

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City of Sunnyvale – Public Health Goals Report 2025 3
The following section presents a discussion of the constituent that was detected in the purchased water from SFPUC at levels above the PHG or MCLG.

Chromium VI (Hexavalent Chromium)
On October 1, 2024, the new MCL of 10 ppb became effective for chromium VI. Previously, chromium VI was regulated under the 50 ppb primary drinking water standard for total chromium established in California in 1977. The California PHG for chromium VI has been set at 0.02 ppb.

The established detection limit for reporting results is 0.1 ppb, meaning that lab results returned under 0.1 ppb can be unreliable due to the fact that equipment is not sensitive enough to detect levels under the 0.1 ppb level.

Chromium VI can be naturally occurring and found in natural deposits throughout California.

However, chromium VI was used in industrial and manufacturing and contaminated waste can migrate into groundwater supplies. Chromium VI has been categorized in the health risk category as being carcinogenic through inhalation and ingestion. The cancer risk at the California MCL is 5 x 10-4, or five per 10,000, and the risk at the PHG is 1 x 10-6 or one per million1.

Best Available Technology Identified for Chromium VI
The approved technologies for removing chromium VI from drinking water include:
 Ion exchange
 Coagulation/Filtration
 Reverse osmosis
Two applications of treatment technologies have been tested in recent history and have reduced chromium VI levels to 1 ppb. The estimated cost to install and operate such treatment systems are within the range of $2.14 to $13.38 per thousand gallons treated. Based on historical billing data and SFPUC allocations, Sunnyvale purchases approximately 10,300 acre feet of water annually from SFPUC. The cost to implement treatment for the incoming SFPUC supply would be approximately within the range of $7.2 to $44.9M. In addition, the treatment systems would have associated operations and maintenance costs that are unknown at this time. The result would be an assumed increase in cost for each customer of up to $1,500 over the span of a typical loan payback time of 30 years and not including the continuous cost of O&M2.

SFPUC Chromium VI Monitoring Results
The City purchases water from SFPUC, which includes treated water from the Sunol Valley Water Treatment Plant (SVWTP). SFPUC conducts annual chromium VI testing for SVWTP effluent.

Including the one-round of initial monitoring required in 2024, there are three SVWTP effluent chromium VI samples, with results averaging 0.1 ppb. This is well below the MCL of 10 ppb and at the 0.1 ppb level that treatment systems can reliably detect. As such, the City will continue to 1 Office of Environmental Health Hazard Assessment, Water Toxicology Section, Health Risk Information for Public Health Goal Exceedance Reports, February 2025 2 Costs for BATs come from the 2025 PHG Report Guidance to Water Systems, ACWA, April 2025 Attachment 1

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City of Sunnyvale – Public Health Goals Report 2025 4
monitor SFPUC results and has no plans currently to install treatment systems at the SFPUC turnouts due to the increased cost and marginal/unknown benefit.

SUMMARY AND CONCLUSION
The drinking water for the City of Sunnyvale meets all standards established by DDW and USEPA to protect public health. No additional treatment is recommended in an effort to decrease the incidence of hexavalent chromium in source water testing. The level of hexavalent chromium detected is well below the MCL, and elimination may be impossible. Therefore, no additional actions are proposed at this time for reducing hexavalent chromium. Hexavalent chromium will continue to be monitored as required by DDW.

Attachments:

1. Table of Regulated Constituents with MCLs, PHGs or MCLGs

2. Consumer Confidence Reports for 2022, 2023 and 2024.

Attachment 1

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City of Sunnyvale – Public Health Goals Report 2025 5
ATTACHMENT NO. 1
MCLs, DLRs and PHGs for Regulated Drinking Water Contaminants Last Update: November, 2024
Prepared and provided by the Association of California Water Agencies (ACWA).

Attachment 1

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Association of California Water Agencies
12PHG REPORT GUIDELINES | Attachment 1
Chemicals with MCLs in 22 CCR §64431 — Inorganic Chemicals Regulated Contaminant MCL DLR PHG Date of PHG
Aluminum 1 0 .05
0 .6 2001
Antimony 0 .006
0 .006
0 .001
2016
Arsenic 0 .010
0 .002
0 .000004
2004
Asbestos (MFL = million fibers per liter; for fibers
>10 microns long)
7 MFL 0 .2 MFL
7 MFL 2003
Barium 1 0 .1 2 2003
Beryllium 0 .004
0 .001
0 .001
2003
Cadmium 0 .005
0 .001
0 .00004
2006
Chromium, Total 0 .05
0 .01
withdrawn
Nov
. 2001
1999
Chromium,
Hexavalent 0 .01
0 .0001
0 .00002
2011
Cyanide 0 .15
0 .1 0 .15 1997
Fluoride 2 0 .1 1 1997
Mer
cury (inorganic) 0 .002
0 .001
0 .0012 1999 (r
ev2005)*
Nickel 0 .1 0 .01
0 .012
2001
Nitrate (as nitrogen, N) 10 as N 0 .4 45 as
NO3
(=10 as N)
2018
Nitrite (as N) 1 as N 0 .4 1 as
N 2018
Nitrate + Nitrite (as N) 10 as N -- 10 as N 2018
Perchlorate 0 .006
0 .004
0 .001
2015
Selenium 0 .05
0 .005
0 .03
2010
Thallium 0 .002
0 .001
0 .0001 1999 (r
ev2004)
*OEHHA’s review of this chemical during the year indicated (rev20XX) resulted in no change in the PHG.

MCLs, DLRs, and PHGs for Regulated Drinking Water Contaminants Last Update: November 2024
This table includes:

• California
’s maximum contaminant levels (MCLs)
• Detection limits for purposes of r
eporting (DLRs)
• Public he
alth goals (PHGs) from the Office of Environmental Health Hazard Assessment (OEHHA) • The PHGs for NDMA,
PFOA and PFOS (which are not yet regulated in California) are included at the bottom of this table .
• The F
ederal MCLs for PFOA and PFOS are also listed at the end of this table .

Units are in milligr
ams per liter (mg/L), unless otherwise noted.

Attachment 1

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Association of California Water Agencies
13PHG REPORT GUIDELINES | Attachment 1
Radionuclides with MCLs in 22 CCR §64441 and §64443 — Radioactivity Units are picocuries per liter (pCi/L), unless otherwise stated; n/a = not applicable Regulated Contaminant MCL DLR PHG Date of PHG
Gross alpha particle activity - OEHHA concluded in
2003 that a PHG was not practical
15 3 none n/a
Gross beta particle activity - OEHHA concluded in
2003 that a PHG was not practical
4 mrem/yr 4 none n/a
Radium-226 -- 1 0
.05
2006
Radium-228 -- 1 0.019 2006
Radium-226 + Radium-228 5 -- -- --
Strontium-90 8 2 0 .35 2006
Tritium 20,000
1,000 400 2006
Uranium 20 1 0 .43
2001
Chemicals with MCLs in 22 CCR §64444 — Organic Chemicals (a) Volatile Organic Chemicals (VOCs)
Regulated Contaminant MCL DLR PHG Date of PHG
Benzene 0 .001
0 .0005
0 .00015
2001
Carbon tetrachloride 0 .0005
0 .0005
0 .0001
2000
1,2-Dichlorobenzene 0 .6
0 .0005
0 .6 1997 (r
ev2009)
1,4-Dichlorobenzene (p-DCB) 0 .005
0 .0005
0 .006 1997
1,1-Dichlor
oethane (1,1-DCA) 0 .005
0 .0005
0 .003
2003
1,2-Dichloroethane (1,2-DCA) 0 .0005
0 .0005
0 .0004 1999 (r
ev2005)
1,1-Dichloroethylene (1,1-DCE) 0 .006
0 .0005
0 .01 1999
Cis-1,2-Dichlor
oethylene 0 .006
0 .0005
0 .013
2018
Trans-1,2-Dichloroethylene 0 .01
0 .0005
0 .05
2018
Dichloromethane (Methylene chloride) 0 .005
0 .0005
0 .004
2000
1,2-Dichloropropane 0 .005
0 .0005
0 .0005 1999
1,3-Dichlor
opropene 0 .0005
0 .0005
0 .0002 1999 (r
ev2006)
Ethylbenzene 0 .3
0 .0005
0 .3 1997
Methyl ter
tiary butyl ether (MTBE) 0 .013
0 .003
0 .013 1999
Monochlor
obenzene 0 .07
0 .0005
0 .07
2014
Styrene 0 .1
0 .0005
0 .0005
2010
1,1,2,2-Tetrachloroethane 0 .001
0 .0005
0 .0001
2003
Tetrachloroethylene (PCE) 0 .005
0 .0005
0 .00006
2001
Toluene 0 .15
0 .0005
0 .15 1999
1,2,4-
Trichlorobenzene 0 .005
0 .0005
0 .005 1999
1,1,1-
Trichloroethane (1,1,1-TCA) 0 .2
0 .0005
1 2006
1,1,2-Trichloroethane (1,1,2-TCA) 0 .005
0 .0005
0 .0003
2006
Trichloroethylene (TCE) 0 .005
0 .0005
0 .0017 2009
T
richlorofluoromethane (Freon 11) 0 .15
0 .005
1 .3 2014
1,1,2-
Trichloro-1,2,2-Trifluoroethane (Freon 113) 1 .2
0 .01 4 1997 (r
ev2011)
Vinyl chloride 0 .0005
0 .0005
0 .00005
2000
Xylenes 1 .75
0 .0005
1 .8 1997
Attachment 1

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Association of California Water Agencies
14PHG REPORT GUIDELINES | Attachment 1
(b) Non-Volatile Synthetic Organic Chemicals (SOCs)
Regulated Contaminant MCL DLR PHG Date of PHG
Alachlor 0 .002
0 .001
0 .004 1997
Atr
azine 0 .001
0 .0005
0 .00015 1999
Bentazon 0 .018
0 .002
0 .2 1999 (r
ev2009)
Benzo(a)pyrene 0 .0002
0 .0001
0 .000007
2010
Carbofuran 0 .018
0 .005
0 .0007
2016
Chlordane 0 .0001
0 .0001
0 .00003 1997 (r
ev2006)
Dalapon 0 .2
0 .01 0.79
1997 (rev2009)
1,2-Dibromo-3-chloropropane (DBCP) 0 .0002
0 .00001
0 .000003
2020
2,4-Dichlorophenoxyacetic acid (2,4-D) 0 .07
0 .01 0 .02 2009
Di(2-ethylhe
xyl) adipate 0 .4
0 .005
0 .2 2003
Di(2-ethylhe
xyl) phthalate (DEHP) 0 .004
0 .003
0 .012 1997
Dinoseb 0 .007
0 .002
0 .014 1997 (r
ev2010)
Diquat 0 .02
0 .004
0 .006
2016
Endothal 0 .1
0 .045 0.094 2014
Endrin 0 .002
0 .0001
0 .0003
2016
Ethylene dibromide (EDB) 0 .00005
0 .00002
0 .00001
2003
Glyphosate 0 .7
0 .025 0.9 2007
Heptachlor 0 .00001
0 .00001
0 .000008 1999
Heptachlor epo
xide 0 .00001
0 .00001
0 .000006 1999
He
xachlorobenzene 0 .001
0 .0005
0 .00003
2003
Hexachlorocyclopentadiene 0 .05
0 .001
0 .002
2014
Lindane 0 .0002
0 .0002
0 .000032 1999 (r
ev2005)
Methoxychlor 0 .03
0 .01 0.00009 2010
Molina
te 0 .02
0 .002
0 .001
2008
Oxamyl 0 .05
0 .02 0 .026 2009
P
entachlorophenol 0 .001
0 .0002
0 .0003 2009
P
icloram 0 .5
0 .001
0 .166
2016
Polychlorinated biphenyls (PCBs) 0 .0005
0 .0005 0.00009 2007
Simazine 0 .004
0 .001
0 .004
2001
Thiobencarb 0 .07
0 .001
0 .042
2016
Toxaphene 0 .003
0 .001
0 .00003
2003
1,2,3-Trichloropropane 0 .000005
0 .000005
0 .0000007 2009
2,3,7,8-
TCDD (dioxin) 3x10–8 5x10–9 5x10–11 2010
2,4,5-TP (Silvex) 0 .05
0 .001
0 .003
2014
Copper and Lead, 22 CCR §64672.3
Values referred to as MCLs for lead and copper are not actually MCLs; instead, they are called “Action Levels” under the lead and copper rule
Regulated Contaminant MCL DLR PHG Date of PHG
Copper 1 .3 0 .05
0 .3 2008
Le
ad 0 .015
0 .005
0 .0002 2009
Attachment 1

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Association of California Water Agencies
15PHG REPORT GUIDELINES | Attachment 1
Chemicals with MCLs in 22 CCR §64533 — Disinfection Byproducts Regulated Contaminant MCL DLR PHG Date of PHG
Total Trihalomethanes 0
.
080 -- -- --
Bromodichloromethane -- 0
.
0010 0
.
00006 2020
Bromoform -- 0
.
0010 0
.
0005 2020
Chloroform -- 0
.
0010 0
.
0004 2020
Dibromochloromethane -- 0
.
0010 0
.
0001 2020
Haloacetic Acids (five) (HAA5) 0
.
060 -- -- --
Monochloroacetic Acid -- 0
.
0020 -- --
Dichloroacetic Adic -- 0
.
0010 -- --
Trichloroacetic Acid -- 0
.
0010 -- --
Monobromoacetic Acid -- 0
.
0010 -- --
Dibromoacetic Acid -- 0
.
0010 -- --
Bromate 0
.
010 0.0050** 0
.
0001 2009
Chlorite 1
.
0 0
.
020 0
.
05 2009
**The DLR for Bromate is 0.0010 mg/L for analysis performed using EPA Method 317.0 Revision 2.0, 321.8, or 326.0.

Chemicals with PHGs established in response to DDW requests. These are not currently regulated drinking water contaminants.***
Regulated Contaminant MCL DLR PHG Date of PHG
N-Nitrosodimethylamine (NDMA) -- -- 0
.
000003 2006
Perfluorooctanoic acid (PFOA)*** -- -- 0
.
00000007 2024
Perfluorooctane sulfonic acid (PFOS)*** -- -- 0
.
000001 2024
***PFOA and PFOS have US EPA MCLGs and MCLs.

PFOA – MCLG is zero. MCL is 4 ng/L
PFOS – MCLG is zero. MCL is 4 ng/L
Attachment 1

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City of Sunnyvale – Public Health Goals Report 2025 6
ATTACHMENT NO. 2
City of Sunnyvale Consumer Confidence Reports:
 2022 Water Quality Report
 2023 Water Quality Report
 2024 Water Quality Report
Attachment 1

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City of Sunnyvale Water Quality Report 2022 | 1
What's inside
Important information about
6 Your drinking water
6 Water conservation
6 Ways to contact the City
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이해하실수 있는 분에게 번역을 부탁하십시요.
इस रिपोर्ट में आपके पीने के पानी से संबंधित महत्वपूर्ण जानकारी है। कृपया इसका अनुवाद करें, या किसी ऐसे व्यक्ति से बात करें जो इसे समझता है। This report contains important information about your drinking water. Translate it, or speak with someone who understands it.

Water Quality Report 2022
Attachment 1

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2 | City of Sunnyvale Water Qual ity Report 2022
SFPUC supply
The City purchases water from SFPUC to serve the northern part of the City. Filtered water turbidity from SFPUC met the standard of 0.3 NTU or less, 95% of the time. SFPUC’s major drinking water supply consists of surface water and groundwater that are well protected and carefully managed by the SFPUC. These sources are diverse in both origin and location with the surface water stored in reservoirs located in the Sierra Nevada, Alameda County, and San Mateo County, and groundwater stored in a deep aquifer in the northern part of San Mateo County.

To meet drinking water standards for consumption, all surface water supplies from SFPUC undergo treatment before it is delivered to customers. Water from the Hetch Hetchy Reservoir is exempt from state and federal filtration requirements but receives the following treatment: ultraviolet light and chlorine disinfection, pH adjustment for optimum corrosion control, fluoridation for dental health protection, and chloramination for maintaining disinfectant residual and minimizing the formation of regulated disinfection byproducts.

Water from local Bay Area reservoirs in Alameda and San Mateo Counties is delivered to Sunol Valley Water Treatment Plant (SVWTP) and Harry Tracy Water Treatment Plant (HTWTP), respectively, and is subject to filtration, disinfection, fluoridation, optimum corrosion control, and taste and odor removal.

In 2022, average fluoride levels in the treated water were maintained at levels up to 0.8 mg/L as required by the State Water Resources Control Board (State Water Board). Since May 2015, water has been fluoridated at the new optimum level of 0.7 mg/L.

The SFPUC actively protects the water resources entrusted to its care. Its annual update of the Hetch Hetchy Watershed Sanitary Survey evaluates the sanitary conditions, water quality, potential contamination sources, and the results of watershed protection and management activities with partner agencies (such as the National Park Service and US Forest Service).

The SFPUC also conducts sanitary surveys every five years to detect and track sanitary concerns for non-Hetch Hetchy watersheds. The latest 5-year surveys were completed in 2021 for the period of 2016-2020.

These surveys identified wildlife, livestock , and human activities as potential contamination sources. To review the Sanitary Surveys at the District office, contact DDW at (510) 620-3474.

More information on SFPUC and the San Francisco Regional Water System (SFRWS)
Visit sfwater.org
Valley Water supply
The City purchases treated surface water from the Santa Clara Valley Water District, now Valley Water, and delivers it to the southern portion of the City. Valley Water’s surface water is mainly imported from the South Bay Aqueduct, Dyer Reservoir, Lake Del Valle, and San Luis Reservoir, which all draw water from the Sacramento - San Joaquin Delta watershed. Calero Reservoir is Valley Water’s local water source. Water from imported and local sources is pumped to and treated at three water treatment plants located in Santa Clara County.

Valley Water’s source waters are vulnerable to potential contamination from a variety of land use practices, such as agricultural and urban runoff, recreational activities, livestock grazing, and residential and industrial development. The imported sources are also vulnerable to wastewater treatment plant discharges, seawater intrusion, and wildfires in open space areas. In addition, local sources are also vulnerable to potential contamination from commercial stables and historic mining practices. No contaminant associated with any of these activities has been detected in Valley Water’s treated water. The water treatment plants provide multiple barriers for physical removal of contaminants and disinfection of pathogens. To review the Sanitary Surveys, contact DDW at (510) 620-3474.

More information on Valley Water
Visit valleywater.org
Local groundwater
The City owns, operates, and maintains six deep wells. The wells are used to help supplement the imported water supplies during peak demands in the summer months and emergency situations.

The City is always working to increase flexibility in local groundwater supplies, enhance water quality, reduce operating costs, and increase reliability. The City maintains and monitors the wells on a regular basis.

Groundwater pumped from these wells is taxed by Valley Water.

The City completed a Drinking Water Source Assessment Program (DWSAP) in January 2003 for these groundwater sources. The City’s groundwater sources are considered most vulnerable to contamination by leaky underground fuel tanks, dry cleaning chemicals, sewer collection systems, old septic systems, and machine shops.

Visit
waterboards.ca.gov/drinking_water/certlic/drinkingwater/DWSAP .html for more information, or call (408) 730-7400 to schedule a time to view the City’s DWSAP .

Hetch Hetchy Reservoir
Where your water comes from
The City of Sunnyvale has three different sources of drinking water supply: treated surface water from the San Francisco Regional Water System managed by the San Francisco Public Utilities Commission (SFPUC), treated surface water from the Santa Clara Valley Water District (Valley Water), and local groundwater. There are also pockets of Sunnyvale cus- tomers who receive water from the California Water Service Company (Cal Water); questions regarding the source and delivery of water provided by Cal Water can be directed to its local office at (650) 917-0152.

Attachment 1

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City of Sunnyvale Water Quality Report 2022 | 3
To ensure that tap water is safe to drink, the U.S. Environmental Protection Agency (USEPA) and the State Water Board prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. The U.S. Food and Drug Administration regulations and California law also establish limits for contaminants in bottled water that provide the same protection for public health.

The sources of drinking water (both tap water and bottled 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, radioactive material, and can pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include:
•
Microbial Contaminants such as viruses and bacteria that may come fr
om sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
• Inorganic Contaminants such as salts and metals, that can be naturally-occurring or r
esult from urban stormwater runoff, industrial
or domestic wastewater discharges, oil and gas production, mining, or farming.
•
Pesticides and Herbicides
that may come from a variety of sources
such as agriculture, urban stormwater runoff, and residential uses. • Organic Chemical Contaminants including synthetic and volatile or
ganic chemicals that are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems. •
Radioact
ive Contaminants that can be naturally-occurring or be the result of oil and gas production and mining activities.

Protecting the water supply is important to ensure that water is safe from contamination and aesthetically pleasing for use, and it begins in the watersheds. Contamination requires treatment, which increases the cost to deliver water to your tap. Here are ways that you can help protect our watershed:
•
Eliminate excess use of lawn and garden fertilizers and pesticides. • Pick up after your pets.
• Take used motor oil and other r
ecyclables to the SMaRT Station.
• Dispose of pharmaceuticals at any Sunnyvale fire station. Medications should not be flushed down drains or put in the garbage. • Dispose of cleaners, chemicals, and paints at a Household Hazardous W
aste Drop-off Event.
• Volunteer in your community
. The Creek Connections Action Group
works to protect the County's waterways. Visit cleanacreek.org. • Participate in public meetings and forums. It allows decision-makers to hear your perspective and you to be involved in pr
otecting your water
supply.

More information about disposal and recycling
Call (408) 730-7262
SMaR
T Station
301 Carl Road, Sunnyvale, CA 94089
Open daily, 8 a.m. to 5 p.m., Tel: (408) 752-8530
Household hazardous waste drop-off
Third Saturday in January, April, July, and October, 8 a.m. to 1 p.m.

Visit hhw.org or call (408) 299-7300 to schedule an appointment.

Protecting your
water supply
Water conservation –
a way of life
The City works
cooperatively with our
water wholesalers to
provide residents with
advice, assistance, and
access to programs.

The following water-
saving tips are simple
ways to conserve water
indoors and out and are
provided jointly by the
City and Valley Water.

Steps to save water indoors
• Turn off the faucet while you brush your teeth or soap up your hands. • Install water-efficient faucet aerators and showerheads in your kitchen and bathr
ooms.
• Take shorter showers. Y
ou will save 2.5 gallons of water each minute.
• Do not use the toilet as a wastebasket.
• Rinse fruits and vegetables in a bowl of water instead of running water. • Keep a pitcher of drinking water in the refrigerator. Running tap water to cool is wasteful.
•
Only wash full loads of laundry and dishes.
• Replace your old top-loading clothes washer with a high-efficiency model.
•
If your toilet uses more than 3.5 gallons per flush, r
eplace it with a high-
efficiency toilet. New models use 70% less water.

Steps to save water outdoors
• Use a broom to sweep off pavement. Using a hose to wash sidewalks, driveways, and patios wastes money and water
.
• Plant native or drought-tolerant plants that r
equire less watering.
• Apply organic mulch ar
ound plants to reduce moisture loss, keep weed
growth down and promote healthier soil.
• Check for leaks in pipes, sprinkler heads, and valves. • Water during cool parts of the day
. Early morning is the best time
because it helps prevent growth of fungus.
• Water your lawn only when it needs it. If the grass springs back up after stepping on it, it does not need watering.
•
Avoid watering on windy days and deeply soak your lawn to ensure moistur
e reaches the roots.
• Use drip irrigation in larger gar
dens with weather-based irrigation
control.

For more information about water saving fixture and appliance rebates call the Water Conservation Hotline.

Water Conservation Hotline
Call (408) 630-2554
Visit valleywater.org
Attachment 1

Page 13 of 31 ends

City of Sunnyvale Water Quality Report 2022 | 54 | City of Sunnyvale W ater Quality Report 2022 To ensure water quality standards are met, drinking water samples are collected weekly throughout Sunnyvale and analyzed for a variety of regulated and unregulated contaminants. Samples are tested by our certified laboratory and by an independent certified laboratory using the latest testing procedures and equipment. We collect more samples than required by the State Water Board to provide you with the highest quality of water at all times. In addition, the City’s wholesalers, SFPUC and Valley Water, conduct their own testing before delivering water to the City.

Such measures help us to continue meeting established water quality standards.

The table to the right shows the results of the distribution system and source water analyses conducted by the City, SFPUC, and Valley Water. Water quality data are grouped by water source.

Compliance testing for 2022 required more than 20,000 tests for more than 80 parameters. We detected only 12 of these parameters, and none were detected at levels higher than the State Water Board allows.

Only the parameters detected are shown. Other constituents were analyzed but are not listed because they were not detected. Additionally, unregulated parameters are shown to provide you with supplemental information.

Some data—although representative—were collected prior to 2022, as the State Water Board requires monitoring for some constituents less than once per year since the concentrations do not vary frequently or significantly.

The City of Sunnyvale has instituted a comprehensive water quality monitoring program that encompasses City-owned wells and all water purchased from SFPUC and Valley Water. This program ensures that all of our customers receive water that complies with all regulatory criteria and that no maximum contaminant levels (MCLs) or action levels (ALs) for regulated chemicals, bacteria, or pollutants are exceeded.

Water quality test results
2022

PRIMARY DRINKING WATER STANDARDS (PUBLIC HEALTH RELATED STANDARDS) PARAMETER Unit
MCL,
(AL), or
[MRDL]
PHG,
(MCLG), or
[MRDLG]
Groundwater Well Valley Water SFPUC
Typical
Sources*
Average
or [Max] Range
Average
or [Max] Range
Average
or [Max] Range

SOURCE WATER SAMPLING

INORGANIC CHEMICALS
Barium ppm 1 2 ND ND–0.11 ND ND ND ND 3, 21
Fluoride ppm 2 1 0.16 0.14–0.18 ND ND–0.13 0.3 ND–0.8 3, 5, 6 Nitrate (as Nitrogen) ppm 10 10 3.4 2.3–6.3 0.4 ND–0.7 ND ND 3, 7, 8

DISINFECTION BYPRODUCT PRECURSORS
TOC (precursor control) ppm TT NA 2.3 1.5–3.0 2.3 1.3–3.9 10

MICROBIOLOGICAL
Giardia Lamblia cysts/L TT (0) ND ND 0.01 ND–0.04 1
T urbidity NTU TT NA [0.28]
a 100%a
[2.2]a
[3.4]b

99.3–100%a

0.2–0.4b
2 DISTRIBUTION SYSTEM SAMPLING
LEAD AND COPPER RULE STUDY (SUNNYVALE 2022 AT -THE-TAP SAMPLING) 90th Percentile # of Samples Above AL Lead ppb (15) 0.2 ND 0 out of 54 3, 17, 19
Copper ppm (1.3) 0.3 0.234 0 out of 54 3, 17, 18
DISINFECTION RESIDUALS AND BYPRODUCTS Highest Location RAA Range Disinfectant Residual as Chlorine ppm [4] [4] 2.28 0.03–4.6 20 T otal Trihalomethanes ppb 80 NA 77.6 10.6–95.9 9
Haloacetic Acids ppb 60 NA 32 5.1–41 9

SECONDARY DRINKING WATER STANDARDS (AESTHETIC STANDARDS) PARAMETER Unit MCL Average Range Average Range Average Range Sources* Chloride ppm 500 45 33–66 83 71–95 8.7 ND–15 11, 12, 14 Color Color Unit 15 ND ND 2 ND–5 ND ND–5 13
Odor TON 3 ND ND 1 1 ND ND 13
Specific Conductance µS/cm 1600 680 610–740 581 562–626 140 37–210 14, 16 Sulfate ppm 500 35 26–43 65 50–74 15 1.1–29 11, 12, 15
T otal Dissolved Solids ppm 1000 413 380–440 335 308–362 61 ND–104 11, 12 T urbidity NTU 5 0.14 ND–0.33 ND ND–0.28 0.12 0.1–0.2 2

UNREGULATED PARAMETERS
PARAMETER Unit MCL Average Range
Haloacetic Acids 6c ppb NS 17.2 0.3–37.0
Haloacetic Acids 9c ppb NS 34.2 20.7–53.4
Manganesed ppb 50 1.4 ND–4.8 12
Alpha-hexachlorocyclohexaned ppb NS ND ND–0.016
n-Butyl alcohol (1-butanol)d ppb NS ND ND–2.3

OTHER WATER QUALITY PARAMETERS
PARAMETER Unit MCL Average Range Average Range Average Range Chlorate ppm 800 ND ND 150 96–221 147 45–650 4
Hardness (as Calcium Carbonate) ppm NS 287 270–310 114 92–122 32 9.1–49 pH Units NS 7.9 7.8–7.9 7.8 7.5–8.0 9.2 8.2–9.6
Sodium ppm NS 27 21–38 71 65–79 14 3.5–21
T emperature ºC NS 65.5 59–72 NA NA NA NA
Attachment 1

Page 14 of 31 ends

6 | City of Sunnyvale W ater Quality Report 2022
°C Degr ees Celsius
cysts/L
Cysts per liter
DDW
Division of Drinking W
ater
Max

Maximum
NA
Not applicable
ND
Not detected
NS
No standar
d
NTU
Nephelometric turbidity unit
ppb
parts per billion (micr
ograms per liter)
ppm
parts per million (milligrams per liter)
μS/cm
micr
oSiemens per centimeter
RAA
Running annual average
TON
Thr
eshold odor number
USEPA
United States Envir
onmental Protection Agency
a.

For filter
ed water, the MCL is <0.3 NTU 95% of the time.
b.

For unfilter
ed Hetch Hetchy water, the MCL is 5.0 NTU.
c.

Levels in the distribution system.
d.

Levels in the distribution system and gr
oundwater wells.

Table Notes
* Typical sources in drinking water
1 Naturally pr esent in the environment
2 Soil runof
f
3 Er
osion of natural deposits
4 A degradation pr
oduct of sodium hypochlorite used for disinfection
5 W
ater additive that promotes strong teeth
6 Dischar
ge from fertilizer and aluminum factories
7 Runof
f and leaching from fertilizer use
8 Leaching fr
om septic tanks and sewage
9 Bypr
oduct of drinking water disinfection
10 V
arious natural and man-made sources
11 Runof
f from natural deposits
12 Leaching fr
om natural deposits
13 Naturally-occurring or
ganic materials
14 Seawater influence
15 Industrial wastes
16 Substances that for
m ions when in water
17 Inter
nal corrosion of household plumbing systems
18 Leaching fr
om wood preservatives
19 Dischar
ges from industrial manufacturers
20 Drinking water disinfectant added for tr
eatment
21 Dischar
ges of oil drilling wastes and from metal refineries
Maximum contaminant level (MCL). The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible.

Secondary MCLs are set to protect the odor, taste, and appearance of drinking water. MCLs are established by USEPA and the State Water Board.

Maximum contaminant level goal (MCLG). The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the USEPA.

Maximum residual disinfectant level (MRDL). The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

Maximum residual disinfectant level goal (MRDLG). The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Notification level (NL). Notification levels are health-based advisory levels established by the State Water Board for chemicals in drinking water that lack MCLs. When chemicals are found at concentrations greater than their notification levels, certain requirements and recommendations apply.

Primary drinking water standard (PDWS). MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements and water treatment requirements.

Definitions of key terms
Public health goal (PHG). The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Office of Environmental Health Hazard Assessment.

Regulatory action level (AL). The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.

Treatment technique (TT). A required process intended to reduce the level of a contaminant in drinking water.

Total organic carbon (TOC). TOC has no health effects. However, TOC provides a medium for the formation of disinfection byproducts including trihalomethanes and haloacetic acids. Drinking water containing disinfection byproducts in excess of the MCL may lead to adverse health effects, liver or kidney problems, or nervous system effects and may lead to an increased risk of cancer.

Turbidity. Turbidity has no health effects. It is a measure of the clarity of the water and is monitored because it is a good indicator of water quality and the effectiveness of a filtration system. The MCL for turbidity is based on the TT. For unfiltered water, the MCL is 5.0 NTU. For filtered water, the MCL is ≤0.3 NTU 95% of the time.

Unregulated Contaminant Monitoring Rule (UCMR). UCMR requires monitoring for contaminants not currently regulated. This monitoring provides a basis for future regulatory actions to protect public health.

Waiver. State permission to decrease the monitoring frequency for a particular contaminant.

Abbreviations
Attachment 1

Page 15 of 31 ends

City of Sunnyvale Water Quality Report 2022 | 7
Important information about your
water quality
Fluoride
Currently, all water from SFPUC is fluoridated while water from Valley Water, the City’s other wholesale water provider, is not. The City also does not fluoridate well water. As a result, some areas of Sunnyvale receive fluoridated water, other areas receive non-fluoridated water, and some areas receive a mixture of both. See map at bottom left.

According to the Centers for Disease Control and Prevention (CDC), if a child under the age of six months is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance of dental fluorosis. Consult your child’s health care provider for more information.

Lead
If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with privately owned service lines and home plumbing. The City is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to two minutes before using water for drinking or cooking. If you do so, you may wish to collect the flushed water and use it for another purpose, such as watering plants. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline at (800) 426-4791 or at epa.gov/safewater/lead.

Disinfection
The City’s system distributes water disinfected with chloramine and well water that is tested but not treated. Chloramine, a combination of chlorine and ammonia, lasts longer in water to provide more protection against pathogens such as bacteria and viruses, and produces lower levels of disinfection byproducts such as trihalomethanes. The water provided by SFPUC and Valley Water is disinfected with chloramines, which can affect dialysis treatment. Residents on home dialysis should contact their physicians to discuss the impact on their treatment. The End Stage Renal Disease Network 17, at (415) 897-2400, can provide more information about chloramines and dialysis. Fish and aquarium owners should check with their local pet stores for information on chloramine removal.

Crytosporidium/Giardia
Cryptosporidium and Giardia are microbial pathogens naturally present in the environment and commonly found in surface water throughout the U.S. Monitoring of source water by SFPUC in 2022 indicated a low presence of these organisms. However, current test methods approved by the USEPA do not distinguish between dead organisms and those capable of causing disease. They must be ingested to cause disease and may be spread through means other than drinking water. Ingestion of either pathogen can cause abdominal infection. Symptoms include nausea, diarrhea, abdominal cramps, and associated headaches.

Nitrate
Nitrate in drinking water at levels above 10 ppm is a health risk for infants younger than six months of age. Such nitrate levels in drinking water can interfere with the capacity of the infant’s blood to carry oxygen, resulting in serious illness; symptoms include shortness of breath and blueness of the skin. Nitrate levels above 10 ppm 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. If you are caring for an infant, or you are pregnant, you should ask for advice from your health care provider.

Hardness
Water hardness is determined mainly by the presence of calcium and magnesium salts. Although hard water does not pose a health risk, it may be considered undesirable for other reasons. Some benefits of water softening are reductions in soap usage, longer life for water heaters and a decrease in encrustation of pipes; disadvantages are an increase in sodium intake, an increase in maintenance and servicing, and potential adverse effects on salt-sensitive plants. To convert hardness from ppm to grains per gallon, divide by 17.1. A hardness scale is provided below for your reference.

Hardness classification Grains per gallon mg/L or ppm
Soft < 1.0 < 17.1
Slightly hard 1.0–3.5 17.1–60
Moderately hard 3.5–7.0 60–120
Hard 7.0–10.5 120–180
Very hard > 10.5 > 180
SFPUC
VALLEY
WATER

BLENDED AREA

CENTRAL
E. FREMONT

EL CAMINO REAL
S. WOLFE
S. MATHILDA
S. FAIR OAKS

SUNNYVALE-SARATOGA

CARIBBEAN
MAUDE

LAWRENCE
MARY
MARY

HOMESTEAD

Groundwater wells,
which are not shown on
this map, are located
throughout the City.

Local groundwater is
blended with surface
water supplies from
SFPUC and Valley
Water. SFPUC water is
fluoridated but Valley
Water and groundwater
supplies are not.

Attachment 1

Page 16 of 31 ends

To provide input on decisions that affect drinking water quality, you are welcome to speak on any issue specifically coming before the City Council at a regularly scheduled council meeting. You can also speak on any topic you wish to bring to the Council’s attention during the “Oral Communications” portion of the meeting agenda. Alternatively, you can send a letter in advance of a meeting.

City Council Meetings
City Hall Council Chambers
456 West Olive Ave.

Sunnyvale, CA 94086
Tuesdays, 7 p.m.

A list of City Council meetings, agenda items and study issues can be obtained by visiting Sunnyvale.ca.gov or by calling the City Clerk’s office at (408) 730-7483.

To get involved
8 | City of Sunnyvale W ater Quality Report 2022
Important contact information
Division of Drinking Water
waterboards.ca.gov/drinking_water
US EPA
water.epa.gov/drink
Department of Water Resources
water.ca.gov
Bay Area Water Supply and
Conservation Agency
bawsca.org
American Water Works
Association
awwa.org or DrinkTap.org
Web Resources
City of Sunnyvale
456 West Olive Ave.

Sunnyvale, CA 94086
Tel: (408) 730-7500
TTY: 711 (CA Relay Service)
Sunnyvale.ca.gov
Utility Division (Billing)
(408) 730-7400
City contacts Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence 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 USEPA Safe Drinking Water Hotline.

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-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 advice from their health care providers.

USEPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the USEPA Safe Drinking Water Hotline.

USEPA Safe Drinking Water Hotline

(800) 426-4791
Health and education information
Water Conservation
(408) 630-2554
[email protected]
Access Valley Water
Reporting and Requests
valleywater.org/AVWapp
To Report Water Waste
(408) 630-2000
[email protected]
Pollution Hotline
(888) 510-5151 (24 Hours)
Hours of operation
8 am to 5 pm, Monday–Friday
Valley Water Resources
More information
For more information about this report or the City’s water quality monitoring program, please contact:

After hydrant flushing,
your tap water may
be temporarily
cloudy/discolored;
however, it is safe
to drink. Discolored
water is caused by
harmless sediment
and mineral deposits
in pipes that can be
stirred up during
hydrant flushing. This
does not present any
health hazard. The discoloration may be removed by flushing your tap; run the water in your sink and/or shower until it runs clear.

For more information

Call Field Services at (408) 730-7400
Hydrant and Main Flushing
Attachment 1

Page 17 of 31 ends

City of Sunnyvale Water Quality Report 2023 | 1
What's inside
Important information about
6 Y
our drinking water
6 W
ater conservation
6 W
ays to contact the City
Este informe contiene información muy importante sobre su agua para beber. Tradúzcalo o hable con alguien que lo entienda bien.

Itong documento ay naglalaman nang mahalagang impormasyon tungkol sa tubig na maaring inumin. Mangyaring ipagsalin ito.

Báo cáo này chứa thông tin quan trọng về nước uống của bạn.

Water Quality Report 2023
Attachment 1

Page 18 of 31 ends

2 | City of Sunnyvale W ater Quality Report 2023
SFPUC supply
The City purchases water from SFPUC to serve the northern part of the City. Filtered water turbidity from SFPUC met the standard of 0.3 NTU or less, 95% of the time. The SFPUC’s drinking water supply consists of surface water and groundwater that are well protected and carefully managed by the SFPUC. These sources are diverse in both origin and location with the surface water stored in reservoirs located in the Sierra Nevada, Alameda County, and San Mateo County, and groundwater stored in a deep aquifer in the northern part of San Mateo County.

Water from local Bay Area reservoirs in Alameda County and upcountry non-Hetch Hetchy sources is delivered to Sunol Valley Water Treatment Plant; whereas water from local reservoirs in San Mateo County is delivered to Harry Tracy Water Treatment Plant. Water treatment at these plants consists of filtration, disinfection, fluoridation, optimum corrosion control, and taste and odor removal. In 2023, neither upcountry non- Hetch Hetchy sources nor groundwater was used by the SFRWS.

In 2023, average fluoride levels in the treated water were 0.6 mg/L. Since May 2015, SFPUC’s objective has been to fluoridate water at the new optimum level of 0.7 mg/L, as required by the State Water Resources Control Board (State Water Board).

SFPUC actively protects water resources entrusted to its care. Its annual update of the Hetch Hetchy Watershed Sanitary Survey evaluates sanitary conditions, water quality, potential contamination sources, and the results of watershed protection and management activities with partner agencies (such as the National Park Service and US Forest Service).

These surveys identified wildfire, wildlife, livestock, and human activities as potential contamination sources. To review the Sanitary Surveys at the District office, contact DDW at (510) 620-3474.

More information on SFPUC and the SFRWS
Visit sfwater.org
Valley Water supply
The City purchases treated surface water from the Santa Clara Valley Water District, now Valley Water, and delivers it to the southern portion of the City. Valley Water’s surface water is mainly imported from the South Bay Aqueduct, Dyer Reservoir, Lake Del Valle, and San Luis Reservoir, which all draw water from the Sacramento - San Joaquin Delta watershed. Calero Reservoir is Valley Water’s local water source. Water from imported and local sources is pumped to and treated at three water treatment plants located in Santa Clara County.

Groundwater pumped from these wells is taxed by Valley Water.

The City completed the initial groundwater source assessments for the Drinking Water Source Assessment Program (DWSAP) in January 2003.

The assessment is the first step in assuring source water protection and is required for new or rehabilitated wells. The DWSAP regulates proper wellhead protection and routine water quality monitoring assures the continued protection of those groundwater sources. The City’s groundwater sources are considered most vulnerable to contamination by leaky underground fuel tanks, dry cleaning chemicals, sewer collection systems, old septic systems, and machine shops.

Visit
waterboards.ca.gov/drinking_water/certlic/drinkingwater/DWSAP .html for more information, or call (408) 730-7400 to schedule a time to view the City’s DWSAP .

Hetch Hetchy Reservoir
Where your water comes from
The City of Sunnyvale has three different sources of drinking water supply: treated surface water from the San Francisco Regional Water System (SFRWS) managed by the San Francisco Public Utilities Commission (SFPUC), treated surface wa- ter from the Santa Clara Valley Water District (Valley Water), and local groundwater. There are also pockets of Sunnyvale customers who receive water from the California Water Service Company (Cal Water); questions regarding the source and delivery of water provided by Cal Water can be directed to its local office at (650) 917-0152.

Attachment 1

Page 19 of 31 ends

City of Sunnyvale Water Quality Report 2023 | 3
To ensure that tap water is safe to drink, the U.S. Environmental Protection Agency and the State Water Board prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. The U.S. Food and Drug Administration regulations and California law also establish limits for contaminants in bottled water that provide the same protection for public health.

The sources of drinking water (both tap water and bottled 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 can pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include:
•
Micr
obial Contaminants such as viruses and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
•
Inor
ganic Contaminants such as salts and metals, that can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
•
Pest
icides and Herbicides that may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses. •
Or
ganic Chemical Contaminants including synthetic and volatile organic chemicals that are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems. •
Rad
ioactive Contaminants that can be naturally-occurring or be the result of oil and gas production and mining activities.

Protecting the water supply is important to ensure that water is safe from contamination and aesthetically pleasing for use, and it begins in the watersheds. Contamination requires treatment, which increases the cost to deliver water to your tap. Here are ways that you can help protect our watershed:
•
Eliminate excess use of lawn and gar
den fertilizers and pesticides.
•
Pick up after your pets.
•
T
ake used motor oil and other recyclables to the SMaRT Station®. •
Dispose of phar
maceuticals at any Sunnyvale fire station. Medications
should not be flushed down drains or put in the garbage. •
Dispose of cleaners, chemicals, and paints at a Household Hazar dous
Waste Drop-off Event.
•
V
olunteer in your community. The Creek Connections Action Group works to protect the County's waterways. Visit cleanacreek.org. • Participate in public meetings and forums. This allows decision-makers

to hear your perspective and enables you to be involved in protecting your water supply.

More information about disposal and recycling
Call (408) 730-7262
SMaRT Station®
301 Carl Road, Sunnyvale, CA 94089
Open daily, 8 a.m. to 5 p.m., Tel: (408) 752-8530
Household hazardous waste drop-off
Weekly drop-off events, Fridays and Saturdays, excluding holidays.

Visit hhw.org or call (408) 299-7300 to schedule an appointment.

Protecting your
water supply
Water conservation –
a way of life
The City works cooperatively
with our water wholesalers
to provide residents with
advice, assistance, and
access to programs. The
following water-saving tips
are simple ways to conserve
water indoors and out and
are provided jointly by the
City and Valley Water.

Steps to save water indoors
• T urn off the faucet while you brush your teeth or soap up your hands. •
Install water
-efficient faucet aerators and showerheads in your kitchen and bathrooms.
•
T
ake shorter showers. You will save 2.5 gallons of water each minute. •
Do not use the toilet as a wastebasket.
•
Rinse fruits and vegetables in a bowl of water instead of running water .
•
Keep a pitcher of drinking water in the r
efrigerator. Running tap water
to cool is wasteful.
•
Only wash full loads of laundry and dishes.
•
Replace your old top-loading clothes washer with a high-efficiency model.
•
If your toilet uses mor
e than 3.5 gallons per flush, replace it with a
high-efficiency toilet. New models use 70% less water.

Steps to save water outdoors
• Use a br oom to sweep off pavement. Using a hose to wash sidewalks, driveways, and patios wastes money and water.
•
Plant native or dr
ought-tolerant plants that require less watering.
•
Apply or
ganic mulch around plants to reduce moisture loss, keep weed growth down and promote healthier soil.
•
Check for leaks in pipes, sprinkler heads, and valves.
•
W
ater during cool parts of the day. Early morning is the best time because it helps prevent growth of fungus.
•
W
ater your lawn only when it needs it. If the grass springs back up after stepping on it, it does not need watering.
•
A
void watering on windy days and deeply soak your lawn to ensure moisture reaches the roots.
•
Use drip irrigation in lar
ger gardens with weather-based irrigation
control.

For more information about water saving fixture and appliance rebates call the Water Conservation Hotline.

Water Conservation Hotline
Call (408) 630-2554
Visit valleywater.org
Attachment 1

Page 20 of 31 ends

City of Sunnyvale Water Quality Report 2023 | 54 | City of Sunnyvale W ater Quality Report 2023 To ensure water quality standards are met, drinking water samples are collected weekly throughout Sunnyvale and analyzed for a variety of regulated and unregulated contaminants. Samples are tested by our certified laboratory and by an independent certified laboratory using the latest testing procedures and equipment. We collect more samples than required by the State Water Board to provide you with the highest quality of water at all times. In addition, the City’s wholesalers, SFPUC and Valley Water, conduct their own testing before delivering water to the City. Such measures help us to continue meeting established water quality standards.

The table to the right shows the results of the distribution system and source water analyses conducted by the City, SFPUC, and Valley Water. Water quality data are grouped by water source. Compliance testing for 2023 required more than 20,000 tests for more than 80 parameters. We detected only 12 of these parameters, and none were detected at levels higher than the State Water Board allows.

Some data—although representative—were collected prior to 2023, as the State Water Board requires monitoring for some constituents less than once per year since the concentrations do not vary frequently or significantly.

The City of Sunnyvale has instituted a
comprehensive water quality monitoring
program that encompasses City-owned
wells and all water purchased from SFPUC
and Valley Water. This program ensures
that all of our customers receive water
that complies with all regulatory criteria
and that no maximum contaminant
levels (MCLs) or action levels (ALs)
for regulated chemicals, bacteria,
or pollutants are exceeded.

Water quality test results
2023

SOURCE WATER SAMPLING

INORGANIC CHEMICALS
Barium ppm 1 2 ND ND–0.11 ND ND ND ND 3, 21
Fluoride ppm 2 1 0.16 0.14–0.18 ND ND–0.16 0.6 0.4–2.6 3, 5, 6 Nitrate (as Nitrogen) ppm 10 10 3.5 2.2–6.8 0.6 ND–1.3 ND ND–0.6 3, 7, 8

DISINFECTION BYPRODUCT PRECURSORS
TOC (precursor control) ppm TT NA 1.8 1.2–2.2 [1.5] 1.2–1.8 10

MICROBIOLOGICAL
Giardia Lamblia cysts/L TT (0) ND ND 0.03 0–0.13 1
T urbidity NTU TT NA [0.30]
a 100%a
[0.2]a
[2]b
100%a

0.3–0.9b
2 DISTRIBUTION SYSTEM SAMPLING
LEAD AND COPPER RULE STUDY (SUNNYVALE 2022 AT -THE-TAP SAMPLING) 90th Percentile # of Samples Above AL Lead ppb (15) 0.2 ND 0 out of 54 3, 17, 19
Copper ppm (1.3) 0.3 0.234 0 out of 54 3, 17, 18
DISINFECTION RESIDUALS AND BYPRODUCTS Highest Location RAA Range Disinfectant Residual as Chlorine ppm [4] [4] 2.18 ND–5.5 20 T otal Trihalomethanes ppb 80 NA 69.8 26.5–95.9 9
Haloacetic Acids ppb 60 NA 39.0 9.9–56.0 9

SECONDARY DRINKING WATER STANDARDS (AESTHETIC STANDARDS) PARAMETER Unit MCL Average Range Average Range Average Range Sources* Chloride ppm 500 45 33–66 37 11–52 4.6 ND–9.3 11, 12, 14 Color Color Unit 15 ND ND 4 1–5 ND ND–5 13
Odor TON 3 ND ND 1.9 1.4–2.0 ND ND 13
Specific Conductance µS/cm 1600 680 610–740 369 188–463 160 32–289 14, 16 Sulfate ppm 500 35 26–43 56 34–78 19 1.2–36 11, 12, 15
T otal Dissolved Solids ppm 1000 413 380–440 213 112–272 77 ND–153 11, 12 T urbidity NTU 5 0.14 ND–0.33 ND ND–0.30 0.3 0.1–0.6 2

OTHER WATER QUALITY PARAMETERS
PARAMETER Unit MCL Average Range Average Range Average Range Chloratee ppm 800 ND ND 84 68–108 168 30–749 4
Hardness (as Calcium Carbonate) ppm NS 287 270–310 82 42–114 47 7.5–86 pH Units NS 7.9 7.8–7.9 7.6 7.4–7.9 9.3 8.4–9.8
Sodium ppm NS 27 21–38 40 20–52 11 2.7–19
T emperature ºC NS 63 58–71 NA NA NA NA
Losse Well is the only standby groundwater well in the City and is designated for emergency use only. Six other groundwater wells are considered active. We are required to test standby groundwater wells for specific contaminants every nine years regardless of whether the well is used for drinking water. Active wells are tested more frequently. Results of regular testing are an indicator of whether your drinking water supply meets health standards and when wells are not tested in accordance with their respective monitoring schedule, the health effects of drinking that water are unknown. Testing at Losse Well was last completed in 2014 and was due to be completed by December 2023 in accordance with the nine-year compliance cycle. We did not conduct the scheduled testing at Losse Well in 2023. However, Losse Well was not utilized for the City’s drinking water supply in 2023 or at any time in the prior decade. Testing was conducted for Losse Well in March 2024 in response to the monitoring violation and results met all drinking water quality standards.

Notice of Monitoring Violation
Attachment 1

Page 21 of 31 ends

6 | City of Sunnyvale W ater Quality Report 2023
°C Degr ees Celsius
cysts/L
Cysts per liter
DDW
Division of Drinking W
ater
Max

For filter
ed water, the MCL is <0.3 NTU 95% of the time.
b.

For unfilter
ed Hetch Hetchy water, the MCL is 5.0 NTU.
c.

Levels in the distribution system.
d.

Levels in the distribution system and gr
oundwater wells.
e.

The detected chlorate in the SFPUC tr
eated water is a
degradation product of sodium hypochlorite used by the
SFRWS for water disinfection.

Maximum contaminant level goal (MCLG). The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the USEPA.

Primary drinking water standard (PDWS). MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements and water treatment requirements.

Regulatory action level (AL). The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.

Treatment technique (TT). A required process intended to reduce the level of a contaminant in drinking water.

Waiver. State permission to decrease the monitoring frequency for a particular contaminant.

Abbreviations
Attachment 1

Page 22 of 31 ends

City of Sunnyvale Water Quality Report 2023 | 7
Important information about your
water quality
Fluoride
Currently, all water from SFPUC is fluoridated while water from Valley Water, the City’s other wholesale water provider is not. The City also does not fluoridate well water. As a result, some areas of Sunnyvale receive fluoridated water, other areas receive non-fluoridated water, and some areas receive a mixture of both. See map below. According to the Centers for Disease Control and Prevention (CDC), if a child under the age of six months is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance of dental fluorosis. Consult your child’s health care provider for more information.

Crytosporidium/Giardia
Cryptosporidium and Giardia are microbial pathogens naturally present in the environment and commonly found in surface water throughout the U.S. Monitoring of source water by SFPUC in 2023 indicated a low presence of these organisms. However, current test methods approved by the USEPA do not distinguish between dead organisms and those capable of causing disease. They must be ingested to cause disease and may be spread through means other than drinking water. Ingestion of either pathogen can cause abdominal infection. Symptoms include nausea, diarrhea, abdominal cramps, and associated headaches.

BLENDED AREA

CENTRAL
E. FREMONT

EL CAMINO REAL
S. WOLFE

MATHILDA
S. FAIR OAKS

SUNNYVALE-SARATOGA

CARIBBEAN
MAUDE

LAWRENCE
MARY
MARY

HOMESTEAD

Groundwater wells,
which are not shown on
this map, are located
throughout the City.

Local groundwater is
blended with surface
water supplies from
SFPUC and Valley
Water. SFPUC water is
fluoridated but Valley
Water and groundwater
supplies are not.

Attachment 1

Page 23 of 31 ends

City Council Meetings
City Hall Council Chambers
456 West Olive Ave.

Sunnyvale, CA 94086
Tuesdays, 7 p.m.

A list of City Council meetings, agenda items and study issues can be obtained by visiting Sunnyvale.ca.gov or by calling the City Clerk’s office at (408) 730-7483.

To get involved
8 | City of Sunnyvale W ater Quality Report 2023
Important contact information
Division of Drinking Water
waterboards.ca.gov/drinking_water
US EPA
water.epa.gov/drink
Department of Water Resources
water.ca.gov
Bay Area Water Supply and
Conservation Agency
bawsca.org
American Water Works
Association
awwa.org or DrinkTap.org
Web resources
City of Sunnyvale
456 West Olive Ave.

USEPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the USEPA Safe Drinking Water Hotline.

USEPA Safe Drinking Water Hotline
(800) 426-4791
Health and education information
Water Conservation
(408) 630-2554
[email protected]
Access Valley Water
Reporting and Requests
valleywater.org/AVWapp
To Report Water Waste
(408) 630-2000
[email protected]
Pollution Hotline
(888) 510-5151 (24 Hours)
Hours of operation
8 a.m. to 5 p.m., Monday–Friday
Valley Water resources
More information
For more information about this report or the City’s water quality monitoring program, please contact:

Joseph De la Cruz
City of Sunnyvale
Water Operations Manager
(408) 730-7900
[email protected]
Environmental Services
Department (Leaks, Breaks,
Water Quality Questions)
(408) 730-7900
Backflow and Cross-Connection
Control Program
(669) 600-7322
[email protected]
Cross-connection control is vital for protecting the City’s water supply from contamination. A cross-connection refers to a connection between a safe drinking water supply and non-potable source not suitable for consumption. Backflow is the unintended reversal of flow, where non-potable water enters the City’s distribution system. The primary objective of the City’s Cross-Connection Control Program is to prevent backflow into the City’s distribution network, thereby safeguarding customers and water supply from potential contamination. Properly installed and regularly maintained/inspected Backflow Prevention Assemblies (BPAs) and a well-developed program serve as effective safeguards against cross-connection and contamination.

The City’s Cross-Connection Control Program enables the City to actively identify and rectify any cross-connections present in either the distribution system or individual service connections. Corrective measures, such as flushing the distribution system, are conducted after a detected cross-connection to mitigate any potential for adverse health effects from affected water in the distribution system.

City residents play an important role in preventing cross-connections and maintaining water safety. The City wishes to raise awareness and encourage responsible water usage so that we can all contribute to the overall protection of our water resources.

Cross connection control program
Sunnyvale City Hall
Attachment 1

Page 24 of 31 ends

City of Sunnyvale Water Quality Report 2024 | 1
What's inside
Important information about
6 Y
our drinking water
6 W
ater conservation
6 W
ays to contact the City
Este informe contiene información muy importante sobre su agua para beber. Tradúzcalo o hable con alguien que lo entienda bien.

Itong documento ay naglalaman nang mahalagang impormasyon tungkol sa tubig na maaring inumin. Mangyaring ipagsalin ito.

Báo cáo này chứa thông tin quan trọng về nước uống của bạn.

Water Quality Report 2024
We are pleased to report that
in 2024 your tap water met
all state and federal drinking
water health standards
Attachment 1

Page 25 of 31 ends

2 | City of Sunnyvale W ater Quality Report 2024
SFPUC supply
The City purchases water from SFPUC to serve the northern part of the City. Filtered water turbidity from SFPUC met the standard of 0.3 NTU or less, 95% of the time. The SFPUC’s drinking water supply consists of surface water and groundwater that are well protected and carefully managed by the SFPUC. These sources are diverse in both origin and location with the surface water stored in reservoirs located in the Sierra Nevada, Alameda County, and San Mateo County, and groundwater stored in a deep aquifer in the northern part of San Mateo County.

Water from local Bay Area reservoirs in Alameda County and upcountry non-Hetch Hetchy sources is delivered to Sunol Valley Water Treatment Plant; whereas water from local reservoirs in San Mateo County is delivered to Harry Tracy Water Treatment Plant. Water treatment at these plants consists of filtration, disinfection, fluoridation, optimum corrosion control, and taste and odor removal. In 2024, neither upcountry non- Hetch Hetchy sources nor groundwater was used by the SFRWS.

In 2024, average fluoride levels in the treated water were 0.7 mg/L. Since May 2015, SFPUC’s objective has been to fluoridate water at the new optimum level of 0.7 mg/L, as required by the State Water Resources Control Board (State Water Board).

These surveys identified wildfire, wildlife, livestock, and human activities as potential contamination sources. To review the Sanitary Surveys at the District office, contact DDW at (510) 620-3474.

More information on SFPUC and the SFRWS
Visit sfpuc.gov
Valley Water supply
The City purchases treated surface water from the Santa Clara Valley Water District, now Valley Water, and delivers it to the southern portion of the City. Valley Water’s surface water is mainly imported from the South Bay Aqueduct, Dyer Reservoir, Lake Del Valle, and San Luis Reservoir, which all draw water from the Sacramento - San Joaquin Delta watershed. Calero Reservoir is Valley Water’s local water source. Water from imported and local sources is pumped to and treated at three water treatment plants located in Santa Clara County.

Groundwater pumped from these wells is taxed by Valley Water.

The City completed the initial groundwater source assessments for the Drinking Water Source Assessment Program (DWSAP) in January 2003.

Visit
waterboards.ca.gov/drinking_water/certlic/drinkingwater/DWSAP .html for more information, or call (408) 730-7400 to schedule a time to view the City’s DWSAP .

Where your water comes from
The City of Sunnyvale has three different sources of drinking water supply: treated surface water from the San Francisco Regional Water System (SFRWS) managed by the San Francisco Public Utilities Commission (SFPUC), treated surface wa- ter from the Santa Clara Valley Water District (Valley Water), and local groundwater. There are also pockets of Sunnyvale customers who receive water from the California Water Service Company (Cal Water); questions regarding the source and delivery of water provided by Cal Water can be directed to its local office at (650) 917-0152.

The spillway at O'Shaughnessy Dam
Hetch Hetchy Reservoir
Attachment 1

Page 26 of 31 ends

The City works cooperatively with our water
wholesalers to provide residents with advice,
assistance, and access to programs. The
following water-saving tips are simple ways
to conserve water indoors and out and are
provided jointly by the City and Valley Water.

Steps to save water indoors
• T urn off the faucet while you brush your
teeth or soap up your hands.
•
Install water
-efficient faucet aerators and
showerheads in your home.
•
T
ake shorter showers. For each minute you
will save 2.5 gallons of water.
•
Do not use the toilet as a wastebasket.
•
Rinse fruits and vegetables in a bowl of water
instead of running water
.
•
Keep a pitcher of drinking water in the
r
efrigerator. Running tap water to cool is
wasteful.
•
Only wash full loads of laundry and dishes.
•
Replace your old top-loading clothes washer
with a high-efficiency model.
•
If your toilet uses mor
e than 3.5 gallons per
flush, replace it with a high-efficiency toilet.

New models use 70% less water.

Steps to save water outdoors
• Use a br oom to sweep off pavement. Using
a hose to wash sidewalks, driveways, and
patios wastes money and water.
•
Plant native or dr
ought-tolerant plants that
require less watering.
•
Apply or
ganic mulch around plants to reduce
moisture loss, keep weed growth down and
promote healthier soil.
•
Check for leaks in pipes, sprinkler heads, and
valves.
•
W
ater during cool parts of the day. Early
morning is the best time because it helps
prevent growth of fungus.
•
W
ater your lawn only when it needs it. If the
grass springs back up after stepping on it, it
does not need watering.
•
A
void watering on windy days. Deeply soak
your lawn to ensure moisture reaches the
roots.
•
Use drip irrigation in lar
ger gardens with
weather-based irrigation control.

City of Sunnyvale Water Quality Report 2024 | 3
To ensure that tap water is safe to drink, the U.S. Environmental Protection Agency and the State Water Board prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. The U.S. Food and Drug Administration regulations and California law also establish limits for contaminants in bottled water that provide the same protection for public health.

The sources of drinking water (both tap water and bottled 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 can pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include:
•
Micr
obial Contaminants such as viruses and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
•
Inor
ganic Contaminants such as salts and metals, that can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
•
Pest
icides and Herbicides that may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses. •
Or
ganic Chemical Contaminants including synthetic and volatile organic chemicals that are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application, and septic systems. •
Rad
ioactive Contaminants that can be naturally-occurring or be the result of oil and gas production and mining activities.

Protecting your water supply
Water conservation – a way of life
Protecting the water supply is important to ensure that water is safe from contamination and aesthetically pleasing for use, and it begins in the watersheds. Contamination requires treatment, which increases the cost to deliver water to your tap. Here are ways that you can help protect our watershed:
•
Eliminate excess use of lawn and gar
den fertilizers and pesticides.
•
Pick up after your pets.
•
T
ake used motor oil and other recyclables to the SMaRT Station®. •
Dispose of phar
maceuticals at any Sunnyvale fire station. Medications
should not be flushed down drains or put in the garbage. •
Dispose of cleaners, chemicals, and paints at a Household Hazar dous
Waste Drop-off Event.
•
V
olunteer in your community. The Creek Connections Action Group works to protect the County's waterways. Visit cleanacreek.org. • Participate in public meetings and forums. This allows decision-makers

to hear your perspective and enables you to be involved in protecting your water supply.

More information about disposal and recycling Call (408) 730-7262 SMaRT Station®
301 Carl Road, Sunnyvale, CA 94089
Open daily, 8 a.m. to 5 p.m., Tel: (408) 752-8530
Household hazardous waste drop-off
Weekly drop-off events, Fridays and Saturdays, excluding holidays.

Visit hhw.santaclaracounty.gov or call (408) 299-7300 to schedule an appointment.

For more information about water saving
fixture and appliance rebates call the Water
Conservation Hotline.

Water Conservation Hotline
Call (408) 630-2554
Visit valleywater.org
Attachment 1

Page 27 of 31 ends

City of Sunnyvale Water Quality Report 2024 | 54 | City of Sunnyvale W ater Quality Report 2024

SOURCE WATER SAMPLING

INORGANIC CHEMICALS
Aluminumf ppm 1 0.6 ND ND ND ND ND ND–0.06 3, 22
Barium ppm 1 2 ND ND–0.12 ND ND ND ND 3, 21
Fluoride ppm 2 1 0.15 0.14–0.17 ND ND–0.11 0.2 ND–0.8 3, 5, 6 Hexavalent Chromiumg ppb 10 0.02 NA NA ND ND 0.01 ND–0.1 3, 18, 23 Nitrate (as Nitrogen) ppm 10 10 3.0 1.8–6.3 ND ND–0.7 ND ND–0.4 3, 7, 8

DISINFECTION BYPRODUCT PRECURSORS
TOC (precursor control) ppm TT NA 1.6 1.2–2.0 [1.5] 1.1–1.8 a 10

MICROBIOLOGICAL
Giardia Lamblia cysts/L TT (0) ND ND 0.02 0–0.06 1
T urbidity NTU TT NA [0.30]
a 100%a
[0.4]b
[2.1]c

99.97%b

0.3–0.5c,d
2 DISTRIBUTION SYSTEM SAMPLING
LEAD AND COPPER RULE STUDY (SUNNYVALE 2022 AT -THE-TAP SAMPLING) 90th Percentile # of Samples Above AL Lead ppb (15) 0.2 ND 0 out of 54 3, 17, 19
Copper ppm (1.3) 0.3 0.234 0 out of 54 3, 17, 18
DISINFECTION RESIDUALS AND BYPRODUCTS Highest RAA Range Disinfectant Residual as Chlorine ppm [4] [4] 2.3 ND–4.0 20 T otal Trihalomethanes ppb 80 NA 47.2 21.8–59.1 9
Haloacetic Acids ppb 60 NA 37.5 6.9–48.0 9

SECONDARY DRINKING WATER STANDARDS (AESTHETIC STANDARDS) PARAMETER Unit MCL Average Range Average Range Average Range Sources* Chloride ppm 500 43 32–62 50 47–53 4.9 ND–9.9 11, 12, 14 Color Color Unit 15 ND ND 2 ND–3 ND ND 13
Iron ppb 300 ND ND ND ND 20 ND–41 12, 15
Manganese ppb 50 ND ND ND ND ND ND–2.7 12
Odor TON 3 ND ND 1.6 1.4–2.0 ND ND 13
Specific Conductance µS/cm 1600 662 600–700 466 414–522 174 31–317 14, 16 Sulfate ppm 500 34 23–41 66 57–80 21 1–41 11, 12, 15
T otal Dissolved Solids ppm 1000 427 390–450 268 238–298 97 24–169 11, 12 T urbidity NTU 5 0.25 0.13–0.38 ND ND–0.30 0.2 0.1–0.4 2

OTHER WATER QUALITY PARAMETERS
PARAMETER Unit NL Average Range Average Range Average Range Chloratee ppm 800 ND ND ND ND 134 24–597 4
Hardness (as Calcium Carbonate) ppm NS 290 270–310 111 93–133 57 8.4–106 pH Units NS 7.5 7.4–7.6 7.7 7.5–8.0 NA NA
Sodium ppm NS 28 22–41 47 45–49 13 3.1–24
T emperature ºC NS 64 59–71 NA NA NA NA
To ensure water quality standards are met, drinking
water samples are collected weekly throughout
Sunnyvale and analyzed for a variety of regulated
and unregulated contaminants. Samples are tested
by our certified laboratory and by an independent
certified laboratory using the latest testing
procedures and equipment. We collect more
samples than required by the State Water Board to
provide you with the highest quality of water at all
times. In addition, the City’s wholesalers, SFPUC
and Valley Water, conduct their own testing before
delivering water to the City. Such measures help us
to continue meeting established
water quality standards.

The table to the right shows the results of the
distribution system and source water analyses
conducted by the City, SFPUC, and Valley Water.

Water quality data are grouped by water source.

Compliance testing for 2024 required more than
45,000 tests for more than 80 parameters. We
detected only 10 of these parameters, and none
were detected at levels higher than the
State Water Board allows.

Only the parameters detected are shown. Other
constituents were analyzed but are not listed
because they were not detected. Additionally,
unregulated parameters are shown to provide you
with supplemental information.

Some data—although representative—were
collected prior to 2024, as the State Water Board
requires monitoring for some constituents less
than once per year since the concentrations
do not vary frequently or significantly.

The City of Sunnyvale has instituted a
comprehensive water quality monitoring
program that encompasses City-owned
wells and all water purchased from SFPUC
and Valley Water. This program ensures
that all of our customers receive water that
complies with all regulatory criteria and that
no maximum contaminant levels (MCLs) or
action levels (ALs) for regulated chemicals,
bacteria, or pollutants are exceeded.

Water quality
test results
2024
a. The range and average values of the TOC wer e
from operational monitoring results
at Tesla Treatment Facilities.
b.

For filter
ed water, the MCL is <0.3 NTU
95% of the time.
c.

For unfilter
ed Hetch Hetchy water, the MCL
is 5.0 NTU.
d.

These ar
e monthly average turbidity values
measured every four hours daily at Tesla
Treatment Facilities.
e.

The detected chlorate in the SFPUC tr
eated
water is a degradation product of sodium
hypochlorite used by the SFRWS for water
disinfection.
f.

Aluminum also has a secondary MCL of 200
ppb.
g.

Monitoring compliance for hexavalent chr
omium
begins on October 1, 2026.

Table notes
* Typical sources in drinking water
1 Naturally pr esent in the environment
2 Soil runof
f
3 Er
osion of natural deposits
4 A degradation pr
oduct of sodium
hypochlorite used for disinfection
5 W
ater additive that promotes strong teeth
6 Dischar
ge from fertilizer and aluminum

factories
7 Runof
f and leaching from fertilizer use
8 Leaching fr
om septic tanks and sewage
9 Bypr
oduct of drinking water disinfection
10 V
arious natural and man-made sources
11 Runof
f from natural deposits
12 Leaching fr
om natural deposits
13 Naturally-occurring or
ganic materials
14 Seawater influence
15 Industrial wastes
16 Substances that for
m ions when in water
17 Inter
nal corrosion of household plumbing

systems
18 Leaching fr
om wood preservatives
19 Dischar
ges from industrial manufacturers
20 Drinking water disinfectant added for

treatment
21 Dischar
ges of oil drilling wastes and from
metal r
efineries
22 Residue fr
om some surface water treatment

processes
23 T
ransformation by natural processes and
human activities such as dischar
ges from
electr
oplating factories, leather tanneries,
chemical synthesis, r
efractory production,
and textile manufacturing facilities
Attachment 1

Page 28 of 31 ends

6 | City of Sunnyvale W ater Quality Report 2024
Maximum contaminant level (MCL). The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible. Secondary MCLs are set to protect the odor, taste, and appearance of drinking water. MCLs are established by USEPA and the State Water Board.

Maximum contaminant level goal (MCLG). The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the USEPA.

Primary drinking water standard (PDWS). MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements and water treatment requirements.

Regulatory action level (AL). The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.

Treatment technique (TT). A required process intended to reduce the level of a contaminant in drinking water.

Waiver. State permission to decrease the monitoring frequency for a particular contaminant.

Cross-connection control is vital for protecting the City’s water supply from contamination. A cross-connection refers to a connection between a safe drinking water supply and non-potable source not suitable for consumption. Backflow is the unintended reversal of flow, where non-potable water enters the City’s distribution system.

The primary objective of the City’s Cross-Connection Control Program is to prevent backflow into the City’s distribution network, thereby safeguarding customers and water supply from potential contamination. Properly installed and regularly maintained/inspected Backflow Prevention Assemblies (BPAs) and a well-developed program serve as effective safeguards against cross-connection and contamination.

Cross connection control program
Backflow Prevention Assembly
Abbreviations
°C Degr ees Celsius
cysts/L
Cysts per liter
DDW
Division of Drinking W
ater
Max

Maximum
NA
Not applicable
ND Not detected
NS
No standar
d
NTU
Nephelometric turbidity unit
ppb
parts per billion (micr
ograms per liter)
ppm
parts per million (milligrams per liter)
μS/cm micr oSiemens per centimeter
RAA
Running annual average
TON
Thr
eshold odor number
USEPA
United States Envir
onmental
Pr
otection Agency
Attachment 1

Page 29 of 31 ends

City of Sunnyvale Water Quality Report 2024 | 7
Information about your water quality
Fluoride
Currently, all water from SFPUC is fluoridated while water from Valley Water, the City’s other wholesale water provider is not. The City also does not fluoridate well water. As a result, some areas of Sunnyvale receive fluoridated water, other areas receive non-fluoridated water, and some areas receive a mixture of both. See map below. According to the Centers for Disease Control and Prevention (CDC), if a child under the age of six months is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance of dental fluorosis. Consult your child’s health care provider for more information.

Lead
Lead can cause serious health effects in people of all ages, especially pregnant people, infants (both formula-fed and breastfed), and young children. Lead in drinking water is primarily from materials and parts used in service lines and in home plumbing. The City is responsible for providing high quality drinking water and removing lead pipes but cannot control the variety of materials used in the plumbing in your home. Because lead levels may vary over time, lead exposure is possible even when your tap sampling results do not detect lead at one point in time. You can help protect yourself and your family by identifying and removing lead materials within your home plumbing and taking steps to reduce your family’s risk. Using a filter, certified by an American National Standards Institute accredited certifier to reduce lead, is effective in reducing lead exposures. Follow the instructions provided with the filter to ensure the filter is used properly. Use only cold water for drinking, cooking, and making baby formula. Boiling water does not remove lead from water. Before using tap water for drinking, cooking, or making baby formula, flush your pipes for several minutes. You can do this by running your tap, taking a shower, doing laundry or a load of dishes. If you have a lead service line or galvanized requiring replacement service line, you may need to flush your pipes for a longer period. If you are concerned about lead in your water and wish to have your water tested, contact the City at (408) 730-2718. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at www.epa.gov/safewater/lead.

The State Water Resources Control Board, in partnership with the USEPA, enforces regulations designed to reduce lead exposure and ensure all water service lines are lead-free. As part of these requirements, water systems must create and submit a detailed inventory of all service lines within their service area.

The City of Sunnyvale has completed its inventory and confirmed that its water system contains no lead service lines or galvanized service lines that require replacement.

To learn more about the City’s service line inventory, visit www.sunnyvale.ca.gov/homes-streets-and-property/water-and-sewer/ water/water-quality/lead-free-water-systems.

Crytosporidium/Giardia
Cryptosporidium and Giardia are microbial pathogens naturally present in the environment and commonly found in surface water throughout the U.S. Monitoring of source water by SFPUC in 2024 indicated a low presence of these organisms. However, current test methods approved by the USEPA do not distinguish between dead organisms and those capable of causing disease. They must be ingested to cause disease and may be spread through means other than drinking water. Ingestion of either pathogen can cause abdominal infection. Symptoms include nausea, diarrhea, abdominal cramps, and associated headaches.

Hardness
Water hardness is determined mainly by the presence of calcium and magnesium salts. Although hard water does not pose a health risk, it may be considered undesirable for other reasons. Some benefits of water softening are reductions in soap usage, longer life for water heaters and a decrease in encrustation of pipes; disadvantages are an increase in sodium intake,
an increase in maintenance
and servicing, and potential
adverse effects on salt-
sensitive plants. To convert
hardness from ppm to
grains per gallon, divide by

17.1. A hardness scale is
provided for your reference.

Per- and Poly-fluoroalkyl Substances (PFAS)
On April 26, 2024, the USEPA published a final per- and polyfluoroalkyl substances (PFAS) National Primary Drinking Water Regulation for six PFAS. This regulation requires public water systems to monitor these six PFAS over three years, with initial monitoring to be completed by April 26, 2027. All regulated PFAS are part of the current Unregulated Contaminant Monitoring Rule (UCMR) testing cycle.

The USEPA uses the UCMR to collect data every five years for up to 30 unregulated contaminants that may be present in drinking water but do not yet have health-based standards set under the Safe Drinking Water Act. The fifth cycle, UCMR 5, which is the current cycle, requires monitoring for 29 PFAS and lithium between 2023 and 2025. This monitoring provides a basis for future regulatory actions to protect public health. The City monitored from April 2024 to January 2025 and no chemicals, including regulated PFAS, were detected. To learn more about UCMR visit
www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule Hardness
classification
Grains per
gallon
mg/L or
ppm
Soft < 1.0 < 17.1
Slightly hard 1.0–3.5 17.1–60
Moderately hard 3.5–7.0 60–120
Hard 7.0–10.5 120–180
Very hard > 10.5 > 180
Attachment 1

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City Council Meetings
City Hall Council Chambers
456 West Olive Ave.

Sunnyvale, CA 94086
Tuesdays, 7 p.m.

A list of City Council meetings, agenda items and study issues can be obtained by visiting Sunnyvale.ca.gov or by calling the City Clerk’s office at (408) 730-7483.

To get involved
8 | City of Sunnyvale W ater Quality Report 2024
Important contact information
Division of Drinking Water
waterboards.ca.gov/drinking_water
US EPA
water.epa.gov/drink
Department of Water Resources
water.ca.gov
Bay Area Water Supply and
Conservation Agency
bawsca.org
American Water Works
Association
awwa.org
Web resources
City of Sunnyvale
456 West Olive Ave.

Sunnyvale, CA 94086
Tel: (408) 730-7500
TTY: 711 (CA Relay Service)
Sunnyvale.ca.gov
Utility Division (Billing)
(408) 730-7400
City contacts
Water Conservation
(408) 630-2554
[email protected]
Access Valley Water
Reporting and Requests
access.valleywater.org
To Report Water Waste
(408) 630-2000
[email protected]
Pollution Hotline
(888) 510-5151 (24 Hours)
Hours of operation
8 a.m. to 5 p.m., Monday–Friday
Valley Water resources
More information
For more information about this report or the City’s water quality monitoring program, please contact:

BLENDED AREA

CENTRAL
E. FREMONT

EL CAMINO REAL
S. WOLFE

MATHILDA
S. FAIR OAKS

SUNNYVALE-SARATOGA

CARIBBEAN
MAUDE

LAWRENCE
MARY
MARY

HOMESTEAD

OLD SAN FRANCISCO
REED
JAVA
Water supply map
The adjacent map indicates which
areas of the City are supplied
by SFPUC, Valley Water, or
a mixture of the two. The
colored regions correspond
to the colored columns in
the water quality table
(pages 4-5). Groundwater
wells, which are not
shown on this map, are
located throughout the
City. Local groundwater
is blended with surface
water supplies from
SFPUC and Valley
Water. SFPUC water is
fluoridated but Valley
Water and groundwater
supplies are not.

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence 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 USEPA Safe Drinking Water Hotline.

USEPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the USEPA Safe Drinking Water Hotline.

USEPA Safe Drinking Water Hotline
(800) 426-4791
Health and education information
Attachment 1

Page 31 of 31 ends

Sunnyvale City CouncilAugust 26, 2025

Sunnyvale City Council
August 26, 2025