Drinking water quality · 2026

· Verified

What's in City of Daly City, CA tap water

119 contaminants were measured in the City of Daly City, CA water system's 2026 annual report. Each is shown below against its federal limit 1 sit at or above that limit.

Reporting year
2026
Contaminants measured
119
Over federal limit
1
Approaching the limit
1
Worst contaminant
Chromium, Hexavalent
1.4× the limit
Service area
CA
state-level CCR
Source
Utility CCR

PFAS — EPA UCMR5 (2023–2025)

1 PFAS compound detected in City of Daly City, CA

About this data

The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.

Lithium

● Detected (no federal limit)
Measured 13 mg/LSample year 2023Samples 2 detect / 20

below national p90 (76.59999999999991 mg/L across detecting U.S. systems)

PWSID CA4110013 · Source: EPA UCMR5. Limits per EPA's April 2024 PFAS National Primary Drinking Water Regulation. PFAS values reported in nanograms per liter (ng/L) — note that 1 ng/L = 1 part per trillion.

Where your water comes from · EPA SDWIS

City of Daly City, CA's drinking water comes from ground water, drawn from 5 sources.

Source

5ground water
  • JEFFERSON WELL
  • WESTLAKE WELL
  • WELL 04 - STANDBY
  • JUNIPERO SERRA WELL
  • + 1 more

Treatment

2treatment plants
  • WESTLAKE PUMP STATION - BLENDED-TREATED
  • CITRUS PUMP STATION - BLENDED - TREATED

Distribution

0storage units

Also buys water from SAN FRANCISCO REGIONAL WATER SYSTEM, NORTH COAST COUNTY WATER DIST, and 4 more.

Historical readings · EPA Six-Year Review (2012–2019)

2 contaminants historically over EPA limits in City of Daly City, CA

About this data

Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.

ContaminantWorst detectionEPA limitYears (2012–2019)
NITRATE
worst: 2014
38.4 mg/L
3.8×
10 mg/L
'12'13'14'15'16'17'18'19
HAA5
worst: 2018
0.0638 mg/L
1.1×
0.06 mg/L
'12'13'14'15'16'17'18'19
TTHM
worst: 2019
0.0688 mg/L
86%
0.08 mg/L
'12'13'14'15'16'17'18'19
GROSS BETA
worst: 2019
1.27 mrem/yr
within
4 mrem/yr
'19
ARSENIC
worst: 2013
0.003 mg/L
within
below national p90
0.01 mg/L
'13'15
CHROMIUM
worst: 2013
0.025 mg/L
within
2.5× the national p90
0.1 mg/L
'13'15'16'17'18'19
DIQUAT
worst: 2013
0.0022 mg/L
within
0.02 mg/L
'13
FLUORIDE
worst: 2015
0.24 mg/L
within
4 mg/L
'12'13'15'16'17
TCAA
worst: 2012
0.0163 mg/L
'12'13'14'15'16'17'18'19
DBAA
worst: 2013
0.0022 mg/L
'13'14'15'16'17
DCAA
worst: 2012
0.0213 mg/L
'12'13'14'15'16'17'18'19
MBAA
worst: 2017
0.001 mg/L
'17
MCAA
worst: 2016
0.004 mg/L
'16'17'19
BROMODICHLOROMETHANE
worst: 2012
0.00107 mg/L
'12'13'14'15'16'17'18'19
BROMOFORM
worst: 2012
0.00183 mg/L
'12'13'14'15'16
CHLOROFORM
worst: 2012
0.0299 mg/L
'12'13'14'15'16'17'18'19
DIBROMOCHLOROMETHANE
worst: 2013
0.00296 mg/L
'13'14'15'16'17'18'19
PWSID CA4110013 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.

Metals

ContaminantMeasuredStatus
Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium.14.118 UG/LAverageSource waterAt or above the limit
AluminumA common element sometimes used as a treatment coagulant.Not detected UG/LHighest single sampleSource waterNone detected
AntimonyNot detected UG/LHighest single sampleSource waterNone detected
BariumA metal from erosion of natural deposits and industrial discharge.Not detected UG/LHighest single sampleSource waterNone detected
BerylliumNot detected UG/LHighest single sampleSource waterNone detected
BoronA naturally occurring element from rock and soil.Not detected UG/LHighest single sampleSource waterNone detected
CadmiumNot detected UG/LHighest single sampleSource waterNone detected
CopperA metal that enters water from corroding household plumbing.Not detected UG/LHighest single sampleSource waterNone detected
IronA naturally occurring metal common in groundwater.Not detected UG/LHighest single sampleSource waterNone detected
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.Not detected UG/LHighest single sampleSource waterNone detected
ManganeseA naturally occurring metal from soil and rock.Not detected UG/LHighest single sampleSource waterNone detected
MercuryA toxic metal from erosion of natural deposits and industrial runoff.Not detected UG/LHighest single sampleSource waterNone detected
NickelA metal from natural deposits and industrial discharge.Not detected UG/LHighest single sampleSource waterNone detected
SeleniumA trace element from natural deposits and industrial discharge.Not detected UG/LHighest single sampleSource waterNone detected
StrontiumNot detected PCI/LHighest single sampleSource waterNone detected
ThalliumNot detected UG/LHighest single sampleSource waterNone detected
ZincA naturally occurring metal that can also enter water from corroding pipes.Not detected UG/LHighest single sampleSource waterNone detected
CalciumA naturally occurring mineral that contributes to water hardness.16.25 MG/LAverageSource waterDetected — no federal limit
MagnesiumA naturally occurring mineral that contributes to water hardness.30 MG/LAverageSource waterDetected — no federal limit
PotassiumA naturally occurring mineral from rock and soil.1.3 MG/LAverageSource waterDetected — no federal limit
SodiumA naturally occurring salt component.38 MG/LAverageSource waterDetected — no federal limit
Vanadium4.1 UG/LAverageSource waterDetected — no federal limit

Physical & aggregate

ContaminantMeasuredStatus
Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content.570 UMHO/CMAverageSource waterWithin the limit
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.300 MG/LAverageSource waterWithin the limit
ColorA measure of visible tint in the water.Not detected UNITSHighest single sampleSource waterNone detected
OdorA measure of detectable smell in the water.Not detected TONHighest single sampleSource waterNone detected
TurbidityA measure of cloudiness from suspended particles in the water.Not detected NTUHighest single sampleSource waterNone detected
AlkalinityA measure of the water's capacity to neutralize acids.94.16666666666667 MG/LAverageSource waterDetected — no federal limit
HardnessA measure of dissolved calcium and magnesium minerals.197 MG/LAverageSource waterDetected — no federal limit
pHA measure of how acidic or basic the water is.7.9 PHAverageSource waterDetected — no federal limit

Inorganic chemicals

ContaminantMeasuredStatus
ChlorideA naturally occurring salt compound.49 MG/LAverageSource waterWithin the limit
SulfateA naturally occurring mineral from rock and soil.28 MG/LAverageSource waterWithin the limit
AsbestosNot detected MFLHighest single sampleSource waterNone detected
CyanideNot detected UG/LHighest single sampleSource waterNone detected
NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits.Not detected MG/LHighest single sampleSource waterNone detected

Disinfection byproducts

ContaminantMeasuredStatus
PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection.Not detected UG/LHighest single sampleSource waterNone detected

Other

ContaminantMeasuredStatus
CarbofuranNot detected UG/LHighest single sampleSource waterNone detected
Carbon TetrachlorideNot detected UG/LHighest single sampleSource waterNone detected
ChlordaneNot detected UG/LHighest single sampleSource waterNone detected
ChlorobenzeneNot detected UG/LHighest single sampleSource waterNone detected
Cis Dichloroethylene 12Not detected UG/LHighest single sampleSource waterNone detected
DehaNot detected UG/LHighest single sampleSource waterNone detected
DehpNot detected UG/LHighest single sampleSource waterNone detected
Dichloroethane 12Not detected UG/LHighest single sampleSource waterNone detected
Dichloroethylene 11Not detected UG/LHighest single sampleSource waterNone detected
Dichloropropane 12Not detected UG/LHighest single sampleSource waterNone detected
DinosebNot detected UG/LHighest single sampleSource waterNone detected
EdbNot detected UG/LHighest single sampleSource waterNone detected
EndothallNot detected UG/LHighest single sampleSource waterNone detected
EndrinNot detected UG/LHighest single sampleSource waterNone detected
GlyphosateNot detected UG/LHighest single sampleSource waterNone detected
HeptachlorNot detected UG/LHighest single sampleSource waterNone detected
Heptachlor EpoxideNot detected UG/LHighest single sampleSource waterNone detected
HexachlorobenzeneNot detected UG/LHighest single sampleSource waterNone detected
HexachlorocyclopentadieneNot detected UG/LHighest single sampleSource waterNone detected
MethoxychlorNot detected UG/LHighest single sampleSource waterNone detected
O DichlorobenzeneNot detected UG/LHighest single sampleSource waterNone detected
OxamylNot detected UG/LHighest single sampleSource waterNone detected
P DichlorobenzeneNot detected UG/LHighest single sampleSource waterNone detected
Pcb TotalNot detected UG/LHighest single sampleSource waterNone detected
PceNot detected UG/LHighest single sampleSource waterNone detected
PentachlorophenolNot detected UG/LHighest single sampleSource waterNone detected
PicloramNot detected UG/LHighest single sampleSource waterNone detected
StyreneNot detected UG/LHighest single sampleSource waterNone detected
TceNot detected UG/LHighest single sampleSource waterNone detected
ToxapheneNot detected UG/LHighest single sampleSource waterNone detected
Trans Dichloroethylene 12Not detected UG/LHighest single sampleSource waterNone detected
Trichlorobenzene 124Not detected UG/LHighest single sampleSource waterNone detected
Trichloroethane 111Not detected UG/LHighest single sampleSource waterNone detected
Trichloroethane 112Not detected UG/LHighest single sampleSource waterNone detected
TwofourdNot detected UG/LHighest single sampleSource waterNone detected
Vinyl ChlorideNot detected UG/LHighest single sampleSource waterNone detected

PFAS ("forever chemicals")

ContaminantMeasuredStatus
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound.Not detected NG/LHighest single sampleSource waterNone detected
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound.Not detected NG/LHighest single sampleSource waterNone detected
4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound.Not detected NG/LHighest single sampleSource waterNone detected
Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound.Not detected NG/LHighest single sampleSource waterNone detected
Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound.Not detected NG/LHighest single sampleSource waterNone detected
Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluoropentanoic acidPerfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected
PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected

Radionuclides

ContaminantMeasuredStatus
UraniumA naturally occurring radioactive metal from erosion of natural deposits.Not detected PCI/LHighest single sampleSource waterNone detected

VOCs & pesticides

ContaminantMeasuredStatus
1,2,3-TCPNot detected UG/LHighest single sampleSource waterNone detected
AtrazineA widely used agricultural herbicide that reaches water through runoff.Not detected UG/LHighest single sampleSource waterNone detected
BenzeneNot detected UG/LHighest single sampleSource waterNone detected
Benzo(a)pyreneNot detected UG/LHighest single sampleSource waterNone detected
DalaponNot detected UG/LHighest single sampleSource waterNone detected
DichloromethaneNot detected UG/LHighest single sampleSource waterNone detected
EthylbenzeneNot detected UG/LHighest single sampleSource waterNone detected
SimazineNot detected UG/LHighest single sampleSource waterNone detected
TolueneNot detected UG/LHighest single sampleSource waterNone detected
XylenesA group of industrial solvents found in gasoline and paint.Not detected UG/LHighest single sampleSource waterNone detected
Source: City of Daly City, CA's 2026 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.

People also ask about City of Daly City, CA's water

+Is City of Daly City, CA tap water safe to drink in 2026?

The 2026 Consumer Confidence Report for the City of Daly City, CA water utility lists 1 contaminant at or above the federal limit: Chromium, Hexavalent. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.

+What contaminants are in City of Daly City, CA tap water?

119 contaminants were measured in City of Daly City, CA's 2026 Consumer Confidence Report, spanning other, metals, and pfas ("forever chemicals"). 80 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.

+Which contaminants exceed federal limits in City of Daly City, CA tap water?

One contaminant in City of Daly City, CA's 2026 report sits at or above the federal limit: Chromium, Hexavalent (1.4× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.

+What is the worst contaminant in City of Daly City, CA tap water?

The contaminant with the highest measured value relative to its federal limit in the 2026 report is Chromium, Hexavalent, at 1.4× the federal threshold. It belongs to the metals family of contaminants.

+Are any contaminants in City of Daly City, CA tap water approaching the federal limit?

One contaminant is between 80% and 100% of the federal limit in this report: Nitrate. Approaching means measured but not in violation — a margin that can close quickly if conditions change.

+Where does the data on this page come from?

Every value is transcribed from City of Daly City, CA's 2026 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.

+How often is City of Daly City, CA's water quality data updated?

Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2026 report; a new report will replace it once the utility publishes its next annual update.

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