What's in City of Mountain View — Mountain View, Ca, CA tap water

36 contaminants were measured in the City of Mountain View — Mountain View, Ca, CA water system's 2023 annual report. Each is shown below against its federal limit.

Browse the mapFull source report ↗

Reporting year: 2023
Contaminants measured: 36
Over federal limit: 0
Approaching the limit: 0
Service area: CA
Source: Utility CCR

All within federal limits. Every measured contaminant in this report is below its federal threshold.

Compliance history

Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.

Treatment technique violationHealth-based
3 violations on record · most recent Mar 2015
resolved

Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗

Other

Contaminant	Measured	Federal limit	Status
Chlorine Total	2.76 mg/LReported levelSystem-wide	4 mg/LMCL	Within the limit
Chromium	0.1 ug/LAverageSFPUC	100 ug/LMCL	Within the limit
+By source (2)— CMV Wells, SFPUC CMV WellsPlant range0.36–12 ug/L12% of limit SFPUCZone avg0.1 ug/Lrange0–0.1 ug/L0% of limit

Radionuclides

Contaminant	Measured	Federal limit	Status
Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances.	3.3 pCi/LAverageValley Water	15 pCi/LMCL	Within the limit
UraniumA naturally occurring radioactive metal from erosion of natural deposits.	1.3 pCi/LAverageValley Water	None set	Detected — no federal limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter.	14.6–13 ug/LReported levelSystem-wide	None set	Within the limit
TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter.	34.1–13 ug/LReported levelSystem-wide	None set	Within the limit
ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade.	134 ug/LAverageSFPUC	None set	Detected — no federal limit

Physical & aggregate

Contaminant	Measured	Federal limit	Status
TurbidityA measure of cloudiness from suspended particles in the water.	0.2 NTUAverageSFPUC	1 NTUMCL	Within the limit
+By source (3)— SFPUC, Valley Water, CMV Wells SFPUCZone avg0.2 NTUrange0.1–0.4 NTU40% of limit Valley WaterZone avg0.04 NTUrange0.02–0.3 NTU30% of limit CMV WellsPlant range0–0.06 NTU6% of limit
AlkalinityA measure of the water's capacity to neutralize acids.	77 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, SFPUC, Valley Water CMV WellsPlant range220–250 mg/L SFPUCZone avg56 mg/Lrange7.4–120 mg/L Valley WaterZone avg77 mg/Lrange68–87 mg/L
ColorA measure of visible tint in the water.	2AverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, CMV Wells Valley WaterZone avg2range0–3 CMV WellsPlant rangeNot detected
HardnessA measure of dissolved calcium and magnesium minerals.	111 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range220–339 mg/L Valley WaterZone avg111 mg/Lrange93–133 mg/L SFPUCZone avg57 mg/Lrange8.4–106 mg/L
OdorA measure of detectable smell in the water.	1.6AverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, CMV Wells Valley WaterZone avg1.6range1.4–2 CMV WellsPlant rangeNot detected
pHA measure of how acidic or basic the water is.	7.7AverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, CMV Wells Valley WaterZone avg7.7range7.5–8 CMV WellsPlant range7.34–7.89
Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content.	466AverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range560–770 Valley WaterZone avg466range414–522 SFPUCZone avg174range31–317
TOCTotal organic carbon — a measure of organic material dissolved in the water.	1.6 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, SFPUC Valley WaterZone avg1.6 mg/Lrange1.2–2 mg/L SFPUCZone avg1.5 mg/Lrange1.1–1.8 mg/L
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.	268 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range330–490 mg/L Valley WaterZone avg268 mg/Lrange238–298 mg/L SFPUCZone avg97 mg/Lrange24–169 mg/L

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
FluorideA mineral often added to drinking water to help prevent tooth decay.	0.7 mg/LAverageSFPUC	None set	Within the limit
+By source (3)— SFPUC, CMV Wells, Valley Water SFPUCZone avg0.7 mg/Lrange0.5–9 mg/L225% of limit CMV WellsPlant range0–0.13 mg/L3% of limit Valley WaterZone avgNot detected mg/Lrange0–0.11 mg/L3% of limit
NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits.	Not detected mg/LAverageSFPUC	None set	Within the limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range3.4–6.3 mg/L63% of limit Valley WaterZone avgNot detected mg/Lrange0–0.7 mg/L7% of limit SFPUCZone avgNot detected mg/Lrange0–0.4 mg/L4% of limit
Ammonia	0.05 mg/LReported levelSystem-wide	None set	Detected — no federal limit
ChlorideA naturally occurring salt compound.	50 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range28–62 mg/L Valley WaterZone avg50 mg/Lrange47–53 mg/L SFPUCZone avg4.9 mg/Lrange0–9.9 mg/L
SulfateA naturally occurring mineral from rock and soil.	66 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— Valley Water, SFPUC, CMV Wells Valley WaterZone avg66 mg/Lrange57–80 mg/L SFPUCZone avg21 mg/Lrange1–41 mg/L CMV WellsPlant range31–38 mg/L

Metals

Contaminant	Measured	Federal limit	Status
CopperA metal that enters water from corroding household plumbing.	0.12 mg/LReported levelSystem-wide	None set	Within the limit
BariumA metal from erosion of natural deposits and industrial discharge.	130–140 ug/LRangeCMV Wells	None set	Within the limit
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.	Not detected ug/LReported levelSystem-wide	None set	None detected
AluminumA common element sometimes used as a treatment coagulant.	Not detected ug/LAverageSFPUC	None set	Detected — no federal limit
+By source (2)— SFPUC, CMV Wells SFPUCZone avgNot detected ug/Lrange0–59 ug/L CMV WellsPlant rangeNot detected ug/L
BoronA naturally occurring element from rock and soil.	133 ug/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— Valley Water, CMV Wells, SFPUC Valley WaterZone avg133 ug/Lrange114–151 ug/L CMV WellsPlant range0–140 ug/L SFPUCZone avg44 ug/Lrange2–65 ug/L
CalciumA naturally occurring mineral that contributes to water hardness.	23 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, SFPUC, Valley Water CMV WellsPlant range60–84 mg/L SFPUCZone avg15 mg/Lrange3.2–28 mg/L Valley WaterZone avg23 mg/Lrange19–28 mg/L
IronA naturally occurring metal common in groundwater.	20 ug/LAverageSFPUC	None set	Detected — no federal limit
+By source (2)— SFPUC, CMV Wells SFPUCZone avg20 ug/Lrange0–41 ug/L CMV WellsPlant rangeNot detected ug/L
LithiumA naturally occurring element found in some groundwater.	2 ug/LAverageSFPUC	None set	Detected — no federal limit
MagnesiumA naturally occurring mineral that contributes to water hardness.	13 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— CMV Wells, Valley Water, SFPUC CMV WellsPlant range17–31 mg/L Valley WaterZone avg13 mg/Lrange11–16 mg/L SFPUCZone avg4.9 mg/Lrange0.2–9.5 mg/L
ManganeseA naturally occurring metal from soil and rock.	Not detected ug/LAverageSFPUC	None set	Detected — no federal limit
+By source (2)— SFPUC, CMV Wells SFPUCZone avgNot detected ug/Lrange0–2.7 ug/L CMV WellsPlant rangeNot detected ug/L
PotassiumA naturally occurring mineral from rock and soil.	3 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, CMV Wells Valley WaterZone avg3 mg/Lrange2.6–3.3 mg/L CMV WellsPlant range1–1.1 mg/L
SilicaA naturally occurring compound from sand and rock.	12 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (2)— Valley Water, SFPUC Valley WaterZone avg12 mg/Lrange11–12 mg/L SFPUCZone avg7.4 mg/Lrange4.9–9.9 mg/L
SodiumA naturally occurring salt component.	47 mg/LAverageValley Water	None set	Detected — no federal limit
+By source (3)— Valley Water, CMV Wells, SFPUC Valley WaterZone avg47 mg/Lrange45–49 mg/L CMV WellsPlant range32–37 mg/L SFPUCZone avg13 mg/Lrange3.1–24 mg/L
Vanadium	2 ug/LAverageValley Water	None set	Detected — no federal limit
+By source (2)— CMV Wells, Valley Water CMV WellsPlant range4.3–6.4 ug/L Valley WaterZone avg2 ug/Lrange1–2 ug/L

Microbial

Contaminant	Measured	Federal limit	Status
Giardia lamblia	0.02AverageSFPUC	None set	Detected — no federal limit

Source: City of Mountain View — Mountain View, Ca, CA's 2023 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.