Sunnyvale Water Hardness & Quality Report (2026)
Water Hardness
2.1 grains per gallon
Source
mixed
pH Level
7.2
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
73.1 mg/L
Est. Daily Cost
$0.09
energy & soap waste
Source: USGS Water Quality Portal · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Sunnyvale, your appliances are currently losing 5% efficiency due to mineral buildup.
| Appliance | In Sunnyvale | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 8.4 yrs | 8.5 yrs | -1% |
| Washing Machine | 12.3 yrs | 12 yrs | — |
| Water Heater | 14.2 yrs | 15 yrs | -5% |
Regional Water Comparison
How Sunnyvale compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Sunnyvale, California | 35.5 mg/L | 3 ppt | 🟢 Soft | mixed |
| Cupertino, California | 62 mg/L | 3.8 ppt | 🟡 Moderately Hard | mixed |
| Mountain View, California | 112.5 mg/L | 5.3 ppt | 🟡 Moderately Hard | mixed |
| Los Altos, California | 150.5 mg/L | 6.4 ppt | 🟠 Hard | mixed |
| Santa Clara, California | 79 mg/L | 4.3 ppt | 🟡 Moderately Hard | mixed |
National Benchmark
How Sunnyvale compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Sunnyvale | 35.5 mg/L | 🟢 None |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
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What Makes Sunnyvale's Water Unique?
Local geology and source profile
Sunnyvale, California receives its municipal water supply through the City of Sunnyvale Environmental Services Department, sourced from the Santa Clara Valley Water District (SCVWD), which blends San Francisco Public Utilities Commission (SFPUC) Hetch Hetchy water — delivered from the Tuolumne River's Hetch Hetchy Reservoir in Yosemite National Park via 167 miles of aqueduct — with locally managed groundwater from the Santa Clara Subbasin beneath Silicon Valley in Santa Clara County. SCVWD distributes treated Hetch Hetchy water through its regional infrastructure while managing local groundwater recharge. Sunnyvale's supply achieves a hardness of just 35.5 mg/L — classified as soft, one of the lowest values in the South Bay.
Sunnyvale's exceptionally soft supply reflects the dominant Hetch Hetchy fraction in SCVWD's blended distribution. Hetch Hetchy water originates from Tuolumne River snowmelt draining the Yosemite granite batholith and metamorphic terranes of the Central Sierra Nevada — ancient granitic rocks that are among the most chemically resistant in California and contribute negligible calcium or bicarbonate to passing water. Hetch Hetchy water is among the softest large-city water sources in the United States. The Santa Clara Subbasin groundwater fraction adds some dissolved minerals from Quaternary alluvial plain sediments, but the high Hetch Hetchy volume dominates, maintaining a very soft final supply throughout most of Sunnyvale's distribution zone.
With hardness at just 35.5 mg/L, Sunnyvale residents enjoy very soft water. Scale accumulation on faucets, showerheads, and in appliances is minimal — light occasional cleaning is all that is needed. Soap and shampoo lather exceptionally well with minimal product, and dishwashers produce consistently spot-free glassware. Hot water systems remain scale-free over long operational periods. SCVWD and the City of Sunnyvale consistently deliver water meeting all California SWRCB and EPA Safe Drinking Water Act standards throughout Silicon Valley.
Geology & Source: Mixed supply predominantly from the San Francisco Public Utilities Commission (SFPUC) Hetch Hetchy Tuolumne River system (Sierra Nevada Yosemite granite snowmelt) via the Santa Clara Valley Water District (SCVWD), blended with local Santa Clara Subbasin groundwater — the very high Hetch Hetchy fraction in Silicon Valley supply produces one of the Bay Area's softest supplies at 35.5 mg/L.