What's in your tap water, and what it costs
The City of Mountain View runs your water and sewer and bills them every two months, along with garbage. Nearly all of it is Hetch Hetchy water from Yosemite: soft, with no PFAS detected.
Last checked Oct 20, 2026 · Rates effective July 1, 2026
Where it comes from
Hetch Hetchy, 87–90%
Yosemite snowmelt delivered by the San Francisco PUC. Very soft.
Valley Water, about 10%
Treated at Valley Water's Rinconada plant. Harder.
City wells, 2–3%
Local groundwater. Very hard.
About 4% of homes, in a few formerly unincorporated neighborhoods, are served by Cal Water instead. Enter your address on the main page and we check the state's official boundary map.
What's in it
| Measure | Result | What it means |
|---|---|---|
| Hardness | ~57–62 ppm Hetch Hetchy (about 3.3 grains/gal); 96–111 Valley Water; 220–339 wells | Most homes don't need a softener. |
| Disinfectant | Chloramine | Safe to drink. Remove it for fish tanks; dialysis patients should talk to their clinic. |
| PFAS | None detected | |
| Lead | Not detected at the 90th percentile; 40 homes tested, none over | No lead service lines in the city system. |
| Nitrate | Wells 3.9–6.3 ppm (limit 10) | |
| Violations | None |
Hardness ranges combine the city's 2023 and 2025 reports and SFPUC's 2025 regional report.
What you pay
| Charge (per month) | 2025–26 | 2026–27 |
|---|---|---|
| Meter charge (single-family) | $21.25 | $22.55 |
| Water, 0–3 units | $8.05 | $8.53 |
| Water, 3–13 units | $9.29 | $9.85 |
| Water, above 13 units | $14.49 | $15.36 |
| Sewer (single-family) | $57.75 | $61.50 |
| Typical month (10 units) | $117.09 + $61.50 sewer |
1 unit (CCF) = 748 gallons. These are step increases inside a 5-year schedule approved at a Prop 218 hearing on June 25, 2024; the council adopted this year's step on June 23, 2026. The city's website still shows last year's table. Homes with a backflow device also pay $19.80 a month.
Ways to pay less
Stay under 13 units in summer
$15.36 per unit above 13The top tier costs 56% more than the middle one. Lawn watering is what usually pushes a house over.
Replace lawn: $2 per square foot back
Up to $3,000Valley Water's landscape rebate, funded through June 30, 2027. Get approval before removing the lawn. Our City Forest's Lawn Busters program helps seniors, veterans and low-income households do the work. Laundry-to-landscape graywater: $200.
Free from the city
A free street tree, the Arbor Day tree giveaway, WaterInsight home water-use reports, and free compost and mulch at the SMaRT Station.
Facts are checked against the public sources listed on each page. Rates change every year; each page shows when it was last checked. Individual bills are confidential in California, so personal numbers are estimates from public rates. Nothing here is legal, tax or insurance advice.