Is San Ramon, CA tap water safe?
Data: U.S. EPA · How we read the data · How we check it
Summary
No federal limits exceeded in EPA data for East Bay Municipal Utility District. 2 PFAS were detected below the limits.
2 public water systems serve parts of San Ramon. The largest, East Bay Municipal Utility District, serves 1.5 million people. Your water bill names your system.
Largest system
East Bay Municipal Utility District
1.5 million people · Surface water · EPA ID CA0110005
Buys treated water from Contra Costa Water District.
| PFAS | Highest average | Limit |
|---|---|---|
| PFOA Not detected | – | 4 ppt |
| PFOS Not detected | – | 4 ppt |
| PFHxS Not detected | – | 10 ppt |
| PFNA Not detected | – | 10 ppt |
| HFPO-DA (GenX) Not detected | – | 10 ppt |
ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.
Lead: 0 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0
Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.
San Ramon homes and lead pipes
Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. East Bay Municipal Utility District's service line inventory lists 0 lead lines and 3,935 galvanized lines that need replacing (as of 2026-04-21). Look up your address. How to check your own line.
Housing: Census American Community Survey 2020–2024 5-year estimates for San Ramon city (tables B25034, B25003). Estimates for small places have a margin of error.
Other water systems serving San Ramon
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Danville 4 mi East Bay Municipal Utility District | None above limits | 0 ppb |
| Dublin 4 mi East Bay Municipal Utility District | None above limits | 0 ppb |
| Pleasanton 7 mi City of Pleasanton | Above limit | 0 ppb |
| Livermore 11 mi City of Livermore | None above limits | 0 ppb |
| Walnut Creek 11 mi East Bay Municipal Utility District | None above limits | 0 ppb |
| Union City 12 mi Alameda County Water District | None above limits | 0 ppb |
San Ramon ZIP codes (2)
- 94582
- 94583
Questions
Is San Ramon tap water safe to drink?
East Bay Municipal Utility District has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.
Who supplies water in San Ramon, CA?
2 public water systems serve parts of San Ramon. The largest is East Bay Municipal Utility District (1.5 million people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.
Does San Ramon tap water have PFAS?
East Bay Municipal Utility District had 2 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.
Do San Ramon homes have lead pipes?
Census estimates put 25% of San Ramon homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. East Bay Municipal Utility District's service line inventory lists 0 lead lines. The only way to know for your home is to check the line where it enters the house and test your tap.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.