Is National City, CA tap water safe?
Data: U.S. EPA · How we read the data · How we check it
Summary
Sweetwater Authority had PFAS above the 2024 federal limits (PFOA) in EPA's 2023–2025 testing.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility issues a boil-water or do-not-drink notice, follow it.
Sweetwater Authority supplies National City (184,915 people).
Water system
Sweetwater Authority
184,915 people · Surface water · EPA ID CA3710025
Buys treated water from City of San Diego, San Diego County Water Authority, California American Water – Coronado, Otay Water District.
| PFAS | Highest average | Limit |
|---|---|---|
| PFOA Above limit | 9.2 ppt | 4 ppt |
| PFOS One sample above limit | 3.88 ppt | 4 ppt |
| PFHxS Detected, below limit | 7.88 ppt | 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.
For context: the PFOA average is higher than at 95% of the California systems EPA tested.
Lead: 0 ppb at the 90th percentile (Dec 2023, 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.
National City homes and lead pipes
Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.
Housing: Census American Community Survey 2020–2024 5-year estimates for National City city (tables B25034, B25003). Estimates for small places have a margin of error.
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Chula Vista 6 mi Otay Water District | None above limits | 0 ppb |
| Lemon Grove 6 mi Helix Water District | None above limits | 0 ppb |
| Imperial Beach 7 mi California American Water – Coronado | None above limits | 2 ppb |
| La Mesa 8 mi Helix Water District | None above limits | 0 ppb |
| San Diego 11 mi City of San Diego | None above limits | 0 ppb |
| El Cajon 12 mi Helix Water District | None above limits | 0 ppb |
National City ZIP codes (2)
- 91950
- 92136
Questions
Is National City tap water safe to drink?
Sweetwater Authority has had no health-based violations since 2016, and EPA testing found PFAS above the 2024 federal limits, which it must meet by 2029. 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 National City, CA?
Sweetwater Authority, which serves 184,915 people.
Does National City tap water have PFAS?
Yes. EPA's 2023–2025 testing found entry-point averages above the 2024 federal limits for PFOA at Sweetwater Authority. Systems have until 2029 to meet them.
Do National City homes have lead pipes?
Census estimates put 70% of National City 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. Sweetwater Authority's service line inventory says what your line is made of. 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.