Is Williston, ND 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 City of Williston.
City of Williston supplies Williston (26,426 people).
Water system
City of Williston
26,426 people · Surface water · EPA ID ND5301012
| 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 2023, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0
Across North Dakota, 0 of 41 water systems EPA tested had PFAS above a 2024 federal limit, and 3 systems were above the lead action level in results from the last five years. North Dakota results.
Williston 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 Williston city (tables B25034, B25003). Estimates for small places have a margin of error.
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Dickinson 97 mi City of Dickinson | None above limits | 5.29 ppb |
| Minot 109 mi City of Minot | None above limits | 13.5 ppb |
| Mandan 157 mi City of Mandan | None above limits | 4.2 ppb |
| Bismarck 162 mi City of Bismarck | None above limits | 2.8 ppb |
| Grand Forks 302 mi Grand Forks Regional Water Treatment Plant | None above limits | 8.91 ppb |
| West Fargo 323 mi City of West Fargo | None above limits | 0 ppb |
Williston ZIP codes (1)
- 58801
Questions
Is Williston tap water safe to drink?
City of Williston 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 Williston, ND?
City of Williston, which serves 26,426 people.
Does Williston tap water have PFAS?
None detected above EPA's reporting limits. City of Williston had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.
Do Williston homes have lead pipes?
Census estimates put 35% of Williston homes as built before 1980 (North Dakota: 48%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. City of Williston'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.