What was found in Williamsport's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 790 µg/L 7.9% of the EPA limit 10000 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 3574 µg/L — OAK LYNN MANOR MOBILE HOME PK · 250 people · 2019 | 4/5 | SYR4 |
| Barium | 53.405 µg/L 2.7% of the EPA limit 2000 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 1957 µg/L — AMERICAN TEMPO VILLAGE PARK · 88 people · 2019 | 5/5 | SYR4 |
| Fluoride | 847.5 µg/L 21% of the EPA limit 4000 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 3/5 | SYR4 |
| Copper | 54.61 µg/L 4.2% of the EPA limit 1300 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 797.4 µg/L — COLLOMSVILLE MUTUAL WATERWORKS · 250 people · 2019 | 5/5 | SYR4 |
| TTHM | 56.68 µg/L 71% of the EPA limit 80 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 4/5 | SYR4 |
| Chloroform | 48.23 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 4/5 | SYR4 |
| Lithium | 45.6 µg/L No EPA limit set Highest in the city: FOXCROFT MANOR MOBILE HOME PK · 200 people · 2024 | 1/5 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 28.29 µg/L 47% of the EPA limit 60 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 2/5 | SYR4 |
| Lead | 8.4945 µg/L 57% of the EPA limit 15 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 17.278 µg/L — OAK LYNN MANOR MOBILE HOME PK · 250 people · 2019 | 5/5 | SYR4 |
| Dichloroacetic Acid | 12.815 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 1/5 | SYR4 |
| Bromodichloromethane | 12.23 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 3/5 | SYR4 |
| Trichloroacetic Acid | 11.61 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 1/5 | SYR4 |
| Dibromochloromethane | 7.5735 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 3/5 | SYR4 |
| Bromoform | 1.4 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 4.7925 µg/L — AMERICAN TEMPO VILLAGE PARK · 88 people · 2016 | 2/5 | SYR4 |
| Chromium | 2.392 µg/L 2.4% of the EPA limit 100 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019
Highest in the city: 4.628 µg/L — AMERICAN TEMPO VILLAGE PARK · 88 people · 2018 | 4/5 | SYR4 |
| Monochloroacetic Acid | 1.365 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 1/5 | SYR4 |
| Dibromoacetic Acid | 1.285 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 1/5 | SYR4 |
| Arsenic | 1.02 µg/L 10% of the EPA limit 10 µg/L Highest in the city: AMERICAN TEMPO VILLAGE PARK · 88 people · 2018 | 3/5 | SYR4 |
| Xylenes, Total | 0.5200 µg/L 0% of the EPA limit 10000 µg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2019 | 1/5 | SYR4 |
| PFNA | 0.0097 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2024 | 1/5 | UCMR-5 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2025
Highest in the city: 0.0060 mg/L — AMERICAN TEMPO VILLAGE PARK · 88 people · 1996 | 5/5 | LCR |
| PFOS | 0.0051 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2024 | 1/5 | UCMR-5 |
| Pfpea | 0.0041 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2024 | 1/5 | UCMR-5 |
| PFHXS | 0.0036 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2024 | 1/5 | UCMR-5 |
| Pfhxa | 0.0035 µg/L No EPA limit set Main supplier: WILLIAMSPORT MUN WATER AUTH · 51,000 people · 2024 | 1/5 | UCMR-5 |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Williamsport
| Supplier | Population served |
|---|---|
| WILLIAMSPORT MUN WATER AUTH | 51,000 |
| OAK LYNN MANOR MOBILE HOME PK | 250 |
| COLLOMSVILLE MUTUAL WATERWORKS | 250 |
| FOXCROFT MANOR MOBILE HOME PK | 200 |
| AMERICAN TEMPO VILLAGE PARK | 88 |
Frequently asked questions about Williamsport tap water
Is Williamsport tap water safe to drink?
EPA testing detected 25 contaminants in the water serving Williamsport. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Williamsport?
5 public water suppliers report drinking-water monitoring for Williamsport, Pennsylvania to the EPA. Each is listed above with its population served.
What contaminants are in Williamsport's water?
The contaminants EPA monitoring detected in Williamsport include Nitrate, Barium, Fluoride, Copper, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.