What was found in Portsmouth'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 | 1650 µg/L 17% of the EPA limit 10000 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Chlorite | 663.5 µg/L 66% of the EPA limit 1000 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Nitrate-Nitrite | 497.5 µg/L 5% of the EPA limit 10000 µg/L Highest in the city: PRUDENCE ISLAND WATER DISTRICT · 1,500 people · 2017 | 1/3 | SYR4 |
| Copper | 52.11 µg/L 4% of the EPA limit 1300 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 144.75 µg/L — PRUDENCE ISLAND WATER DISTRICT · 1,500 people · 2018 | 3/3 | SYR4 |
| TTHM | 107.25 µg/L 134% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Chloroform | 31.525 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 43.375 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2019 | 2/3 | SYR4 |
| Nitrite | 29 µg/L 2.9% of the EPA limit 1000 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 28.425 µg/L 47% of the EPA limit 60 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 20.475 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 21.2 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2019 | 2/3 | SYR4 |
| Dibromochloromethane | 20.125 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Lead | 10.125 µg/L 68% of the EPA limit 15 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 19.05 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2018 | 3/3 | SYR4 |
| Dichloroacetic Acid | 13 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 13.68 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2019 | 2/3 | SYR4 |
| Barium | 12 µg/L 0.6% of the EPA limit 2000 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Monochloroacetic Acid | 10.02 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 11.86 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2019 | 2/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 9.87 pCi/L 66% of the EPA limit 15 pCi/L Highest in the city: PRUDENCE ISLAND WATER DISTRICT · 1,500 people · 2018 | 1/3 | SYR4 |
| Bromoform | 7.9 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 4.2 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 3.9 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 2.4 µg/L 40% of the EPA limit 6 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Arsenic | 2 µg/L 20% of the EPA limit 10 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Chromium | 1.9 µg/L 1.9% of the EPA limit 100 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 2 µg/L — PRUDENCE ISLAND WATER DISTRICT · 1,500 people · 2018 | 2/3 | SYR4 |
| Combined Radium (-226 And -228) | 1.79 pCi/L 36% of the EPA limit 5 pCi/L Highest in the city: PRUDENCE ISLAND WATER DISTRICT · 1,500 people · 2018 | 1/3 | SYR4 |
| Monobromoacetic Acid | 1.48 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2019
Highest in the city: 1.72 µg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2019 | 2/3 | SYR4 |
| Selenium | 1 µg/L 2% of the EPA limit 50 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 2/3 | SYR4 |
| Simazine | 0.3000 µg/L 7.5% of the EPA limit 4 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Benzo(A)Pyrene | 0.2000 µg/L 100% of the EPA limit 0.2000 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Atrazine | 0.1000 µg/L 3.3% of the EPA limit 3 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Lasso | 0.1000 µg/L 5% of the EPA limit 2 µg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2019 | 1/3 | SYR4 |
| Pfpea | 0.0061 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2024 | 1/3 | UCMR-5 |
| Pfba | 0.0059 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2024 | 1/3 | UCMR-5 |
| Pfhxa | 0.0051 µg/L No EPA limit set Main supplier: NEWPORT-CITY OF · 42,155 people · 2024 | 1/3 | UCMR-5 |
| Lead | 0.0044 mg/L 29% of the EPA limit 0.0150 mg/L Main supplier: NEWPORT-CITY OF · 42,155 people · 2027
Highest in the city: 0.0048 mg/L — PORTSMOUTH WATER & FIRE DISTRICT · 17,090 people · 2024 | 3/3 | LCR |
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 Portsmouth
| Supplier | Population served |
|---|---|
| NEWPORT-CITY OF | 42,155 |
| PORTSMOUTH WATER & FIRE DISTRICT | 17,090 |
| PRUDENCE ISLAND WATER DISTRICT | 1,500 |
Frequently asked questions about Portsmouth tap water
Is Portsmouth tap water safe to drink?
EPA testing detected 32 contaminants in the water serving Portsmouth. 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 Portsmouth?
3 public water suppliers report drinking-water monitoring for Portsmouth, Rhode Island to the EPA. Each is listed above with its population served.
What contaminants are in Portsmouth's water?
The contaminants EPA monitoring detected in Portsmouth include Nitrate, Chlorite, Nitrate-Nitrite, 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.