What was found in Denison'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 |
|---|---|---|---|
| Fluoride | 430.4 µg/L 11% of the EPA limit 4000 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 1910 µg/L — STARR WSC · 3,100 people · 2019 | 2/6 | SYR4 |
| Copper | 169.2 µg/L 13% of the EPA limit 1300 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 1430 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2018 | 5/6 | SYR4 |
| Chlorite | 780 µg/L 78% of the EPA limit 1000 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 1/6 | SYR4 |
| Nitrate | 508.8 µg/L 5.1% of the EPA limit 10000 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 2/6 | SYR4 |
| Nitrate-Nitrite | 504 µg/L 5% of the EPA limit 10000 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2012 | 2/6 | SYR4 |
| Barium | 112.25 µg/L 5.6% of the EPA limit 2000 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 2/6 | SYR4 |
| TTHM | 91.13 µg/L 114% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 100.16 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2019 | 6/6 | SYR4 |
| Cyanide | 83.59 µg/L 42% of the EPA limit 200 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 1/6 | SYR4 |
| Chloroform | 54.42 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 59.08 µg/L — THOMPSON HEIGHTS WATER SYSTEM · 414 people · 2019 | 5/6 | SYR4 |
| Total Haloacetic Acids (HAA5) | 44.22 µg/L 74% of the EPA limit 60 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 45.22 µg/L — OAK RIDGE SOUTH GALE WSC · 3,153 people · 2019 | 6/6 | SYR4 |
| Dibromochloromethane | 38.8 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 41.275 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2019 | 6/6 | SYR4 |
| Bromoform | 30.665 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 33.24 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2019 | 6/6 | SYR4 |
| Dichloroacetic Acid | 24.31 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 27.69 µg/L — OAK RIDGE SOUTH GALE WSC · 3,153 people · 2019 | 5/6 | SYR4 |
| Bromodichloromethane | 24.045 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 25.54 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2019 | 6/6 | SYR4 |
| Lithium | 20.1 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2025 | 1/6 | UCMR-5 |
| Trichloroacetic Acid | 19.5 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019 | 5/6 | SYR4 |
| Dibromoacetic Acid | 15.15 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 15.5 µg/L — MUNSON POINT PROPERTY OWNERS ASSOCIATION · 87 people · 2019 | 6/6 | SYR4 |
| Lead | 4.1185 µg/L 27% of the EPA limit 15 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 11.795 µg/L — STARR WSC · 3,100 people · 2018 | 5/6 | SYR4 |
| Monobromoacetic Acid | 9 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 9.35 µg/L — THOMPSON HEIGHTS WATER SYSTEM · 414 people · 2019 | 5/6 | SYR4 |
| Selenium | 7.774 µg/L 16% of the EPA limit 50 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 2/6 | SYR4 |
| Gross Alpha, Excl. Radon And U | 7.62 pCi/L 51% of the EPA limit 15 pCi/L Highest in the city: STARR WSC · 3,100 people · 2015 | 1/6 | SYR4 |
| Monochloroacetic Acid | 4.9 µg/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 7.4 µg/L — OAK RIDGE SOUTH GALE WSC · 3,153 people · 2019 | 6/6 | SYR4 |
| Gross Beta Particle Activity | 5.1 pCi/L No EPA limit set Main supplier: CITY OF DENISON · 27,500 people · 2017 | 1/6 | SYR4 |
| Chromium | 5.046 µg/L 5% of the EPA limit 100 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 2/6 | SYR4 |
| Carbon Tetrachloride | 1.11 µg/L 22% of the EPA limit 5 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 2.83 µg/L — STARR WSC · 3,100 people · 2019 | 2/6 | SYR4 |
| Arsenic | 2.408 µg/L 24% of the EPA limit 10 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019
Highest in the city: 2.555 µg/L — STARR WSC · 3,100 people · 2018 | 2/6 | SYR4 |
| Combined Radium (-226 And -228) | 1.5 pCi/L 30% of the EPA limit 5 pCi/L Main supplier: CITY OF DENISON · 27,500 people · 2017 | 2/6 | SYR4 |
| Thallium, Total | 0.3170 µg/L 16% of the EPA limit 2 µg/L Main supplier: CITY OF DENISON · 27,500 people · 2019 | 1/6 | SYR4 |
| Lead | 0.0018 mg/L 12% of the EPA limit 0.0150 mg/L Main supplier: CITY OF DENISON · 27,500 people · 2025
Highest in the city: 0.0021 mg/L — THOMPSON HEIGHTS WATER SYSTEM · 414 people · 2025 | 5/6 | 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 Denison
| Supplier | Population served |
|---|---|
| CITY OF DENISON | 27,500 |
| OAK RIDGE SOUTH GALE WSC | 3,153 |
| STARR WSC | 3,100 |
| THOMPSON HEIGHTS WATER SYSTEM | 414 |
| MUNSON POINT PROPERTY OWNERS ASSOCIATION | 87 |
| GREATER TEXOMA UTILITY AUTHORITY | 0 |
Frequently asked questions about Denison tap water
Is Denison tap water safe to drink?
EPA testing detected 29 contaminants in the water serving Denison. 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 Denison?
6 public water suppliers report drinking-water monitoring for Denison, Texas to the EPA. Each is listed above with its population served.
What contaminants are in Denison's water?
The contaminants EPA monitoring detected in Denison include Fluoride, Copper, Chlorite, Nitrate, Nitrate-Nitrite. 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.