What was found in Westlake'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 |
|---|---|---|---|
| Copper | 400 µg/L 31% of the EPA limit 1300 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 800 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Barium | 188.5 µg/L 9.4% of the EPA limit 2000 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 326 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Fluoride | 310 µg/L 7.8% of the EPA limit 4000 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019 | 2/2 | SYR4 |
| Lithium | 14 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2024
Highest in the city: 18.9 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2025 | 2/2 | UCMR-5 |
| TTHM | 8.405 µg/L 11% of the EPA limit 80 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 17.155 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 4.135 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 7.79 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 4.575 µg/L 7.6% of the EPA limit 60 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 5.305 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Bromoform | 2.145 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 4.995 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 2.15 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 4.745 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Gross Beta Particle Activity | 2.455 pCi/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 3.838 pCi/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Lead | 3.1 µg/L 21% of the EPA limit 15 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019 | 2/2 | SYR4 |
| Chloroform | 0.7680 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 3.06 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 2.2 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 2.87 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Combined Radium (-226 And -228) | 1.23195 pCi/L 25% of the EPA limit 5 pCi/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 2.1995 pCi/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 1.6 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019
Highest in the city: 1.855 µg/L — WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 1.0755 µg/L No EPA limit set Highest in the city: WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 1/2 | SYR4 |
| Monobromoacetic Acid | 0.9925 µg/L No EPA limit set Highest in the city: WESTLAKE CITY OF WATER SYSTEM · 4,858 people · 2019 | 1/2 | SYR4 |
| Dalapon | 0.9400 µg/L 0.5% of the EPA limit 200 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019 | 1/2 | SYR4 |
| Trichloroacetic Acid | 0.8080 µg/L No EPA limit set Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019 | 2/2 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 0.4900 µg/L 8.2% of the EPA limit 6 µg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2019 | 1/2 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: CALCASIEU PARISH WW DISTRICT NO 4 · 5,340 people · 2024 | 2/2 | 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 Westlake
| Supplier | Population served |
|---|---|
| CALCASIEU PARISH WW DISTRICT NO 4 | 5,340 |
| WESTLAKE CITY OF WATER SYSTEM | 4,858 |
Frequently asked questions about Westlake tap water
Is Westlake tap water safe to drink?
EPA testing detected 21 contaminants in the water serving Westlake. 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 Westlake?
2 public water suppliers report drinking-water monitoring for Westlake, Louisiana to the EPA. Each is listed above with its population served.
What contaminants are in Westlake's water?
The contaminants EPA monitoring detected in Westlake include Copper, Barium, Fluoride, Lithium, 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.