Is Rockwall, TX Tap Water Safe? Quality & Contaminants

What was found in Rockwall'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	696 µg/L 54% of the EPA limit 1300 µg/L Main supplier: CITY OF ROCKWALL · 55,250 people · 2017 Highest in the city: 1055 µg/L — R C H WSC · 7,863 people · 2018	3/3	SYR4
TTHM	55.8 µg/L 70% of the EPA limit 80 µg/L Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 67.92 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Total Haloacetic Acids (HAA5)	29.8 µg/L 50% of the EPA limit 60 µg/L Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 39.49 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Bromoform	5.7 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 26.32 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Chloroform	16.6 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 24.42 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Bromodichloromethane	20.2 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 24.41 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Dichloroacetic Acid	17.2 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 17.21 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Monobromoacetic Acid	4.74 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 16.02 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Dibromochloromethane	15.4 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019	3/3	SYR4
Dibromoacetic Acid	7.74 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 9.91 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Monochloroacetic Acid	5.26 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 8.56 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Lead	5.625 µg/L 38% of the EPA limit 15 µg/L Main supplier: CITY OF ROCKWALL · 55,250 people · 2017 Highest in the city: 7.334 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Trichloroacetic Acid	5.4 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2019 Highest in the city: 6.84 µg/L — MOUNT ZION WSC · 2,028 people · 2019	3/3	SYR4
Pfba	0.0096 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2025	2/3	UCMR-5
Pfpea	0.0070 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2025 Highest in the city: 0.0075 µg/L — R C H WSC · 7,863 people · 2024	2/3	UCMR-5
Pfhxa	0.0063 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2025 Highest in the city: 0.0067 µg/L — R C H WSC · 7,863 people · 2024	2/3	UCMR-5
PFBS	0.0044 µg/L No EPA limit set Main supplier: CITY OF ROCKWALL · 55,250 people · 2025 Highest in the city: 0.0049 µg/L — R C H WSC · 7,863 people · 2024	2/3	UCMR-5
Lead	0.0022 mg/L 15% of the EPA limit 0.0150 mg/L Main supplier: CITY OF ROCKWALL · 55,250 people · 2025	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 Rockwall

Supplier	Population served
CITY OF ROCKWALL	55,250
R C H WSC	7,863
MOUNT ZION WSC	2,028

Frequently asked questions about Rockwall tap water

Is Rockwall tap water safe to drink?

EPA testing detected 18 contaminants in the water serving Rockwall. 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 Rockwall?

3 public water suppliers report drinking-water monitoring for Rockwall, Texas to the EPA. Each is listed above with its population served.

What contaminants are in Rockwall's water?

The contaminants EPA monitoring detected in Rockwall include Copper, TTHM, Total Haloacetic Acids (HAA5), Bromoform, Chloroform. 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.