Is Rowland Heights, CA Tap Water Safe? Quality & Contaminants

What was found in Rowland Heights'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
TTHM	61.34999999999998 µg/L 77% of the EPA limit 80 µg/L Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Lithium	48 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2023	1/1	UCMR-5
Total Haloacetic Acids (HAA5)	25.4 µg/L 42% of the EPA limit 60 µg/L Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Chloroform	24.575 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Dibromochloromethane	22.325 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Bromodichloromethane	19.389999999999997 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Dichloroacetic Acid	13.229999999999995 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Bromoform	8.459999999999992 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Dibromoacetic Acid	7.2 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Trichloroacetic Acid	7.149999999999994 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Monochloroacetic Acid	3.19 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Monobromoacetic Acid	1 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2019	1/1	SYR4
Pfba	0.0100 µg/L No EPA limit set Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2023	1/1	UCMR-5
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: ROWLAND WATER DISTRICT · 56,100 people · 2024	1/1	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 Rowland Heights

Supplier	Population served
ROWLAND WATER DISTRICT	56,100

Frequently asked questions about Rowland Heights tap water

Is Rowland Heights tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Rowland Heights. 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 Rowland Heights?

1 public water supplier report drinking-water monitoring for Rowland Heights, California to the EPA. Each is listed above with its population served.

What contaminants are in Rowland Heights's water?

The contaminants EPA monitoring detected in Rowland Heights include TTHM, Lithium, Total Haloacetic Acids (HAA5), Chloroform, Dibromochloromethane. 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.