Is Arnold, CA Tap Water Safe? Quality & Contaminants

What was found in Arnold'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	128.5 µg/L 3.2% of the EPA limit 4000 µg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
TTHM	63.36 µg/L 79% of the EPA limit 80 µg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Chloroform	59.21899999999999 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Total Haloacetic Acids (HAA5)	56.82999999999999 µg/L 95% of the EPA limit 60 µg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Trichloroacetic Acid	37.45499999999998 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Dichloroacetic Acid	20.285000000000004 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Lithium	20 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2024	1/1	UCMR-5
Toluene	12.51 µg/L 1.3% of the EPA limit 1000 µg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Bromodichloromethane	12.08 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Monochloroacetic Acid	4.9399999999999995 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Arsenic	4.59 µg/L 46% of the EPA limit 10 µg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Dibromochloromethane	3.006 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Dibromoacetic Acid	1.7650000000000001 µg/L No EPA limit set Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 people · 2019	1/1	SYR4
Lead	0.0160 mg/L 107% above the EPA limit of 0.0150 mg/L Main supplier: BLUE LAKE SPRINGS MUT WTR · 4,841 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 Arnold

Supplier	Population served
BLUE LAKE SPRINGS MUT WTR	4,841

Frequently asked questions about Arnold tap water

Is Arnold tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Arnold. 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 Arnold?

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

What contaminants are in Arnold's water?

The contaminants EPA monitoring detected in Arnold include Fluoride, TTHM, Chloroform, Total Haloacetic Acids (HAA5), Trichloroacetic Acid. 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.