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Tap water quality report

Arnold, MO

EPA monitoring detected 14 contaminants across the 5 water suppliers serving Arnold. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

5
water suppliers
38,712
people served
14
contaminants found
Missouri rankings Lead in Missouri PFAS in Missouri

What was found in Arnold's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
TTHM
134 µg/L 168%
of the EPA limit, in the worst sample — 80 µg/L
 2/5 SYR4
Chloroform
130 µg/L
No EPA limit set
 2/5 SYR4
Copper
115 µg/L 8.8%
of the EPA limit 1300 µg/L
 2/5 SYR4
Total Haloacetic Acids (HAA5)
68.6 µg/L 114%
of the EPA limit, in the worst sample — 60 µg/L
 2/5 SYR4
Dichloroacetic Acid
56.7 µg/L
No EPA limit set
 2/5 SYR4
Lead
36.4 µg/L 243%
of the EPA limit, in the worst sample — 15 µg/L
 2/5 SYR4
Dibromochloromethane
16.9 µg/L
No EPA limit set
 2/5 SYR4
Bromodichloromethane
15.4 µg/L
No EPA limit set
 2/5 SYR4
Monochloroacetic Acid
13 µg/L
No EPA limit set
 2/5 SYR4
Bromoform
9.38 µg/L
No EPA limit set
 1/5 SYR4
Monobromoacetic Acid
8.85 µg/L
No EPA limit set
 1/5 SYR4
Trichloroacetic Acid
8.66 µg/L
No EPA limit set
 2/5 SYR4
Dibromoacetic Acid
8.36 µg/L
No EPA limit set
 2/5 SYR4
Lead
0.0073 mg/L 48%
of the EPA limit 0.0150 mg/L
 5/5 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 single worst sample on record — 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

SupplierPopulation served
JEFFERSON COUNTY PWSD 1 21,113
JEFFERSON COUNTY PWSD 3 17,000
STARLING MHP 342
OZARK HILLS MHP 230
LYNN ACRES MHP 27

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?

5 public water suppliers report drinking-water monitoring for Arnold, Missouri 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 TTHM, Chloroform, Copper, Total Haloacetic Acids (HAA5), Dichloroacetic Acid. The full list, with the highest level found 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.