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Tap water quality report

Rock Falls, IL

EPA monitoring detected 20 contaminants across the 2 water suppliers serving Rock Falls. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

2
water suppliers
8,740
people served
20
contaminants found
Illinois rankings Lead in Illinois PFAS in Illinois

What was found in Rock Falls'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.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
1400 µg/L 14%
of the EPA limit 10000 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2019
1/2 SYR4
Fluoride
870.8 µg/L 22%
of the EPA limit 4000 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2018
1/2 SYR4
Copper
498.3999999999992 µg/L 38%
of the EPA limit 1300 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2017
2/2 SYR4
Nitrate-Nitrite
335.5 µg/L 3.4%
of the EPA limit 10000 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2018
1/2 SYR4
Barium
145.5 µg/L 7.3%
of the EPA limit 2000 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2018
1/2 SYR4
TTHM
75.55 µg/L 94%
of the EPA limit 80 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Chloroform
47.405 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Total Haloacetic Acids (HAA5)
30.854999999999997 µg/L 51%
of the EPA limit 60 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Bromodichloromethane
19.175 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Dichloroacetic Acid
18.259999999999998 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Arsenic
10.915 µg/L 109%
of the EPA limit, at the 95th percentile of samples — 10 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2018
1/2 SYR4
Lead
10.669999999999995 µg/L 71%
of the EPA limit 15 µg/L
Main supplier: ROCK FALLS · 8,620 people · 2017
2/2 SYR4
Trichloroacetic Acid
10.605 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Dibromochloromethane
10.135 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Dibromoacetic Acid
2.77 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Bromoform
2.4739999999999998 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
2/2 SYR4
Monobromoacetic Acid
1.59 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2019
1/2 SYR4
Combined Radium (-226 And -228)
0.8700 pCi/L 17%
of the EPA limit 5 pCi/L
Main supplier: ROCK FALLS · 8,620 people · 2016
1/2 SYR4
Pfba
0.0110 µg/L
No EPA limit set
Main supplier: ROCK FALLS · 8,620 people · 2025
1/2 UCMR-5
Lead
0.0044 mg/L 29%
of the EPA limit 0.0150 mg/L
Main supplier: ROCK FALLS · 8,620 people · 2025
Highest in the city: 0.0072 mg/L — RIVERSIDE MHP, LLC · 120 people · 2025
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 Rock Falls

SupplierPopulation served
ROCK FALLS 8,620
RIVERSIDE MHP, LLC 120

Frequently asked questions about Rock Falls tap water

Is Rock Falls tap water safe to drink?

EPA testing detected 20 contaminants in the water serving Rock Falls. 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 Rock Falls?

2 public water suppliers report drinking-water monitoring for Rock Falls, Illinois to the EPA. Each is listed above with its population served.

What contaminants are in Rock Falls's water?

The contaminants EPA monitoring detected in Rock Falls include Nitrate, Fluoride, Copper, Nitrate-Nitrite, Barium. 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.