Rockdale, IL tap water
Supplied mostly by Rockdale, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chlorine or chloramine
Utilities here use chlorine or chloramine, depending on which one serves your address. Chlorine slowly gases off from standing water; chloramine doesn't.
Safety for fish and shrimp
Ammonia (with conditioner)
Estimate0.24–0.49 ppm (Low)
Typical 0.44 ppm
This is what a conditioner frees when it breaks the chloramine apart. A cycled filter clears it within a day.
Estimated from the chloramine level City of Joliet Department of Public Utilities reports (2025).
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2012–2019).
Nitrate (NO₃)
Up to 2.2 ppm (Low)
Typically not detected
Not detected in testing, so water changes lower your tank's nitrate well.
From EPA monitoring data; City of Joliet Department of Public Utilities' 2025 water quality report (2012–2025).
Copper at home taps (first draw)
1.01 ppm (High)
The 90th percentile of first-draw samples from homes: water that sat in household pipes for at least six hours.
Shrimp and snails are sensitive to copper. Water that sits in household pipes picks up the most; it drops once the tap has run for a minute.
Published by your utility: City of Joliet Department of Public Utilities' 2025 water quality report.
Chlorine or chloramine at the tap
1–2 ppm
Typical 1.8 ppm
At tap levels, chlorine and chloramine are toxic to fish, shrimp and the bacteria in a filter. Water conditioners are made for this range.
Published by your utility: City of Joliet Department of Public Utilities' 2025 water quality report.
Water chemistry
General hardness
206–377 ppm
Typical 291 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
Published by your utility: City of Joliet Department of Public Utilities' website.
Carbonate hardness (alkalinity)
270–390 ppm
Typical 380 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From EPA monitoring data (2017–2019).
pH
Area estimate6.6–7.5
Typical 7
Most community fish do well here. Stable water matters more than the exact number.
Area estimate from nearby wells: USGS well samples in your county (2001–2017).
Total dissolved solids
Area estimate177–1220 ppm
Typical 475 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
Area estimate from nearby wells: USGS well samples in your county (2007–2017).
- Rockdale and City of Joliet Department of Public Utilities add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Rockdale, IL
Rockdale
Serves 69% of residents · Groundwater (wells) · Chlorine
- 2025 water quality report
City of Joliet Department of Public Utilities
Serves 7% of residents · Groundwater (wells) · Chloramine
Our data comes from public records and is still incomplete. Many utilities don't publish every number, so we're adding more all the time. Your city's range is a starting point: testing your own tap is the only way to know exactly what's in it.
Tap water lookup covers US cities only for now. Want to know why it matters? Read our story on tap water.
Compiled by Shoal & Stem from public records. Free to cite with a link.