Forest Lake, IL tap water
Supplied mostly by Lake Zurich, plus 2 other utilities. Here's what the water means for your fish.
Disinfectant
Chlorine
Your water is treated with chlorine. It slowly gases off from standing water, and any water conditioner removes it.
Safety for fish and shrimp
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2012–2018).
Nitrate (NO₃)
Not detected (Low)
Not detected in testing, so water changes lower your tank's nitrate well.
From EPA monitoring data; Aqua Illinois-Hawthorn Woods, which supplies Lake County Pw- Hawthorn Woods (2012–2019).
Water chemistry
General hardness
Area estimate211–704 ppm
Typical 312 ppm
Hard. Ideal for livebearers and African cichlids. Soft-water species may struggle to breed.
Area estimate from nearby wells: USGS well samples in your county (2000–2023).
Carbonate hardness (alkalinity)
270–313 ppm
Typical 281 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From EPA monitoring data; Aqua Illinois-Hawthorn Woods, which supplies Lake County Pw- Hawthorn Woods (2017–2019).
pH
Area estimate7.1–7.7
Typical 7.2
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 (2000–2023).
Total dissolved solids
Area estimate308–880 ppm
Typical 365 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 (2000–2023).
Who supplies Forest Lake, IL
Lake Zurich
Serves 67% of residents · Groundwater (wells) · Chlorine
Aqua Illinois-Hawthorn Woods
Serves 6% of residents · Groundwater (wells) · Chlorine
Lake County Pw- Hawthorn Woods
Serves 5% of residents · Buys water from Aqua Illinois-Hawthorn Woods · Chlorine
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.