Illinois · system IL1990550 · serves 16,855 people · purchased water
This system purchases its water; the band reflects the supplier's most recent reported result within a rolling three-year window. The three-year range below is the supplier's, not this system's own sampling. The water comes from Rend Lake Inter-City Water System (IL0555100).
The reading
A single reading is not a complete account of what a household drinks, so the three-year range and the number of tests behind it are shown too — a reading backed by many tests over three years is a fuller picture than one from a single sample.
Source: purchased water - values inherited from IL0555100 · Illinois · system IL1990550 · the three years from August 9, 2023 to August 9, 2026
Where this ranks
The water this system purchases sits near the low end nationally. Systems reporting less serve about 9% of everyone on NitrateSmart's tracked supply; the other about 91% are on systems reporting the same or more. That compares what systems reported, not what comes out of any one tap.
What "Natural background" means
This system's nitrate sits within the range that occurs naturally in groundwater[1]. There is no sign of a human fingerprint in the water. It is a statement about the source, not a clean bill of health — nitrate is only one thing a water test looks at.
Sources
The bands describe how strongly human activity, read from nitrate, has marked a water source — they are not a safety verdict. More on what the numbers mean and where nitrate comes from.
Nitrate in community water systems, from the utilities’ own compliance reporting.
Results reaching back to July 2023 · current through August 9, 2026.
Educational information, not medical or personal safety advice.