We read 12 results from Dekalb’s 2024 water quality report. No results over a legal limit; 3 above a health goal or guideline.
Serves about 45,000 people · Water system ID IL0370100 · Read the district’s 2024 report (opens in a new tab)
Open this district in the water lookupCompare with your own test results, see the district map and get matched filters.
Results from the 2024 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Arsenichighest measured · range ND to 1.5 · listed as a violation in the report · Treatment plants · 2024 report, page 5 | 1.5 ppb | 0.004 ppb | 10 ppb | Above the health goal375x the health goal |
| Copper90th percentile of homes tested, 0 over the action level · listed as a violation in the report · sampled 2025 · Customer taps · 2024 report, page 5 | 0.57 ppm | 0.3 ppm | 1.3 ppm (action level) | Above the health goal1.9x the health goal |
| Lead90th percentile of homes tested, 5 over the action level · listed as a violation in the report · sampled 2025 · Customer taps · 2024 report, page 5 | 12 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal60x the health goal |
| Bariumhighest measured · range 0.14 to 0.69 · listed as a violation in the report · Treatment plants · 2024 report, page 5 | 0.69 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorinehighest measured · range 0.7 to 1 · listed as a violation in the report · sampled 2025 · Distribution system · 2024 report, page 5 | 0.9 ppm | None set | 4 ppm | Below the legal limit |
| Disinfection byproducts (HAA5)highest measured · range 6.84 to 9.52 · listed as a violation in the report · sampled 2025 · Distribution system · 2024 report, page 5 | 9.52 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest measured · range 10.7 to 17 · listed as a violation in the report · sampled 2025 · Distribution system · 2024 report, page 5 | 17 ppb | None set | 80 ppb | Below the legal limit |
| Fluoridehighest measured · range 0.46 to 0.77 · listed as a violation in the report · sampled 2025 · Treatment plants · 2024 report, page 5 | 0.77 ppm | 1 ppm | 4 ppm | Below the health goal |
| Ironhighest measured · range 0.06 to 0.26 · listed as a violation in the report · Treatment plants · 2024 report, page 5 | 0.26 ppm | — | 0.3 ppm guideline | Within the guideline |
| Manganesehighest measured · range 0.0012 to 0.02 · listed as a violation in the report · printed as 19 ppb · Treatment plants · 2024 report, page 5 | 0.02 ppm | — | 0.05 ppm guideline | Within the guideline |
| Nitrate (as N)highest measured · range ND to 0.25 · listed as a violation in the report · sampled 2025 · Treatment plants · 2024 report, page 5 | 0.25 ppm | 10 ppm | 10 ppm | Below the health goal |
| Sodiumhighest measured · range 62 to 84 · listed as a violation in the report · Treatment plants · 2024 report, page 5 | 84 ppm | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper. 2 numbers we weren’t sure about are held back until a person checks.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Dekalb’s water between Apr 2023 and Oct 2023. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- Lithium18.9 ppbFound in 3 of 10 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)
Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Lead
Found: Copper, Lead
What removes it: Reverse osmosis or Certified carbon block or RO.
More districts: Illinois water quality · All states · Something look wrong? Tell us