DeKalb County, Illinois — public water systems
At a glance
43 active public water systems are filed under DeKalb County, Illinois in EPA's SDWIS records, together reporting 95,450 people served. The largest is Dekalb, which reports serving 40,290 people. 20 are community water systems serving people where they live; the other 23 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
43
Population served
95.5K
Community systems
20
Groundwater share
100%
How does DeKalb County compare with other Illinois counties?
DeKalb County has the 26th-most active public water systems among the 149 counties listed for active Illinois systems in EPA records; among the 104 with 3 or more systems, the median has 18. Its systems report 95,450 people served in total, the 18th-largest county figure in the state and 0.8% of the statewide total. The average system here reports serving 2,220 people, about 31% below the Illinois average of 3,204. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.
Where does DeKalb County's drinking water come from?
By primary water source, DeKalb County's active systems draw on groundwater (38, 88%) and purchased groundwater (5, 12%). Overall, all rely mainly on groundwater (including purchased groundwater) and none on surface water, compared with 82% and 18% across Illinois. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Dekalb, draws primarily on groundwater.
What kinds of water systems operate in DeKalb County?
DeKalb County's active systems break down as 20 community systems (47%), 2 non-transient non-community systems (4.7%) and 21 transient non-community systems (49%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (58%), local government (30%), public/private partnership (9.3%) and state government (2.3%).
Water systems in DeKalb County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Dekalb | DeKalb | 40,290 | Community | Groundwater |
| 2 | Sycamore | DeKalb | 18,500 | Community | Groundwater |
| 3 | Sandwich | DeKalb | 7,156 | Community | Groundwater |
| 4 | Northern Illinois University-Dekalb | DeKalb | 6,500 | Community | Purchased groundwater |
| 5 | Genoa | DeKalb | 5,298 | Community | Groundwater |
| 6 | Cortland | DeKalb | 4,398 | Community | Groundwater |
| 7 | Hinckley | DeKalb | 2,006 | Community | Groundwater |
| 8 | Kirkland | DeKalb | 2,000 | Community | Groundwater |
| 9 | Somonauk | DeKalb | 1,860 | Community | Groundwater |
| 10 | Waterman | DeKalb | 1,497 | Community | Groundwater |
| 11 | Kingston | DeKalb | 1,160 | Community | Groundwater |
| 12 | Malta | DeKalb | 1,143 | Community | Groundwater |
| 13 | Suburban Apartments (De Kalb Univ Dvl) | DeKalb | 1,050 | Community | Groundwater |
| 14 | Shabbona | DeKalb | 913 | Community | Groundwater |
| 15 | Cortland Corners MHP | DeKalb | 205 | Community | Groundwater |
| 16 | Kishwaukee College | DeKalb | 200 | Non-transient non-community | Groundwater |
| 17 | Buck Lake Estates Subdivision | DeKalb | 150 | Community | Groundwater |
| 18 | Triangle Manufactured Home Community | DeKalb | 124 | Community | Purchased groundwater |
| 19 | Valley View Subdivision (Dekalb) | DeKalb | 120 | Community | Groundwater |
| 20 | Sycamore Park District - Soccer Fields | DeKalb | 100 | Transient non-community | Groundwater |
| 21 | Sandwich Estates MHP | DeKalb | 90 | Community | Purchased groundwater |
| 22 | Sycamore Rv Resort | DeKalb | 75 | Transient non-community | Groundwater |
| 23 | Indian Oaks Country Club | DeKalb | 75 | Transient non-community | Groundwater |
| 24 | Bayer Co - Waterman Research Facility | DeKalb | 50 | Non-transient non-community | Groundwater |
| 25 | Walcamp Lutheran Retreat-Bathhouse North | DeKalb | 35 | Transient non-community | Groundwater |
| 26 | Donny Brook Estates Subdivision | DeKalb | 30 | Community | Groundwater |
| 27 | Meijer 313 | DeKalb | 25 | Transient non-community | Purchased groundwater |
| 28 | Harvest Chapel Assembly of God | DeKalb | 25 | Transient non-community | Groundwater |
| 29 | Franks Freshway Market - Genoa | DeKalb | 25 | Transient non-community | Purchased groundwater |
| 30 | Walcamp Lutheran Retreat-Bathhouse South | DeKalb | 25 | Transient non-community | Groundwater |
| 31 | Walcamp Lutheran Retreat-Kitchen | DeKalb | 25 | Transient non-community | Groundwater |
| 32 | Walcamp Lutheran Retreat-Pavillion | DeKalb | 25 | Transient non-community | Groundwater |
| 33 | North Grove School Association | DeKalb | 25 | Transient non-community | Groundwater |
| 34 | Mayfield Congregational Church | DeKalb | 25 | Transient non-community | Groundwater |
| 35 | Gum Farm Hunt Club | DeKalb | 25 | Transient non-community | Groundwater |
| 36 | Dekalb County Animal League | DeKalb | 25 | Transient non-community | Groundwater |
| 37 | Waterman Winery and Vineyards Inc. | DeKalb | 25 | Transient non-community | Groundwater |
| 38 | Evangelical Lutheran Church | DeKalb | 25 | Transient non-community | Groundwater |
| 39 | Paw Paw Township Park | DeKalb | 25 | Transient non-community | Groundwater |
| 40 | Trinity Lutheran Church Genoa | DeKalb | 25 | Transient non-community | Groundwater |
| 41 | Sandwich Sportsmans Club | DeKalb | 25 | Transient non-community | Groundwater |
| 42 | Calvary Lutheran Church | DeKalb | 25 | Transient non-community | Groundwater |
| 43 | Jonamac Orchard | DeKalb | 25 | Transient non-community | Groundwater |
DeKalb County water systems: frequently asked questions
How many public water systems are in DeKalb County, Illinois?
EPA's SDWIS records file 43 active public water systems under DeKalb County, Illinois: 20 community systems (47%), 2 non-transient non-community systems (4.7%) and 21 transient non-community systems (49%).
Who supplies drinking water in DeKalb County, IL?
The largest community water systems filed under DeKalb County are Dekalb (40,290 people served), Sycamore (18,500 people served) and Sandwich (7,156 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.
Does DeKalb County's drinking water come from groundwater or surface water?
Of the 43 active public water systems in DeKalb County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Dekalb, uses groundwater.
Where can I find a water quality report for DeKalb County?
Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 20 community systems are filed under DeKalb County, so the report to look for is the one from the system that supplies your address.
How can I check violations for a water system in DeKalb County?
Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.
More Illinois water systems
- All Illinois public water systems· 3,872 active
- Grundy County· 51 systems
- Kankakee County· 50 systems
- Boone County· 47 systems
- Kendall County· 47 systems
- Sangamon County· 43 systems
- St. Clair County· 42 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Public water systems in DeKalb County, Illinois”, https://aquacensus.com/water-systems/illinois/dekalb (data as of October 1, 2026).