Skip to content
AquaCensus

Rock Island County, Illinois — public water systems

At a glance

102 active public water systems are filed under Rock Island County, Illinois in EPA's SDWIS records, together reporting 162,391 people served. The largest is Moline, which reports serving 44,500 people. 48 are community water systems serving people where they live; the other 54 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

102

Population served

162.4K

Community systems

48

Groundwater share

90.2%

How does Rock Island County compare with other Illinois counties?

Rock Island County has the 10th-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 162,391 people served in total, the 14th-largest county figure in the state and 1.3% of the statewide total. The average system here reports serving 1,592 people, about half of 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 Rock Island County's drinking water come from?

By primary water source, Rock Island County's active systems draw on groundwater (87, 85%), purchased surface water (6, 5.9%), purchased groundwater (5, 4.9%) and surface water (4, 3.9%). Overall, 90% rely mainly on groundwater (including purchased groundwater) and 9.8% 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, Moline, draws primarily on surface water.

What kinds of water systems operate in Rock Island County?

Rock Island County's active systems break down as 48 community systems (47%), 9 non-transient non-community systems (8.8%) and 45 transient non-community systems (44%). 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 (66%), local government (16%), public/private partnership (16%) and state government (2%).

The 50 largest water systems in Rock Island County

🔒 Create a free account to export CSV
Active public water systems in Rock Island County, Illinois
#Water systemCountyPopulation servedTypeSource
1MolineRock Island44,500CommunitySurface water
2Rock IslandRock Island39,018CommunitySurface water
3East MolineRock Island21,374CommunitySurface water
4Rock Island Arsenal, Us ArmyRock Island7,800CommunitySurface water
5SilvisRock Island7,473CommunityPurchased surface water
6Niabi ZooRock Island5,000Transient non-communityGroundwater
7MilanRock Island4,945CommunityGroundwater
8Coal ValleyRock Island3,873CommunityGroundwater
9Carbon CliffRock Island2,134CommunityGroundwater
10Tyson Fresh Meats Inc.Rock Island2,100Non-transient non-communityPurchased surface water
11HamptonRock Island1,863CommunityPurchased surface water
12Port ByronRock Island1,678CommunityGroundwater
13Silvis Heights Water CorpRock Island1,450CommunityGroundwater
14Riverdale School District #100Rock Island1,340Non-transient non-communityGroundwater
15Il American-AndalusiaRock Island1,184CommunityGroundwater
16Rapids CityRock Island962CommunityGroundwater
17Constellation Energy Generation LLCRock Island950Non-transient non-communityGroundwater
18Mississippi Rapids Rest AreaRock Island930Transient non-communityGroundwater
19Sherrard Jr/Sr High SchoolRock Island800Non-transient non-communityGroundwater
20Clover Leaf Village MHPRock Island732CommunityPurchased surface water
21CordovaRock Island640CommunityGroundwater
22ReynoldsRock Island508CommunityGroundwater
23Mississippi Manufactured Home CommunityRock Island503CommunityPurchased surface water
24East Moline Correctional CenterRock Island500CommunityPurchased surface water
25Croppers 1st 4th and 5th AdditionRock Island495CommunityGroundwater
26Woodland A and B MHPRock Island490CommunityGroundwater
27Cedar Brook Estates SubdivisionRock Island450CommunityGroundwater
28High Cliff EstatesRock Island448CommunityPurchased groundwater
29Wildwood Baptist ChurchRock Island440Transient non-communityGroundwater
30Edgington Water DistrictRock Island391CommunityGroundwater
31Falcon FarmsRock Island350CommunityGroundwater
32Greater Quad City Auto AuctionRock Island340Non-transient non-communityGroundwater
33Snowstar Inc.Rock Island320Transient non-communityGroundwater
34Quad City Hitmen Sports ComplexRock Island300Transient non-communityGroundwater
35Ridgewood Ledges Water AssociationRock Island300CommunityGroundwater
363m Chemical Operations LLCRock Island300Non-transient non-communityGroundwater
37Illinois City Untd Methodist ChurchRock Island200Transient non-communityGroundwater
38Paradise Manor MHPRock Island200CommunityGroundwater
39Faith Walk World Outreach/CntrRock Island200Transient non-communityGroundwater
40Golfmohr Golf CourseRock Island200Transient non-communityGroundwater
41Air View MHPRock Island200CommunityGroundwater
42Taylor Ridge Elementary SchoolRock Island162Non-transient non-communityGroundwater
43East Lawn Water AssociationRock Island160CommunityGroundwater
44Duckys LagoonRock Island150Transient non-communityGroundwater
45Coyne Center CoopRock Island150CommunityGroundwater
46Ilcv Candle MHP, LLCRock Island148CommunityPurchased groundwater
47Oak Grove MHP - Rock Island CountyRock Island138CommunityGroundwater
48Indian Bluffs SubdivisionRock Island138CommunityGroundwater
49Illinois City Elementary SchooRock Island136Non-transient non-communityGroundwater
50Beulah Presbyterian ChurchRock Island120Transient non-communityGroundwater

All other water systems in Rock Island County (52)

The remaining active systems filed under Rock Island County, largest first, with the population each reports serving.

Rock Island County water systems: frequently asked questions

How many public water systems are in Rock Island County, Illinois?

EPA's SDWIS records file 102 active public water systems under Rock Island County, Illinois: 48 community systems (47%), 9 non-transient non-community systems (8.8%) and 45 transient non-community systems (44%).

Who supplies drinking water in Rock Island County, IL?

The largest community water systems filed under Rock Island County are Moline (44,500 people served), Rock Island (39,018 people served) and East Moline (21,374 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 Rock Island County's drinking water come from groundwater or surface water?

Of the 102 active public water systems in Rock Island County, 90% draw mainly on groundwater and 9.8% on surface water, counting purchased supplies. The largest system, Moline, uses surface water.

Where can I find a water quality report for Rock Island 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. 48 community systems are filed under Rock Island 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 Rock Island 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

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 Rock Island County, Illinois”, https://aquacensus.com/water-systems/illinois/rock-island (data as of October 1, 2026).