Public water system · IL3161448
ActiveNorthbrook Montessori School
At a glance
Northbrook Montessori School (PWSID IL3161448) is an active non-transient non-community water system in Cook County, Illinois. It reports serving 48 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
48
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Northbrook Montessori School compare with other water systems in Cook County?
By EPA's size categories, Northbrook Montessori School is a very small system (500 people or fewer). Cook County has 251 active public water systems. Its population served is well below the county average of 20,993 people per system, and accounts for less than 0.1% of the 5,269,212 people reported by systems filed under the county. Across Illinois, the 3,872 active systems average 3,204 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Northbrook Montessori School is well below that figure.
What does “non-transient non-community water system” mean?
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. Illinois has 396 active non-transient non-community water systems, 10% of the state's 3,872 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,808 Illinois systems (73%) list groundwater as their primary source.
Who owns and regulates Northbrook Montessori School?
EPA lists Northbrook Montessori School as privately owned. The IL state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 108 of the 251 active systems in Cook County (43%) are also privately owned.
Does Northbrook Montessori School have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2023. The violations listed here began between January 2023 and July 2023. By type: 11 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Public Notice, 1,1,2-Trichloroethane, p-Dichlorobenzene and Styrene. EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2023-07-22 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Northbrook Montessori School: frequently asked questions
Who runs Northbrook Montessori School?
Northbrook Montessori School (PWSID IL3161448) is a non-transient non-community water system privately owned. It is regulated by the IL state drinking water program.
How many people does Northbrook Montessori School serve?
Northbrook Montessori School reports serving 48 people through 1 service connection in Cook County, Illinois.
Where does Northbrook Montessori School get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Northbrook Montessori School have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2023. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Northbrook Montessori School's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2023. For current results, consult EPA ECHO, or the IL state drinking water program.
Where can I find Northbrook Montessori School's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Northbrook Montessori School is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Cook County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Chicago | Cook | 2,721,308 | Community | Surface water |
| Cicero | Cook | 83,000 | Community | Purchased surface water |
| Schaumburg | Cook | 75,750 | Community | Purchased surface water |
| Evanston | Cook | 74,486 | Community | Surface water |
| Arlington Heights | Cook | 73,320 | Community | Purchased surface water |
| Palatine | Cook | 70,875 | Community | Purchased surface water |
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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, “Northbrook Montessori School, PWSID IL3161448, Illinois”, https://aquacensus.com/water-systems/illinois/northbrook-montessori-school-il3161448 (data as of October 1, 2026).