PWSID IL0315185
OASIS MHP
Community water system based in Northbrook, IL
Service area on file with EPA: Cook County. EPA's recorded service area can be incomplete for regional authorities. The cities and counties above are what the utility has filed with EPA; the utility may serve additional areas.
- Population served
- 3,000
- Source
- Groundwater
- Status
- Active
At a glance
Recent tests are below federal safety limits
-
This utility's inventory reports no confirmed lead service lines and a low share of unclassified lines.
From the utility's published inventory · See details below
-
CDC's My Water's Fluoride listing does not report this system as fluoridating its drinking water.
Per CDC My Water's Fluoride · See details below
Risk classification follows EPA's published values for safe drinking water, with caution and concern bands reviewed by a clinician. Past resolved violations do not influence this card. See methodology.
Lead service line inventory
Utility reports no confirmed lead service lines
Oasis MHP (PWS) reports 0 confirmed lead service lines, 602 non-lead, 0 unknown (total 602) in its Illinois EPA Service Line Material Inventory (reporting year 2022).
- 0 confirmed lead service lines
- 0 galvanized requiring replacement (LCRI treats these as lead)
- 0 unknown (0.0% of total)
- 602 confirmed non-lead (100.0%)
- 602 total service lines in the system
What to do if your service line might be lead
- Ask your utility to check the service-line classification for your specific address. Many utilities provide a public address-lookup tool linked from the inventory page.
- Get on the replacement queue. Under the LCRI, utilities must replace all lead and galvanized-requiring- replacement lines within 10 years (clock generally starts November 2027). Some prioritize requests.
- Until the line is replaced: flush the tap 30 seconds after long stagnation, use cold water for drinking and cooking, and consider an NSF/ANSI 53 lead-rated tap filter.
- Talk to your clinician about a blood lead test for anyone in the home, especially a pregnant person or a child under 6. Lead in drinking water guide.
Inventory data sourced from Oasis MHP (PWS) (reporting date April 12, 2023; retrieved May 24, 2026 ; curator confidence: high ). Confirmed against the original source automatically each month; see methodology.
Lead and copper test results
The most recent measurement per contaminant from EPA's Lead and Copper Rule sampling.
Why only lead and copper, and not arsenic, nitrate, or others?
EPA's bulk SDWIS download is the only nationwide per-system sample data they publish, and it only includes the Lead and Copper Rule table. Values for other regulated contaminants (TTHMs, nitrate, arsenic, etc.) appear on this page only when they trigger a violation. For the full per-system contaminant suite, see the utility's annual Consumer Confidence Report (link further down the page).
| Contaminant | Most recent | Date | Risk |
|---|---|---|---|
| PB90 | 0 mg/L | December 31, 2024 | Below regulatory thresholds |
Data from EPA SDWIS (Lead and Copper Rule sample table) , last refreshed May 24, 2026.
Fluoride
Per CDC My Water's Fluoride
OASIS MHP does not add fluoride to its drinking water.
This system has not reported adding fluoride to its water on CDC's My Water's Fluoride listing. Natural fluoride may still be present at trace levels from the source water; the utility's annual water quality report has the latest measured concentration.
Source: CDC My Water's Fluoride, listed under OASIS MHP (Cook County). Verify on CDC's site .
Area context
Cook County, IL (2020 data)
- Community water systems
- 146 of 162 add fluoride
- Population on fluoridated water
- 4,899,999 of 4,938,611 (99.2%)
Illinois statewide (2020 data)
- Population on fluoridated water
- 11,457,094 of 11,640,823 (98.4%)
- Community water systems adding fluoride
- 1,639 of 1,815
Data from CDC My Water's Fluoride (per-system status) , last refreshed May 19, 2026.
Data from CDC Water Fluoridation Reporting System (state and county aggregates) , last refreshed May 16, 2026.
Compliance history
EPA-recorded violations against this system over the last 5 years.
How to read this section
Health-based violations are when a measured limit was exceeded; the measured concentration is shown alongside the EPA federal limit where SDWIS published it. Monitoring and reporting items are paperwork issues (missed sample dates, late filings) that do not themselves indicate unsafe water.
No health-based violations
No health-based violations on file in the last 5 years. EPA recorded 8 monitoring or reporting items (paperwork) during the same period.
8 monitoring and reporting item s (paperwork) · these are not health risks
| Period start | Relates to | Item | Status |
|---|---|---|---|
| September 1, 2021 | Tthm | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Tthm | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Total Haloacetic Acids (Haa5) | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Total Haloacetic Acids (Haa5) | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Tthm | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Tthm | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Total Haloacetic Acids (Haa5) | Monitoring and Reporting (DBP) | Resolved |
| September 1, 2021 | Total Haloacetic Acids (Haa5) | Monitoring and Reporting (DBP) | Resolved |
37 older violation s (5-10 years ago) · all paperwork (monitoring/reporting), none health-based , all resolved
| Period start | Relates to | Item | Measured level | Status |
|---|---|---|---|---|
| January 1, 2020 | Antimony, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Antimony, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Antimony, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Antimony, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Beryllium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Beryllium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Beryllium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Beryllium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Nickel | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Nickel | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Nickel | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Nickel | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Selenium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Selenium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Selenium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Selenium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Barium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Barium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Barium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Barium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Mercury | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Mercury | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Mercury | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Mercury | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Cadmium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Cadmium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Cadmium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Cadmium | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Total Polychlorinated Biphenyls (Pcb) | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Total Polychlorinated Biphenyls (Pcb) | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Total Polychlorinated Biphenyls (Pcb) | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Total Polychlorinated Biphenyls (Pcb) | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Thallium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Thallium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Thallium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2020 | Thallium, Total | Monitoring, Regular | — | Resolved |
| January 1, 2017 | Combined Radium (-226 and -228) | Monitoring, Regular | — | Resolved |
Data from EPA SDWIS (violation records) , last refreshed May 24, 2026.
Where to see every contaminant this utility tested for
EPA's bulk SDWIS dataset gives MyTapWater.us per-system measured values for lead and copper, plus violation records for everything else. To see every regulated contaminant this utility tested for in the past year (TTHMs, HAA5, nitrate, arsenic, fluoride, chromium, etc.) with measured values, read the utility's Consumer Confidence Report (CCR).
Every community water system is required by EPA to publish a CCR annually, by July 1, listing every contaminant they sampled, the measured value, the federal limit, and any health-based exceedances. Most utilities post the report online; some mail it with your bill.
How to find OASIS MHP's CCR:
- Search the web for "OASIS MHP consumer confidence report" . The PDF is usually on the utility's own website.
- Or call the utility directly. Their phone number is in the contact section below.
Other water systems in Cook County, IL
Compare nearby utilities by population served.
- CHICAGO
2.7M served · Cook County
- CICERO
83k served · CICERO
- SCHAUMBURG
76k served · SCHAUMBURG
- EVANSTON
74k served · EVANSTON
- ARLINGTON HEIGHTS
73k served · ARLINGTON HEIGHTS
Contact this utility
Public administrative contact information for this water system, as filed with the EPA. Use this to ask about your service line, request your home's lead status, or report a water quality issue.
- Administrator
- BARRON, JOSH
- Phone
- 847-827-6694
- Mailing address
- 900 Skokie BlvdSuite 285NORTHBROOK, IL 60062
Where this page's data comes from
Bundle released 2026-Q2, regenerated May 24, 2026. Each section above also shows its own source date so you can tell at a glance how fresh that part of the page is.
- EPA SDWIS bulk download — last refreshed May 24, 2026 (system info, violations, lead and copper samples).
- Lead service line inventory — last refreshed May 24, 2026 (from the utility's reported inventory).
- CDC My Water's Fluoride — last refreshed May 19, 2026 (per-system Yes/No fluoridation status).
- CDC Water Fluoridation Reporting System — last refreshed May 16, 2026 (state and county fluoridation aggregates).
Every value on this page is cross-verified before publication; read our methodology for the verification steps and corrections process.