PFOS
1.3× the limitPerfluorooctanesulfonic acid
5ng/L
Each block = 4.0 ng/L federal MCL (2024)
EPA UCMR 5 · sampled 2024Evidence
Fox Lake serves 11,780 people from groundwater. 32 results are on record. Copper (90th percentile) is above its federal limit, and PFOS had a sample above a 2024 EPA limit (not a violation: the limit is judged on a yearly average, due 2029); lithium sits above a screening level.
Each bar is drawn in blocks of its own limit, so the length shows how far above it the result sits.
5ng/L
Each block = 4.0 ng/L federal MCL (2024)
1.58mg/L
Each block = 1.3 mg/L federal action level
3,409service lines inventoried
From the utility's inventory reported to EPA (2026Q2). Look up your address with the utility.
0health-based violations in the last 10 years
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.
No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.
A federal limit (an MCL or action level) is an enforceable legal cap; a health goal is often stricter. Meeting the limit is a compliance fact, not a health clearance, and PurityMap publishes no overall compliance verdict.
Plumbing inside a home can add lead that the system record can't show. A tap test tells you what reaches your glass.
PFOS 5 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024 (+1 more PFAS detected)
lead 3.2 µg/L, below the 15 µg/L action level
Understand water treatment technologies →
Understand:PFAS in Fox LakeGeneral guide: Copper (90th percentile)Lead in Fox Lake
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Screening: quick check, not lab-grade
Silver Lake Research
Lead, bacteria, nitrate, copper, iron, chlorine, hardness and pH
FOX LAKE (PWS ID IL0970200) is a public water system serving 11,780 people in Fox Lake, Illinois.
FOX LAKE is on record as drawing from groundwater. The source shapes which contaminants matter most for this system.
PurityMap's record for FOX LAKE holds 32 findings: 3 above a reference, 1 detected within the reference, 1 detected with no limit and 27 not detected, from 32 evidence records. Every finding links to its source; a substance that was never monitored is shown as pending, not as a pass.
PurityMap does not issue a safety verdict. It publishes FOX LAKE's measured results against each contaminant's benchmark so you can read them in context. Safety depends on the specific finding, your plumbing, and how the water reaches your tap.
The latest published record for FOX LAKE is dated 2026-10-15. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.
No. It is assessed at the water-system level from FOX LAKE's own monitoring. It does not cover the service line to your building or the plumbing inside it, which can add lead and other metals after the water leaves the system. A tap test is the way to know what reaches your glass.
Perfluorooctanesulfonic acid (PFOS), Copper (90th percentile), Lithium, Lead (90th percentile) and Perfluoropentanoic acid (PFPeA) were detected in this record. Each finding shows its measured value, its reference and its source on this page.
Start with what the record shows: the PFAS findings above list each measured value against its reference. This record cannot show your home's plumbing, so a tap test tells you what reaches your glass. If you decide to treat your water, look for a filter whose certification covers the specific PFAS compounds in your record; the section "Certified for a concern found here" lists only products with a current certification record for these concerns.
Start with what the record shows: the lead findings above list each measured value against its reference. This record cannot show your home's plumbing, so a tap test tells you what reaches your glass. If you decide to treat your water, look for a filter whose certification covers the specific contaminant in your record; the section "Certified for a concern found here" lists only products with a current certification record for these concerns.
Follow Fox Lake
One email when a new sampling round is published, a result moves above or below its reference, or the system's score changes.
Follow this water →As listed for this system in EPA's records. Your water bill names your supplier.
| Substance | Result | Reference | Sampled | Status | Evidence |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | 2024-02-27 to 2024-08-12 | Not detected | — |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit) | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | 2024-02-27 to 2024-08-12 | Not detected | View evidence |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | 2024-02-27 to 2024-08-12 | Not detected | View evidence |
| Perfluorooctanesulfonic acid (PFOS) | 5 ng/L | 4.0 ng/L federal MCL (2024) | 2024-02-27 to 2024-08-12 | Above guideline | View evidence |
| Perfluoropentanoic acid (PFPeA) | 3.5 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Detected, no limit | View evidence |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | 2024-02-27 to 2024-08-12 | Not detected | — |
| Lithium | 10.6 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit) | 2024-02-27 to 2024-08-12 | Above guideline | View evidence |
| Lead (90th percentile) | 3.2 µg/L | 15 µg/L federal action level | 2026–2026 monitoring period (still open) | Below limit | View evidence |
| Copper (90th percentile) | 1.58 mg/L | 1.3 mg/L federal action level | 2025–2025 monitoring period | Above guideline | View evidence |
UCMR5 Analytical Results
UCMR5 Analytical Results: FOX LAKE (IL0970200)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: FOX LAKE (IL0970200)
US EPA SDWIS
What it can't tell you: Each test gives a yes/no or a rough range, not a lab number, and it cannot detect PFAS or arsenic.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
When your results arrive, read them here → · Compare every kit we list
★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOS and lead.
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| ★ Best choice | Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200) | Certified for PFOS (NSF/ANSI 53, WQA) | $$ | Check price on Amazon |
| Also good | Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M) | Certified for PFOS (NSF/ANSI 53, WQA) | $$ | Check price at Aquasana |
| Also good | Aquasana Clean Water Machine Countertop Filter (AQ-CWM2) | Certified for PFOS (NSF/ANSI 53, WQA) | $$ | Check price at Aquasana |
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| Also good | SmartFlow® Reverse Osmosis | Certified for PFOS (NSF/ANSI 53 (includes P473), WQA) | $$$ | Check price at Aquasana |
| Also good | Waterdrop G3P600 Tankless Reverse-Osmosis System | Certified for PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price at Waterdrop |
| Also good | Waterdrop G3P800 Tankless Reverse-Osmosis System |
★ Best choice: HealthShield™, certified for PFOS.
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| ★ Best choice | HealthShield™ | Certified for PFOS (NSF/ANSI 53, WQA) | $$$$ | Check price at Aquasana |
| $ Budget pick | iSpring WGB32B-PFKS PFAS & Heavy Metals Whole House FilterUse code REFISPRING at checkout: 10% off your first iSpring order. | Brand lab-tested for PFAS, not independently certified for PFOS and Perfluoropentanoic acid (PFPeA) | $$$ | Check price at iSpring |
Also: lead picks →
Certified filters for copper (90th percentile) and lithium →
PurityMap earns a commission from these links. "Best choice" and "Budget pick" go to certified products first; commission never decides them. As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Lead service lines
FOX LAKE reported 70 lead and 32 galvanized service lines to replace in EPA’s inventory (2026Q2). Many utilities replace these lines for free or share the cost. Ask FOX LAKE whether your home’s line is on its list before you pay anyone.
Local help
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
| $$$ |
| Check price at Waterdrop |
| Also good | AquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100) | Certified for PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
| Also good | AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000) | Certified for PFOS (NSF/ANSI 53, IAPMO) | $$$ | Check price on Amazon |
| Also good | Patriot Pure Ultimate Water Filtration System | Certified for PFOS (NSF/ANSI 53, NSF, IAPMO) | $$ | Check price on Amazon |
| Also good | iSpring RCC7AK Alkaline Reverse Osmosis SystemUse code REFISPRING at checkout: 10% off your first iSpring order. | Brand lab-tested for PFAS, not independently certified for PFOS and Perfluoropentanoic acid (PFPeA) | $$ | Check price at iSpring |
| Also good | iSpring RO5004F Tankless Reverse Osmosis System with UVUse code REFISPRING at checkout: 10% off your first iSpring order. | Brand lab-tested for PFAS, not independently certified for PFOS and Perfluoropentanoic acid (PFPeA) | $$$ | Check price at iSpring |
| Also good | Waterdrop X12 Reverse Osmosis System | Brand lab-tested for PFAS, not independently certified for PFOS and Perfluoropentanoic acid (PFPeA) | $$$$ | Check price at Waterdrop |