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  1. PurityMap
  2. Water Quality
  3. Wisconsin
  4. FOND DU LAC WATERWORKSWI4200469
Change
Updated 2026-09-16
Water system record · WI4200469

Fond du Lac Waterworks

Fond du Lac Waterworks serves 44,678 people from groundwater. 31 results are on record. No measured result is above a legal limit; lithium sits above a screening level.

Explore the findingsIs this my supplier?Follow
Purity ScoreHow the 90 is builtWI4200469 · 44,678 served
90/100 · ExcellentConfidence: moderate
above a reference
1
detected, within reference or no limit
1
not detected
29
  • PFAS (forever chemicals)100
  • Metals & lead84
  • Disinfection by-products—Not monitored
  • Track record (violations)80

Subject scores out of 100. 3 of 4 subjects measured; disinfection pending a source.

Not in this score: Lithium. Listed in the findings, not graded by the Purity Score.

System-level record, not a test of your tap. How we score

Source
Groundwater
Serves 1 city area on record.
Population
44,678
as reported to EPA
Type
Community Water System
Wisconsin
Cities
1
Fond du Lac
Records
31 results
latest 2025
FindingsAll resultsComplianceWhat you can doProductsRecordsFAQ
What stands out

No measured result is above a legal limit

No measured result is above a legal limit; lithium sits above a screening level.

Coverage by group

31 results on record
  • PFAS (forever chemicals)
    29 not detected
  • Metals & lead
    1 detected
  • Disinfection by-products
    Not monitored
  • Other
    1 above
  • Above a limit or reference
  • Detected
  • Not detected
  • Not monitored
Every detected result

2 detected results, by distance from their limit

  • Li
    LithiumEPA UCMR 5 · 2023
    10 µg/L EPA health reference level (screening, not a legal limit)
    20µg/L
    Above screening
  • Pb
    Lead (90th percentile)EPA SDWIS (Lead & Copper Rule) · 2025
    15 µg/L federal action level
    6.1µg/L
    Within reference
29 other contaminants tested, none detected
  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Compliance and coverage

Lead service lines

16,049service lines inventoried

  • Lead3,116
  • Galvanized, to replace56
  • Material unknown377
  • Not lead12,500

From the utility's inventory reported to EPA (2026Q2). Look up your address with the utility.

Compliance

1health-based violation in the last 10 years

From EPA SDWIS. Counted once per contaminant per year, as in the Track record score.

Not in this recordDisinfection by-products weren't monitored in this dataset

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.

What you can do

Test first, then treat what was found

  1. 01 · TestTest your own tap

    Plumbing inside a home can add lead that the system record can't show. A tap test tells you what reaches your glass.

    Certified lab
    How to test your tap →
  2. 02 · LeadLead-certified carbon filter, or reverse osmosis

    lead 6.1 µg/L, below the 15 µg/L action level

    NSF/ANSI 53 (lead)
    Treatment for Lead →
  3. 03 · LithiumDepends on the contaminant

    Lithium 20 µg/L, above the 10.0 µg/L EPA health reference level

    The certifier's listing for each named contaminant
    Treatment for Lithium →

Understand water treatment technologies →

Understand:Lead in Fond du Lac

Test your own tap

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

    Safe Home DIY Lead in Drinking Water Combo Test Kit

    Safe Home (EnviroTestKits)

    Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb

    • Turnaround: 5 minutes

    What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.

    Check price on Amazon
  • Lab-certified results

    ETR Labs Basic Water Quality Test Kit

    ETR Laboratories

    50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria

    • Analyzed by Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638
    • Turnaround: 2–4 business days after the lab receives it

    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.

    Check price on Amazon
Commercial

Certified for a concern found here

Each card names which of this system’s findings its current certification covers, and which it doesn’t.

As an Amazon Associate, PurityMap earns from qualifying purchases. A product appears here only when a current certification record covers at least one identified concern; every concern stays listed. The retail offer is looked up afterwards and never changes which products appear or their order. Affiliate disclosure.

Under-Sink Filter

Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M)

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (5)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
  • Anyone who can't plumb, drill or hire an installer
  • Renters who can't modify plumbing
See the evidenceCheck price on Amazon
Countertop System

Aquasana Clean Water Machine Countertop Filter (AQ-CWM2)

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (3)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
See the evidenceCheck price on Amazon
See all 9 products certified for a concern in this system →
Countertop System

AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000)

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (3)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
See the evidenceCheck price on Amazon
Water Pitcher

Culligan ZeroWater 10-Cup Pitcher (ZEROP10)

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (3)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
See the evidenceCheck price on Amazon
Faucet Attachment

Faucet-Mount Filter

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (3)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
See the evidenceCheck price on Amazon
Under-Sink Filter

Under-Sink Carbon Block Filter

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (4)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
  • Anyone who can't plumb, drill or hire an installer
See the evidenceCheck price on Amazon
Under-Sink Filter

Under-Sink Reverse-Osmosis System

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (5)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
  • Anyone who can't plumb, drill or hire an installer
  • Renters who can't modify plumbing
See the evidenceCheck price on Amazon
Under-Sink Filter

Waterdrop G3P600 Tankless Reverse-Osmosis System

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (5)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
  • Anyone who can't plumb, drill or hire an installer
  • Renters who can't modify plumbing
See the evidenceCheck price on Amazon
Refrigerator Filter

Whirlpool Filter 3 Refrigerator Water Filter (WHR3RXD1)

  • ✓Lead: eligible, evidence match
  • –Not established: Lithium
Not suitable for (3)
  • Treating every tap in the home
  • A whole-home hard-water or scale problem
  • All PFAS: its evidence covers only the compounds it names
See the evidenceCheck price on Amazon
Questions

Frequently asked questions

Who does FOND DU LAC WATERWORKS serve?

FOND DU LAC WATERWORKS (PWS ID WI4200469) is a public water system serving 44,678 people in Fond du Lac, Wisconsin.

Where does FOND DU LAC WATERWORKS get its water?

FOND DU LAC WATERWORKS is on record as drawing from groundwater. The source shapes which contaminants matter most for this system.

What does FOND DU LAC WATERWORKS's monitoring record show?

PurityMap's record for FOND DU LAC WATERWORKS holds 31 findings: 1 above a reference, 1 detected within the reference and 29 not detected, from 31 evidence records. Every finding links to its source; a substance that was never monitored is shown as pending, not as a pass.

Is FOND DU LAC WATERWORKS's water safe to drink?

PurityMap does not issue a safety verdict. It publishes FOND DU LAC WATERWORKS'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.

How current is this FOND DU LAC WATERWORKS data?

The latest published record for FOND DU LAC WATERWORKS is dated 2026-09-16. Utilities report on regulatory cycles, so results reflect the monitoring period rather than a live reading.

Does this assessment represent my home's tap water?

No. It is assessed at the water-system level from FOND DU LAC WATERWORKS'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.

What contaminants were detected in FOND DU LAC WATERWORKS?

Lithium and Lead (90th percentile) were detected in this record. Each finding shows its measured value, its reference and its source on this page.

What should I do if I'm concerned about lead in FOND DU LAC WATERWORKS's water?

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 this water

Follow Fond du Lac Waterworks

One email when a new sampling round is published, a result moves above or below its reference, or the system's score changes.

Double opt-in: we email a confirmation link. Unsubscribe anytime. No spam.

Cities served by this system
  • Fond du Lac

As listed for this system in EPA's records. Your water bill names your supplier.

Sources and dataAll 31 records and their sourcesEPA UCMR 5 · EPA SDWIS (Lead & Copper Rule)+
SubstanceResultReferenceSampledStatusEvidence
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)< 5 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)< 5 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)< 5 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)< 2 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)< 5 ng/L10 ng/L federal MCL (2024)2023-03-21 to 2023-10-09Not detected—
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)< 5 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)< 20 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)< 6 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorobutanoic acid (PFBA)< 5 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorobutanesulfonic acid (PFBS)< 3 ng/L2,000 ng/L EPA health advisory (screening, not a legal limit)2023-03-21 to 2023-10-09Not detected—
Perfluorodecanoic acid (PFDA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorododecanoic acid (PFDoA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoroheptanoic acid (PFHpA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoroheptanesulfonic acid (PFHpS)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorohexanoic acid (PFHxA)< 3 ng/L400,000 ng/L Michigan EGLE state MCL (strictest US state)2023-03-21 to 2023-10-09Not detected—
Perfluorohexanesulfonic acid (PFHxS)< 3 ng/L10 ng/L federal MCL (2024)2023-03-21 to 2023-10-09Not detectedView evidence
Perfluoro-4-methoxybutanoic acid (PFMBA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoro-3-methoxypropanoic acid (PFMPA)< 4 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorononanoic acid (PFNA)< 4 ng/L10 ng/L federal MCL (2024)2023-03-21 to 2023-10-09Not detected—
Perfluorooctanoic acid (PFOA)< 4 ng/L4.0 ng/L federal MCL (2024)2023-03-21 to 2023-10-09Not detectedView evidence
Perfluorooctanesulfonic acid (PFOS)< 4 ng/L4.0 ng/L federal MCL (2024)2023-03-21 to 2023-10-09Not detectedView evidence
Perfluoropentanoic acid (PFPeA)< 3 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoropentanesulfonic acid (PFPeS)< 4 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorotetradecanoic acid (PFTA)< 8 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluorotridecanoic acid (PFTrDA)< 7 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Perfluoroundecanoic acid (PFUnA)< 2 ng/LNo federal or state limit; shown for transparency2023-03-21 to 2023-10-09Not detected—
Lithium20 µg/L10 µg/L EPA health reference level (screening, not a legal limit)2023-03-21 to 2023-10-09Above guidelineView evidence
Lead (90th percentile)6.1 µg/L15 µg/L federal action level2025–2025 monitoring periodBelow limitView evidence
  • UCMR5 Analytical Results

    UCMR5 Analytical Results: FOND DU LAC WATERWORKS (WI4200469)

    US EPA

    Published
    2026-01-15
    Newest sample
    2023-10-09
    Findings here
    30

    View source ↗Source record

  • State SDWIS Compliance Record

    Lead & Copper Rule 90th-percentile: FOND DU LAC WATERWORKS (WI4200469)

    US EPA SDWIS

    Published
    2026-07-09
    Newest sample
    2025
    Findings here
    1

    View source ↗Source record

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