Short answer: No measured result is above a legal limit. Walnut Park Mutual Water Co. serves 16,180 residents.
Your water bill or annual water quality report names your actual supplier.
WALNUT PARK MUTUAL WATER CO. (EPA PWSID CA1910169) delivers groundwater to 16,180 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. Water hardness and disinfectant type are pending the utility's own annual report.
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.
The records describe the system. A certified lab test shows what reaches your glass.
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
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 →
PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Walnut Park, no regulated PFAS were detected in EPA's 2024 testing. WALNUT PARK MUTUAL WATER CO. (PWSID CA1910169) has a Purity Score of 100/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap.
WALNUT PARK MUTUAL WATER CO. (PWS ID CA1910169) is the public water system on record for Walnut Park, California, serving about 16,180 people. Confirm the utility on your water bill before acting on a specific finding.
Groundwater (primary source of record in EPA SDWIS).
None of the 29 PFAS in EPA's UCMR 5 testing (2023-09-18 to 2024-01-16) was detected. "Not detected" means below the lab's reporting limit, not proven zero.
Lead is not in Walnut Park's current published record. Lead usually enters from a building's own pipes and fixtures, so a certified home test is the way to know yours.
PurityMap's current record for Walnut Park holds 31 findings: 31 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass.
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| Contaminant | Result | Benchmark | Status | Sampled | Source |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Lead (90th percentile) | Non-Detect (ND) | 15 µg/L federal action level | Not detected above the reporting limit | 2024–2026 monitoring period (still open) | Lead & Copper Rule 90th-percentile: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Lithium | < 9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-09-18 to 2024-01-16 | UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169) |
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
Perfluoro-3-methoxypropanoic acid (PFMPA)
Perfluoro-4-methoxybutanoic acid (PFMBA)
Perfluorobutanesulfonic acid (PFBS)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluorooctanesulfonic acid (PFOS)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)
Every value is the published result from the cited public record. A reporting limit is the lowest level the method could reliably quantify; a non-detect is not a guarantee of zero.
UCMR5 Analytical Results
UCMR5 Analytical Results: WALNUT PARK MUTUAL WATER CO. (CA1910169)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: WALNUT PARK MUTUAL WATER CO. (CA1910169)
US EPA SDWIS
Methodology: how we analyze water. Prepared with AI assistance and reviewed by the PurityMap Editorial Team before publication.
Start with the hot-or-cold tap check. Where Walnut Park Mutual Water Co. reported something related, it's shown below.
Lead at Walnut Park Mutual Water Co.: not detected (90th percentile, 2024–2026 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.