Short answer: No measured result is above a legal limit. Yarmouth Water Department serves 38,900 residents.
Your water bill or annual water quality report names your actual supplier.
YARMOUTH WATER DEPARTMENT (EPA PWSID MA4351000) delivers groundwater to 38,900 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.
1health-based violation in the last 10 years
From EPA SDWIS. Counted once per contaminant per year, as in the Track record score.
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.
Every filing is listed; the Track record score counts at most one per contaminant per year.
Resolved
to Resolved
Plumbing inside a home can add lead that the system record can't show. A tap test tells you what reaches your glass.
lead 1.5 µg/L, below the 15 µg/L action level (detected below the limit); 5 galvanized lines to replace (context, not a tap measurement)
PFHxS 3.1 ng/L, below the 10 ng/L limit (+4 more PFAS detected)
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 (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
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.
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 →
Each card names which South Yarmouth 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.
PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For South Yarmouth, PFAS were detected below their limits, and PFBA 12.7 ng/L, PFHpA 7.7 ng/L and PFPeA 59.4 ng/L with no federal or state limit; the lead 90th-percentile result was 1.5 µg/L against the 15 µg/L action level. YARMOUTH WATER DEPARTMENT (PWSID MA4351000) has a Purity Score of 92/100 (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.
YARMOUTH WATER DEPARTMENT (PWS ID MA4351000) is the public water system on record for South Yarmouth, Massachusetts, serving about 38,900 people. Confirm the utility on your water bill before acting on a specific finding.
Groundwater (primary source of record in EPA SDWIS).
In EPA's UCMR 5 testing (2025-01-13 to 2025-07-29), PFHxA was detected at 40.6 ng/L, below the 400,000 ng/L state limit and PFHxS was detected at 3.1 ng/L, below the 10 ng/L federal limit. PFBA (12.7 ng/L), PFHpA (7.7 ng/L) and PFPeA (59.4 ng/L) were also detected; they have no federal or state limit.
YARMOUTH WATER DEPARTMENT's most recent lead 90th-percentile result (2025) was 1.5 µg/L, below the 15 µg/L action level. That figure comes from sampled homes; lead usually enters from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.
PurityMap's current record for South Yarmouth holds 31 findings: 3 detected within the reference, 3 detected with no limit and 25 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass.
Follow South Yarmouth's water
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.
| Contaminant | Result | Benchmark | Status | Sampled | Source |
|---|---|---|---|---|---|
| Perfluorohexanesulfonic acid (PFHxS) | 3.1 ng/L | 10 ng/L federal MCL (2024) | Within a historical reference; current applicability unverified | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Lead (90th percentile) | 1.5 µg/L | 15 µg/L federal action level | Below the listed reference | 2025–2025 monitoring period | Lead & Copper Rule 90th-percentile: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorohexanoic acid (PFHxA) | 40.6 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Within a historical reference; current applicability unverified | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorobutanoic acid (PFBA) | 12.7 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoroheptanoic acid (PFHpA) | 7.7 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoropentanoic acid (PFPeA) | 59.4 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| 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 | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-01-13 to 2025-07-29 | UCMR5 Analytical Results: YARMOUTH WATER DEPARTMENT (MA4351000) |
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluoroheptanoic acid (PFHpA)
Perfluoropentanoic acid (PFPeA)
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)
Perfluorooctanesulfonic acid (PFOS)
Perfluoropentanesulfonic acid (PFPeS)
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: YARMOUTH WATER DEPARTMENT (MA4351000)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: YARMOUTH WATER DEPARTMENT (MA4351000)
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 Yarmouth Water Department reported something related, it's shown below.
Lead at Yarmouth Water Department: 1.5 µg/L (90th percentile, 2025 monitoring period). Lead has no taste, so a taste neither shows nor rules it out.
A ZIP code is a postal area, not a water service area. Your water bill names your supplier.