Is Onset, MA Tap Water Safe to Drink?
Onset tap water meets federal Safe Drinking Water Act standards but 1 of 1 ZIP code show detections above EPA health guidelines, primarily for PFOS. A certified filter is recommended for households that want an additional layer of protection.
Where Does Onset Get Its Water?
Water in Onset, MA is provided by 1 public water system: ONSET FIRE DISTRICT.
What's in Onset Tap Water?
The following contaminants were detected most frequently in Onset public water systems. 1 of 1 ZIP codes showed detections above EPA health guidelines.
| Contaminant | Peak detected | EPA guideline | ZIPs detected | Status |
|---|---|---|---|---|
| PFOS | 0.0071 µg/L | 0.004 µg/L | 1 ZIP | Above guideline |
| lithium | 9 µg/L | — | 0 ZIPs | Within guideline |
| PFTrDA | 0.007 µg/L | — | 0 ZIPs | Within guideline |
| 8:2 FTS | 0.005 µg/L | — | 0 ZIPs | Within guideline |
| 11Cl-PF3OUdS | 0.005 µg/L | — | 0 ZIPs | Within guideline |
Health Risk Profile for Onset
Based on EPA monitoring data, 1 of 1 ZIP codes in Onset have recorded detections above EPA health guidelines. Sensitive populations such as infants, pregnant individuals, and those with weakened immune systems may benefit from an additional layer of protection such as a certified point-of-use filter.
Best Filters for PFAS Water Profile
PFAS compounds are detected in this water supply. A reverse osmosis (RO) system or an activated-carbon filter specifically certified under NSF/ANSI P473 is required for reliable PFAS reduction. Standard pitcher and faucet filters without P473 certification do not remove PFAS.
8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.
NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.
See recommendations matched to your exact address: choose your ZIP code below.
Frequently Asked Questions about Onset Tap Water
Is Onset tap water safe to drink?
Onset tap water meets Safe Drinking Water Act requirements but 1 of 1 ZIP codes show contaminant levels above EPA health-based guidelines. A certified point-of-use filter adds an extra layer of protection.
What contaminants are in Onset tap water?
The most commonly detected contaminants in Onset water systems include: PFOS, lithium, PFTrDA. See the ZIP-level reports for exact measurements and EPA guideline comparisons.
Where does Onset get its drinking water?
Onset receives water from one public water system, including ONSET FIRE DISTRICT.
Do I need a water filter in Onset?
If your ZIP code is among those with detections above EPA health guidelines, choose a filter certified for the specific contaminants shown in your ZIP report. Reverse osmosis is generally the broadest option for PFAS, lithium, and many other dissolved contaminants.
How often is Onset tap water tested?
Public water systems in Onset are required by the EPA to test for regulated contaminants on schedules ranging from daily (for microbials and disinfectants) to annual or triennial (for many chemical contaminants). Results are published in annual Consumer Confidence Reports (CCRs). The data on this page reflects the most recent available EPA monitoring results, with the latest sample date of 2025-06-24.
Tap water reports by ZIP in Onset
- 02558 - Onset tap water report Higher concern
Water utilities serving Onset, MA
Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.
- ONSET FIRE DISTRICTAction advised
Also covers / overlaps with
- Wareham, MA · Township