Onset Fire Districtwater Dept., MA
Lead detected, under the action levels
Latest 90th-percentile lead: 3 ppb (monitoring period 2021-2023). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Onset Fire Districtwater Dept. at a glance
Onset Fire Districtwater Dept. serves about 5,392 people through 2,982 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Plymouth County, Massachusetts. EPA system ID: MA4310003; phone on file: 5082950603. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Onset Fire Districtwater Dept.'s lead record
Against the period ending 2020 (3 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Onset Fire Districtwater Dept. is 10 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 3 ppb |
| 2020 | 3 ppb |
| 2019 | 10 ppb |
| 2016 | 2 ppb |
How Onset Fire Districtwater Dept. compares
Of the 535 Massachusetts systems with a lead result, the median latest reading is 1.7 ppb; 13 are over 15 ppb right now and 66 have gone over at some point. Onset Fire Districtwater Dept.'s 3 ppb sits at the 71st percentile in Massachusetts and the 83rd nationally (higher means more lead).
Other water systems in Plymouth County
44 other systems share Plymouth County; 13 of them have a higher latest lead result than Onset Fire Districtwater Dept.. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Brockton Water Department | 105,788 | 4 ppb |
| Plymouth Water Department | 47,100 | 2.5 ppb |
| Weir River Water System | 45,339 | 0 (not detected) |
| Marshfield Water Department | 34,000 | 4 ppb |
| Abington/Rockland Joint Wtr. Works | 33,387 | 4 ppb |
| Mattapoisett River Valley W.D. | 29,600 | - |
| Bridgewater Water Department | 28,633 | 3 ppb |
| Wareham Fire District | 20,102 | 2 ppb |
| Scituate Water Division | 19,297 | 2 ppb |
| Pembroke Water Division Dpw | 18,175 | 3 ppb |
Next steps for Onset, MA
Test your own tap with a certified lab first-draw sample; Onset, MA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Onset Fire Districtwater Dept. whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.