Medfield Water Dept., MA
Lead detected, under the action levels
Latest 90th-percentile lead: 7 ppb (monitoring period 2025-2025). 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.
Who runs the water here
Medfield Water Dept. serves about 12,713 people through 4,136 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Norfolk County, Massachusetts. EPA system ID: MA2175000; phone on file: 5089063004. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
Against the period ending 2024 (8 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Medfield Water Dept. is 11 ppb across 7 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 7 ppb |
| 2024 | 8 ppb |
| 2023 | 4 ppb |
| 2023 | 5 ppb |
| 2022 | 10 ppb |
| 2019 | 10 ppb |
| 2016 | 11 ppb over 10 |
Against other Massachusetts systems
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. Medfield Water Dept.'s 7 ppb sits at the 91st percentile in Massachusetts and the 95th nationally (higher means more lead).
Nearby utilities
38 other systems share Norfolk County; 2 of them have a higher latest lead result than Medfield Water Dept.. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Tri Town Water Board | 856,000 | - |
| Quincy Water Dept. (Mwra) | 106,000 | 14.4 ppb |
| Brookline Water And Sewer Division | 63,191 | 2 ppb |
| Weymouth Water Department | 57,871 | 1.2 ppb |
| Randolph/Holbrook Joint Water Board | 46,519 | - |
| Dedham Westwood Water Dist. | 41,630 | 2 ppb |
| Braintree Water And Sewer Dept. | 39,143 | 4.8 ppb |
| Randolph Water Department | 35,114 | 3 ppb |
| Franklin Water Department | 33,706 | 5 ppb |
| Needham Water Dept | 31,664 | 2 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Medfield, 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 Medfield Water 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. Systems that went over once often dip back under; here is what that means.