Tonka Bay, MN
Lead detected, under the action levels
Latest 90th-percentile lead: 2 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.
About Tonka Bay
Tonka Bay serves about 1,442 people through 684 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Hennepin County, Minnesota. EPA system ID: MN1270013; phone on file: 9524747994. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Tonka Bay's lead record
The highest 90th-percentile result EPA holds for Tonka Bay is 2 ppb across 1 monitoring period, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 2 ppb |
Against other Minnesota systems
Of the 966 Minnesota systems with a lead result, the median latest reading is 0 ppb; 7 are over 15 ppb right now and 48 have gone over at some point. Tonka Bay's 2 ppb sits at the 72nd percentile in Minnesota and the 72nd nationally (higher means more lead).
Neighbouring systems
41 other systems share Hennepin County; 6 of them have a higher latest lead result than Tonka Bay. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Minneapolis | 425,300 | 2 ppb |
| Bloomington | 91,300 | 2 ppb |
| Brooklyn Park | 89,995 | 1 ppb |
| Maple Grove | 82,000 | 2 ppb |
| Plymouth | 76,546 | 2 ppb |
| Eden Prairie | 63,726 | 0 (not detected) |
| Minnetonka | 54,474 | 0 (not detected) |
| Edina | 53,494 | 0 (not detected) |
| Saint Louis Park | 50,010 | 4 ppb |
| Richfield | 38,482 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Excelsior, MN 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 Tonka Bay 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.