Maxwell Colony, SD
Lead detected, under the action levels
Latest 90th-percentile lead: 8 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
Maxwell Colony serves about 163 people through 34 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Bon Homme County, South Dakota. EPA system ID: SD4602023. Ask the utility on your bill for your address in their service line inventory.
Maxwell Colony's lead record
That is up 8 ppb from 0 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Maxwell Colony is 8 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 8 ppb |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 1 ppb |
How Maxwell Colony compares
Of the 458 South Dakota systems with a lead result, the median latest reading is 2 ppb; 0 are over 15 ppb right now and 6 have gone over at some point. Maxwell Colony's 8 ppb sits at the 97th percentile in South Dakota and the 96th nationally (higher means more lead).
Neighbouring systems
5 other systems share Bon Homme County; 0 of them have a higher latest lead result than Maxwell Colony. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Springfield | 2,108 | 1 ppb |
| Tyndall | 1,012 | 2 ppb |
| Scotland | 785 | 0 (not detected) |
| Avon | 590 | 6 ppb |
| Tabor | 423 | 1 ppb |
Next steps for Scotland, SD
Test your own tap with a certified lab first-draw sample; Scotland, SD 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 Maxwell Colony 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.