Mount Vernon, SD
Lead detected, under the action levels
Latest 90th-percentile lead: 6 ppb (monitoring period 2023-2023). 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.
Mount Vernon at a glance
Mount Vernon serves about 461 people through 204 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Davison County, South Dakota. EPA system ID: SD4600220; phone on file: 6052365207. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is up 2 ppb from 4 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Mount Vernon is 6 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 6 ppb |
| 2020 | 4 ppb |
| 2017 | 4 ppb |
Against other South Dakota systems
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. Mount Vernon's 6 ppb sits at the 93rd percentile in South Dakota and the 93rd nationally (higher means more lead).
Neighbouring systems
2 other systems share Davison County; 0 of them have a higher latest lead result than Mount Vernon. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mitchell | 15,651 | 1 ppb |
| Ethan | 320 | 1 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Mount Vernon, 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 Mount Vernon 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. The lead result guide covers how utilities pick the homes they sample. Size matters more than most people expect: small vs large water systems.