Cs Old Concho Water Users, MO
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Cs Old Concho Water Users at a glance
Cs Old Concho Water Users serves about 40 people through 31 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Apache County, Missouri. EPA system ID: AZ0401011; phone on file: 602-698-9786. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is down 1.6 ppb from 1.6 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Cs Old Concho Water Users is 6.6 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 1.6 ppb |
| 2021 | 0 (not detected) |
| 2020 | 6.6 ppb |
| 2019 | 1.85 ppb |
| 2017 | 0 (not detected) |
Where this result ranks
Of the 1,674 Missouri systems with a lead result, the median latest reading is 1.04 ppb; 2 are over 15 ppb right now and 74 have gone over at some point. Cs Old Concho Water Users's reported as 0 (not detected) sits at the 2nd percentile in Missouri and the 2nd nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Next steps for St. Louis, MO
Look up your address in Cs Old Concho Water Users's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Cs Old Concho Water Users 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. A zero today does not rule out a jump later - the rules are tightening in 2027.