West Siloam Springs, OK
Lead detected, under the action levels
Latest 90th-percentile lead: 1.4 ppb (monitoring period 2026-2026). 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
West Siloam Springs serves about 877 people through 429 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 surface water, in Delaware County, Oklahoma. EPA system ID: OK3002109; phone on file: 918-422-5101. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
Against the period ending 2025 (1.4 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for West Siloam Springs is 10.7 ppb across 10 monitoring periods, none of them over 15 ppb (2 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.4 ppb |
| 2025 | 1.4 ppb |
| 2025 | 10.2 ppb over 10 |
| 2024 | 10.7 ppb over 10 |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
| 2017 | 0 (not detected) |
| 2016 | 0 (not detected) |
| 2016 | 0 (not detected) |
Where this result ranks
Of the 870 Oklahoma systems with a lead result, the median latest reading is 0.81 ppb; 6 are over 15 ppb right now and 66 have gone over at some point. West Siloam Springs's 1.4 ppb sits at the 62nd percentile in Oklahoma and the 62nd nationally (higher means more lead).
Nearby utilities
25 other systems share Delaware County; 7 of them have a higher latest lead result than West Siloam Springs. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Grove Municipal Services Auth. | 7,311 | 9.3 ppb |
| Grand Lake Pwa | 2,800 | 3.1 ppb |
| Jay | 2,482 | 0 (not detected) |
| Ketchum Pwa Delaware Co System | 1,805 | 2.3 ppb |
| South Delaware Co Regional Water Auth. | 1,500 | 1.8 ppb |
| Delaware Co Rwd #10 | 1,295 | 1.2 ppb |
| Colcord Pwa | 819 | 0 (not detected) |
| Kansas Public Works Authority | 802 | 0 (not detected) |
| Delaware Co Rwd # 12 | 785 | 0 (not detected) |
| Delaware Co Rwsg&Swm District 11 | 750 | 2.5 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Colcord, OK 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 West Siloam Springs 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.