Delphian School, OR
Lead detected, under the action levels
Latest 90th-percentile lead: 1.1 ppb (monitoring period 2023-2025). 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
Delphian School serves about 350 people through 3 service connections, which makes it a very small system under EPA's size classes. It is under mixed public and private ownership and draws groundwater, in Yamhill County, Oregon. EPA system ID: OR4100812; phone on file: 503-843-3521. 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 1.1 ppb from 2.2 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Delphian School is 4.2 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.1 ppb |
| 2022 | 2.2 ppb |
| 2019 | 0 (not detected) |
| 2016 | 4.2 ppb |
Where this result ranks
Of the 909 Oregon systems with a lead result, the median latest reading is 1 ppb; 15 are over 15 ppb right now and 71 have gone over at some point. Delphian School's 1.1 ppb sits at the 54th percentile in Oregon and the 57th nationally (higher means more lead).
Neighbouring systems
37 other systems share Yamhill County; 12 of them have a higher latest lead result than Delphian School. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mcminnville Water & Light | 34,515 | 1.2 ppb |
| Newberg, City Of | 25,138 | 2.32 ppb |
| Sheridan, City Of | 6,494 | 0 (not detected) |
| Lafayette, City Of | 4,423 | 0 (not detected) |
| Dundee, City Of | 2,960 | 1.1 ppb |
| Dayton, City Of | 2,535 | 0 (not detected) |
| Carlton, City Of | 2,270 | 1.8 ppb |
| Willamina, City Of | 2,239 | 2.4 ppb |
| Amity, City Of | 1,810 | 0 (not detected) |
| Yamhill, City Of | 1,199 | 2.92 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Sheridan, OR 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 Delphian School 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.