Knoll Terrace Park, 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.
Knoll Terrace Park at a glance
Knoll Terrace Park serves about 452 people through 210 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Benton County, Oregon. EPA system ID: OR4100174; phone on file: 541-752-2225. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is down 10.3 ppb from 11.4 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Knoll Terrace Park is 11.4 ppb across 4 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.1 ppb |
| 2022 | 11.4 ppb over 10 |
| 2019 | 3 ppb |
| 2016 | 1 ppb |
How Knoll Terrace Park compares
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. Knoll Terrace Park's 1.1 ppb sits at the 54th percentile in Oregon and the 57th nationally (higher means more lead).
Neighbouring systems
14 other systems share Benton County; 10 of them have a higher latest lead result than Knoll Terrace Park. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Corvallis, City Of | 61,468 | 1.9 ppb |
| Philomath Public Works | 4,670 | 3.3 ppb |
| Adair Village Water System | 875 | 1.9 ppb |
| Monroe, City Of | 723 | 1.5 ppb |
| Vineyard Mountain Water | 325 | 4.56 ppb |
| Alsea County Service District | 202 | 3.2 ppb |
| Fir View Water Company | 150 | 4.2 ppb |
| Columbia Place Llc | 125 | 0 (not detected) |
| Cascade View Estates | 113 | 0 (not detected) |
| North Corvallis Mhp-Well #1 | 100 | 6.4 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Corvallis, 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 Knoll Terrace Park 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. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.