Rainbow Ends Water System, OR
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2021-2023). 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.
Who runs the water here
Rainbow Ends Water System serves about 50 people through 19 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Washington County, Oregon. EPA system ID: OR4101350; phone on file: 503-628-2230. They can tell you what your service line is made of and whether they pay to replace it.
Rainbow Ends Water System's lead record
Against the period ending 2020 (2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Rainbow Ends Water System is 2 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 1 ppb |
| 2020 | 2 ppb |
| 2017 | 0 (not detected) |
How Rainbow Ends Water System 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. Rainbow Ends Water System's 1 ppb sits at the 50th percentile in Oregon and the 50th nationally (higher means more lead).
Neighbouring systems
28 other systems share Washington County; 15 of them have a higher latest lead result than Rainbow Ends Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Tualatin Valley Water District | 224,600 | 5.3 ppb |
| Hillsboro, City Of | 92,632 | 0 (not detected) |
| Beaverton, City Of | 88,045 | 2.6 ppb |
| Tigard, City Of | 62,500 | 0.98 ppb |
| Tualatin, City Of | 28,106 | 4.93 ppb |
| Forest Grove, City Of | 26,838 | 3.6 ppb |
| Sherwood, City Of | 20,781 | 1.3 ppb |
| Cornelius, City Of | 14,490 | 0 (not detected) |
| West Slope Water District | 11,000 | 5.01 ppb |
| Raleigh Water District | 4,500 | 5.01 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Hillsboro, 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 Rainbow Ends Water System 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. The action level is dropping - the 10 ppb rule from 2027.