Riverwood Water System, WA
Lead detected, under the action levels
Latest 90th-percentile lead: 2 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
Riverwood Water System serves about 43 people through 21 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Ferry County, Washington. EPA system ID: WA5373032. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
Against the period ending 2022 (1.6 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Riverwood Water System is 2 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 2 ppb |
| 2022 | 1.6 ppb |
| 2019 | 1.3 ppb |
| 2016 | 1.4 ppb |
Where this result ranks
Of the 2,218 Washington systems with a lead result, the median latest reading is 1 ppb; 18 are over 15 ppb right now and 62 have gone over at some point. Riverwood Water System's 2 ppb sits at the 67th percentile in Washington and the 69th nationally (higher means more lead).
Other water systems in Ferry County
10 other systems share Ferry County; 4 of them have a higher latest lead result than Riverwood Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Republic City Of | 1,673 | 2.2 ppb |
| Inchelium Water District | 540 | 0 (not detected) |
| Curlew Conservation Center | 349 | 3.6 ppb |
| Curlew Water & Sewer District | 316 | 0.9 ppb |
| Lakeside Park | 180 | 1 ppb |
| Orient Water Company | 167 | 5 ppb |
| Curlew Kai Homeowner Water System | 133 | 1 ppb |
| Martin Creek Community Assn | 109 | 0 (not detected) |
| North Twin Lakeview Assn | 88 | 33.3 ppb |
| Fourth Of July Creek Estates | 29 | - |
Next steps for Tonasket, WA
Test your own tap with a certified lab first-draw sample; Tonasket, WA 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 Riverwood 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. Size matters more than most people expect: small vs large water systems.