Plymouth Water District, WA
Lead detected, under the action levels
Latest 90th-percentile lead: 0.6 ppb (monitoring period 2022-2024). 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
Plymouth Water District serves about 288 people through 109 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Benton County, Washington. EPA system ID: WA5368045. Ask the utility on your bill for your address in their service line inventory.
Plymouth Water District's lead record
Against the period ending 2021 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Plymouth Water District is 1 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0.6 ppb |
| 2021 | 1 ppb |
| 2018 | 1 ppb |
Against other Washington systems
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. Plymouth Water District's 0.6 ppb sits at the 40th percentile in Washington and the 45th nationally (higher means more lead).
Other water systems in Benton County
42 other systems share Benton County; 11 of them have a higher latest lead result than Plymouth Water District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Kennewick City Of | 118,164 | 0 (not detected) |
| Richland City Of | 106,499 | 2.4 ppb |
| West Richland City Of | 21,231 | 0 (not detected) |
| Prosser City Of | 8,030 | 0 (not detected) |
| Benton City Water | 5,626 | 0 (not detected) |
| Badger Mountain Irrigation District | 2,331 | 2.8 ppb |
| Summit View Water System | 1,869 | 0 (not detected) |
| Bc Water Co | 1,262 | 0 (not detected) |
| Community Sewer And Water District | 1,200 | 0 (not detected) |
| Oasis Water Corporation | 556 | 0 (not detected) |
Next steps for West Richland, WA
Test your own tap with a certified lab first-draw sample; West Richland, 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 Plymouth Water District 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.