Yak Co - Terrace Heights, WA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Yak Co - Terrace Heights serves about 8,410 people through 2,725 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Yakima County, Washington. EPA system ID: WA5306029. Ask the utility on your bill for your address in their service line inventory.
Yak Co - Terrace Heights's lead record
Against the period ending 2020 (0.9 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Yak Co - Terrace Heights is 1.7 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 0 (not detected) |
| 2020 | 0.9 ppb |
| 2017 | 1.7 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. Yak Co - Terrace Heights's reported as 0 (not detected) sits at the 34th percentile in Washington and the 36th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Yakima County
88 other systems share Yakima County; 35 of them have a higher latest lead result than Yak Co - Terrace Heights. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Yakima Water Division City Of | 112,858 | 0 (not detected) |
| Nob Hill Water Association | 38,050 | 0 (not detected) |
| Sunnyside City Of | 17,194 | 1.4 ppb |
| Toppenish Water Department | 13,382 | 0 (not detected) |
| Grandview City Of | 11,010 | 1.2 ppb |
| Selah City Of | 9,331 | 0 (not detected) |
| Union Gap Water | 6,433 | 0 (not detected) |
| Moxee Water Department | 5,599 | 2.2 ppb |
| Wapato Waterworks | 5,255 | 0 (not detected) |
| Granger Water Department | 3,993 | 0 (not detected) |
Your move
Look up your address in Yak Co - Terrace Heights's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Yak Co - Terrace Heights 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. A zero today does not rule out a jump later - the rules are tightening in 2027.