Rocky Bay, WA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. 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
Rocky Bay serves about 34 people through 13 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Pierce County, Washington. EPA system ID: WA5373620. Ask the utility on your bill for your address in their service line inventory.
Rocky Bay'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 Rocky Bay is 1 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0 (not detected) |
| 2021 | 1 ppb |
| 2018 | 1 ppb |
How Rocky Bay compares
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. Rocky Bay's reported as 0 (not detected) sits at the 2nd percentile in Washington and the 1st nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Pierce County
226 other systems share Pierce County; 151 of them have a higher latest lead result than Rocky Bay. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Tacoma Water Division City Of | 446,245 | 0 (not detected) |
| Puyallup City Of | 94,520 | 2.7 ppb |
| Lakewood Water District | 82,425 | 1.1 ppb |
| Southwood | 64,155 | 1.6 ppb |
| Bonney Lake Water Department City | 43,371 | 2.4 ppb |
| Firgrove Mutual Inc | 36,168 | 2.9 ppb |
| Jblm Lewis | 35,414 | 0 (not detected) |
| Spanaway Water Company | 34,506 | 2.4 ppb |
| Parkland Light & Water Company | 33,775 | 2.4 ppb |
| Fife Dept Of Public Works | 29,091 | 2 ppb |
What to do in your house
Look up your address in Rocky Bay'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 Rocky Bay 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. Small systems behave differently: why small systems go over more often.