South Tongass Water Utility, AK
Lead detected, under the action levels
Latest 90th-percentile lead: 1.9 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.
About South Tongass Water Utility
South Tongass Water Utility serves about 975 people through 327 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Ketchikan Gateway Borough County, Alaska. EPA system ID: AK2121510; phone on file: 907-228-6664. Call that number and ask whether your address has a lead, galvanized or unknown service line.
South Tongass Water Utility's lead record
Against the period ending 2020 (1.3 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for South Tongass Water Utility is 13 ppb across 3 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 1.9 ppb |
| 2020 | 1.3 ppb |
| 2017 | 13 ppb over 10 |
Against other Alaska systems
Of the 394 Alaska systems with a lead result, the median latest reading is 1.6 ppb; 3 are over 15 ppb right now and 53 have gone over at some point. South Tongass Water Utility's 1.9 ppb sits at the 56th percentile in Alaska and the 69th nationally (higher means more lead).
Neighbouring systems
7 other systems share Ketchikan Gateway Borough County; 3 of them have a higher latest lead result than South Tongass Water Utility. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Ketchikan Public Utilities | 8,937 | 2.5 ppb |
| Saxman | 450 | 9 ppb |
| Vallenar View Mobile Home Park | 225 | 1.85 ppb |
| Ketchikan Water, Truck 1 | 100 | - |
| Kasaan | 66 | 2 ppb |
| Port Protection | 60 | 0 (not detected) |
| Ketchikan H2o | 25 | - |
What to do in your house
Test your own tap with a certified lab first-draw sample; Ketchikan, AK 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 South Tongass Water Utility 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. Size matters more than most people expect: small vs large water systems.