Swt Main System, PA
Lead detected, under the action levels
Latest 90th-percentile lead: 6 ppb (monitoring period 2025-2025). 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.
About Swt Main System
Swt Main System serves about 14,500 people through 6,284 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Lehigh County, Pennsylvania. EPA system ID: PA3390065; phone on file: 610-398-0407. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2022 (6 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Swt Main System is 6 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 6 ppb |
| 2022 | 6 ppb |
| 2019 | 5 ppb |
| 2016 | 4.76 ppb |
Where this result ranks
Of the 516 Pennsylvania systems with a lead result, the median latest reading is 2 ppb; 143 are over 15 ppb right now and 156 have gone over at some point. Swt Main System's 6 ppb sits at the 69th percentile in Pennsylvania and the 93rd nationally (higher means more lead).
Other water systems in Lehigh County
38 other systems share Lehigh County; 2 of them have a higher latest lead result than Swt Main System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Lca Allentown Division | 118,000 | 7 ppb |
| Lca Wlsa Central Division | 47,693 | 2 ppb |
| Emmaus Borough Public Water | 14,000 | 3 ppb |
| Whitehall Twp Authority | 13,063 | 4 ppb |
| Salisbury Twp Water System | 8,522 | 3 ppb |
| Upper Saucon Twp Water Supply | 7,300 | 0 (not detected) |
| Catasauqua Mun Water Works | 6,598 | 5 ppb |
| Slatington Borough Water Sys | 4,450 | 0 (not detected) |
| Macungie Borough Authority | 3,039 | - |
| Lca North Whitehall Division | 2,910 | - |
Your move
Test your own tap with a certified lab first-draw sample; Allentown, PA 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 Swt Main 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. Why sampled homes are the worst-case ones is in the guide to reading the number. Systems that went over once often dip back under; here is what that means.