- EPA's UCMR 5 testing looked for 30 contaminants here and found none.
- Lead: 9 in 10 homes tested came in at or below 1.8 ppb, at or below EPA's 15 ppb action level (latest EPA result for a testing period that ran on or after July 1, 2021: Jan 1, 2024–Dec 31, 2026). This is one number for the whole water system, from homes the utility tested. It isn't a result for your home.
Public EPA test results
Can you drink Lake Oswego tap water? What EPA records show
EPA system ID OR4100457 · serves Clackamas County, OR · about 40,000 people (EPA records)
Here's what EPA has on file for this water system: its testing for newer contaminants like PFAS (UCMR 5), lead testing and violations. It's not a test of your tap, and there's no Water Score here.
Public EPA test results
Lake Oswego Municipal Water (EPA OR4100457)
EPA data as of October 14, 2026. For Lake Oswego's main utility, Lake Oswego Municipal Water: We found no health-standard violations in EPA's records for this system (OR4100457) since July 1, 2021, as of October 14, 2026. PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
What EPA records show for Lake Oswego Municipal Water, as of October 14, 2026
We found no health-standard violations in EPA's records for this system (OR4100457) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for Lake Oswego Municipal Water (SDWIS). Data as of October 14, 2026.
Lead: 9 in 10 homes tested came in at or below 1.8 ppb, at or below EPA's 15 ppb action level (latest EPA result for a testing period that ran on or after July 1, 2021: Jan 1, 2024–Dec 31, 2026). This is one number for the whole water system, from homes the utility tested. It isn't a result for your home.
EPA's UCMR 5 testing looked for 30 contaminants here and found none.
PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does Lake Oswego Municipal Water use chloramine?
We didn't find chloramine in Lake Oswego Municipal Water's EPA treatment records. That's not a complete list; your utility's annual water quality report says which disinfectant it uses.