LAKE OSWEGO MUNICIPAL WATER
Oregon - Community Water System - PWSID: OR4100457
System Information
| PWSID | OR4100457 |
| System Name | LAKE OSWEGO MUNICIPAL WATER |
| System Type | Community Water System |
| Water Source | Surface Water Purchased |
| Activity Status | Active |
| Owner Type | Local |
| EPA Region | 10 |
| Serves School | No |
| Wholesaler | No |
| First Reported | Mar 12, 1979 |
| Last Reported | Mar 25, 2026 |
Location & Contact
| State | Oregon |
| City | LAKE OSWEGO |
| ZIP Code | 97035 |
| Address | 17601 PILKINGTON RD |
| Organization | LAKE OSWEGO MUNICIPAL WATER |
| Phone | 503-635-0280 |
Population & Service
| Population Served | 40,000 |
| Service Connections | 13,000 |
Drinking Water Violations (39)
This water system has 39 violations recorded in the EPA SDWIS database.
| Begin Date | End Date | Contaminant | Category | Health-Based | Major | Measured | Federal MCL | State MCL | Status | Return to Compliance | Rule |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jul 1, 2025 | - | Other | No | No | - | - | - | Resolved | Sep 2, 2025 | - | |
| Jul 1, 2024 | - | Other | No | No | - | - | - | Resolved | Jul 3, 2024 | - | |
| Jan 1, 2019 | Mar 31, 2019 | MR | No | Yes | - | 0.010 mg/L | - | Resolved | Mar 31, 2019 | - | |
| Aug 1, 2009 | Aug 31, 2009 | MR | No | No | - | 5% of samples | - | Resolved | Aug 31, 2009 | - | |
| Aug 1, 2009 | Aug 31, 2009 | MR | No | No | - | 5% of samples | - | Resolved | Aug 31, 2009 | - | |
| Apr 1, 2008 | Jun 30, 2008 | MR | No | Yes | - | 0.07 mg/L | - | Resolved | Jun 30, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.07 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.2 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Mar 31, 2008 | MR | No | Yes | - | 0.07 mg/L | - | Resolved | Mar 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.007 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.1 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.6 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 10 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.1 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 10 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.075 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.002 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.7 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.07 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.1 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 0.005 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2008 | Dec 31, 2008 | MR | No | Yes | - | 1 mg/L | - | Resolved | Dec 31, 2008 | - | |
| Jan 1, 2002 | Dec 31, 2002 | MR | No | Yes | - | 10 mg/L | - | Resolved | Dec 31, 2002 | - | |
| Jan 1, 2000 | - | TT | Yes | No | - | TT | - | Resolved | Mar 1, 2000 | - | |
| Jan 1, 2000 | - | TT | Yes | No | - | TT | - | Resolved | Mar 1, 2000 | - | |
| Jan 1, 1996 | Jan 31, 1996 | MR | No | No | - | 5% of samples | - | Resolved | Jan 31, 1996 | - | |
| Dec 1, 1995 | Dec 31, 1995 | MR | No | No | - | 5% of samples | - | Resolved | Dec 31, 1995 | - | |
| Nov 1, 1995 | Nov 30, 1995 | MR | No | No | - | 5% of samples | - | Resolved | Nov 30, 1995 | - | |
| Oct 1, 1995 | Oct 31, 1995 | MR | No | No | - | 5% of samples | - | Resolved | Oct 31, 1995 | - | |
| Jun 1, 1976 | May 31, 1980 | MR | No | No | - | 5 pCi/L | - | Archived | May 31, 1980 | - | |
| Jun 1, 1976 | May 31, 1980 | MR | No | No | - | 15 pCi/L | - | Archived | May 31, 1980 | - | |
| - | - | - | No | No | - | - | - | - | - | - |
About This Water System
Public water system data comes from the EPA Safe Drinking Water Information System (SDWIS). Systems with violations must notify customers. Contact your water utility for the latest annual water quality report.