MONTESANO CITY OF
Washington — Community Water System — PWSID: WA5356000
System Information
| PWSID | WA5356000 |
| System Name | MONTESANO CITY OF |
| System Type | Community Water System |
| Water Source | Ground Water |
| Activity Status | Active |
| Owner Type | Local |
| EPA Region | 10 |
| Serves School | No |
| Wholesaler | Yes |
| First Reported | Feb 7, 1981 |
| Last Reported | Dec 11, 2025 |
Location & Contact
| State | Washington |
| City | Montesano |
| ZIP Code | 98563 |
| Address | 112 North Main Street |
| Organization | MONTESANO CITY OF |
| Phone | — |
Population & Service
| Population Served | 5,492 |
| Service Connections | 2,213 |
Drinking Water Violations (25)
This water system has 25 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, 2022 | — | Consumer Confidence Rule | Other | No | No | — | — | — | Resolved | Dec 28, 2022 | Consumer Confidence Rule |
| Jan 1, 2022 | Dec 31, 2022 | Total Haloacetic Acids (HAA5) | MR | No | Yes | — | 0.060 mg/L | — | Resolved | Dec 31, 2022 | Stage 2 Disinfectants and Disinfection Byproducts Rule |
| Jan 1, 2022 | Dec 31, 2022 | TTHM | MR | No | Yes | — | 0.080 mg/L | — | Resolved | Dec 31, 2022 | Stage 2 Disinfectants and Disinfection Byproducts Rule |
| Jul 1, 2012 | — | Consumer Confidence Rule | Other | No | No | — | — | — | Resolved | Oct 19, 2012 | Consumer Confidence Rule |
| Oct 1, 2007 | Dec 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2007 | Synthetic Organic Chemicals |
| Oct 1, 2007 | Dec 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2007 | Synthetic Organic Chemicals |
| Oct 1, 2007 | Dec 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2007 | Synthetic Organic Chemicals |
| Oct 1, 2007 | Dec 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2007 | Synthetic Organic Chemicals |
| Oct 1, 2007 | Dec 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Dec 31, 2007 | Synthetic Organic Chemicals |
| Jul 1, 2007 | Sep 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Sep 30, 2007 | Synthetic Organic Chemicals |
| Jul 1, 2007 | Sep 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Sep 30, 2007 | Synthetic Organic Chemicals |
| Jul 1, 2007 | Sep 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Sep 30, 2007 | Synthetic Organic Chemicals |
| Jul 1, 2007 | Sep 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Sep 30, 2007 | Synthetic Organic Chemicals |
| Apr 1, 2007 | Jun 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Jun 30, 2007 | Synthetic Organic Chemicals |
| Apr 1, 2007 | Jun 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Jun 30, 2007 | Synthetic Organic Chemicals |
| Apr 1, 2007 | Jun 30, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Jun 30, 2007 | Synthetic Organic Chemicals |
| Jan 1, 2007 | Mar 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Mar 31, 2007 | Synthetic Organic Chemicals |
| Jan 1, 2007 | Mar 31, 2007 | Diquat | MR | No | Yes | — | 0.02 mg/L | — | Resolved | Mar 31, 2007 | Synthetic Organic Chemicals |
| Nov 1, 2006 | Nov 30, 2006 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Nov 30, 2006 | Total Coliform Rule |
| Apr 1, 2004 | Apr 30, 2004 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Apr 30, 2004 | Total Coliform Rule |
| Jun 1, 1994 | Jun 30, 1994 | Coliform (TCR) | MCL | Yes | No | — | 5% of samples | — | Archived | Jun 30, 1994 | Total Coliform Rule |
| Oct 1, 1992 | Oct 31, 1992 | Coliform (TCR) | MR | No | No | — | 5% of samples | — | Archived | Oct 31, 1992 | Total Coliform Rule |
| Aug 1, 1992 | Aug 31, 1992 | Coliform (TCR) | MR | No | No | — | 5% of samples | — | Archived | Aug 31, 1992 | Total Coliform Rule |
| Dec 1, 1991 | Dec 31, 1991 | Coliform (TCR) | MR | No | No | — | 5% of samples | — | Archived | Dec 31, 1991 | Total Coliform Rule |
| Oct 1, 1979 | Oct 31, 1979 | Gross Alpha, Excl. Radon and U | MR | No | No | — | 15 pCi/L | — | Archived | Oct 31, 1979 | Radionuclides and Revised Rad Rule |
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.