Public water system · OR4100357
ActiveGresham, City of
At a glance
City of Gresham (PWSID OR4100357) is an active community water system in Multnomah County, Oregon. It reports serving 73,932 people through 17,513 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
73,932
Service connections
17,513
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of Gresham compare with other water systems in Multnomah County?
By EPA's size categories, City of Gresham is a large system (10,001 to 100,000 people). Multnomah County has 58 active public water systems, and City of Gresham is the 2nd-largest of them by population served. Its population served is about 5 times the county average of 14,736 people per system, and accounts for 8.7% of the 854,671 people reported by systems filed under the county. Across Oregon, the 2,536 active systems average 1,587 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Gresham is about 11 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Oregon has 940 active community water systems, 37% of the state's 2,536 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 105 Oregon systems (4.1%) list purchased surface water as their primary source.
Who owns and regulates City of Gresham?
EPA lists City of Gresham as owned by a local government. The OR state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 22 of the 58 active systems in Multnomah County (38%) are also owned by a local government.
Does City of Gresham have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2022. The violations listed here began between January 1995 and July 2022. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2022-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2022-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2006-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-09-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-06-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-11-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-06-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
City of Gresham: frequently asked questions
Who runs City of Gresham?
City of Gresham (PWSID OR4100357) is a community water system owned by a local government. It is regulated by the OR state drinking water program.
How many people does City of Gresham serve?
City of Gresham reports serving 73,932 people through 17,513 service connections in Multnomah County, Oregon.
Where does City of Gresham get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does City of Gresham have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2022. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is City of Gresham's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the OR state drinking water program.
Where can I find City of Gresham's water quality report?
As a community water system, City of Gresham must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Multnomah County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Portland Water Bureau | Multnomah | 666,200 | Community | Surface water |
| Rockwood PUD | Multnomah | 65,443 | Community | Purchased surface water |
| Troutdale, City of | Multnomah | 16,185 | Community | Groundwater |
| Fairview, City of | Multnomah | 9,963 | Community | Groundwater |
| Wood Village, City of | Multnomah | 4,388 | Community | Groundwater |
| Usfs Multnomah Falls/Wahkeena | Multnomah | 3,200 | Transient non-community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Gresham, City of, PWSID OR4100357, Oregon”, https://aquacensus.com/water-systems/oregon/gresham-city-of-or4100357 (data as of October 1, 2026).