Columbia County, Oregon — public water systems
At a glance
57 active public water systems are filed under Columbia County, Oregon in EPA's SDWIS records, together reporting 40,191 people served. The largest is City of St Helens, which reports serving 13,410 people. 37 are community water systems serving people where they live; the other 20 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
57
Population served
40.2K
Community systems
37
Groundwater share
84.2%
How does Columbia County compare with other Oregon counties?
Columbia County has the 15th-most active public water systems among the 57 counties listed for active Oregon systems in EPA records; among the 38 with 3 or more systems, the median has 41. Its systems report 40,191 people served in total, the 19th-largest county figure in the state and 1% of the statewide total. The average system here reports serving 705 people, about 56% below the Oregon average of 1,587. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.
Where does Columbia County's drinking water come from?
By primary water source, Columbia County's active systems draw on groundwater (47, 82%), surface water (9, 16%) and groundwater under influence of surface water (1, 1.8%). Overall, 84% rely mainly on groundwater (including purchased groundwater) and 16% on surface water, compared with 88% and 12% across Oregon. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of St Helens, draws primarily on groundwater under influence of surface water.
What kinds of water systems operate in Columbia County?
Columbia County's active systems break down as 37 community systems (65%), 6 non-transient non-community systems (11%) and 14 transient non-community systems (25%). 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. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (75%), local government (23%) and public/private partnership (1.8%).
The 50 largest water systems in Columbia County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | St Helens, City of | Columbia | 13,410 | Community | Groundwater under influence of surface water |
| 2 | Scappoose, City of | Columbia | 8,710 | Community | Surface water |
| 3 | Mcnulty Water PUD | Columbia | 2,500 | Community | Groundwater |
| 4 | Clatskanie, City of | Columbia | 2,188 | Community | Surface water |
| 5 | Vernonia, City of | Columbia | 2,100 | Community | Surface water |
| 6 | Warren Water Association | Columbia | 2,050 | Community | Groundwater |
| 7 | Columbia City Mun Waterworks | Columbia | 1,995 | Community | Groundwater |
| 8 | City of Rainier | Columbia | 1,932 | Community | Surface water |
| 9 | Rainier Sd #13 | Columbia | 950 | Non-transient non-community | Groundwater |
| 10 | Western Hills Mh Estates | Columbia | 375 | Community | Groundwater |
| 11 | Fishhawk Lake Reserve and Community | Columbia | 350 | Community | Surface water |
| 12 | Quincy Water Association | Columbia | 300 | Community | Groundwater |
| 13 | Columbia Co Pks-Hudson/Parcher | Columbia | 200 | Transient non-community | Groundwater |
| 14 | Columbia Co Pks-Camp Wilkerson | Columbia | 200 | Transient non-community | Groundwater |
| 15 | Midland Water Association | Columbia | 160 | Community | Surface water |
| 16 | Rainier Or LDS Church | Columbia | 150 | Transient non-community | Groundwater |
| 17 | Columbia Co Pks-Big Eddy | Columbia | 125 | Transient non-community | Groundwater |
| 18 | Columbia Acres Water Assoc | Columbia | 110 | Community | Groundwater |
| 19 | Shell Star Mart | Columbia | 100 | Transient non-community | Groundwater |
| 20 | Scappoose Brew & Thru | Columbia | 100 | Transient non-community | Groundwater |
| 21 | Alston Corners-Assembly of God | Columbia | 100 | Transient non-community | Groundwater |
| 22 | Lost Creek Heights Wtr Assoc | Columbia | 100 | Community | Groundwater |
| 23 | Deer View Cooperative | Columbia | 90 | Community | Groundwater |
| 24 | Paradise Moorage | Columbia | 90 | Community | Groundwater |
| 25 | Country Villa Mobile Estates | Columbia | 90 | Community | Groundwater |
| 26 | Deer Island Waterworks | Columbia | 90 | Community | Groundwater |
| 27 | Rainier Congregation of Jw | Columbia | 90 | Transient non-community | Groundwater |
| 28 | Goble Water Association | Columbia | 85 | Community | Groundwater |
| 29 | Columbia Hills Hoa | Columbia | 84 | Community | Groundwater |
| 30 | Olympic Forest Products | Columbia | 80 | Non-transient non-community | Groundwater |
| 31 | Tamarack Mobile Home Park | Columbia | 80 | Community | Groundwater |
| 32 | Maple Terrace Mobile Home Park | Columbia | 70 | Community | Groundwater |
| 33 | Prescott, City of | Columbia | 70 | Community | Groundwater |
| 34 | Mccuddys Landing | Columbia | 70 | Community | Groundwater |
| 35 | Marshland Water Association | Columbia | 70 | Community | Surface water |
| 36 | Laurel Ridge MHP | Columbia | 70 | Community | Groundwater |
| 37 | Columbia River Nitrogen, LLC | Columbia | 65 | Non-transient non-community | Groundwater |
| 38 | Deer Island Heights Ws | Columbia | 60 | Community | Groundwater |
| 39 | Laurelwood Water Assoc | Columbia | 50 | Community | Groundwater |
| 40 | Deer Island Village MHP-Fawn Lane | Columbia | 50 | Community | Groundwater |
| 41 | Cedar Tree Mobile Home Park | Columbia | 50 | Community | Groundwater |
| 42 | Deer Island Village MHP | Columbia | 50 | Community | Groundwater |
| 43 | Valley of the Moon | Columbia | 46 | Transient non-community | Groundwater |
| 44 | Berndt Creek Water Corp | Columbia | 45 | Community | Surface water |
| 45 | Columbia River PUD | Columbia | 45 | Non-transient non-community | Groundwater |
| 46 | J & M Mobile Home Park | Columbia | 45 | Community | Groundwater |
| 47 | Dikeside Moorage | Columbia | 45 | Community | Groundwater |
| 48 | Island Community LLC | Columbia | 41 | Transient non-community | Groundwater |
| 49 | Swedetown Water Assoc | Columbia | 40 | Community | Groundwater |
| 50 | Hogg Heaven MHP | Columbia | 40 | Community | Groundwater |
All other water systems in Columbia County (7)
The remaining active systems filed under Columbia County, largest first, with the population each reports serving.
Columbia County water systems: frequently asked questions
How many public water systems are in Columbia County, Oregon?
EPA's SDWIS records file 57 active public water systems under Columbia County, Oregon: 37 community systems (65%), 6 non-transient non-community systems (11%) and 14 transient non-community systems (25%).
Who supplies drinking water in Columbia County, OR?
The largest community water systems filed under Columbia County are City of St Helens (13,410 people served), City of Scappoose (8,710 people served) and Mcnulty Water PUD (2,500 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.
Does Columbia County's drinking water come from groundwater or surface water?
Of the 57 active public water systems in Columbia County, 84% draw mainly on groundwater and 16% on surface water, counting purchased supplies. The largest system, City of St Helens, uses groundwater under influence of surface water.
Where can I find a water quality report for Columbia County?
Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 37 community systems are filed under Columbia County, so the report to look for is the one from the system that supplies your address.
How can I check violations for a water system in Columbia County?
Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.
More Oregon water systems
- All Oregon public water systems· 2,536 active
- Yamhill County· 91 systems
- Umatilla County· 66 systems
- Tillamook County· 63 systems
- Multnomah County· 58 systems
- Lincoln County· 52 systems
- Benton County· 51 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
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, “Public water systems in Columbia County, Oregon”, https://aquacensus.com/water-systems/oregon/columbia (data as of October 1, 2026).