Drinking Water

Over 80% of Oregon resident's get drinking water from public water systems. Many of these systems rely on some combination of ground and surface water sources. From the pristine Bull Run watershed, to the groundwater wells of Eastern Oregon, maintaining quality drinking water requires continual testing and communication.



Created by Gareth Baldrica-Franklin, Institute for Water and Watersheds, Oregon State University





















Surface Sources

Only 10% of Oregon drinking water authorities offer solely surface water. 55% offer some combination of surface water and groundwater. Elsewhere within the Willamette Valley, surface water is often stored in reservoirs, although river water can be treated and distributed as well.


Surface Source Protection Zone


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Groundwater Sources

35% of Oregonians rely on groundwater for drinking – typically from either small public water systems or private wells. Groundwater recharge areas require different protection strategies than surface watersheds.

In the Willamette Valley, groundwater is often used as an emergency water source. It is typically utilized when contaminants are found in surface water areas, or when reservoirs are low.


Groundwater Source Protection Zone

Bottled Water

In addition to municipally provided drinking water, over 20 companies utilize Oregon's water for bottling. These range from multi-national corporations, such as Coca-Cola, to local businesses.

A bottling facility proposed by Nestle in Cascade Locks has sparked debate between the economic benefit and ecological cost of bottling water.


Bottling Facility

Drinking Water Protection

The Oregon Department of Environmental Quality (DEQ), in combination with the Oregon Health Authority (OHA), assesses potential contaminants in drinking water source zones. Assessments allow local communities to address and prevent drinking water pollution. While areas with high populations are prone to large numbers of potential contaminants, rural agricultural areas can also have a variety of contaminant sources.


Number of Contaminants




 >1000   500-1000  100-500  50-100  <50


Groundwater Zones

Surface Water Zones


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Contaminant Sources

Surface and ground water sources are susceptible to different contaminant sources. The OHA mandates specific treatment and filtration requirements for public water providers.

Potential contaminants are sorted into three risk categories, with highest risk sources having the greatest potential harm. Even if drinking water providers do identify contaminants, it can be difficult to locate their origin.

Potential Contaminant Sources

Lowest-Risk

Medium-Risk

Highest-Risk


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