Source water assessment
Between 1999 and 2005, each public water system in Oregon received a source water assessment report completed by the Oregon Department of Environmental Quality and Oregon Health Authority drinking water programs. The assessment gives the water system and community information on the watershed or recharge area that supplies the well, spring or intake (the “drinking water source area”) and identifies potential risks within the source area.
In 2016 and 2017, the agencies are completing Updated Source Water Assessments to provide the water systems and communities more detailed information on the watershed or recharge area that supplies their well, spring or intake. DEQ opened public comment on the content and format of an USWA prototype on May 18, 2016. This public comment period allowed partner state agencies, stakeholders, and public water providers an opportunity to help make the information more useful and relevant. Comments received were used to improve the document. The prototype was finalized in August 2016.
Updated Source Water Assessments will be provided to all public water systems using surface water and are posted at the link below as they are completed. For groundwater systems, OHA has prioritized new Community and Non-Transient Non-Community water systems and systems that have added a new water source since their original source water assessment was completed. For groundwater system reports, contact Drue Edney, OHA, at 541-726-2587 ext. 25.
Statewide assessment reports, results and methods
Source Water Assessment and Updated Source Water Assessment results for Oregon Public Water Systems
Provides links to assessment reports and additional information for individual public water systems in Oregon
Land use/ownership summary for surface water source areas
As part of the Updated Source Water Assessments, DEQ developed a statewide land use/ownership GIS layer to evaluate land cover in drinking water source areas. Statewide surface water maps and land use data are available on the Maps and Data page. Maps for each individual public water system are provided in the Updated Source Water Assessment report.
Source water assessment methods and inventory results, June 2005
Source Water Assessment Inventory Results as of June 2005 for Potential Contaminant Sources identified in Oregon Drinking Water Source Areas for Community and Non-transient Non-community Public Water Systems
Water quality data
Water quality data for public water systems in Oregon can be found in a number of places.
Additional raw water quality monitoring data in the waterbodies serving public water systems may be available from other sources including DEQ's water quality monitoring data portal, USGS, individual water providers, local partners (i.e. soil and water conservation districts or watershed councils) or local volunteer monitoring.
Drinking water source monitoring
During the period of 2008 through 2014, Oregon DEQ conducted a series of monitoring tests at the source waters at 35 surface water intakes and 48 groundwater wells. Raw water samples were collected upstream of intakes and at groundwater wells that serve as public water systems in 27 counties across the state. The samples were analyzed at the DEQ Laboratory for over 250 Oregon-specific herbicides, insecticides, pharmaceuticals, VOCs (including cleaners), fire retardants, PAHs, personal care products, and plasticizers. Of all surface water intake sites sampled, 88% had typical wastewater constituents detected and 59% had pesticide detections. In the groundwater sources, 85% had wastewater constituents and 39% of the samples had pesticide detections. With the exception of one chemical (arsenic), the levels of all parameters detected thus far have been very low and have met health standards where available on an individual basis.
Low-level detections of chemicals in drinking water sources are important priorities for prevention because we lack health standards for many individual chemicals and there is no toxicity data for synergistic effects when multiple chemicals are present in finished drinking water. Sampling and analyzing for low levels of a broad range of chemicals in streams provides DEQ and others the ability to prioritize pollutant reduction efforts on activities/land uses that impact those streams.
Summary of drinking water source monitoring
Drinking Water Source Monitoring project that included collecting groundwater and surface water samples from 34 high-risk drinking water sources as identified through the SWAs. A total of 17 surface water intakes, 16 wells, and 1 spring were tested by DEQ to determine characteristics and detections in the source waters.
Results of the 2008-2010 monitoring
Articles summarizing Phase I 2008-09 monitoring
Additional source water monitoring was conducted between 2012 and 2014 by DEQ and others as part of regional projects. This included sampling for the Cities of Toledo, Lincoln City, Siletz, Irrigon and The Dalles; North Coast Sampling by the Tillamook Estuary Partnership; and USGS sampling of schools.