Drinking Water Source Monitoring Report/Results

Oregon state agencies are working to reduce risks of contamination to public water supplies. Safe drinking water supplies will increasingly depend upon reducing the contamination in the source waters. This is important for reducing the future costs of treatment and reducing the health risks associated with the contaminants that are not monitored and/or removed through existing regulatory requirements. Standard drinking water treatment technologies may not be adequate for contaminants in sources of drinking water such as new synthetic chemical compounds, strong microbial pathogens, and pharmaceuticals in the waste stream. In order to move forward on a stronger prevention program, DEQ collects data on the source waters in Oregon that serve public water systems.

Summary of Phase I and Phase II Drinking Water Source Monitoring: 2008-2010

DEQ completed Phase I and Phase II of the 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. The samples were taken above the surface water intakes and at wells for analysis of a list of over 250 Oregon-specific herbicides, insecticides, pharmaceuticals, VOCs (including cleaners), fire retardants, PAHs, personal care products, and plasticizers. The purpose of the Source Monitoring was to collect data from multiple contaminant sources to assist in determining priorities for technical assistance and prevention, and to collect screening level data on whether there are potential human health risks beyond those routinely monitored within the SDWA regulations. OHA toxicologists reviewed and interpreted analytical results of each round of samples and sent the results to the individual public water systems.

In general, data from this project show that very low levels of some contaminants are present in these drinking water source waters. The levels of these contaminants meet existing applicable standards and guidelines and are well within acceptable limits. Contaminants detected were consistent with other studies conducted in similar source areas across the country.    

Results of the 2008-2010 monitoring:

• Drinking Water Source Monitoring Project Phase I and Phase II Report (2008-2010) PDF

Articles summarizing Phase I 2008-09 monitoring:

• Oregon Insider Article on Drinking Water Source Monitoring PDF - Summarizes Phase I sampling and results only)
• Summary in the DHS Public Health Division “Pipeline” publication - Volume 25, Issue 1 Winter 2010 PDF

Phase III Drinking Water Source Monitoring: 2012

Planning for Phase III includes selecting locations for sampling public water systems that request assistance in determining the sources of detections of nitrates and other contaminants; those samples will be taken in Mar.-Apr. 2012. Data generated from the sampling in the source areas will provide information on where to prioritize state resources for preventing the contamination of the source waters used for public systems. There is no obligation on the part of the public water system or community to engage in follow up activities, but they will be invited to participate to the extent their resources allow. We are looking forward to working on this next phase of source water monitoring and will post results as they are available.

Agency contacts for more information:

• Sheree Stewart, DEQ, 503-229-5413
• Dave Leland, OHA, 971-673-0405