Dual water supply would be safer, more reliable for Bend residents
Apr 11, 2012
Bend BulletinBy Leo Busch
Published: April 11. 2012 4:00AM PST
The city of Bend has an interesting history in regard to the Bridge Creek surface water supply system. Earlier Bend city councilors worked with the U.S. Forest Service in providing special protection to the Bridge Creek watershed under a 1926 master agreement (with subsequent supplemental updates) in preventing human activities within the watershed in order to assure a safe, clean and reliable surface water supply. Now certain business interests and environmental groups suggest that this surface water source be given up as being: 1) too expensive; and 2) would better serve wildlife needs. These groups propose that the surface water supplies be replaced by cheaper groundwater pumped from hundreds of feet below Bend.
If a groundwater option is selected by Bend city councilors, it would require future groundwater pumping to be at least doubled compared to the present groundwater being pumped from below Bend. This has the likelihood of greater groundwater contamination, in my professional opinion.
Having worked as an engineer for a large portion of my 50-year career on groundwater issues, I would like to express my concerns. During my career I served with the Interior Department managing programs associated with groundwater use issues within the Middle East. I worked with the Justice Department as a groundwater expert in testifying before the court regarding groundwater contamination issues within the Central Valley of California. I spent the last 12 years of my career managing the Bend field office of the Bureau of Reclamation.
Groundwater pumping in many cases creates its own set of issues and problems. A Feb. 7 Bulletin article on hexavalent chromium levels, “In search of a standard,” illustrates only one of many elements of concern found within the volcanic geology surrounding Bend. These types of elements plus man-made chemicals accidently or purposely dumped within a watershed, are also of concern. Deschutes County’s groundwater protection ordinance, which was meant to prevent widespread contamination of groundwater due to the uncontrolled use of thousands of septic systems, was eliminated in recent years.
There are also hundreds of stormwater injection wells within Bend, which inject stormwater runoff directly into the basalt formations below the city. Much of this urban stormwater flows directly or indirectly to the groundwater region, depending on the well configuration. Anyone who observed the recent stormwater runoff would have seen bird droppings, oil and other street debris flowing into these injection wells.
During my career with Reclamation, I managed contractual maintenance activities on similar stormwater injection wells in basalt-type formations within the Snake River Aquifer in eastern Idaho. In 1991, EPA designated this aquifer as a sole source of drinking water under the Federal Safe Drinking Water Act. Studies indicated these wells were contributing measurably to underground contamination issues. This resulted in more stringent water quality standards with complete closure or acceptable modifications of the wells, completed in 2003. This aquifer is many times larger than those groundwater sources found within Deschutes County.
Further information concerning the movement of groundwater under Bend is contained within the 2004 Geological Survey Investigation Report 03-4195, which illustrates the movement of groundwater from outlying areas into a “cone of depression” below Bend, with additional groundwater pumping. This allows groundwater entering the “cone” to either bring in greater amounts of contaminate elements or further strip the volcanic geologic formations of contaminate elements. Higher rates of groundwater pumping also increase the depth within the cone of depression, requiring additional pumping power.
The Bend Surface Water Improvement Project has been termed by various groups as unnecessary and costly. This begs the question as to whether the cheaper groundwater options should be selected. From my professional background, I believe that a dual water supply would better serve the present and future citizens of Bend as a safer and more reliable water supply.
Leo Busch lives in Bend.