Now that we have a new mayor and council, opponents to the Surface Water Improvement Project (SWIP) will again express their opinions to stop the project. While I support opponents’ right to express opinions, the public deserves to know the facts and potential unintended consequences if SWIP is terminated.
Before retiring, I was a geologist licensed in several states working for 30 years on water resources and supply projects. I know of no community that willingly gave up a renewable surface water source providing 30 to 100 percent of their daily water supply. I do know of many communities that spent millions developing surface water supplies to reduce their groundwater dependency.
For example, Phoenix and Tucson area cities spent $4 billion for the CAP to import surface water into central Arizona.
Bend’s surface water supply is a gravity system, meaning little or no pumping is required to provide water to 80 percent of its customers at adequate pressure and for fire protection. If electricity service is interrupted during an emergency, Bend can still provide surface water to its citizens. Groundwater requires pumps to lift water and pressurize the system. As electricity rates go up, pumping costs rise and water bills increase to cover pumping costs. The more groundwater we use the more the bill increases.
SWIP opponents say Bend has sufficient groundwater and can eliminate surface water use, but don’t discuss the unintended consequences. U.S. Geological Survey studies show current pumping lowered the groundwater table beneath Bend, causing some Deschutes River water to percolate into the ground, reducing the river flow. The USGS groundwater model shows additional pumping will increase river seepage, further depleting river flow. This could negate some successful efforts by the Deschutes River Conservancy to increase flow.
The Department of Water Resources requires mitigation to offset the impacts of additional groundwater pumping. Bend could use its wastewater plant effluent for mitigation, but the plant is down gradient from Bend and while meeting the letter of the law, this would not offset Deschutes depletions through Bend.
The city would have to use upstream Deschutes flow for mitigation and some of this mitigation water will seep into the ground and merge with groundwater. This means Bend will still be using groundwater, however, rather than the direct use with the gravity system, we would have an indirect surface water use with costs for water rights, the water and pumping. These costs will increase water bills. My experience with water resources and as a scientist tells me this makes no sense.
You read about hexavalent chromium in groundwater, one of many minerals that dissolve into groundwater as it slowly percolates through basalt aquifers. Bend’s water meets all federal and state standards, but should the EPA reduce allowable mineral concentrations for components such as chromium, Bend would be required to treat groundwater.
Bend’s wells are located throughout the water system and each well could require reverse osmosis treatment equipment. RO treatment is very expensive and operates at 85 percent efficiency, meaning 15 percent of the water is waste containing the concentrated treatment minerals. Additional new wells will be needed to compensate for the 15 percent production loss, and this will increase water bills.
The waste flow could be put in sewers for disposal, but our sewer system is near capacity, so costly improvements will be needed for this flow. Wastewater plants cannot remove minerals, so additional mineral loads could result in the effluent not meeting discharge and reuse permit standards, thus requiring treatment plant upgrades. Costs for these collection and treatment upgrades will increase sewer bills.
I urge you to contact the mayor and council and tell them to continue with the SWIP and not to be influenced by the opinions of a small but vocal group of opponents who want policy changes that will result in higher water and sewer bills for everyone.