One major concern is to make sure the quality of the water isn’t degraded while in ‘storage’. The pilot test showed the formation of disinfection byproducts (DBPs) from treating the injected water with chlorine prior to injection. Ecology’s antidegradation policy says injected water cannot impact native groundwater or source water quality. Groundwater quality monitoring throughout the pilot test showed that DBPs did form in the injection water, but quickly dissipated in the aquifer.
The other hurdle is the recoverable quantity of water or the amount of water recouped from what was originally injected, i.e., “recoverability”. Ecology requires that the same water that is stored be recovered, and any stored water that migrates past the capture zone of the recovery well is no longer available for use. Aspect has estimated, based on water quality monitoring and aquifer hydraulic response to injection and recovery, that the White Salmon ASR system has 85% recoverability of injected water.
Aspect is engaged in ongoing discussions and interactions with Ecology’s water quality and water rights permitting programs regarding these issues and how to efficiently complete the required permitting while protecting groundwater quality and water rights, including instream flows for the City of White Salmon and other ASR projects.
The interpretation and understanding of water quality and water right permitting requirements for ASR projects is evolving as project proponents advance their plans through Ecology. Aspect will continue to work with clients across the state to use ASR as a viable option in providing water where and when it’s needed most.