Hermiston ASR Feasibility Study and Implementation

GSI is helping the City of Hermiston implement an ASR system in a Critical Groundwater Area to increase the supply and resiliency of its municipal potable water system. There are multiple stakeholders involved in the project, including the City (system owner/operator), the Port of Umatilla (water right holder), and private industry (financial contributor and end-user). The ASR system will consist of recharging the Columbia River Basalt Group aquifer at up to three wells and will use treated surface water from the Columbia River as source water.

In 2021, GSI completed an ASR feasibility study for the City based on a review of relevant background information related to existing water system infrastructure, supply and demand information, aquifer characteristics, geochemical mixing analyses, well condition assessments, and available water supply through the Port of Umatilla’s water rights. From this evaluation, we concluded that ASR is feasible. We then developed cost estimates for implementing ASR and identified existing City wells that could be converted to ASR wells or promising locations for new wells.

GSI then assisted the City with permitting by developing and submitting an ASR limited license application to the Oregon Water Resources Department and supporting facility construction. GSI developed technical specifications to construct a new ASR well and oversaw drilling, construction, and testing of the new well. The project is currently under construction and the City expects to begin the first cycle of ASR injection during the winter of 2025.

GSI’s work involved:

• Evaluating existing information related to the City’s water system as well as water supply and demand data.
• Ensuring that the City’s water rights and regulatory frameworks could support an ASR system.
• Looking at hydrogeologic data to determine whether the subsurface conditions were favorable.
• Developing planning-level cost estimates to determine the most cost-effective ASR configurations.
• Assisting with limited license permitting.
• Developing technical specifications and providing oversight for the drilling, construction, and testing of a new ASR well.