Aquifer storage and recovery—known as ASR—is useful and environmentally friendly water management tool. It enables water users to store high-quality surface water underground in the winter for use during drier summer months. GSI has long been a champion of this technology. We have been involved in almost every licensed effort in Oregon, and have more experience than any other firm worldwide in conducting ASR projects in basalt aquifers.
Municipalities across the country use ASR to provide peak-time supply capacity because it typically costs much less than traditional storage, expanding water treatment plant capacity, or other alternative supply solutions. ASR can also be used for irrigating agriculture, aquifer stabilization, stream restoration, and thermal load management.
Cost-effective water supply storage: ASR enables the storage of abundant winter surface water for use later during the summer, when surface water supplies are typically less abundant. This means that cities can develop new peak capacity while limiting the impact on low summer flows. For groundwater-dependent cities, storing winter surface water reduces the overall demand on the groundwater resource and can stabilize declining water levels. Although storage volumes vary widely, ASR projects commonly are developed for about $.01 per gallon—a fraction of the cost of aboveground reservoirs.
Streamflow and temperature mitigation: Because winter flows are cool and the subsurface acts as an insulator, ASR projects store cool wintertime water. In areas where utilities are having thermal load issues—or temperature TMDLs (total maximum daily loads) are common—this cool water can be a valuable asset. It helps mitigate flow or wastewater outfall impacts, and can improve habitat as part of an ecosystem restoration plan.
Stormwater management: Several utilities are evaluating the use of ASR to manage peak stormwater loads. With natural treatment, stormwater can be cooled, filtered, and biologically treated and used for groundwater recharge. Using ASR reduces outfall discharge and the water can be recovered to provide streamflow augmentation or irrigation supply during the summer.
Emergency supply: ASR systems can be used as critical facilities to bank water for use during emergency situations. ASR wells have a greater chance of surviving earthquakes, major storm surges that inundate coastal communities, and tsunami events compared to traditional storage facilities. ASR also can provide critical system resiliency where a watershed has been affected by wildfire.
Industrial uses: Industries can benefit from thermal storage in multiple ways. Storing cool winter water for increased summer cooling efficiency can result in significant energy cost savings and a reduced carbon footprint. If water rights will support it, storing warm summertime water can have the same benefit when recovered for processes that require hot water or steam.
Aquifer conditioning: Using ASR to alter background groundwater quality can benefit utilities that are approaching regulatory limits for elements such as iron, manganese, arsenic, or uranium.
We help our clients assess the feasibility of ASR and see successful pilot programs through to full operation. We are known for our successes in planning, developing, and operating groundwater supply wells and ASR systems, and in pioneering innovative managed aquifer recharge applications.