Groundwater Replenishment
Groundwater replenishment involves the use of surface waters, such as rivers, streams, lakes, and reservoirs, to supplement subsurface groundwater supplies. This replenishment process is used to increase the quantity and/or quality of groundwater resources, such as those found in the subsurface strata of an aquifer. By replenishing the available groundwater, there is an improvement in the water-holding capacity and overall health of a given aquifer. In addition, surface water is also used for aquifer recharge as a method for storage of available water.
Since the beginning of mankind, there have been many techniques used to replenish and recharge groundwater supplies, from the diversion of rivers and streams to the soaking of soil with the annual rains. Today, modern technology has enabled us to use engineering techniques for the purpose of groundwater replenishment. These techniques are generally referred to as aquifer storage and recovery (ASR) systems or managed aquifer recharge (MAR) systems.
In ASR systems, surface water is diverted and stored in an aquifer, typically approaching it in the form of subsurface flows. The stored water is then used directly, or is further processed and treated before use, in order to deliver a more desirable water quality. ASR systems are often employed in areas of high density populations, where large quantities of surface water are needed to supplement groundwater resources.
MAR systems, typically including injection wells, are employed in order to capture surface water and deliver it to the subsurface layers of an aquifer. This stored water is recovered for direct use or for further processing for desired water quality. MAR systems are also employed where other water sources, such as treated wastewater, or naturally occurring sources such as springs and springs, have a limited capacity, or where the availability of surface water is uncertain.
Groundwater replenishment, whether through ASR or MAR systems, is an invaluable tool for maintaining an adequate supply of water in an area, as well as for improving the sustainability of an aquifer and the quality of its resources. By planning and utilizing a suitable groundwater replenishment system, users can improve water availability and water quality, reduce costs associated with water pumping, protect wetlands, and support fish and other wildlife resources. In addition, replenishment can help to prevent the buildup of nitrate and other contaminants that are harmful to ecosystems and human health.
For any given area, the design and engineering of a groundwater replenishment system requires extensive engineering and technical analysis, in order to determine the effectiveness of the system and assess any potential impacts. The costs associated with such systems can vary dramatically, depending on the type and size of the system, the availability of surface water sources, and the required infrastructure. In general, the larger and more complex the system, the more costly it will be. Ultimately, homeowners and businesses should work closely with local and state environmental agencies to develop an economical and effective groundwater replenishment system that meets the specific needs and regulations of the area.
