Part 1: Managed Aquifer Recovery

According to the National Center for Environmental Information, about 51 percent of the continental United States has been experiencing drought conditions in the summer of 2022. More than 70 percent of the western U.S. faces severe drought. The Colorado River basin supply is rapidly declining, and Lake Mead and Lake Powell are at critically low levels. Because of this, the U.S. Bureau of Reclamation has declared a Tier 2 water shortage on the Colorado River impacting seven western states that depend on water from the river. The Tier 2 shortage means Arizona and New Mexico will have to further reduce their Colorado River use beginning in January 2023. These states will be affected the most with a reduction requirement of more than 20 and 10 percent, respectively. California will not have cuts made to its Colorado River usage until a review in early 2023; however, California Governor Newsom has outlined a plan for both preservation and water reserve development to help stem the projected 10 percent decrease in water available to California over the next 20 years.

In the U.S., more than 40 percent of the population relies on groundwater for its drinking water. Groundwater is also used for irrigation, domestic use, public use, and industrial and mining activities. Water used in agricultural production is usually sourced from surface waters (i.e., rivers and streams), or from groundwater stored in aquifers or cisterns. Groundwater volume is dependent on precipitation and, as we experience these abnormal conditions where rainwater is scarce, and as populations increase, we have seen significant depletion of groundwater from porous underground geological formations. Abnormal precipitation, like that which flooded Las Vegas or Corpus Christi recently, can be collected and treated to meet applicable water standards and then directly injected and stored in existing underground aquifers through a well system until it is needed for the water supply or reclamation purposes. This process is called managed aquifer recharge (MAR) or aquifer storage and recovery.

MAR is a cost-effective way to increase the availability of drinking water to the local population by using treated runoff, stormwater, or wastewater. Unlike water in dams, underground storage is not impacted by evaporation. The use of various infiltration techniques, including pumping treated water into existing porous aquifers for storage for use later, can help act as a barrier to saltwater intrusion that may come from other geological layers underground or serve as a method to stabilize the water table in stressed underground systems.

Florida leads the U.S. in using this technology followed by Texas, Colorado, and Utah. However, MAR systems are becoming more prevalent across the U.S. especially in urban centers where the need for fresh water prevails. EPA regulates aquifer recharge injection wells for drinking water usage; however, it does not regulate the recovery of stored water. There are also regulatory challenges on the state level depending on whether or not the water injected into the aquifer is treated to drinking water standards. As of 2007, nine states require that water injected for aquifer recharge and aquifer storage and recovery be potable or treated to national or state standards (Aquifer Recharge and Aquifer Storage and Recovery | US EPA)

References

U.S. Drought: Weekly Report for August 2, 2022 | National Centers for Environmental Information (NCEI) (noaa.gov)

Drought Classification | U.S. Drought Monitor (unl.edu)

2022-8-11 CA Water Supply Strategy - DocumentCloud

Managed Aquifer Recharge: An Overview of Issues and Options | SpringerLink

Rain pours into some Las Vegas casinos and floods streets in the wettest monsoon season in a decade (msn.com)

Managed Aquifer Recharge - ITRC (itrcweb.org)

Aquifer Storage and Recovery | South Florida Water Management District (sfwmd.gov)

Innovative Water Technologies - ASR FAQ | Texas Water Development Board

The pros and cons of Aquifer Storage and Recovery (ASR) – Texas Living Waters Project

Water-sensitive cities: Expert warns how to avoid depending on the weather to cushion drought (pressenza.com)

The United Nations World Water Development Report 2022: groundwater: making the invisible visible - UNESCO Digital Library

news.un.org

Water Law Overview - National Agricultural Law Center (nationalaglawcenter.org)

Aquifer Recharge and Aquifer Storage and Recovery | US EPA

Managed Aquifer Recharge – Green Suffolk (image)

water-10-00239 (1).pdf (image 2)