The State of Mississippi sued the State of Tennessee and the water utility, Memphis, Light, Gas & Water, for overpumping the Memphis Sand Aquifer claiming damages upwards of $1.2 billion dollars. In this precedent setting case, the U.S. Supreme Court ruled in favor of Tennessee with the caveat that groundwater is a shared interstate resource.
Between industrial groundwater use and the pumping and distribution of the public utility, Memphis, Light, Gas & Water (MLGW), massive "cones of depression" have formed around Memphis, TN. When these cones of depression occur, the flow of groundwater is altered. Memphis has, and continues to, siphon millions of gallons of groundwater each day from storage under Mississippi.
The legal battle started with Mississippi in 2005 suing MLGW, but a state court ruling explained that a state has to sue another state - not a local entity. In 2014, Mississippi adjusted the lawsuit to include MLGW, the City of Memphis, and the State of Tennessee. It took sevens years to move through the court system with a final ruling in 2021.
On November 22, 2021 the US Supreme Court issued a 9-0 ruling in favor of Tennessee. It was determined that the flow of groundwater naturally moves towards Memphis and the Mississippi River, even without the affects of major pumping. The judges agree that the pumping in Memphis is drawing water from under Mississippi, but monetary compensation is not the proper remedy. The waters of the Memphis Sand / Middle Claiborne Aquifer are subject to the judicial remedy of "equitable apportionment" and Mississippi’s complaint is dismissed without leave to amend.
You can read the U.S. Supreme Court hearing transcript OR listen to an audio recording from October 4, 2021.
This site contains the OFFICIAL DOCKET with a record of all filings made with or by the Special Master dating back to 2014. The Report of the Special Master is worth the read to understand how the lack of groundwater law and new understandings of science helped shape the decision to consider aquifers an interstate resource.
This groundbreaking decision means that the aquifer can be shared and managed by a compact, much like river compacts across the nation - and world. There are no known discussions between Mississippi and Tennessee to draft a shared compact.
