After a marathon, nearly 10-hour public hearing, the California Coastal Commission voted unanimously on May 12 to deny a permit to Poseidon Water for the construction of a new desalination plant in Huntington Beach, Calif.

The vote brings to an end an odyssey that began more than two decades ago for Poseidon Water, which had attempted to meet the requirements of California’s coastal protection and other environmental laws to be able to build a desalination plant capable of producing 50 million gallons a day of drinking water in Orange County.

Poseidon built a similar plant that went online in Carlsbad, Calif., in 2013. D.J. Moore, an attorney for Poseidon, told the commissioners, “The need for this project is critical and without question.”