General rate cases are litigated proceedings before the CPUC that establishes San Jose Water Company's base rates for a three-year period. Pursuant to state law, San Jose Water Company is required to file a general rate case filing with the CPUC every three years. In the general rate case process, the CPUC sets rates to cover the costs of providing water service and to allow the company to earn a reasonable return on its investment in water system infrastructure. Major costs to operate a water system include purchased water, groundwater extraction tax, electric power, water treatment costs and labor. The processing of San Jose Water Company's filing generally takes the following 12-month path: