applicant &# 39 ; s preferred embodiment utilizes municipal wastewater effluent to replenish a depleted geothermal field . condensate produced by expanding steam produced in the geothermal field through a steam turbine - generator may be pooled with cooked water collected from said field , and then directed through a penstock from a higher elevation to a lower elevation where further energy is extracted through a traditional hydroelectric turbine - generator the cooked water and condensate may be treated to produce potable water and / or distributed for public consumption either before or after being directed to the hydroelectric turbine - generator . the effluent is pumped up to the geothermal field during off - peak periods of electric consumption , and the hydroelectric generation is accomplished during periods of peak electric demand a fraction of the effluent may be used as cooling water for the steam turbine - generator and its associated condenser before injection into the geothermal field . at least a portion of the pipeline to transport the wastewater effluent is preferably routed along an undisturbed riverbed and / or through an excavated tunnel