The City of Sioux City is served by a municipally-owned, 29 million gallon per day wastewater plant. Originally constructed in 1961, the Sioux City Regional Wastewater Treatment Plant serves five communities in Iowa, Nebraska, and South Dakota. An upgrade to the Sioux City Wastewater Treatment Plant’s anaerobic digester is underway that will reduce air emissions, improve odor control, and support our vision for a healthier city. The biogas will be upgraded to renewable natural gas for sale on the national market for renewable vehicle fuel. More >>