Wastewater/Sewer Division

A new sewer plant was built down by the Columbia River in 1999 and is operated by the Public Works Department. The Wastewater Division employs certified professionals who operate and maintain the City's Wastewater/Sewer operations. Wastewater Operations Division is responsible for the operation and oversight of the City of Umatilla Wastewater Treatment Plant (WWTP). The plant operates 24/7 and treats an average of 700 thousand gallons of waster water per day. 

Wastewater that enters the treatment plant (influent) is about 99% water and 1% solids. The wastewater flows through a series of treatment processes that screen out large solids, remove smaller solids that sink or float, and then removes smaller materials that are dissolved in the wastewater. This treatment process involves physical, chemical and biological treatment techniques.

The Wastewater Treatment Plant is a state-of-the-art wastewater treatment plant that utilizes many complex processes to produce treated wastewater and recycled water. Wastewater undergoes primary, secondary and tertiary treatment and disinfection before being released into the Columbia River.