Enterprise Wastewater Treatment Facility
Facts that you need to know:
The City of Enterprise’s wastewater treatment facility was originally constructed in 1955. The 1955 treatment facility project consisted of construction of a preliminary treatment system including headwork’s, one 35 foot diameter primary clarifier, a 54 foot diameter rock-media trickling filter, one 35 foot diameter secondary clarifier, sludge pumping facilities, a control building, an 18.5 foot diameter anaerobic digester with external heat exchanger and mixing pump, sludge drying beds, a gas chlorinator system, and an outfall to the Wallowa River.
In 1986, the City received a Community Development Block Grant for $424,000 to complete limited improvements to the wastewater collection and treatment facilities. The limited improvements focused primarily on isolated repairs of the collection system to target reduction of the severe infiltration/inflow problem the City experiences in their collection system, a minor amount of work at the WWTF, and construction of an effluent polishing and dechlorination lagoon.
This 1955 WWTF was constructed to handle 750,000 gallons of wastewater per day. This treatment facility served the City well for 52 years, regulations over that 52 year period got more stringent over the years and the ageing facility was having problems staying in compliance with the DEQ’s regulations. At times flows would run into the 1,000,000 gallons/day at certain times of year because of the infiltration problems the City had in certain parts of their collection system. This facility was having problems meeting the DEQ’s permit limits for flows, biochemical oxygen demand, suspended solids and E-coli that were being discharged into the Wallowa River.