USGS Scientific Invesigations Report 2012–5068  - Reconnaissance of Contaminants in Selected Wastewater-Treatment-Plant Effluent and Stormwater Runoff Entering the Columbia River, Columbia River Basin, Washington and Oregon, 2008

Table 2. Descriptions of wastewater-treatment plants where samples were collected, Columbia River Basin, Washington and Oregon, 2008–09. 

[Cities shown in downstream order. Abbreviations: Mgal/d, million gallons per day; 7Q10, the lowest streamflow for 7 consecutive days that occurs on average once every 10 years; ft³/s, cubic foot per second; UV, ultraviolet; WWTP, wastewater treatment plant; NA, not available] 

City	Station name	Point of  discharge,  Columbia  River mile	Permit design flow (Mgal/d)	Columbia River 7Q10 streamflow (ft³/s)	Wastewater-treatment  plant description
Wenatchee	City of Wenatchee WWTP effluent at Wenatchee, Wash.	466.6	7.1	51,557	Activated sludge plant, secondary-level treatment and UV disinfection.
Richland	City of Richland WWTP effluent at Richland, Wash.	337.1	11.4	52,700	Semi-plug flow conventional activated sludge, secondary clarification, and chlorination.
Umatilla	City of Umatilla WWTP effluent at Umatilla, Oreg.	289	0.92	NA	Oxidation ditch with UV disinfection.
The Dalles	City of The Dalles WWTP effluent at The Dalles, Oreg.	189.5	4.15	80,637	Activated sludge plant with UV disinfection.
Hood River	City of Hood River WWTP effluent at Hood River, Oreg.	165	2	74,000	Activated sludge plant with UV disinfection.
Portland	Columbia Blvd WWTP effluent at Hayden Island, Oreg.	105.5	72	79,436	Conventional activated sludge, secondary clarification, chlorine disinfection.
Vancouver	Vancouver Westside WWTP effluent at Vancouver, Wash.	105	28	79,436	Industrial Pretreatment Lagoon, secondary activated sludge, UV disinfection, sludge incineration.
St. Helens	City of St. Helens WWTP effluent at St. Helens, Oreg.	86.9	45	88,900	Combined municipal and kraft mill aerated stabilization basin.
Longview	Three Rivers Regional WWTP effluent at Longview, Wash.	67.5	26	97,400	Conventional activated sludge, secondary clarification, chlorine disinfection, dechlorination.

Reconnaissance of Contaminants in Selected Wastewater-Treatment-Plant Effluent and Stormwater Runoff Entering the Columbia River, Columbia River Basin, Washington and Oregon, 2008–10

Reconnaissance of Contaminants in Selected Wastewater-Treatment-Plant Effluent and Stormwater Runoff Entering the Columbia River, Columbia River Basin, Washington and Oregon, 2008–10 