The City of Portland began monitoring Willamette River water quality in the city limits in 1949 and periodically monitored the river for the next 40 years. In 1992, the Bureau of Environmental Services began regular water quality sampling. Environmental Services switched from monitoring fecal coliform to the E. coli standard in 1996 to comply with changes in state regulations.
The Environmental Services Field Operations section collects water samples each month at three locations on the Willamette River for long-term water quality trend analysis. Field staff usually collect samples in the first week of each month for nutrients, metals and bacteria.
From May to October, field staff also collect weekly samples from five recreational areas to give the public more frequent information about bacteria and temperature at Willamette River public access points.
Contact the Investigations and Monitoring Services section to request additional water quality data or for more information about Environmental Services water quality monitoring.