Wastewater Treatment Plant Outfall Temperature Monitoring

In 2010 Water Quality Standards asked for volunteer assistance for a study to consider possible thermal impacts of wastewater treatment facility outfalls on streams. Twenty treatment plants were randomly selected and operators of the facilities agreed to take part in the study.

Volunteers helped place continuous temperature monitoring devices in the streams in December. These “Tidbits” were placed up and down stream from outfalls to see if stream water is fully-mixed with outfall water and back to ambient temperatures by three to five stream widths downstream from the outfall (which are criteria defined in new thermal standards). Volunteers checked the Tidbits on a regular and will collected them in spring for the data to be downloaded and analyzed.

Monitoring Guidance