The high-quality and well-protected nature of the Bull Run Watershed has allowed
the Portland Water Bureau to qualify for a filtration variance since 2012, continuing a
125-year legacy of operating as an unfiltered water system.

However, after a series
of detections for Cryptosporidium, Portland City Council directed the Portland Water
Bureau to add filtration treatment to Bull Run drinking water. This is a major
undertaking and will result in a new drinking water treatment plant for Bull Run water.
The new treatment plant will be online by 2027. 

In addition to providing treatment for Cryptosporidium, the addition of filtration will
provide more consistent water quality through the distribution system, increase the
reliability of the Bull Run by enabling treatment for most instances of increased
turbidity, and filter algae and remove sediment from the water.

Constructing a new treatment plant now is also an investment in Portland's future by
better preparing the Water Bureau to meet future regulations.