Cross Connections

Cross connections between water supplies and sources of contamination represent one of the most significant threats to public health in the water supply industry. A cross connection is a physical connection between the drinking water system and any other piping system containing a non-potable substance. A backflow can occur when a substance flows back into the public water system as water pressure fluctuates.  This could be as a result of a water main break or hydrant usage.

The Portland Water District has made important updates to its Cross Connection Control Program. Effective July 1, 2021, the following changes have been made. 

All year round water services that receive a meter installation are subject to the Cross Connection Control Program. This includes existing facilities, abandoned facilities, and facilities with closed accounts.
Section VI(K) – This is a new section that deals with the requirement that one backflow preventer shall be installed on one service line when multiple buildings on a single lot are supplied with one service line. 
Section VI(L) – This is a new section to address the requirement that the backflow preventer be installed immediately after the meter when the meter is in a meter pit.
Section VI(P) – Moved from Table 1 and includes a statement that if an existing water service does not have a backflow preventer and informs the District that they are installing a landscape irrigation system (typically by request of a subtraction meter), a backflow preventer will be required. 
Appendix B – This is a new section to the manual.  This appendix was created to show a pictorial representation of Section VI(K,L).

Effective January 1, 2019, the updated Program Cross extends the requirement of backflow device installation to the following. 

• New residential construction
• Substantial renovations of buildings and internal plumbing systems
• Fire sprinkler systems that are being upgraded