Mercer Island E. Coli Linked to Backflow?

Officials still don’t know the source of the E. coli that showed up in Mercer Island’s water system last week, prompting the “boil water” notice.  As they continue the investigation, they are examining a potential source of the E. coli – cross connections between the domestic drinking water system and any other non-potable water supply, including landscape irrigation and fire sprinkler systems.

It can take a serious case like this to remind us all of the importance of cross connection prevention and annual backflow testing.

A working backflow assembly prevents irrigation contaminants from seeping into the drinking water.  But all mechanical devices can fail.  The yearly test helps ensure that your assembly is working as designed, protecting your family and neighbors from a potentially hazardous cross connection.

NUD currently identifies around 5,000 backflow assemblies in our District – this number is increasing weekly as new sprinkler systems are identified through ongoing audits of our service area.  The District appreciates all of your help in making sure your annual test is completed on time.  Your effort can make a difference in keeping our water safe for everyone to drink.