The Regional District of Kitimat-Stikine is keeping a boil water advisory in place for the Thornhill Community Water System.
Crews have disinfected water storage facilities and flushed the two distribution systems, but tests have revealed the continued presence of total coliform bacteria in a single area of the lower system.
While officials say the bacteria aren’t likely to cause illness, their presence could mean the system is vulnerable to impacts of more harmful microorganisms.
Residents in the Queensway, Copper Mountain, and Upper and Lower Thornhill areas should continue to boil their water as a precaution.
The regional district says lab test of the two wells which supply water to the system continue to reveal no trace of total coliform bacteria.
Officials plan to flush the water system again and will continue to perform testing.