FERNDALE, WA (MyBellinghamNow.com) – Some Ferndale residents may see smoke in unexpected places next week.

Crews with the city’s public works will use non-toxic, odorless smoke to test their sanitary sewer system next week.

Residents living near Thornton Road and Vista Drive may see the smoke emerging from places like vents, yards, gutters and foundations.

Smoke helps the city determine areas where errant groundwater could infiltrate the sewer system.

Impacted residents will be notified in advance, and are encouraged to pour water into drains that aren’t in frequent use to prevent smoke from entering their properties.

My Bellingham Now previously reported similar testing was done in some Bellingham neighborhoods last month.