The Village of Niles and consulting engineer Hey and Associates will conduct smoke testing of the sanitary sewer system in certain areas of the Village during the weeks of November 7 and November 14, 2016. Affected residents will be receive a door hanger notification of the testing prior to it beginning. This test involves pumping non-toxic, white or gray smoke into the sewer system, and Village personnel looking for smoke rising from improper locations. Only if you see smoke inside your home should you come outside and notify crews.
Learn more in the linked document.