See smoke coming from manholes on Marco Island? It's likely a test to check for leaks

The colors on the map correspond to the work schedule of the sewer smoke test, according to the city of Marco Island. "This map will be updated on Fridays to reflect progress and scheduling adjustments," the city wrote.

The City of Marco Island announced Tuesday it will test the integrity of the sewer collection system utilizing smoke to find and repair leaks beginning Sept. 8, as stated in a news release.

The test involves forcing vegetable-oil-derived and odorless smoke into the sanitary sewer lines and observing where it escapes in order to determine the location of leaks and defects, the city wrote. It leaves no residuals or stains and has no adverse effect on people, plants or animals.

Smoke testing will take approximately three weeks to complete and will occur on weekdays between 8:30 a.m. and 4 p.m.

"This test is part of our continuing effort to provide a safe, economical, efficient and environmentally sound wastewater system throughout Marco Island," the city wrote. "Eliminating system defects and illegal connections will help the city remain in compliance with federal legislation regarding sewer systems maintenance and sanitary sewer overflows."

This smoke testing procedure has been recommended by the U.S. Environmental Protection Agency, the city wrote. 

What to expect

While smoke can be expected to fill manhole covers and vent stacks in roofs, it should not enter homes, the city wrote. 

"To reduce the likelihood of smoke entering a building, the city recommends that you pour at least two gallons of water into seldom-used sinks and floor drains," the city wrote. 

If smoke does enter the home during testing the city asks residents and property owners to immediately leave the building, notify the crews that are conducting the test or call the city at 239-825-9001.

If problems are found

Smoke coming from the vent stacks on houses is normal but smoke coming from holes in the ground is not and is considered a defect, the release states. These defects will be photographed and logged.

The city will contact property owners if a defect is located on private property.

"If smoke enters the home, it is an indication of a plumbing defect," the city wrote. In those cases, "it is the homeowner’s responsibility to notify a plumber and to remedy the problem."