Mount Carmel staff plan smoke testing to find stormwater connections to sanitary sewer; residents warned to disconnect downspouts

City staff told the council they plan to run targeted smoke tests of small areas to identify where stormwater or private downspouts are tied into the sanitary sewer system and are overloading the system during heavy rains.

Staff described the smoke test process: crews will isolate a small area, introduce short-duration non-toxic smoke into the sewer lines, and then inspect where smoke is visibly exiting — which can reveal roof-gutter connections, broken pipes or illegal discharges. Staff cautioned that residents may see smoke in basements, gutters or at ground level during testing and said the smoke does not indicate a fire.

Officials highlighted a persistent drainage challenge in parts of the city where older infrastructure (for example, 10-inch lines tying into 8-inch lines) and terrain create backups during heavy rainfall. Staff said that some residents’ gutter downspouts currently drain directly into the sanitary system and that disconnecting those downspouts to a yard basin or an extension that disperses water five feet from the house is a preferred corrective step.

Timing and follow-up Staff said the city will notify affected areas in advance and only perform smoke testing once conditions are dry enough for accurate results. After testing, the city will follow up with residents where private connections or defects are identified and will provide guidance on fixes; the city cited a similar approach used by a neighboring town to require disconnection of private guttering that was tied into the sanitary system.

Why it matters City staff said smoke testing will help identify private and public defects that cause sanitary sewer overloading, reduce sewage backups and guide repairs or enforcement where private property is improperly connected to the sewer system.