Smoke testing is the quickest and most cost effective method of determining inflow in a sewer system. Inflow is when clear water from illegal connections of sump pumps, downspouts, and foundation drains is channeled directly into sanitary sewer pipes. This causes overflow and flooding in some areas. Smoke testing is used to find the cracks and leaks where water could be infiltrating. The method to smoke testing is simple. First, a gas detector is lowered into the manhole to test for combustible gases. A smoke bomb is then lit, and lowered into the manhole. A blower is placed over the manhole, which pushes the smoke down the sewer line. Within a minute or so smoke will begin issuing from any lines that are connected to the sewer. The crew will then begin walking the line being tested; taking pictures, marking locations, and drawing breakouts to accurately record the location of the breakouts. Smoke will leak out through anything that is connected to the sewer line. Basements, rooflines, lawn vents and sump-pumps, are all possible locations the smoke could emit from. Please notify a member of the crew if you find smoke inside your house.