The job starts by selecting the manhole with access to the main line to be inspected. A typical smoke bomb is shown in the box. This bomb is lowered into the manhole in a bucket.
Then District workers set up the hose to their smoke machine to check the sewer main and seal the top of the manhole so all the smoke is forced down the main line.
Then the blower unit is attached and they start blowing smoke.
Open clean outs at the property line are the most common cause of rainwater entering sewer mains. They also are the most common source of foreign objects entering the sewer system such as rocks, cans, sticks, oil filters and other items that cause stoppage to an entire main line.
But, when it comes up through the street . . .
We know we have a problem. Probably a collapsed line or, at best, fractured by roots or age. Now we plan the big job, dig and replace.
