Pipe bursting is a trenchless method that involves digging an access pit and inserting a bursting head into the existing sewer line. The bursting head breaks the old pipe apart and pulls the new pipe into place behind it. Construction crews retrieve the bursting head from a second access pit. Pipe bursting includes these steps:
- Excavate and expose existing lateral pipes that connect individual properties to the main sewer line in the street
- Connect laterals to the main sewer with a temporary pipe
- Shore the excavation and cover it with a steel plate to allow traffic to use the street (this step takes a week or more per block)
- Dig an insertion shaft about 20 feet long and four to six feet wide
- Weld sections of black plastic pipe the day before pipe-bursting to make a single, block-long pipe. Workers leave this long pipe section at the curb overnight, and it can block driveways.
- Insert a conical bursting head into the existing pipe and lay new pipe behind the bursting equipment for insertion. This can block one or more intersections and driveways for up to several hours.
- The bursting head moves forward, shatters existing pipe and forces pipe fragments into the surrounding soil.
- Pull or push new pipe into place behind the bursting head. This usually takes a few hours per block.
- When the new main sewer is in place, crews make temporary lateral connections to the new pipe, making the sewer fully operational.
- Over the next few days, crews make permanent lateral connections, backfill the lateral trenches, and do temporary paving.
What to Expect During Pipe-Bursting
Pipe-bursting involves a lot of preparation and post-bursting work but actual pipe-bursting takes just a few hours. During pipe-bursting:
- The equipment is loud and causes vibration that you may feel in your home or business. This is standard for this method of construction.
- At the end of each work day crews will cover trenches with steel plates that are bumpy but safe to drive on.
- There may be inactivity between some phases of this process.
- Typical work hours are 7:00 a.m. to 6:00 p.m. Monday through Friday, but the contractor may schedule work during the same hours on Saturdays.