James McRay
Efficiency Production, Inc.

The City of Monroe, Michigan recently awarded an important watermain rehabilitation project to Insituform Technologies USA, Inc. of St. Louis, Missouri.  Insituform is rehabbing 2.5 miles of potable watermain in Monroe using a special process that lines the existing pipe.

"We decided to go with the Insituform Blue system for a couple of reasons, the first is that the watermain pipe is still good, we really just needed to clean it out and shore it up," said Patrick Lewis, Monroe's Director of Engineering.  "Second, that application (lining watermain pipe) really worked well for this situation.  There aren't a lot of leads along the line, and it really provided minimal disruption to the area's traffic, so that alone provided a cost savings."

Insituform is lining the watermain using its Thermopipe system.  The Thermopipe liner is a thin reinforced polyethylene liner ideally suited for rehabilitation of distribution water mains and other pressurized piping systems up to 12 inches in diameter.  Supplied as a factory-folded "C" shape liner, the Thermopipe liner is winched into the host pipe from a reel and reverted with air and steam.  Once inflated and heated, the liner forms a close-fit within the host pipe, creating a jointless, leak-free lining system able to independently carry the full system internal design pressure.

In total, more than 14,000 linear feet of water main will be lined by Insituform over a 2.5 mile area.  Along the pipeline, the watermain will be accessed between 120-140 times, wherever there is a hydrant, tee in the line, or valve.

Even though the watermain isn't particularly deep in the ground (between 5 and 8 feet deep), making multiple excavations in a busy area of Monroe creates its own unique challenges.  Insituform requires the ability to access the host pipes for cleaning, lining and post-rehabilitation inspection.  Multiple small pits will need to be dug and then left open for access--as many as 21 holes at one time.  Although pits will be cut directly in the middle of busy roads, resulting in some lane closures and other traffic redirects, the installation of the Thermopipe system will be less disruptive than traditional dig and replace methods.