Pre-Chlorinated Bursting: Cost Effectiveness On A Large Scale

October 2012, Vol. 67 No. 10

The Charter Township of Brownstown, MI, has undertaken an ambitious water-system improvement program that includes installing nearly eight miles of new water mains. Most of the project involves installation of pre-chlorinated HDPE pipe by the trenchless pipe bursting process.

Construction is occurring at various locations throughout the Township. Much of the construction in the southern end of the township is in an area of one-time cottage communities that have become full-time residences in this pleasant community of 30,000, some 20 miles south of Detroit. Pipes also are being replaced in older subdivisions where deteriorated mains are susceptible to breaks.

Older areas of the Township have experienced interruptions of service caused by breaks and increased capacity is needed in areas that have experienced significant growth with increased water demands.

Township Public Works Director Mark Gahry said the project is Brownstown’s first experience with pipe bursting and the use of pre-chlorinated pipe. “The Township is very progressive,” Gahry said. “I have kept abreast of developments in technology and the various trenchless construction methods appropriate for the Township’s needs. I have been on pipe bursting projects and the contractor conducted an impressive demonstration that really sold me on the technology for our water main improvements.”

Gahry said the use of pre-chlorinated pipe is not common in Michigan, but he has been on projects where it is used and investigated it thoroughly before committing. “I wanted to be sure we understood what we were getting into,” he added. “It is a recognized and accepted process and the Environmental Protection Agency now has guidelines for it.”

Proponents say that pre-chlorination of pipe prior to installation by pipe bursting allows the existing system to remain in use, reducing system downtime and eliminating post-construction testing.

Joint venture contract
The Brownstown water improvement project is a joint venture of Bidigare Contractors Inc., Northville, MI, and D & D Water & Sewer, Inc., Canton, MI. Their contract calls for installation of 43,000 feet of new water mains, most of it 8- and 12-inch pre-chlorinated HDPE pipe. The contract also calls for installation of fire hydrants and gatewells.