By Tony Wittkowski | Business Reporter | The Herald-Palladium
BENTON TOWNSHIP — The sewer rehabilitation project that Benton Township began this summer will cost less than expected, township trustees learned.
Mark Prein and Steve Oosting of the engineering company Prein & Newhof gave a slide show and project update for trustees at Tuesday’s board meeting. The township will save $200,000 from the projected cost of $1.7 million because contractors were able to abandon dozens of private property laterals no longer being used.
The $1.5 million project as a whole included work in four general areas – Territorial Road, McKann Street, Maynard Drive and Pipestone Road.
Prein said work on more than 2 miles of sewer lines in the township included rehabbing manholes, main and lateral lines.
“This project has just concluded,” Prein said. “As a result of all the meetings with township officials, a number of opportunities were taken advantage of, which further reduced the overall cost of the project.”
The township’s sewer infrastructure was given an in-depth look by the Grand Rapids-based engineering company. Oosting said the problems that needed to be addressed in the sewers were corrosion, roots and broken pipes.
The company used a lining process for existing pipes, rather than tearing up the streets to replace the lines. Oosting said they used factory-made, flexible fabric tube saturated in resin to be inserted in the existing sewer lines and manholes. Once the tubes were pushed to the inside walls of the pipe, heated water was pumped through the lines to keep the resin in place.
By using this technique, Oosting said very little digging was required as the project was completed with minimal disruption.
The standard design of the project extended the life of more than 10,000 feet of sewer lines by 50 years.
“You may get a few years more or a few years less,” Prein said. “It depends on various factors. It’s basically considered a new pipe inside the original pipe.”
The original construction records showed 103 lateral lines connected to the main lines within this project. Over the course of the project, Oosting said they discovered there were actually 154 laterals.
“This told us that throughout the history of this system, a number of connections were made without documentation. One of the primary goals in lining these connections was to abandon any of these laterals that were not being used.”
Oosting said the township’s Public Works Office helped to eliminate other lateral lines by making arrangements with property owners to run some dye down the drains inside the buildings to see where it came out in the system.
A video investigation was used to check these lines, which led contractors to abandon 81 empty laterals by sealing them off. Those abandoned lines led to the savings because they would no longer need maintenance or a new liner as part of the rehab project.
Contractors rehabbed 45 manholes – ranging from 6 to 20 feet deep – using the same fabric tubing and locking it in place with water-tight connections.
“The manholes had the same corrosion problem as the concrete sewer mains,” Oosting said. “We removed the corroded material, and a fair amount of concrete work was done at the bottom of these holes to try to provide a more smooth flow transition.”
Treasurer Debbie Boothby said the work has already paid off through lower monthly costs to the wastewater treatment plant.
“The treatment of our flows has gone down with the sewer projects we have done,” Boothby said. “We no longer have to treat infiltration.”
(Author’s Note: This article was originally published on Dec. 4, 2015)