Ongoing Rehab In Indianapolis

By Jeff Griffin, Senior Editor | November 2013, Vol. 68 No. 11

A major sewer rehabilitation program is under way in the city of Indianapolis addressing a backlog of structural repair and inflow and infiltration issues.

The program was initiated in 2011 when Citizens Energy Group (CEG) took over ownership and operation of the city’s water and sewer utilities from the Indianapolis Departments of Water and Public Works, respectively.

Before the changeover to CEG, city budgets had been tight and rehabilitation was often overlooked, said Roger Hanas, Citizens Water project manager.

“However,” said Hanas, “inspections and assessments of the sewer system were being made, so CEG inherited a well-understood system that had significant rehab needs. As a result, CEG made a decision to dedicate substantial funds towards rehab. Projections are we will spend $10 to $15 million per year for the foreseeable future.”

As the 2013 fiscal year ended, Hanas said 75,000 linear feet of pipe had been rehabilitated at a cost of $14.5 million. It was the first full year of rehabilitation since the program was started.

Of pipes rehabilitated, Hanas said there was significant deterioration on most of the large diameter, combined sewer lines. In some cases, large voids in the inverts and sidewalls of the pipe were present and large sinkholes in the road had formed over the pipes.

For the small diameter – pipes 18 inches and less in diameter – projects selected, the driver was inflow and infiltration (I&I) reduction.

“We had neighborhoods that were experiencing basement backups, and our CCTV investigation led to the conclusion that lining would help reduce the problem,” Hanas said. “Our initial conclusion is that the projects have been successful at reducing backups – none has occurred to date during significant rainfall events.”

citizensart1.jpg

MSAs
In order to maximize the amount of rehab that could be completed, CEG decided to enter into Master Service Agreements (MSAs) with three cured-in-place-pipe (CIPP) lining companies, said Hanas.

“MSAs eliminate both a lengthy design and bid process and allow for extremely efficient use of funds,” he pointed out.

The primary method of work completed has been CIPP rehabilitation.

“This method was selected in nearly every case, due to the MSA pricing structure and ability to complete work quickly, meaning minimal disruption to the customer,” explained Hanas. “Exceptions to CIPP were the use of shotcrete in certain situations, as well as an occasional point repair when major breaks were encountered.”