Client:
Oakland Macomb Interceptor Drain Board

Location:
Oakland & Macomb County

Prime Consultant:
NTH Consultants, Ltd.

Sub Consultant:
AEW, Applied Science, FK Engineering, Spaulding DeDecker; Jay Dee Contractors

Client Name/Contact:
Jim Nash, Oakland County Water Resources Commissioner; nashj@oakgov.com; 248.858.0958

Total Project Budget:
$50.2 Million

NTH Budget:
$11.6 Million

Project Start:
2013

Project Completion:
2016


NTH’s Value Added:
NTH was able to exceed the owner’s needs and expectations by using innovative applications of existing materials and new techniques to execute a very complex project. 

Oakland-Macomb Interceptor Drain Contract 4 
​Setting a New Standard for Infrastructure Renewal

National Grand Conceptor Award for Engineering: 
American Council of Engineering Companies (National)

Honorable Conceptor Award for Engineering: 
ACEC / Michigan

Project of the Year:
Trenchless Technology Magazine

Project Overview
The Oakland-Macomb Interceptor Drain (OMID) is a large diameter sewer system that serves over 800,000 residents of Oakland and Macomb Counties. This sewer was constructed in the 1970s, and has experienced several catastrophic collapses over its service life, the latest occurring in 2004. 

The OMID system consists of mostly 8-foot to 3-foot diameter sewers that are up to 110 feet deep, extending below major transportation and power transmission corridors, which serve several million people and businesses. NTH performed several inspections in 2005 through 2008, and found that many areas of the sewer were in poor condition and could be subject to additional collapses. There is no redundancy in the system, so any collapse would disrupt service to the entire service population and would affect millions more in terms of disruption of major roadway and energy supply. Since another sewer collapse like the 2004 sinkhole would be so catastrophic to the population of Michigan, this project was a top priority for the OMID Board and the Michigan Department of Environmental Quality.

Project Scope
The OMID Board chose NTH to lead a team of design consultants and develop an approach for rehabilitation of the system, and to prepare contract documents for three-phase rehabilitation and repair program. Segment 3 of the program began construction in November 2013 and was
substantially completed in July 2016. This segment of the OMID Repair Program was a first for our industry in many ways. Never before had a repair program been attempted at such a large diameter (up to 13 feet), at such extreme depths (up to 110 feet), at these lengths (over seven miles), without the ability to bypass flow. This unprecedented scope of construction required complex flow control systems; innovative construction means, methods, and equipment; and efficient operations in tight work windows.

The interceptor lining and repair in Segment 3 required an extensive study, evaluation, and prequalification program for lining products and manufacturers to assess the available technologies in the industry that could work for this extraordinary project. It was clear that no “off-the-shelf’ product existed that could be installed in these conditions. We worked with manufacturers to customize their products to fit the project needs, and pre-qualified seven customized products.

This also improved competition in the marketplace, providing substantial cost savings (over $10 million). Ultimately, 26,000 lineal feet of 10-foot diameter Hobas pipe was successfully installed. The Hobas liner not only provided a protective barrier against microbially-induced corrosion, but the OMID repair program has also reduced system 1/l by more than 16 MGD.