SAK Construction has begun work on a $9.2 million contract to rehabilitate 5,575 linear feet of aging combined sewer in downtown St. Louis. The project, which targets a major segment of the brick-and-limestone Old Mill Creek Sewer, is jointly funded by the U.S. Army Corps of Engineers and the Metropolitan Sewer District of St. Louis (MSD).

Rehabilitation of the sewer, which was built in the 1860s, is part of a comprehensive plan MSD is implementing to improve the St. Louis wastewater system. 

According to Mike Badgley, SAK project manager, the contract includes renovating the 18-foot-high by 20-foot-wide arch-shaped sewer, 15 manholes and 58 lateral connections, using chemical grout, concrete and shotcrete. To complete the work, an estimated 3,200 cubic yards of concrete, 4,500 cubic yards of shotcrete and 400 tons of reinforced steel will be required. Completion is slated for November 2017.

“SAK’s extensive experience in working on aging combined sewers, including the recently completed successful renovation of another section of the Old Mill Creek Sewer, allows us to tackle assignments of this complexity and size and ensure an on-time seamless project completion for MSD,” Badgley says.

Among the unusual challenges posed by the project is the sewer’s average dry weather flow of 50 million gallons a day. According to Badgley, this means that heavy rainfall or a high river stage — in addition to the normal dry weather flow — can restrict working conditions within the sewer. To minimize potential issues and to progress on schedule, SAK regulates the dry weather flow by using a combination of bypasses and flow diversions.

Going big in Baltimore

Earlier this month, SAK began work on a $17.3 million contract to install 115,000 linear feet of 8-inch to 24-inch cured-in-place pipe (CIPP) in a dozen residential neighborhoods in Baltimore. According to Bob Stier, Atlantic Division general manager, the project also requires SAK to rehabilitate 529 manholes and repair more than 2,100 house connections, using excavation, grouting and CIPP methods.

“SAK’s extensive experience in working with CIPP in residential areas – plus our ability to bring in additional seasoned crews, as needed, from our other locations – allows us to successfully tackle assignments of this complexity and size, and ensure on-time, seamless project completion for the city,” Stier says.

The project is part of Baltimore's plan to improve its wastewater system, scheduled for completion in April 2016. SAK is concurrently working on a separate $18.8 million wastewater rehabilitation project in the Union Square area of Baltimore, scheduled for completion this November.