By Brian Rinehart, Marketing Manager, Hydro-Klean

This past May, Des Moines , IA , hired Hydro-Klean to perform video inspection services on a section of brick sanitary sewer that runs along Grand Avenue near the downtown area. The project's purpose was to evaluate the condition of the sewer for possible future lining. 

What was supposed to be a routine video inspection turned out to be a discovery of scary proportions. Deep below Grand Avenue , in a sixty-inch- diameter section of sewer pipe, HK’s video inspection crew discovered two large voids. These voids existed between the street itself and the sanitary sewer. We jokingly described the voids as potential Volkswagen thoroughfares. In reality, the voids measured approximately eight-feet wide, ten-feet tall and twelve-feet long. The dangers that this posed to the general public walking or driving along the street required immediate attention. The possibility of the street collapsing over the void was imminent, and as a result, HK notified the city immediately.

Averting Street Collapse

Upon review of Hydro-Klean’s video inspection recording of the sewer voids, Des Moines officials quickly requested emergency bids from several local contractors to repair the brick sewer. The city estimated that one lane of Grand Avenue would be closed for up to two weeks. Since Grand Avenue was a direct route to downtown, the traffic backups would be unsettling. However, the work needed to be done to eliminate the possibility of a street caving in.

After reviewing the emergency bids, Des Moines officials chose The Underground Company to make the needed repairs.The Underground Company developed a plan of action to fix the void sections in the sewer line. Due to the potential for dangerous atmospheric conditions (sewer gases or lack of oxygen) inside the pipe, The Underground Company needed trained, confined-space-entry personnel with proper equipment.  Since The Underground was not equipped for this type of work, they hired Hydro-Klean as a sub-contractor. Hydro-Klean’s responsibilities included not only performing confined-space-entry procedures, but also laying new brick and concrete to restore the sewer pipe’s structure.

HK's Expert Crew

Hydro-Klean assembled a crew based on previous, personal work experience laying brick. Jason Lawrence, a senior service technician, had been a bricklayer before joining HK. His experience made the choice of project crew leader an easy one. Chad Sparks, another senior service technician, and Jason Sandy, service technician, assisted Mr. Lawrence with the bricklaying and necessary safety measures that accompanied this project.

Due to the atmospheric conditions in the sewer, the HK crew had to use a supplied-air system. This system sent acontinuous flow of breathing air to the HK crew members in the sewer through an arrangement of hoses and personal, full-face respirator masks. From the beginning, the Hydro-Klean crew mixed cement, assembled brick upon brick and securely reconstructed and repaired the sewer line. While the HK crew worked inside the sewer, The Underground worked above them. The Underground work team filled the void by pouring concrete in between the street and the newly rebuilt section of sanitary sewer pipe.

Fantastic Efficiency

Though everyone anticipated that the work would take up to two weeks to complete, it was actually finished in only four days. The sanitary sewer was fixed; the void under Grand Avenue was filled and the street was opened for traffic. Once again, we saw that with collaboration, teamwork and knowledgeable personnel, anything can be accomplished.