What do you do when the lakebed of your waterfront community sits above eight miles of deteriorating, inaccessible sewer pipes which are leaking raw sewage into your pristine waters? And what if the conventional solutions proposed by your Water District are both extremely costly and unsightly?

If you are the residents of Lake St. Louis in Missouri, you take matters into your own hands and find the right mix of experts to bring creative solutions to the table.

Lake St. Louis is a suburb with 16,000 residents originally planned as a private resort community. Its subaqueous sewer mains were unmaintained for many years. Being completely submerged, the pipes provided no clear access points for conventional inspections nor repairs. To make matters worse, the local Water District informed residents that raw sewage was possibly leaking into two lakes on the property, and a remedy was needed immediately.

One proposed solution was to close off the existing mains and install about 30 lift/pump stations in several backyards to handle wastewater. Not only would this affect the beauty of the development, it would come at a projected cost of up to $70 million.

This was unacceptable to the homeowners, so they united to find an alternative, one which Motivo is proud to have been an integral part of along with partnering firms Marion Hill Associates (commercial diving and marine construction) and SAK Construction (tunneling and pipe rehab contractor).

Three-phase plan

The first step of the solution was to inspect the existing pipes and evaluate their actual condition, one of our specialties. However, they were not only buried about 10 feet under the lakebed but had an additional 10 to 35 feet of water on top. Compounding the challenge was the total lack of access points to insert our remote cameras.

First, we worked with our partner firms to pinpoint the location of the pipes and construct 16 underwater access manholes at regular intervals. The purpose of these was to provide a way to insert our advanced fiber-optic remote inspection technology to facilitate repairs now and maintain the pipes in the future.

Once this phase of the plan was completed, we were able to inspect nearly 36,000 linear feet of pipe and identify three sections of pipe which needed rehabilitation.

These repairs were completed using CIPP, which avoided digging up and removing old sections and replacing with new pipe. Instead, a new pipe was formed within the existing pipe at each damaged section and cured in place.

Back to normal

This project illustrates the power of using remote video inspection (RVI) and CIPP/pipe liners to inspect and repair pipes which are nearly impossible to do with conventional methods. By adopting trenchless pipe repair solutions, this community saved countless millions and preserved its way of life. 

The plan was executed over the course of 24 months with minimal disruption and a fraction of the original projected cost. Life went back to normal and the residents slept easy knowing they had a means to easily inspect and maintain pipes in the future.

Every project is different, but our expertise in this field allows us to meet most challenges. If you have a project you think trenchless pipe repair might be a good fit for, please reach out.