Storm Water Pipe Joint Sealing in Monroe, NC

The Challenge

Multiple sinkholes threatening the integrity of stormwater pipe.

Residents in the Village of Lake Park reported multiple sinkholes, some as deep as five feet, appearing throughout the community. These were traced to stormwater pipe joints that were leaking and allowing surrounding soil to erode into the pipe. Infiltration and inflow not only damaged the ground surface but also reduced the pipe’s capacity, threatening stormwater management performance across the neighborhood.

Key Facts

The Solution

Injecting in layers until stabilization was achieved.

Groundworks was contracted to perform a trenchless remediation of approximately 300 linear feet of stormwater pipe, ranging in segments from 60 to 80 feet. A Rover camera was used by engineers to inspect and identify leaking joints, and GPR was employed to mark those locations at the surface. Groundworks then drove rods from the surface to the joints at approximately 12 feet deep and performed point injection sealing using a two-component polyurethane. In areas with significant sinkholes, multi-depth injections were performed at 12 feet, 8 feet, and 4 feet to reestablish soil stability to the surface.

The Impact

Sinkhole remediation and pipe sealing in a single day.

The project was completed without excavation, much to the relief of residents and local officials. CCTV monitoring confirmed the sealing of pipe joints during injection. Any residual polyurethane that entered the pipe was cleared with hydro jetting. The trenchless process restored the pipe’s function, remediated surface sinkholes, and stabilized soils without disrupting community infrastructure.