Sand Filter Joint Sealing

Henrico, VA

The Job

Two underground stormwater sand filters at an apartment community wouldn’t hold water. The structures, which were assembled from 10′ diameter metal pipes needed to pass a water loss test before the property could come off the bond. Previous repairs attempted included the installation of internal joint rings and seals, which did not stop enough flow to pass the water loss tests.

The Challenge

The proposed repair had to accommodate multiple layers of previous repairs. The joints included four different materials–aluminized metal, galvanized metal, neoprene, and polyethylene. The structures were bedded in washed #57 stone and were connected to the stormwater drainage system, so subject to live flow.

The Solution

Sprayed high-density polyurethane/polyurea hybrid to seal the joints internally. In addition, chemical grouting for joints that had been repaired previously using internal bands and polyethylene seals. The chemical grouting repair was designed to minimize the loss of chemical grout into the surrounding stone beds. The previously-installed internal seals and bands were left in place and encapsulated in the joint sealant.

CJGeo’s large diameter pipe repair crew installed chemical grout to seal the leaking joints. Immediately after the sealing was performed, the structures were tested by the municipality. Neither structure leaked any water after CJGeo sealed the joints.