Manholes and other underground structures commonly account for approximately 25-30% of infiltration and up to 70% of inflow in sanitary sewer collection systems. The deterioration of these manholes can cause sewer overflows and endanger the surface above and the nearby environment.
Manhole rehabilitation solutions can cut back on the costs associated with infiltration. These problems can be overcome by the use of carefully placed flexible chemical grout. Manhole sealing is very effective where pipelines and manholes exist in a high grounds water table conditions. High quantities of ground water infiltrate manholes and this can increase the hydraulic load on the pipeline and this in turn can lead to sewer overflows, overloading of pumping stations and sewage treatment works.
Our trained technicians will drill holes within the manhole and utilize a specialized pump to inject grout behind the structure. When the chemical grout comes into contact with the catalyst (water) the chemical grout gells creating a waterproof, flexible seal.
After the injection has taken place the chemical grout will foam, expand and fill the void forming a tight, impermeable elastomeric seal, stopping the water flow (infiltration). Because the grout is on the outside of the manhole it cannot be pushed back into the sewer system.