What is inflow and infiltration?

Inflow and infiltration (I&I) refers to a condition that affects our underground infrastructure, such as a sanitary sewer collection system, designed to collect sewage and transport it to a treatment plant for processing. In this case, groundwater seeps through the structure’s walls which can cause damage but also adds fluid to the collection system which can significantly burden the downstream treatment plant. However, I&I can place a burden on the system and treatment plants by introducing an influx of clean water that shouldn’t be there. Three things contribute to this problem: soil conditions, the environmental conditions where the system is located, as well as the age of the infrastructure. Aging infrastructure is prone to deterioration due to natural wear and corrosive damage, which exerts constant stress on the system.

What happens if I&I is left untreated?

The issue of I&I poses a significant problem, as it can lead to overflow conditions that have adverse environmental consequences and place strain on infrastructure’s design capabilities. Traditionally, the reactive way municipalities deal with this concern is by building bigger treatment plants with greater capacity, but this infrastructure is a very costly venture. The better environmental and cost-efficient scenario is to proactively line the collection system, so water infiltration stops at the source.

The uses of structural epoxy.

Structural epoxies are specifically designed to line below-grade structures, like concrete pipes, manholes, and lift stations, and can help mitigate the effects of I&I by sealing the substrate. These coatings are spray-applied in a single coat at thicknesses of up to 250 mils, or 1/4", and are sometimes used in conjunction with resurfacers or other substrate repair materials.

Application is fast, and trained applicators can efficiently line large sections of collection systems in just a few days making structural epoxies a cost-effective technique to reduce I&I.