Manhole Infiltration

A manhole doesn't need a visible flood to be a problem. Groundwater seeping in through a cracked wall, a failed joint, or a poorly sealed pipe connection adds up fast, and every gallon of it still has to be pumped and treated downstream. Manhole Infiltration seals those entry points from the inside, without digging up the structure. Municipal engineers and wastewater utilities turn to it whenever a manhole is letting in more than it should.

Why This Happens

Manhole infiltration usually traces back to one of a few common failure points. Here's what URETEK finds most often.

Deteriorated mortar joints or cracks in the manhole wall where precast sections meet, especially in older concrete or brick manholes

A poorly sealed connection where a pipe enters or exits the manhole structure

Rising groundwater or a high water table pushing water through any gap in the manhole wall or base

Previous rehabilitation work that wasn't fully sealed, leaving a partial path for water to keep getting in

Key Signs You Have This Problem

Manhole infiltration is often caught downstream before it's traced back to the source. Watch for these.

Water visibly entering through cracks, joints, or pipe connections inside the manhole

Unusually high flow readings at a pump station or treatment plant that trace back to a specific manhole or collection area

Sewer flow that increases noticeably during or after rain, a sign known as inflow and infiltration, or I&I

Staining, efflorescence, or active dripping on the manhole's interior walls

Ground around the manhole cover staying wet or muddy longer than the surrounding area after rain

A wastewater treatment plant reporting unexplained volume increases traceable to a specific area of the collection system

Is Manhole Infiltration What You're Dealing With?

This is the right page when water is entering specifically through a manhole structure, at the walls, joints, or pipe connections.

It's not the best fit in every case. Check these first:

• The leaking joint isn't part of a manhole, more of an expansion or construction joint elsewhere? See Joint Leaks.
• The leak is inside a tunnel or underground passage? See Tunnel Leaks.
• The problem is a general below-grade wall or floor, not a manhole? See Active Water Intrusion.
• The entry point is specifically where a pipe passes through a wall outside a manhole? See Pipe Penetration Leaks.

A citywide inflow and infiltration problem often involves more than one manhole at once. If several manholes in the same area are affected, it's worth reviewing them as a group rather than one at a time.

Benefits of Manhole Infiltration Control

What sealing manhole infiltration the right way, instead of letting it add up downstream, actually gets you.

Reduces the volume of clean groundwater reaching the wastewater treatment plant, cutting unnecessary treatment costs caused by inflow and infiltration

Reduces the risk of infiltration washing soil out around the manhole structure, which can eventually undermine the surrounding pavement or ground

Keeps the surrounding area undisturbed. In Nederland, Texas, a manhole was sealed in under 4 hours, saving more than 75 percent compared to the alternative approach

Avoids excavation entirely. In Knoxville, Tennessee, sealing a manhole from the inside saved the cost of a 25-foot excavation that would otherwise have been required

Sealing material is injected directly through the manhole wall in an engineered pattern, targeting the actual infiltration points rather than coating the structure generally

Structural Leak Sealing, the Service, performs this fix directly, applied specifically to a manhole's walls, joints, and pipe connections

How It's Solved

URETEK's general approach works from inside the manhole. Crews identify the specific infiltration points, at wall cracks, joints, or pipe connections, and inject sealing material directly through the wall in a pattern matched to the manhole's construction and the water pressure involved.

This is exactly what the Structural Leak Sealing service does, applied specifically to a manhole structure. It's different from Joint Leaks' focus on a single expansion or construction joint elsewhere, and different from Tunnel Leaks' enclosed passage setting.