Violent geysers in combined sewer systems (CSSs) result from the uncontrolled release of air through vertical shafts and can cause significant infrastructure damage. To prevent them, many municipalities operate their systems well below full capacity—leading to more frequent combined sewer overflows (CSOs), a major pollution issue affecting over 770 U.S. cities.

Dr. Arturo Leon's team was the first to reproduce violent geysers in a laboratory setting, capturing multiple consecutive eruptions that reached heights of over 30 meters—closely resembling real-world events. A video of the experiment can be viewed here.

In parallel, 3D numerical simulations using OpenFOAM were developed and validated with lab results. These models are now being used to test retrofitting strategies aimed at reducing geyser risk in existing infrastructure.

Snapshots of maximum eruption heights for four of our geyser experiments

Sequential snapshots of geyser eruption in one of our experiments

Sequential snapshots in the horizontal pipe of one of our geyser experiments

Snapshots of our numerical simulations produced with OpenFoam