Project Type

URC Presentation

College or School


Class Year



Civil Engineering; Environmental Engineering


Civil Engineering, Environmental Engineering

Faculty Research Advisor

James Malley


The Chestnut Street Combined Sewer Separation team worked with Neal Campbell from CDM Smith in Manchester, NH to complete a design for the combined sewer separation of Chestnut Street from Elm Street. CDM Smith won the bid to do a sewer separation for the entire city of Manchester, and this area was the first one to be completed. Combined sewer systems are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. Combined sewer separations are currently occurring all over the east coast. They are necessary because current sewer systems will not be able to handle future precipitation events. As the climate changes, precipitation events become more extreme and intense. Extreme precipitation events put a lot of stress on the piping networks currently in place, and as the events worsen the stress leads to bursting pipes or pipe failures. By adding a new large diameter pipe down Chestnut street, the flow to the pipe that runs down Elm Street will be reduced, allowing the pipe in place to last longer without bursting. Issues with piping are very expensive to fix and have large negative environmental impacts such as flooding and river contamination.