Page 26 - ACEC/PA – 2024 Diamond Awards Program

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Project Name: Monongahela Subaqueous Interceptor CIPP Rehabilitation
Firm: Johnson, Mirmiran & Thompson, Inc.
Owner: Allegheny County Sanitary Authority
Key Partners: ms consultants, inc.; Hatch Ltd.; Collective Efforts, LLC
The CIPP Rehabilitation of Portions of the Monongahela Subaqueous Interceptor was a
sewer project that consisted of lining pipe located below a major river. This project required
that new structures be installed in the river to access the existing interceptor. Construction
of the access structures needed to be done from barges using divers in low visibility
conditions. The Ultraviolet CIPP lining also needed to be done from barges, complicating
the installation. A complex bypass system needed to be installed to bypass sewer flow
while lining was completed, and this work needed to be coordinated around storm events.
An emergency break was discovered during construction that required emergency repair
under the project. This repair was in the parking lot of a local water park and involved
disposal of asbestos pipe, removal of a section of existing stream culvert, and restoration
of the area prior to the water park opening for the season.
Category M | Construction Management/Construction Inspection