Tiber Branch and Sucker Branch Interceptor Improvements

As part of Howard County’s evaluation of their entire sanitary sewer system, the Tiber Branch Interceptor and Sucker Branch Interceptor were both found to have insufficient capacity for current and projected future flows.  To address this need, the County selected GMB to provide preliminary engineering services, design, bidding, and construction phase services for the Tiber Branch and Sucker Branch Interceptor Improvements project. 

Both the Tiber Branch Interceptor and Sucker Branch Interceptor have design challenges due to the location of the existing sewers.  The existing Tiber Branch Interceptor crosses US Route 40 and US Route 29, has sections located in wetlands, plus has a long section located in Main Street in Ellicott City so will involve working around multiple existing utilities and is near houses including some historical structures.  The existing Sucker Branch Interceptor is located primarily off-road following the Sucker Branch stream so includes multiple stream crossings, wetlands, and difficult access.  Following the interceptor downstream the terrain becomes very rocky with severe slopes and includes historical structures and a railroad crossing with parts of the existing interceptor located within the stream.

This project will culminate with bid-ready plans and specifications to construct approximately 10,600 LF of 10-inch to 30-inch diameter supplemental parallel or replacement interceptor sewer and accompanying manholes, 5,700 LF of 12-16 inch CIPP lining, Two (2) new billing meters, 12 stream crossings with approximately 3,900 LF of stream stabilization/restoration, bypass pumping, traffic control, blasting precautions, construction access, SHA coordination, and JPA permit for wetlands and waterways.

This project was complicated further in 2016 by the historic flooding that impacted these sewers.  As a part of the urgent need response, GMB provided engineering services for the repair and replacement of the sanitary sewers and reevaluation of the streams to restore the streams while protecting the sewers.  These restoration efforts proved dividends when flooding repeated in these sewer systems only two (2) years later and held without damage.