Chestnut & Sixth Streets Combined Sewer Rehab

Design completion: October 2008
Construction completion: March 2010
Client: City of Columbus, Division of Sewerage and Drainage

The City of Columbus selected Ribway as a prime consultant to provide professional engineering services related to rehabilitation of a major roadway and the separation of a storm and sanitary sewer system in this heavily congested downtown area. The City embarked on this sewer separation project to reduce infiltration and inflow into the combined sewer system and reconstruct the aging roadway. The Project was divided into 2 parts; Part 1 included the rehabilitation of two (2) large combined brick sewers and removal of storm water connections while Part 2 included the construction of major storm water infrastructure.

he combined sewer rehabilitation project included the rehabilitation of approximately 2,000 lf of 108 through 117-inch brick sewer with fourteen (14) manhole structures along Chestnut and Fourth Streets and approximately 1,600 lf of 27 through 48-inch brick sewer with ten (10) manhole structures along Sixth Street and Mt. Vernon Avenue.

Ribway’s scope of services for Part 1 included:

• Sewer cleaning and inspection services
• Field survey
• Evaluation of existing sewer condition
• Recommendation of rehabilitation techniques
• Geotechnical investigations
• Hydrologic and hydraulic analyses
• Preparation of a design report and detailed plans and specifications
• Engineering services during construction
• Plans for maintenance of traffic and road closures

Following a detailed evaluation, shotcrete was recommended for rehabilitation of the very large brick sewers and CIPP lining was recommended for the medium sized sewers. Challenges on the project included major utility relocations, maintenance of traffic, bypass pumping and easement acquisition.