Sanitary Sewer River Crossing Accomplished with Updated Siphon

Problem

The City of Canton, Ohio has had five siphons in its collection system operating since the early 1900s. Siphons of this age typically feature a single barrel design and are no longer sized correctly for flows coming through the system, making maintenance and upkeep difficult.

The City wanted to upgrade a portion of its collection system with two river crossing siphons and wanted to evaluate whether one of the crossings could be diverted and eliminated and whether the second could be accomplished using an aerial sewer over a newly constructed bridge. After a preliminary study, the bridge was constructed under the 100-year flood line of the river and was not feasible for an aerial crossing. However, it was feasible to divert the flows and eliminate one of the siphons.

Ten State Standards recommends a siphon feature a multiple barrel design to handle a higher range of flows and allow for flow diversion during cleaning and maintenance, so a new siphon needed to be designed.

Solution

The new double barrel siphon features approximately 180 LF of a 12” and 8” double barrel with a diversion vault, junction vault and gate with flow control for maintenance. The open cut trenching of the siphon for the creek crossing required coffer dam design and implementation and USACE coordination for endangered species and wetlands evaluation to obtain permitting to work in the river. In addition, CTI helped coordinate an easement acquisition for the City to purchase land to build access to the vaults.

Project Elements

• 160 LF of 8”/12” double barrel siphon
• 1,600 LF of 8” sanitary sewer, 830 LF of 21” sanitary sewer and 10 new manholes
• Endangered species survey
• Wetland determination
• Subsurface Investigation and soil borings
• Hydraulic evaluation and sewer modeling
• Easement and land acquisition assistance
• Army Corps and Ohio EPA and Railroad Permitting Assistance

CTI Services

• Flow metering and SSES study
• Surveying
• Funding and easement assistance
• Preliminary engineering study
• Final design and contract document preparation
• Bidding
• Construction assistance