Questions answered on status of new bridge
EDITOR’S NOTE: The following letter was sent to Little Current resident Zac Nichols by the Ministry of Transportation in response to a number of questions he had about the Manitoulin Swing Bridge in Little Current. Mr. Nichols has kindly agreed to the publication of his letter in order to provide information to other Islanders. Mr. Nichols has submitted follow-up questions and will supply those answers when recieved.
Dear Zak,
Reference: Little Current Swing Bridge Environmental Concern (MECP Reference: 357-2023-337)
Thank you for your interest in the Planning, Preliminary Design and Class Environmental Assessment (Class EA) Study for the Highway 6 Little Current Swing Bridge, and for taking the time to share your comments and concerns. This letter has been prepared in response to your previous email correspondence with the Ministry of Environment, Conservation and Parks (MECP) between February 18 and March 22, 2023. Please note that the headings below relate to the comments made in your email.
“Maintaining the current bridge makes the most economic sense.”
MTO has undertaken several rehabilitation projects in recent decades to maintain the bridge in good condition and minimize the risk of breakdowns. Since 1985, the Ministry has invested almost $18 million to maintain the bridge and to provide a safe and reliable link between Manitoulin Island and the mainland. This has included extensive maintenance and replacement of the bridge deck, structural steel and centre bearing replacement, and pier and abutment repairs. This annual average investment of over $500,000 per year is much higher than other typical bridges in the provincial highway network (typically<$100,000 per year).
“It would appear to me that the current bridge is sound above the waterline….”
The existing bridge is inspected every two years in accordance with the Ontario Structural Inspection Manual (OSIM) to ensure its safety, quantify the material deteriorations and determine the Bridge Condition Index (BCI). Prior to 2010, the BCI indicated that the bridge was in poor condition. Upon completion of major rehabilitation between 2009 and 2011, the BCI was improved, and the bridge was deemed to be in good condition. The 2020 inspection notes that, while the bridge is still considered to be in good condition, there are numerous elements with severe pitting and perforations due to corrosion. MTO recently engaged a service provider to conduct newly developed testing techniques that use sensors to examine the overall structural health of the bridge. Four of these tests have been carried out to date, the results of which indicate that the fixed spans are showing signs of stiffness degradation. Along with significant maintenance efforts to address recurring issues with outdated bridge components, the potential for further stiffness degradation render maintaining the bridge in service beyond its planned replacement economically and operationally unfeasible.
Underwater inspections were also completed for the bridge in 1984 and 2002. These inspections have not identified any defects or deteriorations that can be attributed to lack of structural integrity of the foundation elements below water. The latest underwater inspection indicated that the pier concrete exhibited adequate strength with some surficial deteriorations. Minor undermining at the bottom of some piers was also observed. The MTO is enhancing its monitoring efforts for the existing bridge until it is replaced, including two additional tests in 2023, and underwater investigations in 2023 and 2024.
“Also, when will the results of the most recent assessment of the bridge be made public?”
The BCI is posted on the MTO’s website and can be found at data.ontario.ca/en/dataset/bridge-conditions. Information for the Swing Bridge can be found within the table on Row 4824. The 2020 BCI is 73.56 and refers to the condition of the structure at the time of inspection. More information on the BCI is found on the MTO bridge safety page at mto.gov.on.ca/english/highway-bridges/ontario-bridges.shtml.
“I am unaware of any emergency concerns…”
The existing swing bridge is over 100 years old and nearing the end of its service life. Residents, emergency service providers, and tourists require that the crossing be in service, and any shutdowns due to structural repairs or mechanical breakdown are problematic. Although past inspections have not identified significant defects or deteriorations that can be attributed to lack of structural integrity of the foundation elements below the water, the operation of the swing span relies upon outdated mechanical and electrical systems with many obsolete moving parts. These mechanical and structural components of the bridge will continue to deteriorate, which will require ongoing inspections, maintenance and repairs. This includes custom manufacturing of bridge components that are not readily available, resulting in longer repair times, traffic delays and significant capital costs.
“A new bridge would cause greater traffic back-ups in the town.”
The new bridge will include one lane in each direction, which will improve overall traffic operations and access to the Town of Little Current and Manitoulin Island. As indicated in Section 6.2.8 of the Transportation Environmental Study Report (TESR), when the new bridge is operating and closed to traffic (in swing motion), it is expected that the maximum queue length will be 500 m for both the northbound and southbound directions. A queue of this length in the northbound direction would extend approximately to Walcot Street. To minimize impacts within the Town, two additional 167 m long auxiliary lanes for northbound traffic will be provided to store vehicles. This will reduce the overall northbound queue length to approximately 165 m. As part of the Recommended Plan, additional lane control measures will be implemented to direct drivers to the queue lanes to reduce the length of queuing. These measures include: lane detectors to identify when a queue has reached a certain length and the lane is full; lane direction signals to identify which lanes are at capacity and to direct drivers to the appropriate lane; traffic signals at the start of the auxiliary lane to control which lanes are to re-enter the roadway based on their arrival sequence; signal timing or sensors to identify when a lane has cleared and that a new lane will be given green time. The operation and implementation of these measures will be investigated further during the design phase; however, the queue in the southbound direction is not expected to require any additional considerations. A Traffic Management Plan will also be developed during the design phase and will include measures that will be applied during construction to maintain access to local businesses. Any long-term nuisance effects are expected to be similar to existing conditions.
“I am concerned about any construction fouling our water intake, and our drinking water quality.”
Although the measures to protect surface water and groundwater will be confirmed during detail design, the potential for impacts associated with construction may be mitigated by the following measures: completing a comprehensive Erosion and Sediment Control Plan during detail design; completing a drainage design to provide appropriate drainage capacity; directing runoff and overland flow away from working areas and areas of exposed soils; storing all oils, lubricants and other chemicals in suitable containers and handle them in accordance with applicable regulations; prohibiting any refuelling activities within 30 m of a watercourse.
Identifying best management practices for fuel management including secondary containment of temporary fuel storage. Identifying spill response plan for construction and clean up all spills immediately and dispose of contaminated materials in an approved manner. The MCEP will be informed of reportable spills. Obtaining draft Permit to Take Water (PTTW), if required.
Regards
Diana Addley
Senior Environmental Planner
