Why does CSST work need to be done in Stanley Park?
The location of the CSST identified through the EA was chosen on its ability to meet the City’s immediate Combined Sewage Overflow (CSO) control objectives, and infrastructure needs. It includes a combination of an East-West Tunnel (EWT) and a North-South Tunnel (NST) that is capable of storing excess combined sewage originating from three (3) main overflow locations associated with four (4) major collector sewers (Booth St. Sewer, Cave Creek Collector, Rideau Canal Interceptor and Rideau River Collector) and releasing the sewage back to the Interceptor-Outfall Sewer (IOS) for transport to the Robert O. Pickard Environmental Centre for treatment when capacity is available.
The East-West tunnel will essentially twin the IOS through the downtown core between Lebreton Flats and Stanley Park, providing necessary redundancy, and greatly reducing potential overflows into the River.
The CSST needs to be in the New Edinburgh area because this is the location of much of the key existing infrastructure, and, to greatly reduce overflows into the River, the CSST needs to connect to this infrastructure. The work in Stanley Park is required to capture and direct overflows from the Rideau River Collector to the EWT.
Are there other construction sites similar to the Stanley Park location?
Yes. Site 10, which is located at the intersection of Kent Street and Chamberlain Avenue, is the portal location for the North-South Tunnel (NST), and the mucking location for that tunnel. Activities at this site began in August 2016.
To date, drilling and excavation have taken place without any related complaints from neighbouring residents and businesses.
How many construction sites are there in New Edinburgh?
There are two construction worksites in New Edinburgh: one at Queen Victoria/River Lane, and the main site in Stanley Park (which contains multiple locations within a single fenced area).
Access shafts will be constructed in Stanley Park, to connect to existing infrastructure and to launch the tunneling operation for the East-West Tunnel, and at River Lane/Queen Victoria to connect to the Rideau River Collector.
How long will construction activities be underway in New Edinburgh?
The total construction period is 36 months for Stanley Park. Construction activities will take place over approximately 12 months at the River Lane/Queen Victoria location.
Trucks will be accessing both worksites during construction, with the exact routes determined in consultation with the community.
Will the CSST affect trees in Stanley Park?
The staging for Stanley Park was designed to minimize impacts on trees and maximize tree conservation. A total of 42 trees will be removed (10 centimetre diameter or larger). For every tree removed, a minimum of two will be planted.
No memorial trees will be removed or impacted by the construction.
What truck volume is anticipated to support construction in New Edinburgh?
During construction, truck volumes will vary depending on the type of activity underway.
The largest volume of construction related trucking in New Edinburgh will occur during the 10-month period that the EWT will be constructed and tunnel spoils (muck) will be removed from Stanley Park. During this 10-month tunnel construction and mucking period, it is estimated that 2 to 4 trucks per hour will be required to support the tunneling operations. The estimated peak truck volume will represent an increase of between 1.6% to 7.7% to the existing vehicle trips per hour depending on the selected route and time of day.
For the remaining 20 months (11 months before tunneling and 9 months after tunneling), the trucking volumes will generally be much lower and will be highly variable; from long periods with no noticeable trucking, to short duration peaks of 3-4 trucks per hour while hauling soil and granular material or concrete deliveries. These peaks will be of short duration due to the modest amount of soil to haul. These are non-coinciding activities and thus non-coinciding trip generations.
Please note that the proposed truck volume, at its peak “heavier trucking” during the project, will represent an increase of between 1.6% to 7.7% to the existing vehicle trips per hour depending on the selected route and time of day. Regardless of the route selected, the temporary incremental volume is considered to be relatively minor from a traffic management perspective.
How will the contractor mitigate noise impacts?
Standard best-practice construction techniques mitigate noise. Some examples include: requiring that certain activities can only be done during the daytime, use of well-maintained equipment, the use of mufflers, and by limiting idling.
The contractor submitted a Noise Monitoring Control Plan prior to construction.
This plan identifies:
- the closest noise-sensitive receptors (residents)
- the noise-generating equipment that will be used
- the noise thresholds permitted
- predicted noise levels
The contractor will monitor noise levels during construction.
Has the project considered potential health impacts to nearby residents?
As with any construction project, the City has taken into consideration the impacts of these activities on nearby residents. The City will be working with the contractor on mitigating these impacts by installing solid fencing at designated locations and ensuring residents are notified in advance of major works. The City will continue to assess the impacts and mitigation measures during construction and adjust when required.
Do residents require the same Health and Safety protections as workers for the project?
Health and safety protections are specifically designed for workers located within an active construction zone and are based on long-term (career-length) exposure to hazards. The active construction zone will be separated by fencing and/or hoarding and not accessible to residents.
When and how will Stanley Park be restored?
The site is expected to be restored by fall 2019.
Restoration of the site will include planting large diameter trees to replace those that were removed. Trees will be planted in the southwestern area of the park; drainage swales, culverts, walking and cycling paths and the multi-use path will be restored.
How can residents get information on the project?Several resources will provide residents with updates on construction activities, impacts and progress during the implementation of the CSST project, including:
- Regularly distributed e-newsletter with updates on construction activities, impacts, and progress. Residents can sign up to receive updates automatically at Ottawa.ca/esubscriptions.
- Webpage Ottawa.ca/CSST with information on the overall project including updates
- Email address firstname.lastname@example.org for inquiries
What types of notifications can residents expect from the City during construction?
The CSST Project e-newsletter (register at Ottawa.ca/esubscriptions) will provide project updates throughout the duration of the project, including information on significant upcoming construction activities.
Residents near Site 5 will be notified directly in the case of significant changes in construction schedule and particularly disruptive construction activities, such as a short-term interruption in a utility service.
What should residents do if they discover damage they believe is a result of the CSST project?
Residents should notify the CSST Project Team through the dedicated email address (email@example.com) to resolve the issue directly. If the issue cannot be resolved directly, City staff will review their concern and provide guidance on submitting a claim to the contractor.
Why does work need to occur at Queen Victoria Street and River Lane?
To ensure the CSST project greatly reduces the frequency of combined sewer overflows to the Ottawa River, it must connect with and intercept combined sewer overflows from existing underground infrastructure. Site 5C was confirmed during the planning phase as one of the four major outfall sewers conveying combined sewer overflows to the Ottawa River is located under River Lane. The CSST Project is required for the City of Ottawa to meet specific commitments under the Ottawa River Action Plan (ORAP).
Has the City ever undertaken work that is similar to the activities at Site 5C?
The City of Ottawa has undertaken similar works at sites across the City, including within New Edinburgh. The CSST work at Site 5C is very similar to the work completed at the corner of Keefer and River Lane during the installation of the Keefer Regulator in 2008/2009. The Keefer and River Lane project involved deep excavation into rock and the construction of a new, large underground chamber. The difference between the installation of the Keefer Regulator and the CSST Project work at Site 5c is the construction of the underground tunnel between Site 5c and Site 5b in Stanley Park.
Lessons learned from the Keefer River Lane project, as well as resident concerns, have been taken into consideration during the planning of the CSST project.
Can residents have access to the pre-construction surveys done by Explotech for Site 5C?
As with all construction projects, a third party company was commissioned to conduct pre-construction inspections of the buildings and structures near Site 5c. These inspections were conducted by Explotech and included recording pre-construction conditions of homes to protect the home owner and the City in the rare event there are concerns identified after construction has occurred.
To remain independent, the data gathered at the homeowner’s property is kept in escrow, and only accessed if required.
Does the City provide financial assistance to residents who choose to relocate during construction?
The Municipal Act does not require the City of Ottawa to provide financial assistance to residents affected by construction projects.
How did the City consider heritage properties during planning for the CSST project?
The vibration limits set for the project will ensure that all buildings, including those with heritage features, are protected. Monitoring during construction will ensure that vibration is kept below the established limit. Reinstatement after construction will match the existing character of the neighbourhood.
What are the contractor’s work hours?
The City of Ottawa noise By-law (By-law No. 2004-253) allows for construction activities between the hours of 7am and 10 pm, from Monday to Saturday. At Site 5C, the contractor expects to work a typical construction work day (up to 12 hours) starting at 7am. The contractor does not currently plan to work on Saturdays. It is important to note that the contractor is permitted to work until 10pm and/or on Saturdays, at their discretion. This may occur if construction falls behind schedule.
How will trucks access Site 5C?
Trucks will come from the direction of Stanley Park, along Queen Victoria Street. The trucks will mainly come to Site 5C during the excavation of soil and bedrock, and during tunnelling. A secondary entrance is located on Queen Victoria Street, from the direction of Crichton Street for access by some equipment and personnel.
How will the contractor excavate bedrock at Site 5C?
The contractor may use a combination of hoe ramming and controlled blasting. Residents will receive advance notification of any controlled blasting. The final construction method is still being determined and could change based on field conditions.
Will noise levels reach 130 dBA at Site 5c?
130 dBA represents the maximum noise threshold permitted and is associated with controlled blasting. Typical construction noise is not expected to be sustained at 130 dBA.
Protection of Heritage Structures in New Edinburgh
To assist in understanding the implications vibration related to construction activity in the vicinity of the Stanley Park and New Edinburgh Heritage Conservation District, please see the following list of frequently asked questions (FAQs):
Does the City of Ottawa permit controlled blasting?
Rock excavation is completed on both City projects and private property via either mechanical excavation or controlled blasting.As dense rock is commonly found close to the surface in various geographical areas within the city, controlled blasting is an acceptable and common construction practice within the City of Ottawa. (Blasting may be required in a variety of construction projects, including the construction and/or installation of roads, sewers, water mains, utilities, foundations, tunnels, etc.)
Whether using mechanical excavation or controlled blasting, adjacent properties will be able to hear the noise produced and feel the vibrations transmitted by the work. In either case, there are standards and regulations that apply in order to reduce the noise/impact of the work and ensure the vibration levels are low enough not to cause damage to adjacent properties. These standards and regulations also cover topics such as: how the work will be conducted, information to be provided to adjacent properties in advance of the work, preparatory work that must be completed, and monitoring activities before, during, and after the work.
You can read more about blasting in the City of Ottawa, including applicable regulatory standards and specifications.
How does the contractor ensure that my property will not be damaged by the vibrations caused by the CSST Project?
Residents should be aware that they may feel vibrations from the construction activity, but these will be well below the levels that could cause damage. The contractor’s plans ensure that the specifications outlined in the City of Ottawa Special Provision F-1201 will be followed. These guidelines define the limits placed on vibration levels in order to protect nearby structures. Controlled blasting is designed to meet regulatory requirements, and every blast is carefully monitored by an independent engineering consultant to ensure compliance to these limits.
By regulation, the excavation contractor must reduce the size of the blast the closer it gets to existing structures. The smaller the blast, the lower the vibration – thus helping protect the integrity of adjacent structures. The CSST Project specifications implement further reductions to the limits placed on vibration levels by the City of Ottawa F-1201
My house is very old and has a rubble stone foundation wall. Will it fall down due to the vibrations?
Well-built rubble foundation walls are not inferior to cast concrete. Buildings with rubble foundations, as opposed to rigid cast concrete basement walls, tend to flex and absorb vibrations that might otherwise be transferred to the upper building structure.
Regardless of foundation type, the strict construction vibration limits set within CSST project specifications serve to reduce the possibility of damage to any existing buildings.
How does repeated controlled blasting affect my property?
The United States Bureau of Mines (USBM) has studied the repeated effect of vibration on structures. Their research included investigating continual daily blasting for 28 years to identify the cumulative effects of blasting on a building. They concluded that if the vibration levels were below the regulated limits within the USBM, cumulative effects were not observed. The CSST project vibration limits are two-and-a-half-times below those recommended by the USBM.
Why am I being asked to allow a survey of my home before the construction has started?
A pre-construction survey, to record pre-construction conditions, is required for comparison should a damage claim be entered. This is a measure taken to protect homeowners during certain construction projects. A pre-construction survey is required for all buildings, utilities, structures, water wells and facilities within 75 m of the location of a controlled blast. In additional to the pre-construction survey, the Contractor must carry liability insurance before any work may proceed.
What is the vibration-monitoring equipment near my home and what is it measuring?
The equipment installed adjacent to existing buildings is a seismograph. A seismograph measures vibration from any source, including drilling, tunneling, hoe-ramming, and controlled blasting.
My neighbour has a seismograph at his house. Why don't I have one?
Seismographs are strategically placed by the Vibration Consulting Engineers who select the most appropriate location to record vibration. The measurements collected by one seismograph are representative of vibration levels at that location and at the neighbouring buildings.
I feel vibration. Does that mean that damage is being caused?
People (and animals) are very perceptive to a small amount of vibration. However, without scientific instruments (seismographs), people cannot accurately place a value on the amount of vibration generated. Human perception of vibration is around a peak particle velocity (PPV) of between 0.2 mm/s and 0.5mm/s. By comparison, the industry-accepted PPV for residential structures is 50mm/s. A door slamming, thunderstorm activity and wind all produce vibrations that we feel but discount since these are “everyday” events. The level of vibration from controlled blasting is generally no higher than these everyday events.
Why do some of the vibrations feel much stronger than others?
The position and orientation of the vibration source may cause the perception that one vibration is stronger than another. Your location - within a building or outdoors - will also change your perception of the vibrations. Seismographs are used to accurately measure vibrations.
Is there any danger from flying debris due to blasting?
Controlled blasting experts design their controlled blasts and use protective equipment to eliminate flying debris (and keep vibrations to a minimum). Each blast is individually-designed and calibrated to remain within specific parameters by using a series of small, successive blasts to reduce the energy released at any one time. Additionally, layers of heavy mats are placed on top of the blasting area.
Why are there cracks in my foundation or cracks in my drywall?
The average person is not aware of the stresses that a home in Canada must endure. The Building Code requires that homes be designed to be flexible to try and accommodate these stresses. There are many reasons for cracks; shortly after a new building is constructed, cracks may appear due to drying of construction materials, and in older buildings, cracks often occur as a result of extreme environmental conditions or simply aging materials.
What should residents do if they discover damage they believe is a result of the CSST project?
Residents should notify the CSST Project Team through the dedicated email address (firstname.lastname@example.org) to resolve the issue directly and, if unable to be resolved directly, for provide guidance on submitting a claim to the contractor.