Stanley Avenue Park Remediation Plan

Please note that the pathways and part of the off-leash area are now open.

Newly seeded areas delineated by temporary fence is not accessible to the public until the seeding is well established

For an update on the work, please refer to Question 6, under “Construction period and operational information.”

Background

Stanley Avenue Park is a public recreational area of approximately 5.6 hectares of open space along the east shore of the Rideau River, adjacent to the community of New Edinburgh.

Prior to ownership by the National Capital Commission (NCC), the land within the park has seen various uses. For example, a railway line used to run through it, and the site has been used as a domestic landfill. In addition, fill from a number of sources was placed on the property to expand the area’s land base. Environmental site assessments and a human health and ecological risk assessment (HHERA) have identified elevated levels of certain metals and a number of hydrocarbon compounds in the soil at the site. Potential risk to surface water such as the Rideau River is not expected.

The results of the environmental site assessments and HHERA have led the NCC to undertake the Stanley Avenue Park remediation plan identified below.

Contamination

1. Why is the site contaminated?
   Prior to NCC ownership, these lands were used for industrial purposes and as waste disposal sites, dating back to the end the 19th century. Over time, fill from a variety of unknown sources was used to expand the area’s land base, as was common practice at that time. While the park is made up of several pieces of land with different ownership, 40 percent of the park is owned and managed by the NCC. The other portions are owned by the City of Ottawa and the Province of Ontario.
   
2. Why did the NCC suspect the contamination in the first place?
   In the 1990s, concerns started to arise about the environmental quality of the NCC’s lands. In 1998, the NCC began a systematic and comprehensive investigation of all of its lands, including Stanley Avenue Park, for possible contamination. In 2007, in examining some of the results for Stanley Avenue Park, Health Canada requested that the NCC study the potential health impact of the findings.
   
   The following environmental studies were conducted at Stanley Avenue Park by the NCC between 2004 and 2009.
   • Preliminary (Phase I): Historical study (air photos, databases, city directories)
   • Phase II: Preliminary sampling to determine the presence or absence, as well as general levels, of contaminants
   • Phase III: Additional soil and surface water samples to further delineate and quantify contamination
   • Risk assessment (2008–2009): Potential impact on human health and the environment caused by the contaminants identified in Phase II and III
     
3. Why is this work being done in Stanley Avenue Park?
   We have found that this site is contaminated. The findings indicate that levels of lead and a group of chemicals known as polycyclic aromatic hydrocarbons (PAHs) exceed provincial and federal standards, and constitute a potential moderate risk to human health. Though the potential risk is deemed to be moderate, the risk nevertheless exists, as is usually the case when elevated levels of heavy metals like lead and hydrocarbons are concerned.
   
4. What are the government regulations that have required the NCC to conduct these tests in Stanley Avenue Park and to provide these remediation measures?
   As a federal landholder, the NCC is required to follow the Treasury Board of Canada Secretariat Policy on Management of Real Property and the Treasury Board Federal Contaminated Sites Management Policy. The NCC’s actions to manage contamination on its lands are guided by Ontario Ministry of the Environment standards and the Canadian Council of Ministers of the Environment’s Canadian Environmental Quality Guidelines.
   
5. Are the results of the human health and ecological risk assessment available to the public?
   Our report is available in our library.
   
   

   Remediation and Construction
   

6. What is the work related to the remediation plan?
   It is important to note that, once the remediation work is completed, the park will return to its original state, and there will be no change in vocation.
   • The following remediation work will be performed in all areas where elevated levels of soil contaminants have been identified within 0.3 metres of the surface.
     • Capping with a minimum of 0.3 metres of clean soil cover and surface vegetation to prevent human exposure to certain metals and hydrocarbons.
     • Installation of boundary fencing on NCC property, adjacent to the residential property line (details to follow). The fencing will jog around any trees along the fence line. 
     • Site drainage will take advantage of seven existing low points along the residential property line to construct shallow overland swales which follow existing drainage patterns toward the Rideau River. 
     • Careful tree management* will ensure that tree removal is kept to a minimum. 
   • Other relevant information
     • A new 1.5-metre stone dust pathway will be installed along the edge of the river.
     • A new lookout area will be created at the old railway abutment along the shoreline.
   • Construction period and Operational information
     • Remediation: Work completed in fall/winter 2009
       • Installation of temporary fencing, sufficient to secure a safe work area during construction, with locked gates to prevent access.
       • Completion of all clearing and pruning of vegetation.
       • All site furnishings, including benches, signs and waste receptacles, have been removed and stored off-site.
       • Removal of all existing fences and other landscape elements that were on NCC property. Fences to be salvaged have been stored off-site.
       • Trees identified as being in poor health and all shrubs within the area to be capped have been removed.
       • Woodlot management (consisting of the removal of dead or dying trees and the removal of all invasive shrubs) in some adjacent areas not identified for capping has been completed.
       • Completion of excavation immediately behind residential properties.
       • Capping of surface contamination, including the construction of shallow overland swales for drainage and the installation of culverts:
         • 85% of the topsoil application has been completed
         • 75% of seeding has been completed, along with the installation of temporary “silt” fencing around these areas
         • the base for the pathway along the river’s edge has been completed.

       Winter 2010: Operational information

       • Since the remediation work is only partially completed, according to the Canada Labour Code, the site remains a construction area under the responsibility of the contractor. Therefore, for health and safety reasons, the park must remain closed to the public until the completion of construction in spring 2010. It is important to note that breach of entry onto the site may damage seeded areas and, as a result, adversely affect the opening of the park in spring 2010. Please refrain from entering the site at any time.

       Spring 2010: Landscaping: Work completed in the spring 2010

       • Completion of topsoil application, seeding and sodding.
       • Reinstallation of benches, waste receptacles and signage.
       • Completion of stone dust top layer for the pathway at the river’s edge. 
       • Raising of the elevation and resurfacing of the asphalt pathway.

        Summer/Fall 2010

       • Installation of permanent boundary fences.

        Spring 2011: Landscaping

       • Tree planting (The timing of the tree planting allows a full year for the new turf cover to become well established.)
       • New lookout area, including additional benches.

       *Trees already in poor health were removed prior to filling. For each healthy tree removed, two trees will be planted as a replacement. All trees affected by filling will have another tree of the same or similar species planted within the park. Preference will be given to replanting native tree species

Best Practices and Recommandations

1. Are the NCC’s remediation plans in line with best practices?
   For the NCC, public health and safety are priorities. Though the potential risk is deemed to be moderate, the risk does exist, as is usually the case when elevated levels of heavy metals like lead and PAHs are found in surface soils. According to the consultant’s report to the NCC, the main risk to human health is associated with direct contact with the contaminated soil, for example, through activities (such as gardening) that involve digging. As a public body, the NCC must plan in a prudent and responsible way. For this reason, these remediation plans constitute a long-term solution, and are fully consistent with best practices.
   
2. Given that Health Canada recommends replacing a vertical metre of soil, whereas the NCC will replace only one third that much, could you publicize your research that justifies the lesser strategy? What was your due diligence here?
   Health Canada recommended that there be a one-metre clean soil cap placed on contaminated NCC soils where digging in these soils, such as backyard gardening, cannot be monitored by the NCC.
    
   Our consultant (Interra Engineering) noted that placing one metre of soil on NCC lands right up to the property line with private residences was not practical for a number of reasons. These include creating local drainage problems, putting too much fill in the flood plain, killing existing trees and creating a major visual impact for residents. Instead, the consultant recommended that a 30-centimetre (one-foot) cover be placed on the NCC soils, coupled with a fence, in order to create an appropriate physical barrier between the soils and users, and to keep gardening activities by private residents within their own properties over the long term.
   
   

   Public usage of the Park and Signage
   

3. What is the purpose of the fence to run behind Stanley Avenue homes? Is it intended to be permanent?
   The rear yard fence will be a permanent fence. A fence is the best long-term measure to ensure that the capped soils on NCC lands are not disturbed by future residents who may not have been properly informed of the underground content of the soil. Activities that involve digging such as gardening will expose residents, park users and NCC workers and contractors to contaminants. The fence will prevent a continuation of the encroachment on NCC lands, much of which consists of digging in the ground. 
   
4. Regarding the reopening the park to the public: a) Do you plan to permanently close any section of the park to the public? b) Which parts exactly will open prior to fall 2010?
   • After the construction period, including the establishment of the new turf cover, the park will be fully open to the public again without any change to its vocation.
   • To ensure public safety, the park will be closed to the public from the beginning of construction in the fall of 2009 until the end of construction in spring 2010.
   • In spring 2010, the asphalt recreational path will reopen. We intend to reopen a portion the off-leash area to the public as soon as possible.
   • However, seeded areas (pink and yellow areas on the Stanley Avenue Park Site Remediation Plan) will be fenced off and will be closed to the public until the turf becomes well established (summer/fall 2010). 
   • In spring 2011, we will proceed with tree planting and the construction of the new outlook area. This work will have minimal impact on park users, as we will not need to close the park.
     
5. Will the park be accessible to the public during winter 2010?
   Given that the construction work is not yet completed, the park will remain inaccessible for public use during winter 2010.
   
6. Will there be NCC signage about closures of path and park areas at the closure points at least one week before the remediation starts? 
   Construction signage has been installed at the beginning of the construction, identifying the project and the fall 2009 / spring 2010 time frame. Park closure signs have been installed at entry points to the park.
   
   

   Off-leash Area
   

7. What is the future of the off-leash dog area and where can we go to walk our dogs?
   The existing off-leash area will continue to be a part of Stanley Avenue Park after the construction is completed. There will be no modification to the current off-leash area. While the off-leash area will be unavailable during construction, there are a number of other dog off-leash area in urban lands including New Edingburgh Park (City of Ottawa property), Rockliffe-Hillsdale Area and Pine Hill.
   
   

   New Path
   

8. Why will there be a new path and lookout?
   There is an existing trodden route along the shoreline. Habitual foot traffic along this route has worn the turf down to bare soil. A similar situation exists at the old railway abutment area along the shoreline. To resolve this degraded site condition and as a precautionary measure, knowing that the site is contaminated, a narrow, 1.5-metre-wide stone dust pathway will be constructed along the shoreline route. This will contribute to an easier walking experience for foot traffic along the river.
   
   The proposed lookout area will be located at the edge of the old railroad abutment. It will consist of a simple stone dust area, edged with cobblestones, with additional benches and a waste receptacle.

Related Link

• Stanley Park Site Remediation (pdf - 2.98 Mb)