Please click on the presentation for an overview of the updated conceptual Sediment Management Plan and the Detailed Impact Assessment Process.
Specific questions about the project or just want to know more? Please see our frequently asked question and answers for the following categories:
Please also view our previous presentation series (2022) on the Kingston Inner Harbour Sediment Management Project for additional details.
Sediment is the soft solid material that lies under the water at the bottom of a harbour, lake, or stream. Similar to how soil can move with the wind and rain, sediment also moves and mixes over time from waves, water currents, or disturbance by people and animals.
Sediment contamination is the presence of chemicals in sediment at levels higher than they would normally be. Many chemicals are naturally occurring, so the presence of a chemical in sediment does not necessarily mean that contamination exists. If there is contamination (chemicals that are in the sediment in higher-than-normal amounts), it is not necessarily dangerous for people or wildlife. Determining if contaminated sediment is safe or not depends on the area, the types of chemicals, the amounts of these chemicals, and the site uses.
Past studies of water quality of the harbour have found that the water quality is good compared to provincial and federal guidelines designed to protect people and wildlife. The main concern is the contaminated sediment that may be harmful to people and wildlife.
The chemicals of concern in the sediment fall into a few main categories: metals, PAHs and PCBs.
Metals in the harbour that are elevated include chromium, mercury, arsenic, and copper. These metals mainly came from historical industry along the harbour front, by either being directly deposited or washed into the harbour with surface water or ground water. For example, chromium in the harbour comes from the chrome tanning process used at the Davis Tannery that was immediately next to the harbour for much of the 20th century. Metals in the harbour can pose both ecological and human health risks depending on the type and where they occur.
PAHs occur naturally in coal, crude oil, and gasoline, and are produced from burning. PAHs are a common contaminant in urban waterways, and come from numerous sources, including storm sewer outlets from road run-off, automobile exhaust, furnace/stack emissions, or spills from fuel depots/marinas. Historical coal stockpiles, oiling docks, and rail yards in Kingston Inner Harbour, along with the former coal gasification plant in downtown Kingston, are thought to be the most significant sources of PAHs to the harbour. These chemicals break down naturally (i.e., biodegrade) in the environment, but this process can take a very long time depending on the type and amount of PAHs present. PAHs in the harbour can pose risks to both ecological and human health.
PCBs are human-made chemicals that were used widely in electrical equipment like capacitors and transformers, and previously found in hydraulic fluids, heat transfer fluids, lubricants, and plasticizers. PCBs were mostly washed into the harbour with surface water and groundwater running through the former Belle Landfill. Because they can cause negative health effects at low levels in people and wildlife, the import, manufacturing, and sales of PCBs were made illegal in Canada in 1977. In Kingston Inner Harbour, PCBs were most likely released into the environment through leaks from a former landfill, scrap yard, and demolition yard. Once in the environment, PCBs stick to soils and sediments and can be transported long distances from their original source. They also bind strongly with fatty animal tissues and magnify in the food chain, meaning they are passed into and accumulate in larger animals when they eat smaller animals. These chemicals break down (i.e., biodegrade) very slowly and can last a very long time in the environment. PCBs in the harbour can pose risks to both ecological and human health.
No, there are no ongoing sources of contamination from historical sites. Understanding and addressing the potential for recontamination is essential for contaminated sites projects. Most of the contamination in the harbour resulted from historical activities in surrounding areas. Left-over contamination in most of those surrounding areas is being managed, or planned for management, which will help prevent future contamination of the harbour. For example, a groundwater system was installed at Emma Martin Park to prevent metals from moving into the harbour, and a leachate management system was installed at the former Belle Park landfill to collect water moving through the landfill and stop PCBs from leaving the landfill site.
The conceptual sediment management plan recognizes that Kingston Inner Harbour is a working harbour, so it could continue to receive new inputs from active uses (e.g., storm water, boat traffic, fuel spills). For that reason, the goal of the plan is to manage the contamination to lower, more acceptable risk levels, not to remediate to pristine conditions. Ongoing sources are not expected to worsen conditions beyond the safe level, and the current environmental regulations and best practices will reduce the likelihood of new contamination. After dredging and sediment capping is complete, the harbour will be monitored long-term to provide confidence that the remaining concentrations of chemicals will stay the same or decrease over time. The federal government is working with the City of Kingston to monitor street runoff and other inputs from storm sewers, and to provide confidence that ongoing flows do not threaten the health of the harbour.
The term “risk” means there is a chance or probability of harm to people and/or the environment if they have been exposed to certain chemicals. It is called a risk because harm is possible, but it may not always happen, or may happen only to a small group of individuals. The risk level depends on the amount of exposure, pre-existing health, and other factors. An environmental risk assessment is a scientific process used to describe and estimate the chance of negative health effects (i.e., potential risks). Risk assessments tend to be conservative and err on the side of caution, as under-estimating the level of risk could have harmful consequences.
Risk refers to the chance or probability of an unwanted effect, so we are looking at the chance or probability of harm to people and/or the environment if they have been exposed to chemicals in the sediment. For humans, the main risks in the harbour are from exposure to PAHs and PCBs (metals are less of a concern, except possibly for methylmercury). High exposure to PAHs and PCBs may cause negative health effects in people. The main concern for exposure to PAHs is an increased risk of cancers, but for PCBs there are also concerns about effects to the immune system, reproductive system, the brain, glands, or organs. Exposure to metals, PAHs, and PCBs are all potential issues for wildlife (birds, mammals, reptiles, amphibians, fish, and benthic invertebrates). Effects of exposure to these chemicals can include poor development of young animals, deformities in adult animals, and potentially death.
Nearly all human activities have some risk. The study of health risk assessment is intended to measure those risks, so that regulators and the public can understand them better, and where necessary, can reduce those risks to an acceptable level. In deciding what levels of risk are acceptable, risk assessors first evaluate whether the risks are voluntary. Most people are willing to take on risk to their health when they understand the nature of the risks involved and when they can exercise some control over the degree to which they take on those risks. For example, the act of driving a car has a moderate risk, yet many people accept the dangers of driving because of the benefits of driving, their understanding of those risks, and partial control over those risks. Risks of chemicals/contaminants in the environment are treated differently because they are mostly non-voluntary and invisible.
An environmental risk assessment is a scientific process used to describe and estimate the chance of negative health effects (i.e., potential risks) to humans and wildlife (e.g., birds, mammals, reptiles, amphibians, fish, and benthic invertebrates). These chemical risks can result from deliberately or accidently touching, breathing in, eating, or drinking contaminants at a site. For a risk to exist, three things must be true: 1. the amount of the chemical in the environment is high enough to potentially harm organisms 2. organisms that can eat or be exposed to the chemical must be present at the site; and, 3. there must be a way for the organism to have contact with the chemicals. When moderate or high risks (see definitions of risk categories below) are observed in an environmental risk assessment, clean-up and/or a risk management plan is required to address the risks so that people, and/or wildlife are protected.
Risk assessors categorize risks based on the level of threat to health. For human health, we look at the chance of a serious negative health outcome (e.g., cancer) or the degree to which a long-term chemical exposure exceeds a level considered by scientists to be safe. In ecological risk assessment, a similar approach is used, and focuses on health risks to communities of animals such as wildlife and their food. To help summarize risks, we often use terms such as “negligible risk”, “low risk”, “moderate risk”, and “high risk”. These categories summarize complex and detailed information into simple categories. Examples are provided below.
Negligible risk (safe for unlimited use): A risk that is so low that it can easily and confidently be concluded to be safe. For human health, this means that people can have unrestricted exposure to the site without increasing their risk in a meaningful way. For ecological health, negligible risk means animals are protected in terms of their survival or ability of grow, develop, or reproduce normally. As an example, negligible risk occurs when site contamination falls within the normal background levels for a chemical substance in water, sediment, and fish tissue.
Low risk (generally safe but with possible restrictions): A risk that is acceptable to nearly all users of the site. Exposure may exceed background levels or screening guidelines, but without causing any major threat to health. Under a low-risk condition, it is possible that a small number of individuals with very high exposure and high sensitivity could be affected. For this reason, controls may be required to keep risks low (e.g., a fish consumption advisory). For ecological risk assessment, low risk means that a small number of individuals of common species might have minor responses, but the populations and communities remain healthy, diverse, and productive.
Moderate risk (may be unsafe): A risk that is considered unacceptable in the long-term, based on the potential for damage to health. A moderate risk does not represent an emergency, or even definitive evidence of harm to health, but instead requires a careful plan to reduce exposure. For human health, moderate risk occurs when people consume more than a daily recommended intake of a substance. For ecological health, moderate risk means that adverse effects are expected to individuals of sensitive species, which may or may not result in a less healthy population.
High risk (clearly unsafe): A risk that is unacceptable, has clear evidence of negative health effects, and that requires fast action to reduce exposure. An example of a high risk that can occur in everyday life is contamination of meat or produce by bacteria such as Escherichia coli (E. coli). Under certain conditions, food products can be contaminated to a degree that requires a response from the Canadian Food Inspection Agency to protect public health. The same principle applies to contamination by chemicals, such that high risks from spills or concentrated areas of chemicals can require a fast response. For ecological health, high risk conditions can occur from an environmental spill, requiring prompt action to prevent widespread environmental damage.
There is no health emergency or need for urgent action. Risks to human health from harbor sediments are considered moderate, but not severe, and would continue for decades if not managed. Water quality remains acceptable and does not require management separate from the sediment management plan. If people do not eat a lot of local fish and do not have regular contact with the contaminated sediments, the risk is low. A fish consumption advisory is in place (https://www.ontario.ca/page/eating-ontario-fish). Most recreational activities in and around the harbour, like boating, kayaking, rowing, and hiking, are safe if skin contact with sediment is minimized or avoided. People should avoid touching the sediments (including contact through swimming). If sediment does contact your skin, simply rinse it off and wash your hands before eating.
No, you should not be worried if you have been swimming/recreating in the harbor. Most recreational activities in and around the harbour, like swimming, boating, kayaking, rowing, and hiking, are considered safe since contact with the sediment is minimized or avoided during these activities. People should avoid touching the sediments and eating anything that may have touched the sediments. If sediment does contact your skin while you are using the harbour, simply rinse it off and wash your hands before eating.
Seeing wildlife in the harbor does not mean that they are not being negatively affected by contamination. Although the presence of turtles and other wildlife in the harbour is a good sign that the sediment is not causing severe negative effects to wildlife in the short-term, it may be causing underlying health conditions or community-level impacts that may not be easily seen or observed in all of the population. Effects of wildlife exposure to metals, PAHs and PCBs can include poor development, decreased reproduction rates, deformities or tumors, and mortality. For example, physical abnormalities, such as skin tumors, have been seen in some brown bullhead fish in the harbour that are likely caused by contact with the sediment.
Yes, most recreational activities in and around the harbour, like swimming, boating, kayaking, rowing, and hiking, are safe if skin contact with sediment is minimized or avoided. People should avoid touching the sediments and eating anything that may have touched the sediments. If sediment does contact your skin, simply rinse it off with and wash your hands before eating. Consumption of fish from the inner harbour is not recommended, and anglers are advised to consult the Guide to Eating Ontario Sport Fish (www.ontario.ca/environment-and-energy/eating-ontario-fish) for identification of areas in the Kingston region where consumption risks for fish flesh are lower.
Contaminated sediment will be safely removed by using standard and acceptable environmental controls and practices. Dredging is a safe and common practice for removing contaminated sediment and has been effectively done in harbours throughout North America. Dredging can be done by using a closed bucket to prevent losing sediment as it is brought up, or through suction dredging using a vacuum-like pump to remove the sediment. As part of the detailed design process, technologies best suited to each area to minimize negative impacts will be selected, and an environmental management plan will be prepared. The environmental management plan will describe how project activities can be conducted safely and what environmental controls must be in place during the project to prevent any accidental environmental effects, such as water or sediment quality impacts, physical danger to wildlife, or damage to archaeological values.
The environmental management plan (to be prepared as part of detailed design) will outline measures to prevent resuspended sediments (i.e., sediments that move from the bottom of the harbour into the water column) from spreading to other areas of the harbour or beyond. Typically, this includes the use of sediment curtains (i.e., physical barriers placed around the areas that are being dredged) at all times when dredging is occurring. The environmental management plan will also require that water quality meet background ranges and/or approved water quality guidelines for the protection of aquatic life outside of the areas actively being dredged. Environmental monitoring and sampling for water quality will be done during dredging to verify that the above conditions are met. These measures, which combine engineering approaches with best management practices, are commonly applied in sediment excavation and capping projects and have been shown to be effective at containing resuspended sediments.
Yes, many similar projects have been done in the past. You can find information on those projects using the links below. Dredging, which is the method we will be using in the harbour, is a standard and reliable technique for removing contaminated sediment. It has been used to clean-up hundreds of aquatic contaminated sites in North America. Examples of recently completed successful clean-ups of aquatic contaminated sites using dredging include:
The project team is still deciding where the removed contaminated sentiment will go and how it will be transported there. These details will be developed further during the detailed design phase. Generally, excess water from the dredged sediment will first be removed (i.e., dewatered) so that it is more stable to transport and then will likely be transported by haul trucks to approved and regulated landfills for disposal. The dredged sediment may also be stabilized and solidified to bind the contaminants in a solid form, and make the material more easily transported by trucks and/or barges. Any excess water generated during this process will be tested and treated if necessary. Disposal facilities, once selected, will hold a valid permit, license, certificate, approval, or any other form of authorization issued by a Facility Regulator (i.e., federal or provincial government) for the handling and disposal of contaminated or Hazardous Waste Quality Materials (if required). As part of the detailed design and impact assessment process, an environmental management plan will be prepared to make sure that the material is appropriately transported and disposed of.
A Detailed Impact Assessment (DIA) will be completed, consistent with Parks Canada’s Impact Assessment Directive and the requirements of the Canadian Impact Assessment Act (https://laws.justice.gc.ca/eng/acts/I-2.75/index.html), to determine whether any aspects of the recommended plan would be likely to cause significant adverse environmental effects. The DIA will consider potential changes to the environment that are likely to be caused by the Project; technically and economically feasible mitigation measures that would prevent or minimize adverse effects; and, the impact that the project may have on the rights of Indigenous Peoples. The DIA will include a summary of formal consultation with Indigenous communities and a public comment period. The Detailed Impact Assessment may result in further design changes if it is found that there is the potential for significant negative effects on the environment from the current proposed project. The need for removing and/or containing chemicals will be balanced with respect for the environment, especially in sensitive areas. It is recognized that some of the areas contain features or habitats of greater sensitivity, such as shipwrecks of archaeological value, wetland and marsh areas, or shoreline areas used by turtles, birds, and other wildlife for nesting, feeding, and basking. The conceptual sediment management plan has been updated to recognize these sensitive areas and proposes different, and less intrusive, methods for sediment management based on the current information. However, more detailed biological and ecological studies are being done as part of the DIA process to finalize the sediment management methods.
In support of the DIA process, a Conceptual Constraints and Impact Considerations (CCIC) document was completed (SNC-Lavalin 2023) to provide preliminary high-level considerations of potential impacts from the project based on information gathered to date.
The need for removing chemicals will be balanced with respect for the environment, especially areas of sensitive or valued habitats. It is recognized that some of the shoreline areas contain habitats of greater sensitivity, such as wetland and marsh areas, or shoreline areas used by turtles, birds, and other wildlife for nesting, feeding, and basking. The conceptual sediment management plan recognizes these sensitive areas and proposes different, less intrusive, methods for sediment management, including nature-based shoreline solutions. In some areas, dredging will be excluded entirely to avoid unacceptable alteration of habitat. There will also be habitat gains through this project in the restoration of shorelines or other low value habitats. The methods being proposed to protect sensitive species, habitats and valued features are provided in the updated conceptual sediment management plan and will be evaluated in detail during the impact assessment.
Removal of the contaminated sediment using the proposed methods is the best way to permanently reduce health risks. The need for removing chemicals will be balanced with respect for the environment, especially areas of sensitive or valued habitats. For example, the sediment will be removed when fish are not spawning and when turtles are not moving across the work area or overwintering. An initial assessment of sensitive habitats and ways to avoid harm to these habitats is included in the conceptual sediment management plan, and will be evaluated in detail during the impact assessment and detailed design.
The current sediment management plan includes the use of dredging exclusion zones (areas where sediment will not be removed) along the shoreline to preserve the integrity of shorelines, sensitive habitats, and archaeological features in some areas. There may also be habitat improvements because of the planned nature-based shoreline rehabilitation along the inner harbour. This will include shoreline plantings that will preserve ecological habitat (including turtle habitat) and prevent/reduce erosion.
We will do as much as possible to reduce the negative effects of this project to local businesses. As part of the project planning and stakeholder engagement process, businesses operating in the harbour will be contacted to ensure the project team has a good understanding of their operational needs, so that potential impacts to operations associated with the project can be identified and managed.
This information will be incorporated into detailed design and project implementation plans. Given the project is still in the planning stages, exact schedule and impact to business operations are still unknown; however, we will work with business operating in the harbour to minimize and/or eliminate impacts to their operations.
No, drinking water in downstream areas will not be an impacted by this project. Sediment management projects such as these are very safe, and the technologies being proposed (such as dredging) are common practice for removing contaminated sediment from harbours. The project will use appropriate environmental controls such as sediment curtains, and environmental monitoring, including taking measurements for water quality and sediment quality outside of the dredging areas, will also be conducted to confirm that chemicals harmful to people, or wildlife are not spread into other areas of the harbour or into Lake Ontario where most of Kingston’s drinking water comes from.
The project team is still deciding how often and for how long the harbour will be monitored after sediment management. Details of the monitoring program will be developed as planning progresses. Federal monitoring programs for this type of work typically involves intensive daily monitoring during project implementation to make sure that it is following the project’s prescribed environmental protection plan, followed by short-term yearly monitoring (~1–5 years) and a long-term monitoring component (~10+ years) that happens less often (e.g., every few years) to confirm that habitat restoration has been successful and that sediment management goals continue to be met.
As part of the project planning and stakeholder engagement process, businesses operating in the harbour will be contacted to ensure the project team has a good understanding of their operational needs, so that potential impacts to operations associated with the project can be identified and managed. This information will be incorporated into detailed design and project implementation plans. Given that the project is still in the planning stages, exact schedule and impact to business operations are still unknown; however, we will work with business operating in the harbour to minimize and/or eliminate impacts to their operations.
Previous industrial activities in areas surrounding Kingston Inner Harbour resulted in the contamination of sediments (sand/silt/clay lining the lake bottom) in Transport Canada, Parks Canada, and City of Kingston water lots. The chemicals of concern include metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The chemicals are mostly from historical land uses, including a former rail yard, landfill, coal gasification plant, tannery, lead smelter, shipyards, fuel and oil docks, scrap/demolition yards, and other industrial activities. Scientific studies have found that the contamination in the Kingston Inner Harbour may pose risks to the health of humans, fish, birds, mammals, and other aquatic life. Despite several decades of being left to recover, some areas have not recovered enough to be safe, and would not be safe for a very long time without help from the sediment management project.
Sediment investigations and risk assessments were completed by Golder Associates (now WSP) on behalf of Transport Canada and Parks Canada following standard federal and provincial guidance. The guidance included the Canada-Ontario Decision-Making Framework for Assessment of Great Lakes Contaminated Sediment (ttps://publications.gc.ca/collections/collection_2010/ec/En164-14-2007-eng.pdf) and the Framework for Addressing and Managing Aquatic Contaminated Sites under the Federal Contaminated Sites Action Plan (https://www.dfo-mpo.gc.ca/pnw-ppe/fcsap-pascf/docs/1-eng.htm).
Federal departments (including Public Services and Procurement Canada, Health Canada, Fisheries and Oceans Canada, and Environment and Climate Change Canada) reviewed the investigations and provided feedback to Parks Canada and Transport Canada during these studies. Where warranted, changes were made to the technical reports in response to the suggestions made by the Federal Expert Support Departments. Independent scientific studies were also done by the Environmental Sciences Group of the Royal Military College over the last fifteen years. The results and recommendations of their studies were reviewed in a similar way and were consistent with those completed by Transport Canada and Parks Canada. Since the same conclusions were reached by different studies, this provides confidence that the outcomes of the investigation are scientifically sound.
The strategy was designed to balance the least amount of environmental disturbance with the greatest degree of contaminant risk removed. With this in mind, the strategy, outlined in the conceptual sediment management plan, includes leaving sediments alone for most of the harbour, because the risks in most areas are low. Physical management (including areas of dredging, capping or shoreline engineering) will only be used in areas where risks are greatest to people, fish, or wildlife. Although sometimes nature can heal itself by either breaking down contaminants or slowing burying them with cleaner deposits, these processes are not always effective and can take a very long time. For example, the recent sediment quality monitoring in Fall 2021 confirmed that there was little improvement in the sediment contamination over the last 15 years. In Kingston Inner Harbour, the burial of contaminated sediment is very slow, as sediments are frequently stirred up by waves, ice, fish, and human activities. So, waiting for the harbour to recover naturally would take a very long time, and people, fish, and wildlife could experience more negative health effects because of this waiting period.
Some areas in the harbour are also an ongoing source of contamination to the cleaner areas because the sediments are redistributed throughout the harbour, as documented by the sediment transport investigations.
Yes, the strategy follows scientific investigation methods, combined with a standardized approach for assessing and managing contaminated sediments across Canada. The process for the sediment management plan was based on guidance developed by both the Canadian and Provincial governments (Canada-Ontario Decision-Making Framework for Assessment of Great Lakes Contaminated Sediment and Framework for Addressing and Managing Aquatic Contaminated Sites under the Federal Contaminated Sites Action Plan). This guidance provides a science-based, ecosystem-wide approach to sediment assessment and considers potential effects on aquatic life, as well as potential for contamination to accumulate in the food chain.
The Framework used was meant to standardize the decision-making process while also being flexible enough to account for site-specific considerations. The Framework provide a tiered scientific process of investigation and, includes some guiding principles that have been applied to the strategy, including: (1) that it will be applied within the context of common sense (not applied inflexibly); (2) that potential sources of ongoing contamination are addressed before undertaking clean-up; and (3) that the impacts of the plan do not cause more environmental harm than good.
No, the plan is not yet final. It is currently at the concept stage, and will be refined based on feedback from Indigenous communities, local stakeholders, and the public, as well as results from further biological, chemical and archeological studies of the harbour. Feedback about the project to date was used to make changes to the conceptual design before the detailed design. More engagement will happen at milestone stages of the project, and are being integrated into the Detailed Impact Assessment that is currently in progress.
The sediment in some areas needs to be removed to keep people and wildlife (fish, aquatic life, mammals, birds, turtles) safe from contamination. The conceptual sediment management plan suggests that we leave sediments alone for most of the inner harbour, because the risks to people and wildlife in most areas are low. Removal of the sediment was only selected in areas where the risks to people and wildlife were unacceptably high. The conceptual sediment management plan also balances the desire to limit the amount of environmental disturbance, and limit the costs and disruptions associated with the clean-up, while reducing the risk to a safe level. Some sediment needs to be removed (i.e., dredged) because it contains high concentrations of chemicals that can cause contamination and are harmful to living organisms. These chemicals can stay in the environment for a long time and treating sediment in place is very difficult. Fish may eat items that have been exposed to the sediment contamination, and birds or people could then eat the fish. Also, the contaminated sediment might touch the skin of people that wade or swim in the harbour, or people could swallow it by accident. By carefully removing areas of contaminated sediments, while using environmental controls to prevent spreading of these contaminants throughout the harbour, we can reduce the amount of contamination in the harbour and the risks to people, mammals, birds, turtles, fish, and their food.
We can't leave the harbor the way it is because it is currently not safe for people and wildlife. The goal of the sediment management project is to make the harbour safe for recreational activities for people (e.g., wading, swimming, and fishing), and for wildlife to live in and around the harbour. In some areas of the harbour, there are visible negative effects (e.g., fish deformities, aquatic community disturbance), while other effects are not easily visible (e.g., long-term human health effects).
It is not possible or necessary to remove all of the contaminants from the sediment, so it is not necessary to completely remediate the harbour. Low levels of chemicals are safe and common in active harbours and urban environments. The goal is to remove the sediments with the highest amounts of chemicals to reduce the risks to an acceptable level, where people and wildlife are unlikely to experience negative health effects. The level deemed safe is based on science and the protection goals for the harbour. Reaching safe levels will be monitored during and after the project to make sure that the methods used to clean up the harbour’s sediment work as they are supposed to.
Remediation typically involves removing contaminants from a site through on-site treatment or off-site disposal. Risk management typically involves managing contaminants in place, using covers and/or measures to block the exposure pathways that could cause potential risk (e.g., through directly contacting the contaminated sediment). Often, risk management does not require any physical changes to the environment, but it does require monitoring how the environment is recovering over time. Both remediation and risk management strategies are designed to reduce risks, and both strategies can be protective of human and ecological health. Various factors (e.g., engineering feasibility, financial responsibility, legal considerations) must be considered when choosing which remediation and/or risk management option(s) to use. Remediation and risk management measures can be used either alone or in combination to successfully manage risks in an environmentally and financially responsible manner.
Shoreline works are being proposed to reduce the levels of these nearshore contaminants and limit accidental contact with the sediment. Nature-based shoreline rehabilitation is planned along the inner harbour. This includes shoreline plantings typical to uplands, wetlands, and submerged aquatic vegetation. This will improve the quality of ecological habitat (including turtle habitat) and prevent/reduce risk of erosion, while limiting the potential for human access to the water and addressing nearshore contamination (where applicable). The plan also includes the use of dredging exclusion zones between the dredging footprint and shoreline, where sediment will not be removed, to preserve the integrity of shorelines, sensitive habitats, and archaeological features in some areas.
To reduce potential human health exposure, any consumption advisories for fish should be followed.
There may also be some potential risks to human health from the contamination that will remain along the shoreline given that there will be no remedial dredging within a buffer zone to protect sensitive ecological habitats. However, the sediment management plan includes planting natural vegetation along the shoreline in these areas that will prevent humans from accessing the shoreline for swimming or wading.
The project team is working on finalizing timelines, and they will be confirmed during the design process. Initial consultation and engagement with Indigenous nations, communities, stakeholders, and interest groups was completed in 2021 to improve the initial conceptual sediment management plan prepared in 2021. Consultation and engagement is still ongoing to get feedback on the revised conceptual sediment management plan that was completed in 2023. Additional engagement will continue as the Detailed Impact Assessment and detailed design process are completed. It is estimated that the Detailed Impact Assessment and detailed design for the Project will end in 2025, and physical works could begin in 2027; however, this could change as planning progresses. Physical works are anticipated to take 3 years to complete. Once the physical works are complete, long-term monitoring of the site will take place. Click here to visit the “Project Timeline” section for more details.
Yes, shoreline work will be as protective of habitats next to the harbor and recreational and aesthetic values. The goal of the project is to reduce the potential for exposure of humans and wildlife to contaminants near the shore, while also preventing shoreline work from negatively impacting wildlife habitat (e.g., turtle access to laying areas), and preventing erosion. To achieve this, sediment management will focus on nature-based shorelines. This will include:
Specific design of shoreline features will be completed during the detailed design phase and will include consideration of feedback received during additional Indigenous and stakeholder engagement, as well as engineering factors, hydrological processes, and beneficial habitat features.
It is understood that the City of Kingston has shoreline improvements planned for the area, and those improvements will be coordinated with the sediment management project.
The sediment management plan is in the conceptual phase, so there is flexibility in design options for shoreline features. Options will be refined through to detailed design based on feedback from Indigenous and stakeholder engagement activities, and results of ongoing studies, including the Detailed Impact Assessment. The ongoing inventory of ecological resources and habitat mapping will be particularly important in refining shoreline plans. Sensitive areas will be accounted for in the design.
The answer depends on the area of the harbour and the nature of the sediment under the proposed dredged layers, but yes, placement of clean sediment is one of the options being considered for several portions of the harbour. The clean sediment would not be a thick layer, but could be thin layers of either clean sand, siltier natural material (with more organic carbon), or a special layer of material (with activated carbon) designed to reduce chemical uptake and with desirable properties for invertebrates. The sediment management program will also include post-management monitoring. Sediment contamination and the regrowth of aquatic plants and invertebrates in natural habitats will be monitored to confirm that the project objectives have been achieved. If plants and invertebrates are not growing back as expected, additional mitigation measures may be implemented to fast track this restoration. The details of the potential cover design will be outlined in the detailed design phase.
Archaeological assessments, including desktop evaluations, geophysical surveys, and visual inspections, were completed in 2023 to ensure areas and objects of archeological significance (including shipwrecks) are appropriately identified as part of project planning. Geophysical surveys captured high resolution imagery and mapped features located on the bottom of the harbour and assisted in identifying submerged features buried under the sediment. A Remotely Operated Vehicle (ROV) was utilized to collect visual data during investigations. This information was used to assess the context and possible cultural significance of features and to help guide the development of mitigation measures that will ensure impacts to these objects of archeological significance can be avoided. Techniques and instruments used include multi-beam echo sounding (MBES), side-scan sonar, marine magnetometer and sub-bottom profiler.