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:

• Esquimalt Harbour Remediation Project in Esquimalt, BC (https://www.canada.ca/en/department-national-defence/maple-leaf/defence/2020/12/esquimalt-harbour-remediation-project-reaches-major-ilestone.html )
• Rock Bay in Victoria Harbour, BC (https://www.canada.ca/en/environment-climate-change/services/federal-contaminated-sites/success-stories.html#rock))
• Hudson River in New York State (the largest environmental dredging project completed in North America; https://www.hudsondredging.com)

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.