Frequently Asked Questions

What is the PHAI Cleanup Criteria?

Past refining practices of former Crown corporation, Eldorado Nuclear Limited, generated waste products comprised of sand, silt, soil and fill intermixed with uranium and radium processing residues and industrial wastes.

When identifying low-level radioactive waste (LLRW) during PHAI testing, four elements are considered “signature parameters” - uranium, radium-226, thorium-230 and arsenic.

The Cleanup Criteria (CC) sets the levels to which CNL will clean up each of these radioactive and nonradioactive elements found in areas contaminated with LLRW.

How were the current Cleanup Criteria developed?

In 2001, the federal government engaged consultants to assist in identifying the CC with the requirement that each element could be compared to known/published criteria and, in accordance with the Legal Agreement, all remediated lands could be used for “foreseeable unrestricted use”.

During the PHAI planning phase (2001 to 2011), there was no generic standard for uranium in Canada. To determine the PHAI Cleanup Criteria value for uranium, studies were conducted on the potential for human exposure to uranium through air, soil, water and food. Based on the results of those studies, it was agreed to by the signatories of the Legal Agreement that a level of 35 ppm for uranium in soil is safe for human health. 

In 2012, the Canadian Council of Ministers of the Environment adopted a generic criterion of 23 ppm for uranium in soil across Canada, and the PHAI Cleanup Criteria value was lowered to align with this more conservative level.

The PHAI Cleanup Criteria for arsenic was set at a conservative level of 18 parts per million (ppm), to align with the existing generic, provincial standard in Ontario. Actual levels of arsenic found in soil vary by community and is higher than 18 ppm in some areas.

Based on information available at the time, the criteria were finalized as follows (parts per million - ppm)
Arsenic  18 ppm
Uranium  23 ppm
Radium-226 0.29 (Bq/g)
Thorium-230  1.16 (Bq/g)

Why is CNL proposing to change the Cleanup Criteria?

Since PHAI testing began in 2012 in Port Hope, CNL has collected more than 25,000 soil samples and determined that a significant number of property cleanups are being driven by the conservative criteria for arsenic and uranium in soil.

This means that remediation is required at more properties than originally intended, taking longer and making a much more significant impact on properties than originally anticipated.

More importantly, it is causing concern from residents due to the impact on their properties and from the general public due to the predicted impact of the PHAI on the natural environment. To avoid further lengthy delays and significant environmental damage, CNL has recommended changing the CC for arsenic and uranium.

What levels of arsenic and uranium are typically found in the LLRW in Port Hope?

Specific levels of each of the “signature parameters” will vary by location and can range from below background (naturally occurring) to 8,900 parts per million (ppm) for arsenic and 10,877 ppm for uranium.

What are the proposed new levels for arsenic and uranium?

CNL has recommended these changes:
Arsenic 18 ppm to 100 ppm
Uranium 23 ppm to 35 ppm

Are the proposed new levels safe for human health?

In 2009, the CNSC published a Health Synthesis report which reviewed over 40 health and epidemiological studies concluding that there is no increased health risk to people as a result of the operations of the nuclear industry in Port Hope.
Subsequent studies commissioned by AECL and CNL have shown no increased risk with the proposed changes to the CC.

In 2019, CNL commissioned a third-party study to determine if cleaning up arsenic to 100 ppm would still be protective of human health, while also being less harmful to the environment. 

  • That study, conducted by third party experts, Wood and Intrinsik, applied the same human health risk model to arsenic as was used to develop the criteria for radiological contaminants.
  • The arsenic study report concludes that there is no increased health risk associated with arsenic at levels of 100 ppm in soil.

Uranium levels at 35 ppm were studied during the initial planning phase of the PHAI. The study looked at human exposure pathways to uranium through soil, water, air, and food, using the example of a toddler as the hypothetical receptor. The study concluded that a level of 35 ppm for uranium is safe for human health.

What are the benefits of changing the Cleanup Criteria?

As a community-requested project, CNL is committed to ensuring the PHAI is meeting the changing needs of the community as they evolve. As such, CNL is employing an adaptive strategy to provide options to stakeholders, including property owners, in an effort to mitigate potential negative impacts of the cleanup.

CNL anticipates that a change to the cleanup criteria will reduce the time it takes to complete PHAI cleanups on public and private properties, and reduce the overall PHAI schedule and the overall cost of the project for the Canadian taxpayer. The proposed changes will also reduce the total number of private properties requiring PHAI cleanup within the municipality and will result in less intrusive and destructive cleanups on private properties while still producing a full Compliance Letter for property owners once remediation is complete on a given property.

What is the process to change the Cleanup Criteria?

CNL will continue to work closely with the Municipality of Port Hope to ensure council and staff are kept informed. Feedback from regulators such as the Ontario Ministry of the Environment, Conservation of Parks will be incorporated as CNL follows the CNSC application and review process.

A formal CNSC review hearing is anticipated to take place in spring 2022 at the earliest.

Is CNL considering stakeholder perspective on the proposed change?

Yes. As part of this process, CNL is undertaking a comprehensive public engagement plan to increase community awareness and to collect public input on the proposed changes.

If the waste poses no health or environmental risk why is the government cleaning it up?

The community and municipal government requested that the cleanup be undertaken because the presence of the historic low-level radioactive waste had a negative effect on development of lands and on public perception.

As the waste was the result of past practices of a Crown corporation – Eldorado Nuclear Limited – the Canadian government, through AECL, agreed to conduct the cleanup and signed a Legal Agreement in 2001 with the two impacted municipalities.



Why is CNL proposing this new approach when a “full” cleanup was promised – does this mean waste will be left behind?

The proposed change to the PHAI Cleanup Criteria is designed to address a number of unanticipated impacts to the environment and individual properties in Port Hope should the cleanup goes ahead as planned.

CNL believes the proposed change will meet the goals of the PHAI cleanup as an environmental remediation project, while still being protective of human health and the environment.

This is a radiological cleanup – how can you clean up less uranium than originally planned?

The original cleanup criteria were set at very conservatives levels to align with generic provincial standards. As part of a review of the PHAI Cleanup Criteria in 2012, CNL commissioned a study of uranium in soil that used the same scientific approach as the Ministry of Environment, Conservation & Parks and Health Canada. The study concluded that no adverse effects to human health would occur in soil concentrations of 35 ppm even for most exposed residential receptor, considered to be a toddler.

CNL is proposing the PHAI Cleanup Criteria for uranium be changed to 35 ppm,  which will help reduce the timeline and extent of the cleanup at many properties while remaining protective of human health.



How would these change impacts existing Remediation Agreements with property owners?

The impact on existing agreements will  depend on timing. Current cleanup packages are proceeding according to signed agreements that were already in place before the application to change the criteria was submitted.

Remediation agreements currently being signed specify that the Cleanup Criteria may change. Should the proposed criteria be accepted, all private property remediations from that point forward would be conducted in accordance with the new criteria.

Will property owners still have the option to have their property cleaned up to the current, more conservative criteria?

No. Should the proposed changes be endorsed by regulators and accepted by the Municipality of Port Hope the new criteria will be implemented and all remediations conducted after that time will be to the new criteria.

Would the change to Cleanup Criteria impact a property owner’s ability to get financing, remortgage or insure their home?

Mortgage companies and financial institutions have indicated to CNL that a Compliance Letter for a given property will be accepted by lenders. Depending on the property, the Compliance Letter will either state that a property has been tested and no historic waste was found on the property; or it will state that historic waste was identified and cleaned up to meet PHAI Cleanup Criteria.

If my property is remediated with the new Cleanup Criteria will I still receive a Compliance Letter?

Yes. A property that has undergone a full or directed remediation (based on the property owner’s request) will be on track to receive a compliance letter once all work in the surrounding area has been completed.



What will the economic impact be for local businesses if there is less remediation taking place?

CNL is committed to carrying out the remediation of properties across Port Hope in accordance with the Legal Agreement. The change to Cleanup Criteria is aimed at limiting impacts to construction schedules and property features.

Will jobs be lost as a result of the proposed change?

There are no planned job losses related to the proposed change to Cleanup Criteria.