Communicating about Migrating Contamination

Communicating about Migrating Contamination


Erika M. Swinton, Associate
Phone:  604-685-3911


Communication is key when contaminants migrate from one property (the “source” property) to a neighbouring property (the “affected” property).

The Ministry of Environment (MOE) sets out communication requirements for parties managing migrating contamination in its guidance document Administrative Guidance 11 (AG11).

AG11 applies to source and affected property owners as they respond to contamination migration, from the initial notification and investigation to remediation and issuance of a MOE legal instrument.


Within 15 days of becoming aware of actual or likely migration, the source owner must provide notice of the migration to the affected owner and copy the MOE’s Director. The source owner should use the “Notification of Likely or Actual Migration” form (available in MOE Protocol 17) and include the required information, such as the source of the contamination and their environmental consultant’s contact information.


The source owner may need to access the affected property to sample and analyze soil, water, or vapour. The source owner should request access from the affected owner for these site investigations. If the affected owner refuses, the source owner may apply to the Director for access, particularly where the affected property is classified as high risk.

The source owner should continue to provide information to the affected owner throughout the investigation, including about the nature and extent of contamination, the human and ecological risks from exposure, and safety issues or impacts to utilities at the affected property.


 The source owner should contact the affected owner to discuss a remediation plan and schedule. Ideally this would lead to the source and affected owners reaching a written agreement setting out a suitable remediation strategy, after respectively receiving technical and legal advice.

However there may be a range of remediation options for the source and affected owners to consider.

Remediation may be performed to numerical or risk-based remediation standards. Risk-based remediation means contamination will remain on the property. AG11 cautions that affected owners should assess the implications of risk-based remediation proposed by the source owner, as it may hinder future land uses of the affected property.

Remediation may be performed independently or with MOE involvement and oversight. AG11 cautions that the affected owners should perform their own due diligence to confirm proper remediation, particularly with independent remediation.

Legal Instruments

The source owner may apply for legal instruments from the MOE in respect of the affected property, such as:

  • an approval in principle, which is the approval of a remediation plan;
  • a determination of contaminated site, which is a determination of whether the contamination exceeds standards;
  • a certificate of compliance, which is a certification of remediation to either numerical or risk-based standards.

AG11 sets out a consultation process for an affected owner to express objections, comments and concerns about the proposed legal instrument.

This consultation process is particularly important because the legal instrument may impact the affected owner’s use of their property. Further, the source owner (who may have caused the contamination) submits the application material, but the affected owner (who may be entirely innocent) is subject to the restrictions imposed by the legal instrument. This dynamic emphasizes the importance of the AG11 consultation requirements.

Generally the parties must adhere to the following communication process when a source owner applies for a legal instrument concerning an affected property:

  • The source owner must request comments and concerns from the affected owner, by way of a registered letter setting out the information required by Appendix 2 of AG11, including a description of the proposed legal instrument, a summary of the remediation plan, and a list of reports relating to the migrated contamination.
  • The affected owner has 30 days to respond with their position on the proposed legal instrument.
  • If after 30 days the affected owner has not provided their written response, the source owner must follow up by telephone, e-mail, or in person to request a response.
  • The affected owner has another 30 days from this follow-up to provide their response.
  • The source owner must provide a record of all communications with the affected owner to the MOE.
  • The Director may require or accept comments or concerns from other parties interested in the proposed legal instrument, such as an operator or mortgage holder.
  • The Director may delay the decision until all communication requirements are fulfilled.
  • The Director may issue a draft of the proposed legal instrument to the interested parties and allow another 30 day comment period before issuing the decision.

The Director may ultimately issue a legal instrument despite opposition by the affected owner. A decision may be appealed to the Environmental Appeal Board.

Both source owners and affected owners should obtain their own legal and technical advice when managing migrated contamination to protect their rights and interests.


WHAT WE DO: Lesperance Mendes has been advising property owners and others on environmental law since 1997. If you are dealing with a contaminated site or other environmental law issue, please contact Robert Lesperance, Partner, at 604-685-8737 or or Erika Swinton, Associate, at 604-674-3357 or


THIS ARTICLE IS NOT LEGAL ADVICE: This article provides general information and should not be relied on without independent legal advice.