Ontario Announces Risk Assessment Changes: Will the promise of quicker, cheaper brownfield risk assessments finally be realised?

12 décembre 2016 | Bryan J. Buttigieg

( Disponible en anglais seulement )

On November 1, 2016, the Ministry of the Environment and Climate Change posted on the Environmental Registry its long awaited decision notice to bring into effect updates to the model used by property owners in submissions of Modified Generic Risk Assessments (“MGRA”) under the Environmental Protection Act. This update was first proposed two years ago, in November 2014, and is the first update to the MGRA scheme that has been in effect since 2011 – the time of the last major change to the brownfields remediation standards.


The Brownfields Regulation (0.Reg 153/04) sets out standards for remediation of contaminated sites that, if met, will allow the filing of a Record of Site Condition. A Record of Site Condition has become a key pre-condition to many property developments in Ontario as banks and municipalities will often require that one be filed even when the legislation does not.

“Generic” and “Risk Assessed” Remediation

A property owner can remediate a site to a pre-determined set of published standards (“generic” standards) that are accepted as being protective of human health and the environment, based on a number of conservative assumptions about how the site will be used, likely contamination pathways and toxicity levels. When it is impractical or uneconomical to meet these standards, the regulation allows the owner to create “customised” standards through the Risk Assessment process. Using the same scientific model used for the generic standards, an owner and their consultant can customise the conservative assumptions in the standard model to more accurately reflect actual site conditions. Specific Risk Management Measures could be proposed that ensure that exposure pathways are eliminated or significantly mitigated. This in turn often results in less stringent standards that are nevertheless equally protective of human health and the environment as long as the site is used in accordance with the assumptions that were made.

The standard Risk Assessment process is expensive and time consuming. Since any of the standard model’s assumptions can in theory be modified in the process, and since the consultant and owner have free rein to propose any type of Risk Management Measure, extensive Ministry and third party peer review is required before approval. It is not unusual for this process to take 24 months or more. It is, of course, also very costly.

In an attempt to alleviate these concerns, the regulation also provides for a “middle ground” form of Risk Assessment. The MGRA was meant to provide owners with some of the efficiencies of the Generic option while allowing some of the flexibility provided by a Risk Assessment. To do so, the Ministry in effect limited the changes that could be made to the standard model by “pre-approving” a set of Risk Management Measures and effectively “pre-calculating” the new standards that would apply if those measures were adopted. The hope was that a number of properties would qualify for this “quicker, cheaper, simpler” form of Risk Assessment.

 The Problem

In practice, only a very small handful of sites ever qualified for MGRAs. The set of allowable Risk Management Measures and the impact on allowable property specific standards were too small. The Ministry responded by allowing a “hybrid” scheme not explicitly contemplated by the regulation in order to allow proponents more of the flexibility allowed by a full blown Risk Assessment. This created much uncertainty, costs and delays.

 A Solution?

The changes just announced by the Ministry are intended to increase the number of sites that would qualify for a MGRA. Drawing on the experience gained since the scheme was first introduced, and adopting some of the ideas that had been used in “hybrid” assessments, the model now allows for greater flexibility in a number of potentially useful areas that include:

  • Risk management measures to prevent vapours from entering buildings;
  • Land use control measure to ensure drinking water is municipally supplied;
  • Additional risk management options for capping a site;
  • Health and safety plan and a soil and groundwater management plan to protect people/community during redevelopment; and
  • Greater ability to utilize soil vapour sampling to help demonstrate that the site meets relevant standards.

In addition, the Ministry has adopted a standardized approach to demonstrate that there is no evidence of free hydrocarbon product (oil) on site, which in part addresses a longstanding complaint about some of the assumptions made in the previous model which were said to be far too conservative and not always reflective of actual site conditions.

These changes are a welcome step in the right direction. Inevitably, there will be criticism that the changes do not go far enough. As always, the Ministry approach reflects the constant tension between not adding unnecessarily to the costs of developing a brownfield site that might otherwise remain vacant, while remaining true to current scientific knowledge as to what levels of contaminants are safe for humans and the natural environment. Whether the new changes are sufficient to allow more sites to be developed using the quicker and cheaper MGRA streamlined approach will only be known after owners and consultants have a chance to work with the new model and apply it to real life situations. It would indeed be a welcome development for all involved if the promise of quicker, cheaper Risk Assessments for more sites finally becomes a reality.

Avis de non-responsabilité

Cette publication est fournie à titre informatif uniquement. Elle peut contenir des éléments provenant d'autres sources et nous ne garantissons pas son exactitude. Cette publication n'est ni un avis ni un conseil juridique.

Miller Thomson S.E.N.C.R.L., s.r.l. utilise vos coordonnées dans le but de vous envoyer des communications électroniques portant sur des questions juridiques, des séminaires ou des événements susceptibles de vous intéresser. Si vous avez des questions concernant nos pratiques d'information ou nos obligations en vertu de la Loi canadienne anti-pourriel, veuillez faire parvenir un courriel à privacy@millerthomson.com.

© 2023 Miller Thomson S.E.N.C.R.L., s.r.l. Cette publication peut être reproduite et distribuée intégralement sous réserve qu'aucune modification n'y soit apportée, que ce soit dans sa forme ou son contenu. Toute autre forme de reproduction ou de distribution nécessite le consentement écrit préalable de Miller Thomson S.E.N.C.R.L., s.r.l. qui peut être obtenu en faisant parvenir un courriel à newsletters@millerthomson.com.