Digging for Answers in Ontario’s On-Site and Excess Soil Management Regulation (Ontario Regulation 406/19) and Excess Soil Risk Assessment

Digging for Answers in Ontario’s On-Site and Excess Soil Management Regulation (Ontario Regulation 406/19) and Excess Soil Risk Assessment

Blog Overview

Ontario’s On-Site and Excess Soil Management Regulation (O. Reg. 406/19) has significantly changed how excess soil is characterized, managed, and reused across the province.  Introduced to promote responsible soil management and increase beneficial reuse opportunities, O. Reg. 406/19 establishes clear requirements for soil assessment, documentation, tracking, and reuse planning.  Central to this framework is risk assessment, which can be used to develop site-specific excess soil quality standards for a reuse site.

This article provides an overview of O. Reg. 406/19 and excess soil risk assessment, outlining key regulatory requirements, various methods of meeting the excess soil quality standards, the development of site-specific standards using risk assessment approaches, and practical considerations for property owners, developers, and contractors managing excess soil in Ontario.

What is excess soil and what are the benefits of excess soil reuse?

Excess soil refers to soil that has been excavated from a site (typically during construction or redevelopment activities), which can no longer be used at the development site.  Local reuse of excess soil can have many financial and environmental benefits associated with marked reductions in transportation and landfilling activities; however, care must be taken to ensure that excess soil reuse occurs in a safe and effective manner.

Excess soil regulatory overview

To support the proper management of excess soils, the Ministry of Environment, Conservation and Parks (MECP) released Ontario Regulation 406/19 On-Site and Excess Soil Management (O. Reg. 406/19) under the Environmental Protection Act.  O. Reg. 406/19 provides guidance and rules on managing and reusing excess soil to facilitate local beneficial reuse, while ensuring the protection of human health and the environment.

1. Reg. 406/19 includes excess soil reuse planning requirements that must be met before excess soil can be removed from a project area.  These include:

1. Completion of an assessment of past uses, a sampling and analysis plan, a soil characterization report and excess soil destination assessment report. These requirements must be completed prior to filing a notice on the Excess Soil Registry (Registry);
2. Registration of a notice in the Registry, developed and implemented by the Resource Productivity and Recovery Authority (RPRA); and,
3. Application of a tracking system.

The excess soil quality standards and role of the Qualified Person

As part of the excess soil reuse planning requirements, O. Reg. 406/19 references risk-based excess soil quality standards that excess soils must meet to ensure the protection of human health and the environment at the reuse site.  The excess soil quality standards were developed using a similar approach as the Site Condition Standards developed under the Records of Site Condition Regulation (O. Reg. 153/04) but with modifications to address soil volume, and groundwater and vapour intrusion protection.  In addition, leachate screening levels have been developed for some contaminants to be protective of several groundwater exposure pathways.  The excess soil quality standards and leachate screening levels are presented in MECP’s .  This document also summarizes important rules for excess soils, reuse sites and use of the excess soil quality standards.

Under O. Reg. 406/19, a Qualified Person (QP), as defined in the Records of Site Condition regulation (O. Reg. 153/04), must be retained to assess the quality and potential reuse of excess soils from a project site.  As a result, the QP plays an important role in the excess soil reuse process.

Frequently Asked Questions

What can I do when excess soils do not meet the generic excess soil quality standards?

In many cases, excess soil will contain elevated concentrations of contaminants which exceed the generic excess soil quality standards.  In these situations, there are several strategies that can be employed to provide flexibility in meeting the applicable standards, including:

1. Use of background concentrations– if a QP can demonstrate that excess soil contains a chemical parameter that is naturally occurring at the reuse site and does not exceed the naturally occurring range of concentrations typically found in soil at the reuse site, then the chemical parameter can be deemed to meet the excess soil quality standard if appropriate supporting documentation can be provided.
2. Statistical analysis– in cases where twenty (20) or more discrete soil samples have been collected within an area of potential environmental concern (APEC) or related area, statistical analysis can be utilized to meet the excess soil quality standards.  Chemical parameters can meet the excess soil quality standards if
   • A statistical metric representative of anticipated exposure (i.e., 90^thpercentile concentration and 95% upper confidence limit of the mean (UCLM) concentration) is below the excess soil quality standards; and,
   • No single soil sample exceeds the corresponding “ceiling value” for the chemical parameter(s) of interest. Ceiling values represent slightly higher generic excess soil quality standards that can be used when a large sample size is collected from an APEC.
3. Risk assessment – if chemical parameters do not meet the generic excess soil quality standards, a risk assessment can be completed which includes the generation of site-specific standards by a QP.

How does a risk assessment affect the excess soil quality standards?

Risk assessments consider site-specific hydrogeological conditions, exposure pathway modifiers, and site use characteristics or risk management measures, designed to block or reduce exposure, to derive site-specific excess soils quality standards that are higher than the generic excess soil quality standards while still being protective of human health and the environment.  Therefore, risk assessments can provide additional flexibility in meeting the excess soil quality standards, maximizing beneficial reuse.

Who can prepare an excess soil risk assessment in Ontario and what qualifications are needed?

In Ontario, an excess soil risk assessment must be prepared or supervised by a Qualified Person (QP) in accordance with O. Reg. 406/19 and O.Reg 153/04 under the Environmental Protection Act.  QPs include a Qualified Person of Risk Assessment (QPRA), Qualified Person of Environmental Site Assessment (QPESA), a Professional Engineer (P.Eng.), or Professional Geoscientist (P.Geo.).

What is the Beneficial Reuse Assessment Tool? 

The Beneficial Reuse Assessment Tool (BRAT) is a spreadsheet model developed by the MECP which allows a QP to generate site-specific standards for a reuse site using a streamlined approach.  The BRAT allows the QP to modify general reuse site characteristics and hydrogeological conditions in a site-specific manner and allows for the modification of certain exposure pathways by using pre-defined “site use characteristics” (e.g., shallow soil cap, fill cap or hard cap, building with a storage garage, etc.).

When can site use characteristics be used in the BRAT? 

Site-use characteristics can be utilized in the BRAT under two scenarios:

1. Where a site-specific instrument (e.g., permit, license, approval), as defined by O Reg. 406/19, is obtained which authorizes the use of the site use characteristic(s), including reference in the instrument to the site-specific excess soil standards developed from the BRAT; and,
2. Where the selected site use characteristic(s) is part of the existing or planned site use (i.e., part of an undertaking related to “infrastructure” within the meaning of O. Reg. 406/19), rather than as a mechanism to manage potential risks associated with excess soil. For example, if an approved plan already includes the creation of a paved parking lot, then a hard cap barrier option could be utilized in the BRAT.

Figure 1.  Site Use Characteristics Provided by the BRAT

When is the BRAT not applicable? 

The BRAT cannot be used for a reuse site that is considered to be an Environmentally Sensitive Area (i.e., Table 1 Site) as defined in O. Reg. 153/04, or in cases where excess soil is designated as hazardous waste as defined in Ontario Regulation 347 (General-Waste Management).  Additional limitations of the BRAT model can be found in A Guide for Developing Site Specific Excess Soil Quality Standards Using the Beneficial Reuse Assessment Tool (BRAT).

Figure 2. Overview of the Development of Site-Specific Standards Using the BRAT and Submission Process

What can I do when the BRAT does not apply or does not support the reuse of excess soils in Ontario? 

The derivation of site-specific soil standards using the BRAT may not always support the use of all excess soils.  Under these circumstances, the project leader does have other options:

1. The BRAT can be used to support the reuse of some excess soils generated at a development site. The remaining excess soils that do not meet the site-specific standards can be brought to a landfill;
2. A risk assessment can be completed to support excess soil reuse. Risk assessments allow for greater flexibility in meeting the appropriate criteria through consideration of additional site characteristics and risk management measures; and,
3. The project leader can find another reuse site where the generic or site-specific standards can be met.

How do tracking, documentation and the Excess Soil Registry tie into risk assessments?

Risk assessments conducted under Ontario’s excess soil framework derive site-specific excess soil quality standards that are higher than the generic excess soil quality standards while still being protective of human health and the environment.  The standards derived with the risk assessment deviate from the generic excess soil quality standards provided by the MECP and often consider additional factors such as risk management measures or information on where excess soils can be placed at a reuse site.  As a result, the registry must be updated to include the site-specific excess soil quality standards derived from the risk assessment and identify the risk management measures that will be put in place to mitigate potential risks and provide support that excess soils meet the proposed standards.

Are there any exemptions from the excess soil planning requirements outlined in O. Reg. 406/19?

Yes, O. Reg. 406/19 does provide several exemptions from some or all of the excess soil planning requirements.  General exemptions are described in Schedule 2 of O. Reg. 406/19, and exemptions for some reporting requirements are described in section 14 of O. Reg. 406/19.  It is generally recommended that these exemptions be reviewed to determine whether a project meets the requirements.

Top 5 reasons to partner with Intrinsik for your excess soil project

1. Intrinsik’s environmental consultants have extensive experience conducting excess soils risk assessment and the generation of site-specific standards, consistent with O. Reg. 406/19 and associated guidance.
2. Our team’s extensive experience and internal systems allow us to provide cost-efficient solutions without compromising quality.
3. Our process includes a thorough review of all relevant data and reports and the completion of a data gap analysis to confirm that all necessary documentation is available to move the project forward and meet regulatory compliance and client deadlines.
4. Our reports are presented in a concise and streamlined format to improve readability and transparency.
5. Our pricing is designed to maximize value for our clients.