Storm water management works guidance for the Environmental Activity and Sector Registry

This guidance was written to provide information on Environmental Activity and Sector Registry requirements. It should not be construed as legal advice. While all efforts are made to ensure the accuracy of the requirements summarized below, if there is any discrepancy between this summary and the Acts or regulations, the provisions of the Acts and regulations take precedence.

Introduction

Storm water management works are works constructed for the collection, transmission, treatment and disposal of storm water. In Ontario, a permission is needed for the use, operation, establishment, alteration, extension or replacement of most storm water management works. For some storm water management works a permission is obtained by registering in the Environmental Activity and Sector Registry (EASR). The following guidance provides more information to help you determine whether your storm water management works must be registered in the EASR. If you are required to register, this guidance outlines what you need to complete before you register, how to register, and requirements you must comply with after you register.

How to use this guidance

This guidance is separated into 3 chapters:

1. Storm water management works guidance for the Environmental Activity and Sector Registry
2. Preparing a storm water management report
3. Significant drinking water threat assessment

At the top of the page is the table of contents that will take you to each chapter of the guidance.

If you are required to register, this guidance outlines what you need to complete before you register and then follow after you register.

Exemptions

In Ontario, some storm water management activities may be exempt from requiring an environmental permission.

Refer to the Ontario Regulation 525/98: Approval Exemptions to learn more.

Storm water management works not subject to registration in the EASR

Ontario Regulation 137/25: Registrations under part II.2 of the Act - storm water management works, does not allow the registration of storm water management works that service the sites listed below. If your works service any of the following sites, your works cannot be registered on the EASR, regardless of whether the works meet the other criteria to register. If the works service the following sites and cannot be registered on the EASR, you may be required to apply for an Environmental Compliance Approval (ECA):

• a waste disposal site as defined in part V of the Environmental Protection Act
• an abandoned motor vehicle site as defined in part VII of the Act
• a snow disposal facility or a site for the storage of snow where the predominant use of the site is for the retention, control, storage or disposal of snow
• a bulk plant as defined in Ontario Regulation 217/01 Liquid Fuels made under the Technical Standards and Safety Act, 2000
• a golf course
• a road salt storage facility
• an aerodrome as defined in the Aeronautics Act (Canada)
• a shipyard and any associated maintenance facility
• a renewable energy generation facility
• a greenhouse
• an outdoor surface consisting of aggregate that includes basic oxygen furnace slag
• a site at which any outdoor repair and maintenance of motorized vehicles, equipment and heavy machinery take place
• a site at which activities described under any of the following NAICS codes takes place:
  • 31, 32, 33 manufacturing
  • 21 mining, quarrying, and oil and gas extraction
  • 2212 natural gas distribution
  • 418110 recyclable metal merchant wholesalers

In addition to works servicing the sites listed above, the use, operation or establishment of a new storm water management works cannot be registered in the EASR or be issued an environmental compliance approval (ECA) if both:

• the activity would be a significant drinking water threat
• the relevant source protection plan prepared under the Clean Water Act, 2006 includes a policy that has the effect of prohibiting the establishment of new storm water management works at the location where the works is proposed to be located

Some source protection plans include policies (listed in “List C” of the appendix of the plan) that prohibit the establishment of storm water management works (facilities and drainage systems) that would be a significant drinking water threat. This is the type of source protection plan policy that would have the effect of prohibiting the establishment of new storm water management works at the location where the works is proposed to be located.

You can learn more about source protection in Ontario and locally developed source protection plans approved under the Clean Water Act at Source Protection and 2021 Technical Rules under the Clean Water Act.

Storm water management works subject to registration in the EASR

Ontario Regulation 137/25 under the EPA prescribes the use, operation, establishment, alteration, extension, or replacement of certain storm water management works to be registered in the EASR.

Except where your works manage storm water from sites listed above, which are not subject to the registration requirements, you must register your storm water management works in the EASR when they meet all the following criteria:

• the works are not owned by one of the following and will not be transferred to or assumed by one of the following under an agreement entered into under the Planning Act or Development Charges Act, 1997:
  1. a municipality within the meaning of the Municipal Act, 2001
  2. any of the following bodies that is established for the purpose of managing public utilities on behalf of or for a municipality within the meaning of the Municipal Act, 2001:
     1. a public utility commission deemed to be a municipal service board under section 195 of the Municipal Act, 2001
     2. a municipal service board established under sections 9, 10, 11 and 196 of the Municipal Act, 2001 or a city board as defined in subsection 3 (1) of the City of Toronto Act, 2006
     3. a corporation established under sections 9, 10 and 11 of the Municipal Act, 2001 in accordance with section 203 of that Act or under sections 7 and 8 of the City of Toronto Act, 2006 in accordance with sections 148 and 154 of that act
• any processing, repair or maintenance of goods and materials at the property where the works are located are conducted indoors
• the works or any part of the works does and will not receive any discharge of process water, cooling water, wash water or sanitary sewage

For example, you are not subject to registration in the EASR and you may need to apply for an ECA for those works if:

• you are repairing or maintaining goods and materials outside where storm water could pick up and carry contaminants into your works
• the works receive storm water that encounters or is mixed with water from processing activities or cooling water or wash water or sanitary sewage.

Municipality is within the meaning of the Municipal Act, 2001, and in addition, the following bodies that are established for the purpose of managing public utilities on behalf of or for a municipality:

• a public utility commission that is deemed to be a municipal service board
• a municipal service board established under the Municipal Act or city board in the City of Toronto Act, 2006
• a corporation established under the Municipal Act or under the City of Toronto Act, 2006

Where the storm water management works is owned by or to be transferred to a municipality or one of these municipal entities, the storm water management works activity cannot be registered on the EASR. The intent in limiting registrations of storm water management works  works owned by a municipality or by these municipal entities is because these storm water management  works should be captured under a consolidated linear infrastructure approval issued to a municipality rather than registration in the EASR. Find out more about municipal consolidated linear infrastructure environmental compliance approvals issued for municipal storm water management systems.

Storm water management works that are contained within a single property owned by a municipality and meet the requirements to register in the EASR include for example storm water management works that service:

• hospitals
• recreation centres
• long-term care facilities

In September 2026, amendments to Ontario Regulation 137/25 came into effect and the regulation now prescribes storm water management works servicing electricity generation, transmission, distribution and battery energy storage sites described by NAICS code 2211, for registration in the EASR. Common types of storm water management works that service these sites include spill containment works and underdrain systems.

The intent in limiting storm water systems owned by a municipality is so that storm water management works that should be captured under a consolidated linear infrastructure approval issued to a municipality are not subject to registration in the EASR. Find out more about municipal consolidated linear infrastructure environmental compliance approvals issued for municipal storm water management systems.

If you have reviewed the criteria to self-register and are still unsure, contact us.

When to register

If you are proposing a new storm water management works (including spill containment works or underdrain systems) and you meet the criteria set out in regulation, you are required to self-register in the EASR prior to the construction of the works.

If you have an ECA that authorizes your existing storm water management works (including spill containment works or underdrain systems), you may continue to operate under your ECA until there is a need to amend your ECA for anything other than an administrative amendment. An administrative amendment can include:

• a change in ownership
• change in address
• name change
• editorial correction

The ministry determines whether an ECA amendment is administrative.

If you are proposing to expand, alter or replace an existing works with an ECA, the works must be self-registered in the EASR before making the alteration or other change to the works.

When you register a new works or an existing works to the EASR, you must meet all the requirements in Ontario Regulation 137/25 prior to registering. For example, you will need to upload a storm water management (SWM) report in the registry that has been signed and sealed by a licensed engineering practitioner.

Learn more about preparing a storm water management report.

Note, existing storm water management works and any spill containment works and underdrain systems described by NAICS code 2211 are not subject to the design requirement of enhanced  protection when registered in the EASR.

Once an existing works is registered in EASR your ECA will cease to apply when you receive your confirmation of registration in the registry. After you self-register, you must follow your SWM report and the activity requirements in Ontario Regulation 137/25.

Learn more about amending an existing ECA in part B of the Guide for applying for an Environmental Compliance Approval.

Registering in the EASR

As the current or future owner of storm water management works (including spill containment works or underdrain systems described by NAICS code 2211) or the person engaging in the activity, you are responsible for completing the following steps to register the activity in the EASR:

 You are expected to provide complete and accurate information to the LEP who prepares your SWM report and your SWM report must contain complete and accurate information. It is your responsibility to operate and maintain your storm water management works by following your SWM report and the activity requirements in Ontario Regulation 137/25.

You must also ensure that relevant consents and approvals have been obtained prior to registering your activity in the EASR. For example, if applicable, you may need to obtain consent from the owner of the land or sewage works to which your works will discharge, or a permit under the Niagara Escarpment Planning and Development Act.

Questions include:

• the location of your works
• site conditions (including if determined to be a significant drinking water threat)
• design of the works
• operations and maintenance of your works
• erosion and sediment control
• the discharge locations and
• upload your SWM report in the registry

There is no fee to register your storm water management in the EASR.

You must operate and maintain your works as directed in your SWM report and Ontario Regulation 137/25 and anytime construction occurs, implement your erosion and sediment control plan.

Your registration, including the information in your SWM report that is filed as part of your registration, must be kept current and updated once you are aware that any information in your registration is no longer accurate or complete, for example, if conditions at the site change in a way that impacts the information in your SWM report. For more information refer to Updating information in the registry.

To register, you will need to access online services for environmental permissions.

Learn more about environmental permissions online services.

Refer to Making changes to registered storm water management works for requirements that must be followed when changes are made after you have registered your.

Comply with the regulation

You must follow the activity requirements set out in Ontario Regulation 137/25, and the procedures and practices set out in your SWM report. The ministry may review your registration for compliance with the regulation and an environmental compliance officer may visit your property to inspect the works and assess compliance with your SWM report and Ontario Regulation 137/25.

The confirmation of registration that you received after completing your registration has important information that will help you understand your compliance obligations, including:

• your registration number
• the date of registration
• the date your registration was updated, if applicable
• schedule A — a summary of post-registration activity requirements
• schedule B — a summary of your registration

Below is a summarized version of the activity requirements. Refer to Ontario Regulation 137/25 for more details and the exact requirements that apply to your activity.

• Your SWM report must be made available to any person who operates or maintains your works.
• You must follow the requirements in your SWM report and any addenda that has been filed; for example, when operating and maintaining your works, you must follow the procedures detailed in your SWMSWM report.
• If your SWM works are a significant drinking water threat, notify the local source protection authority in writing before you begin operating your works. The notice must include:
  • a description of the works, for example, the type of works
  • a statement that your works are a significant drinking water threat
  • your EASR registration number
• After you have registered, you may receive notice from the local source protection authority of proposed changes to the local source protection plan that could affect whether your works are a significant drinking water threat. In this case, once the plan amendments take effect, you must re-assess the works to determine whether the activity is a significant drinking water threat. Refer to Significant Drinking Water Threat Assessment guidance for more details.
• The effluent from your storm water management works must be essentially free of floating and settleable solids and must not have oil or any other substances in amounts sufficient to create a visible film, sheen, foam, or discoloration on the receiving waters. You may consider discussing this requirement with a LEP to make sure you are aware of preventative and corrective measures that can be implemented to address this.
• If your SWM report includes a monitoring plan with effluent objectives provided by a LEP or you have registered spill containment works, you must make your best efforts to meet the effluent objectives. If there is an exceedance of an effluent objective, you must notify the ministry district office immediately and in writing within seven days. In addition, sampling equipment must be maintained and calibrated.
• You must obtain as-built drawings of the works prepared, dated and signed by an LEP within 6 months of construction, alteration, extension or replacement of the works.
• You must retain and make available to anyone operating the works any manufacturer’s specification sheets, relevant technical information and agreements for equipment components of the works.
• Anyone operating a spill containment works and other storm water management works servicing the same site must be trained in spill response.

Spill contingency plan

All persons in Ontario who own or have control of pollutants have obligations under Part X of the EPA and Ontario Regulation 675/98: Classification and Exemption of Spills and Reporting of Discharges related to responding to and reporting on spills. In addition to those obligations, under Ontario Regulation 137/25 you must prepare a spill contingency plan in either of the following cases:

• there is outdoor storage or handling of soil, raw material, intermediate products, finished products or by-products at the property where the works are located
• your storm water management works are determined to be a significant drinking water threat

Note, for spill containment works and any other storm water management works servicing the same site, a LEP must prepare a spill contingency plan as part of the Operations and Maintenance (O&M) section of the SWM report that meets the requirements in Ontario Regulation 137/25. For more information, refer to the O&M section in preparing a storm water management report.    

A spill is defined in Part X of the EPA.

At a minimum, your spill contingency plan must include the following to address potential spills of pollutants that may enter your works or result in the discharge of pollutants from your works into the natural environment:

• procedures to prevent or reduce the risk of a spill
• procedures to prevent, eliminate or ameliorate any adverse effect that may result from a spill
• procedures to provide annual spill response training to anyone who operates the works

Your spill contingency plan must be implemented, including in the event of a spill. You must also make available an inventory of response and clean-up equipment to any person operating or using the works.

Your spill contingency plan may include the following additional information:

• the date on which the plan was prepared
• the name, job title, address and phone number of the owner or person in charge of the site serviced by the storm water management works
• the steps and measures to be taken to report, contain, clean up and dispose of pollutants following a spill that enters or has a potential to enter your storm water management works
• listing of telephone numbers for:
  • local clean-up companies who may be called upon to aid in responding to spills
  • local emergency responders including health institutions
  • the ministry Spills Action Centre Toll-free: 1-800-268-6060
• the procedures by which the plan is activated in response to a spill and the name, job title and 24-hour telephone number of the people responsible for activating the spill contingency plan
• a site plan drawn to scale showing:
  • the catchment area serviced by the storm water management works
  • nearby buildings, streets, catch-basins and manholes
  • drainage patterns (including direction of flow in storm sewers)
  • any receiving body of water that could potentially be significantly impacted by a spill and any features which need to be considered in terms of potential impacts on access and response, including physical obstructions and location of response and clean-up equipment
  • any nearby municipal drinking water system wells or intakes
• safety data sheets for each hazardous material which may be transported or stored within the area serviced by the storm water management works
• procedures for keeping records of any spills per Ontario Regulation 675/98
• if your storm water management works is identified as a significant drinking water threat, include the following:
  • identify that the activity is a significant drinking water threat
  • identify that the activity is taking place in a wellhead protection area or intake protection zone as shown in the source protection plan
  • the name of the drinking water system for the wellhead protection area or intake protection zone that the activity is occurring in
  • list the telephone number for the drinking water system operator for the wellhead protection area or intake protection zone that the activity is occurring in, to contact them, should a spill occur
  • when contacting Spills Action Centre, inform them that you have a storm water management works in an intake protection zone or wellhead protection area, and a spill of pollutants has occurred from the works or has occurred nearby and may enter the works.

Your spill contingency plan should be reviewed and updated on a regular basis to confirm it has accurate information in case of a spill.

Record keeping

The records section of Ontario Regulation 137/25 requires various records relating to the use, operation, establishment, alteration, extension or replacement of your works to be created and retained. Some records must be retained for the lifetime of the works whereas others are required to be retained for a minimum of 5 years. These records must be made available to the ministry upon request and may be used to assess compliance with environmental legislation and associated regulations.

Records required to be kept for the lifetime of the works include:

• as-built drawings
• manufacturer specification sheets and copies of maintenance agreements with equipment manufacturers
• landowner consent if the registrant does not own the land where the works are located
• consent from the owner or land or sewage works to which the storm water management works will discharge, if applicable
• any applicable Niagara Escarpment Planning and Development permit or approval under the Environmental Assessment Act
• Environmental Assessment Act undertakings
• your spill contingency plan, if applicable

Records requiring retention for a minimum of 5 years include:

• monitoring records if monitoring is required, including date and location of an exceedance of an effluent objective and corrective actions taken, and maintenance of sampling equipment
• complaints about your storm water management works that have been received and summary of measures taken, if any, to address the complaint
• inspection and maintenance activities for erosion and sediment control measures
• operation, maintenance and inspection activities of your storm water management works
• abnormal situations including emergency shutdowns and breakdowns
• records for spill response training

Making changes to registered SWM works

If you are planning to alter, extend, or replace your storm water management works, you must:

• upload an updated SWM report or add an addendum to the registry before making those changes

You do not need to register the alteration, extension, or replacement of your storm water management works separately in the registry. However, you must retain an LEP to review your existing SWM report and determine whether it needs to be updated to accurately reflect the proposed alteration, extension or replacement of your storm water management works.

You must either obtain an updated SWM report from your LEP or, if your LEP determines that the SWM report does not need to be updated, obtain an addendum from your LEP that describes the changes to the works and explains why the current information in the SWM report will continue to satisfy the requirements of the regulation and accurately reflect the storm water management works even after the changes are made to the works. The updated SWM report or addendum must be uploaded to the registry before the works are altered, extended, or replaced. Within 6 months after the changes are made to the works, as-built drawings of your works must be updated by a LEP and retained for the lifetime of the works or until they are replaced by a more recent version. When uploading the updated SWM report or addendum to the registry, you should consider updating any other information in your registration that is no longer complete or accurate as you are required to update the registry within 30 days of becoming aware that information is no longer complete or accurate, as outlined in the next section.

Updating information in the registry

Ontario Regulation 245/11, Registration under Part II.2 of the Act - General under the EPA applies to all registered activities in the EASR. Under section 3(1) when any person engaging in an activity that is registered becomes aware that any information filed in the registry is no longer complete or accurate, the person must update the information within 30 days of becoming aware of the change.

This includes updating the registry after SWM works have been expanded, altered or replaced in accordance with an updated storm water management report or addendum, or other changes have happened in the catchment area of the storm water management works that impact any other part of the registration.

There is no fee or added approval process for updating information in the registry, refer to Update your registration under Register in the EASR for more information.

Contact us

For more information, you can contact the Client Services and Permissions Branch at:

• Tel: 416-314-8001 
  Toll-free: 1-800-461-6290, Monday to Friday, 8:30 a.m. to 5 p.m.
• enviropermissions@ontario.ca

Appendix A: legislation and regulations

• Ontario Water Resources Act, R.S.O. 1990, c. O.40
• Environmental Protection Act, R.S.O. 1990, c. E.19
• Ontario Regulation 245/11: Registrations under Part II.2 of the Act - General
• Ontario Regulation 137/25 Registrations under part II.2 of the Act - storm water management works

Appendix B: Preparing a SWM report

Ontario Regulation 137/25 requires that a storm water management report be filed in the registry when registering storm water management works in the EASR.

For more information refer to Preparing a storm water management report.

Appendix C: Significant drinking water threat assessment

Ontario Regulation 137/25 requires an assessment of whether the storm water management works are or would be a significant drinking water threat.

For more information refer to Significant drinking water threat assessment.