The law

By law, to operate a greenhouse in Ontario, you must:

  • get a Permit to Take Water, if you take more than 50,000 litres of water on any given day from a lake, stream, river, pond or groundwater source
  • get approval from the Ministry of the Environment, Conservation and Parks to discharge sewage, including storm water, process water and sanitary sewage
  • get approval to use, operate, establish, alter, extend or replace new or existing sewage works
  • properly store and handle pesticides
  • hold a pesticide licence or certificate such as the Greenhouse/Interior Plant exterminator licence or Grower Pesticide Safety Grower Certificate to apply certain pesticides

Learn more:

Source law

You can find a complete set of rules related to greenhouse operations in:


Wastewater from greenhouses is classified as sewage. Greenhouses typically generate sewage from:

Process wastewater:

  • water with added nutrients
  • water that has been used for irrigation and washing of crops
  • recycled water
  • water carried through floor drains inside the greenhouse operation, including water that mixes with storm water

Storm water:

  • rainfall
  • snowmelt
  • roof and surface runoff

Sanitary wastewater from:

  • showers
  • toilets
  • kitchens located on the greenhouse operation site

Untreated, these sources of sewage can harm the environment. To help control and minimize impacts, discharges from greenhouses require approval from the Ministry of the Environment, Conservation and Parks.


In most cases, you don’t need approval if you:

  • discharge wastewater or sanitary waste water directly to a sanitary sewer
  • discharge storm water directly to an engineered single purpose storm sewer


You are encouraged to contact the Ministry of the Environment, Conservation and Parks office as a first step to discuss what approvals may apply to your operations.

You may also need to:

  • get an Environmental Compliance Approval for wastewater and/or storm water discharges from greenhouses
  • get approval for more than one activity, depending on your greenhouse operations
  • check with your local municipality for any other rules or permits that may apply
  • inform your local conservation authority of your plans
  • contact a qualified consultant or engineer to find out what technical studies may be required

To improve efficiency and reduce burden, the province has developed a streamlined process for obtaining an approval for a Greenhouse Stormwater Management Facility.

Once you obtain your Environmental Compliance Approval you are responsible for:

  • operating within the conditions of your approval
  • applying for an amendment to your approval before altering, extending, or replacing any part of your wastewater system
  • renewing your Environmental Compliance Approval before it expires
  • keeping a copy of your approval on site
  • contacting your local ministry office if you receive any complaints regarding your operation


The ministry may visit your greenhouse periodically to inspect the operations included in your Environmental Compliance Approval or if a complaint is received.

Generally, an Environmental Officer will schedule planned inspections with you ahead of time. However, an Officer may arrive unannounced, especially in the event of a spill, complaint or to address ongoing compliance issues.

Using pesticides

The provincial government regulates the sale, use, transportation, storage and disposal of pesticides in Ontario.

Ontario's Pesticides Act and Ontario Regulation 63/09 provide the province's framework to regulate pesticides to protect human health and the natural environment.

These rules ensure pesticides are used safely by trained users.

When handling pesticides you should always:

  • store, handle and apply pesticides carefully
  • keep detailed pesticide application logs
  • ensure respirators are sealed from exposure to air and are not stored in pesticide storage areas
  • create a spill response plan so that everyone knows their role in the event of a significant spill
  • keep absorptive material near pesticide storage areas to deal with any minor liquid spills
  • ensure that everyone who uses pesticides receives training in both pesticide safety and practical application skills
  • mix pesticides and load the application equipment in a separated area

For farmers

If you are a farmer and hold a Grower Pesticide Safety Course Certificate, you can purchase and use Class B and C pesticides on your farm, including the use of pesticides in a greenhouse.

Farmers do not require a Grower Pesticide Safety Course Certificate to purchase or use Class D pesticides on their own farm or a farm they operate on a regular basis.

For greenhouse exterminators

If you hold a Greenhouse/Interior Plant Exterminator licence, you can use pesticides:

  • inside the greenhouse
  • in the area immediately surrounding the greenhouse

A Greenhouse/Interior Plant Exterminator licence:

  • allows you to use pesticides to control pests that affect the greenhouse crop
  • does not allow the use of fumigant gases, chloropicrin or termiticides


You may need a permit to use higher-risk pesticides.

Learn more:

Storing pesticides

You must store pesticides under safe conditions to protect human health and the environment. The minimum requirements for storage of all pesticides include:

  • no impairments to health and safety
  • no contact with food and drink
  • warning signs posted at entrances to storage areas
  • emergency telephone numbers posted

Report a spill

In case of a spill contact:

Spills Action Centre
Toll-free: 1-800-268-6060