Introduction

This information describes the potential greenhouse nutrient feedwater (GNF) permanent storage exemption for greenhouse operations that expect there will be a period of at least 24 months between GNF generation at their operation (referred to as 24-month generators).

The following are overviews of the regulation as it applies to:

A 24-month generator is exempt from the minimum permanent storage capacity requirements as outlined in Part VII of O. Reg. 300/14, Greenhouse Nutrient Feedwater Regulation. However, all other requirements still apply.

See O. Reg. 300/14, Greenhouse Nutrient Feedwater for more information on the regulation and associated protocols.

Requirements for a 24-month generator

To become a 24-month generator:

  • indicate in your registration that there will be a period of at least 24 months between each time GNF is generated at your operation
  • you cannot receive GNF generated at another farm unit

If a GNF strategy is not required for your operation, you still need to prepare a contingency plan.

Determine nutrient units

When registering your operation under the regulation, identify the number of nutrient units (NUs), using the GNF management table, that you expect your operation to generate. The number of NUs will also help to determine if other documentation, such as a GNF strategy, plan or document is required. Generating greenhouse nutrient feedwater provides more information on these documents.

Since the expected time period between GNF generation is very long for 24-month generators (24 months or greater), the portion of leachate not re-used in the recirculation system is expected to be very low (less than 3.13%). If this is the case for your operation, you need to use Method 2 of the table to calculate the number of NUs.

Method 2: Multiply the estimated volume of GNF generated in a calendar year at the greenhouse operation by 0.0077. For a typical 24-month generator, this volume is the amount of nutrient solution existing in the greenhouse.

For example, if the greenhouse has 500 m3 of storage, multiply 500 m3 by 0.0077 NUs/m3, giving a value of 3.85 NUs.

Applying and storing GNF from a 24-month generator

Except for the permanent storage exemption, 24-month generators must follow all the rules for land applying GNF. See Applying greenhouse nutrient feedwater on agricultural land for more information.

Since there may be no permanent GNF storage facility, manage the timing of GNF generation so that GNF is applied in accordance with the regulation. Consider larger internal nutrient solution tanks to give some flexibility in the timing of GNF generation.

Use portable storage tank(s) as long as you comply with these requirements:

  • 100 m3 is the maximum capacity for all storage tanks, combined, for a single farm unit
  • each tank must be emptied at least once every 14 days

Contingency planning

All 24-month generators need a contingency plan to address potential GNF management issues. A contingency plan is created as a separate document and should be kept at your operation.

In a contingency plan, include:

  • how the GNF will be managed if it is generated within the 24-month period
  • how unanticipated releases of GNF (such as storage seepage) will be safely managed
  • alternative steps if unable to land apply as a result of weather conditions or unavailability of equipment

AgriSuite

AgriSuite is a suite of free web-based decision support tools that can be accessed online from your computer, tablet or smartphone. AgriSuite assists you with key crop fertilization management decisions and how they relate to improving crop production and protecting the environment. It is designed to help farmers meet their obligations under the Nutrient Management Act, 2002 (NMA).

The Greenhouse Nutrient Feedwater (GNF) worksheet in Agrisuite estimates GNF production, storage sizing and land application methods to help certified consultants and greenhouse operators prepare required legal documents for regulatory purposes under the NMA.

Resources

For questions on the regulation, protocols, GNF strategies and plans and AgriSuite, contact the Agricultural Information Contact Centre at 1-877-424-1300 or ag.info.omafra@ontario.ca.

Visit the University of Guelph Ridgetown Campus nutrient management website for a list of Greenhouse Nutrient Feedwater Preparers and for nutrient management training opportunities.

Disclaimer

The information provided is for informational purposes only. This fact sheet provides a general and simplified description of some of the legal requirements of O. Reg. 300/14 (the "Regulation"), the Greenhouse Nutrient Feedwater (GNF) Management Protocol and the GNF Sampling and Analysis Protocol. The protocols are adopted by the regulation and are legally enforceable. This information does not provide a comprehensive description of the rules that are mentioned and there are rules in the regulation and protocols that are not covered at all. To determine your legal obligations, consult the relevant law. If legal advice is required, consult a lawyer. In the event of a conflict between the information in this fact sheet and any applicable law, the law prevails.