Fact Sheet: Aggregate site (pits and quarries)

What you need to know: The basics

  • The Municipal Property Assessment Corporation (MPAC) values more than 3,200 aggregate properties in Ontario.
  • An aggregate site is where aggregate (i.e., sand, stone and gravel) is extracted.

How we assess pit and quarry properties

  • Aggregate properties are assessed using the cost approach.
  • In this approach, value is determined by two key components: the replacement cost new less depreciation for any structures and the land value. It is important to note that, in late 2024, the Government of Ontario introduced a new property tax class for aggregates.
  • If you'd like to learn more about how we assess pit and quarry properties, our Methodology Guide for Pit and Quarry Properties provides greater detail.

2025 Aggregate Information Request 

  • In August 2025, MPAC launched a formal information collection process to better understand the activities undertaken on aggregate sites across Ontario to help inform the ongoing review of the property assessment and taxation system. For more information, visit mpac.ca/aggregates.   
  • MPAC has requested an overview of site details and a summary of the total site breakdown, including licensed, unlicensed, rehabilitated, and depleted sites. This information ensures MPAC has the most up to date information regarding the various activities undertaken on aggregate sites. 

Aggregate site assessments for the 2025 property tax year and beyond

  • On September 25, 2024, the Ministry of Finance filed Ontario Regulation 370/24 to amend Ontario Regulation 282/92 establishing a new property class called the Aggregate Extraction property class.  
  • MPAC has implemented the new property class for eligible land used in aggregate extraction, like gravel pits. Eligible property owners received an updated Property Assessment Notice from MPAC as part of the year-end Notice mailing in 2024 for the 2025 property tax year.  
  • We continue to work with property owners and industry partners throughout the appeal process and continue to engage with affected property owners, municipalities and industry to ensure they are aware of the changes.  

About MPAC

The Municipal Property Assessment Corporation (MPAC) is an independent, not-for-profit corporation funded by all Ontario municipalities and is accountable to the Province, municipalities and property owners. Our role is to value and classify all properties in Ontario in compliance with the Assessment Act and regulations set by the Government of Ontario.

  • We are the largest assessment jurisdiction in North America, assessing more than 5.6 million properties in Ontario, representing more than $3.1 trillion in property value.
  • Our assessments provide the foundation municipalities use to calculate the property taxes needed to pay for community services.
  • Our assessors are trained experts in the field of valuation and apply appraisal industry standards and best practices.
  • Our assessments and data have met international standards of accuracy and are relied upon by banks, insurance companies and the real estate industry.