The Operational Standards contained in the Aggregate Resources of Ontario: Provincial Standards Version 1.0 set out minimum rehabilitation requirements. However, it may be appropriate to enhance or vary these requirements on a site-specific basis to achieve higher quality rehabilitation to meet objectives such as:
- restoration to former use or condition
- compatibility with surrounding land uses, including aesthetics
- agricultural productivity/soil capability
- encouraging biodiversity
- meeting the requirements of the Oak Ridges Moraine Conservation Plan, and/or
- meeting the requirements of the Greenbelt Plan.
The primary objective in rehabilitating land is set out in the legal definition: to restore the land to its former (or compatible) use or condition. Unless bound by other rehabilitation requirements, such as prime agricultural land being returned to agricultural use, there may be opportunities to encourage proponents to have regard for biodiversity values. Consideration should also be given to whether the final appearance of the rehabilitated area will be pleasing, and whether it will be compatible with the surrounding landscape.
Milton Quarry rehabilitation
Photo courtesy of Dufferin Aggregates
The Niagara Escarpment Plan, the Oak Ridges Moraine Conservation Plan and the Greenbelt Plan have additional rehabilitation requirements for aggregate operations. Municipal official plans may also guide rehabilitation towards certain after-uses.
There are many factors that affect rehabilitation requirements for pits and quarries throughout the province. These include the quality and quantity of topsoil present, the climate, whether the site is a pit or a quarry, and the intended future use of the site. The Operational Standards for licences, wayside permits and aggregate permits outline minimum sloping requirements of 3:1 for pits and 2:1 for quarries. However, diversity, variability and creativity in landscape design should be encouraged.
The following are examples of rehabilitation requirements appropriate to particular future uses of sites:
- Extraction below the water table with proposed rehabilitation to include fish habitat could require spawning, rearing and feeding zones. These cannot be accomplished by simply requiring 3:1 sloping.
- Pit slopes that are more gentle than 3:1 could be encouraged when rehabilitating a site to an agricultural use, recreational use or forestry use.
- In some situations it may be appropriate to retain partial sheer quarry walls with talus slopes of loose rock or a series of benches as part of the rehabilitation plan, rather than requiring 2:1 slopes, in order to create a more natural escarpment topography and encourage greater plant and animal diversity.
