Things to consider: Alterations to soil have the potential to impact any connected water resources. These operations can affect water quality, as well as water movement and availability in the environment. Examples include: contaminated excess soil placed at a receiving site causing contaminants to leach into the water system; or a site alteration that changes soil permeability causing ponding and increased surface runoff.

The MOECC document Management of Excess Soil – A Guide for Best Management Practices (BMP) provides the following guidance: “all sites that receive excess soil to be used for a beneficial purpose should be constructed, operated and maintained in a manner that ensures the health and safety of all persons and prevents adverse effects or impairment of water quality within the meaning of the OWRA.” (Ontario Water Resources Act)1

The Ontario Water Resource Act, R.S.O. 1990, c. O.40, governs operations that impact water resources and provides authority for officials to inspect water quality and quantity at location without warrant or court order.


See the Definitions Page for standard definitions relevant to any site alteration or fill by-law


Things to consider: Municipal by-laws may contain specific prohibitions to prevent adverse effects to water quality as a result of site alterations. For example, the language below includes the following prohibition related to water quality:

“No person shall perform, or cause or permit to be performed, any site alteration that may adversely affect the quality or quantity or water in a well, pond or watering hole intended for use as a source of water for agriculture or human consumption on a property with an adjoining property boundary, or any other property.”2


Things to consider: Some municipalities also prescribe specific requirements to protect water quality as conditions of a permit agreement.

For example, the by-law language below permits requirements for large fill operations (volumes greater than 5000 m³ or where the resulting proposed elevation will be greater than 0.5 m above or below the original grades) to include the following requirements:

“provide a report from a Qualified Person that he/she is satisfied that the site alteration will not result in: adverse erosion and environmental impacts on and off-site, as confirmed in writing by the Qualified Person; blockage of a swale, ditch or watercourse; siltation in a watercourse, wetland or storm sewer; transportation of silt to adjacent, neighbouring or downstream properties; pollution of a watercourse; flooding or ponding of adjacent lands; flooding or ponding caused by a watercourse overflowing its banks; detrimental effect on the quality or quantity of water in wells detrimental effect on matters of inherent sensitivity such as, but not limited to, aquifer recharge, soil permeability, water quality and wildlife habitat; detrimental effect on the natural environment, including but not restricted to lands designated as Environmentally Sensitive Areas, Lake Ontario shoreline, Burlington Bay / Hamilton Harbour Shoreline, Niagara Escarpment and Areas of Natural or Scientific Interest and habitat of endangered or threatened species as identified and defined by the Ministry of Natural Resources; detrimental effect within 120 metres of a Provincially Significant Wetland identified by the Ministry of Natural Resources and wetlands regulated under Ontario Regulation 162/06; contamination of, or the degradation of the environmental quality of land.”3

As another example, the language below indicates that for large fill operations (when greater than five hundred (500) cubic metres of fill is being placed or …a change to existing landform of greater than six hundred (600) millimetres from the existing grade), the permit agreement may include the following terms related to water quality:

“provide a report from the qualified person that he/she is satisfied that the site alteration will not result in:
  1. soil erosion;
  2. blockage of a watercourse;
  3. siltation in a watercourse;
  4. pollution of a watercourse;
  5. flooding or ponding on abutting lands;
  6. flooding or ponding caused by a watercourse overflowing its banks;
  7. […]
  8. detrimental effect on matters of inherent biological sensitivity such as, but not limited to, aquifer recharge, water quality, unusual plants or wildlife and overwintering habitats;
(g) undertake soil samples and well monitoring, the frequency of which shall be determined by the Director, at the applicant's expense;”4

The key difference in the second example is the requirement for soil samples and well monitoring for large scale operations. This may be included in fill management plans or specific requirements for large site alteration agreements.

See Fill Management Plan and Large Scale Alteration Agreements pages for more information.