Biosolids: guide to reporting

This document will help wastewater treatment facilities report to the National Pollutant Release Inventory (NPRI). This includes municipal, institutional and industrial facilities.

Insoluble material removed from wastewater treatment processes are referred to as "biosolids". Biosolids can contain organic materials, nutrients, pathogens, metals and organic chemicals. Some of these are NPRI substances. For NPRI purposes, biosolids (and the NPRI substances in the biosolids) are considered waste and are not an intentionally produced product. Wastewater treatment facilities must report the releases, disposals and transfers of NPRI substances in biosolids.

The main categories under which facilities may be required to report substances in biosolids are:

  • on-site disposal
  • off-site disposal
  • off-site transfers for treatment
  • off-site recycling
  • on-site air releases – to be considered if biosolids are incinerated on-site

Disposal of biosolids

Facilities may dispose of biosolids to an on-site landfill or for on-site land treatment (that is, land application or land farming). Facilities can also transfer biosolids off-site for land treatment, incineration, landfill, storage or for treatment prior to final disposal. Report all of these activities under “Disposals”.

Recycling of biosolids

Facilities may transfer biosolids off-site for recycling where they are treated or processed into compost or other products. Report these under the "Recycling" activities in the "Other” category.

Composting of biosolids

Compost of various grades can be produced from biosolids.  Compost that meets the Canadian Council of Ministers of the Environment (CCME) guidelines for category A compost is considered a product for the purposes of the NPRI. All other forms of compost should be reported as transfers for recycling.

Remember to report all NPRI substances in a particular stream in the same way. For example, if you send biosolids to a landfill, report the NPRI substances in the stream as a disposal (even if the product meets CCME category A compost guidelines). If you send the material for recycling into compost, report all NPRI substances in the stream under recycling.

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