Management of Organic Waste and Fertilizing Residuals (FR)

UDA offers management services for organic and inorganic waste through agricultural or silvicultural valorization or composting. Our clients include waste generators (businesses, industries, municipalities, etc.), as well as potential users (farmers, tree nurseries, topsoil manufacturers, etc.). Being either for sporadic disposal or for the development and implementation of a permanent management program, UDA can assist its clients in every step of such projects. Also, UDA is regularly involved in the characterization and assessment of new types of waste or residues, in research and development, in the classification of FR odour within predetermined categories and in the treatment of FR for valorization purposes. The firm is frequently invited to comment, analyze or submit suggestions with respect to the FR regulation.


  • Characterization of organic or inorganic waste and residues;
  • Technical or administrative feasibility of a valorization project;
  • Requests for certificate of authorization from the Ministère du Développement durable, de l'Environnement et de la Lutte contre les changements climatiques (MDDELCC);
  • Relations/communications with municipalities and residents in the neighbourhood of projects;
  • Research of potential receivers;
  • Farms potential analysis;
  • Spreading surveillance;
  • Management of the various valorization operations;
  • Research and development;
  • Olfactometric tests for the classification according to odour categories.

Typical projects : Management of Organic Waste and Fertilizing Residuals (FR)


Liming of Biosolids

When certain types of residues and biosolids became available for agricultural valorization at the end of the 80’s, it was observed that some wastes were nasty in terms of odours, and that others could present a risk in terms of pathogenic content. In order to identify a solution addressing both concerns, UDA conducted various tests, in a laboratory as well as under operating conditions, using lime (slacked and quick) for the treatment of those fertilizing residuals.

Several projects have been implemented for the treatment of slaughterhouse sludge as well as municipal wastewater sludge, in order to verify the hygienization and odour control level achievable with this liming technique at pH 12.

Based on these different R&D projects, the liming technique has been used for more than 25 years in Quebec and is now part of the MDDELCC Guideline for the valorization of fertilizing residuals (FR).

Fertilizing Residuals (FR) Management Program

For over 25 years, UDA has been mandated to develop and implement residual waste management programs through agricultural valorization. For example, in the case of sludge or liquid residues, UDA assists companies in finding storage locations and receivers. The activities include the obtention of the required certificate of authorization, assessment of waste compliance, preparation of the fertilization program, and management of  intakes and offtakes, so that the whole valorization program can be executed on a continuous basis without affecting the operations of the production plants. In some cases, management may include a treatment stage to ensure that the waste complies with the agricultural valorization requirements, including pathogenic and odour level.

Each year, UDA manages FR valorization programs for some 12 generators from various sectors, including the agri-food industry, municipalities and residential septic sludges collectors.

Assessment of Residual Wastes

UDA receives various mandates to determine the agricultural potential of a specific waste, either organic or inorganic. Therefore, UDA assists the client in characterizing the waste, evaluating pros and cons for agricultural purposes and verifying their characteristics according to the requirements of the “Guideline for the valorization of fertilizing residuals (FR)” stipulated by the MDDELCC.

In some specific cases, it will be required to perform demonstration projects in real situation or laboratory tests in order to confirm or refute the information reported in the literature. Once these steps are completed, UDA assists the waste generator in obtaining the specific authorizations, if required, for agricultural valorization, or for other solutions.

Valorization of Biomass in Wooded Area

UDA was involved in the development of a “Guidelines” document for agricultural and silvicultural valorization of forest industry residues (Quebec Association of the Forest Industry). The firm also participated to prefeasibility studies for valorization of residues in wooded areas (Maclaren Industries, Abitibi-Consolidated), annual environmental monitoring of a valorization project in wooded area (Smurfit-Stone) and a R&D project associated with the valorization of wastewater treatment plant residues in a wooded area (exploratory environmental projects for the Quebec Ministry of Environment and Fauna).