The National Film Board documentary 'Crapshoot': The Gamble with Our Wastes is available for viewing or purchase from the National Film Board.
Over the past ten years, more and more industries have been allowed to put their industrial liquid wastes on agricultural lands as a kind of 'soil conditioner'.
Where sewage treatment plants receive industrial wastes into the sewer systems, many provinces and territories now allow these wastes to be spread on farmland and rural lands under provincial
waste management permits.
Lately some municipalities and industries have tried to characterize these residual wastes as 'fertilizer' products to avoid provincial waste management requirements.
The heavy metals, chemicals, toxins, pathogens, and decomposed byproducts from these sludges can imbalance the soil, contaminate crops, harm wildlife and domestic animals, and pollute groundwater and surface waters. Papermill sludge can contain chemicals and components that reduce crop fertility and may cause reproductive difficulties in animals and people.
A study entitled, Interactions of pathogens and irritant chemicals in land applied sewage sludges (bio-solids) has been published in the peer reviewed journal BMC Public Health.
Industry should be responsible for the appropriate treatment and disposal of its wastes and municipalities should explore sustainable approaches to sanitation.
In the short run, composting and landfilling of sludge is preferable to agricultural use. In the long run, green builders and renovators should be encouraged to use composting toilets that are sparing of water sources and do not mix human toilet wastes with industrial chemicals. Source separation is the most environmentally sustainable approach. There are also some green renewable energy technologies for processing sludges.
Sierra Club Canada joins the Canadian Infectious Disease Society in calling for a moratorium on the land application of sewage sludge.