Is land application safe?
Land application of biosolids is considered a safe practice in Ontario when managed in accordance with the Nutrient Management Act (NMA), O.Reg 267/03. The NMA was developed by the Province of Ontario to provide for the management of materials containing nutrients in ways that will enhance protection of the natural environment and provide a sustainable future for agricultural operations and rural development. Excessive amounts of nutrients, which are present in biosolids, fertilizer and manure, can produce negative impacts on the environment. Despite over 30 years of research which show that, when conducted according to regulations, land application of biosolids is safe, concerns remain over soil and groundwater contamination from trace elements, toxic chemicals and potentially harmful disease causing organisms (pathogens). To date, there have been no documented negative human cases where a biosolids program met all the provincial requirements. The NMA provides specific requirements for nitrogen, phosphorus, metal and pathogen concentrations that must be met before biosolids can be land applied. Finally, odours associated with the land application of biosolids are considered more of a nuisance than a health problem. Odours are often times the most objectionable aspect of biosolids use on neighbouring farms.
All restrictions are conservatively set to prevent toxicity or health impacts in plants, animals and humans.