It was only fifty years ago when thousands of North American cities dumped raw sewage directly into water bodies. A growing body of evidence on the risks of this practice to both human health and the environment led to a surge in legislation on water pollution.
The rapid proliferation of such regulatory controls on wastewater treatment plants (WWTPs) resulted in growing attention on alternative applications for biosolids generated in WTTPs .
A key North American regulatory reform occurred in 1972 when the US amended their Federal Water Pollution Control Act in order to place further restrictions on the discharge of wastewater to waterways whilst encouraging other disposal methods such as land application of biosolids. Biosolids are defined by the US Environmental Protection Agency (EPA) as “the nutrient-rich organic materials resulting from the treatment of sewage sludge.”Further incentives to find alternatives to disposal included additional restrictions on typical options such as legislated Ocean Dumping Bans and increasing costs of incineration or landfill disposal.
The convergence of the above two policy approaches opened the door for WWTPs across North America to explore how biosolids can be treated safely for responsible land application as fertilizers. Over 10 million dry tonnes of biosolids are generated annually at municipal WWTPs in Canada and the US alone. Such quantities offer a compelling reason for WWTPs to evaluate how they can generate additional value streams to their core business. Biosolids treated in accordance with federal and/or state/provincial regulations can be used as fertilizer to enhance plant growth and maintain productive soils in agricultural, residential and even mining site regeneration applications. Read more »