Cows in a field

Credit: Kas Stone

By Margaret Webb

You can add two new words to that catchy Foodland Ontario jingle “Good things grow in Ontario”: “sewage sludge.” It is hardly appetizing – or safe, according to a growing number of critics.

Once considered a waste-disposal problem, potentially toxic sludge has received an image makeover to that of a beneficial fertilizer. Effective January 11, 2011, the provincial government will shift regulation of the agricultural application of sludge – under the Nutriment Management Act – from Ontario’s Ministry of the Environment to the Ministry of Agriculture, Food and Rural Affairs (OMAFRA).

Annually, the province generates some 300,000 dry tonnes of biosolids, the semi-solid matter from household, medical and industrial waste that flows into municipal sewers and sewage treatment plants, along with pulp and paper industry waste. Municipal waste treatment plants are responsible for testing biosolids destined for farmland to ensure that the levels of pathogens and 11 metals they contain are below regulated levels. But sewage contains many more metals, as well as thousands of chemicals, pharmaceuticals, viruses and parasites that are not tested, and critics are concerned about how that stew may affect soil organisms, wildlife and waterways.

Nevertheless, on its website OMAFRA is promoting this dubious slurry to farmers as a “valuable nutrient source.” With the cost of synthetic fertilizers skyrocketing, sludge – often provided free – is smelling better for farmers growing industrial cash crops, such as corn and soybeans, which feed livestock and are used in about 75 percent of our processed foods.

But citizens’ groups that have formed across the province are determined to stop the spreading of sludge on farmland, believing that sludge is contaminating soil, water and food. The National Farmers Union and Ecological Farmers of Ontario have called for an end to the practice.

Brant County farmer and environmental health researcher Ella Haley was distraught to see sludge from Kitchener applied to her neighbour’s farm over a period of three days. “There’s very little oversight going on. We found that the applicator had inadequate maps [for setbacks from waterways] and that two of the tested metals were higher than regulated levels, but they were marked as acceptable. I look at scientific uncertainty. When you don’t know what’s in sludge, you follow a precautionary principle. Really, I don’t know if farmers realize they’re contaminating their land.”

Wendy Deavitt is currently suing the town of Coburg and the farmer who spread sludge around her three-hectare country property. She became severely ill, as did her children, horses and dogs, after the sludge contaminated her well. She and her husband were unable to sell their home and have since walked away from it. Deavitt’s physician is treating several other families in the area who have also suffered illnesses believed to be related to the spreading of sludge. Says Deavitt, “My doctor asked if I worked in a paint factory, my lead levels were so high. She told me my immune system was under attack.”

For all the opposition, Tom Hutchinson, a professor of environmental sciences at Trent University, who has studied heavy metals in biosolids, says that this contentious issue includes the danger of “throwing the baby out with the bathwater. There is a conservation aspect … We’re returning low-level nutrients and fibre to the soil and that’s better than using inorganic fertilizer. The problem is contaminating the good stuff [the human manure portion] with industrial waste.”

Currently, alternatives to spreading sludge include putting it in landfills,incinerating it and breaking it down by means of anaerobic digestion, which can produce a biofuel. Says Sludge Watch coordinator Maureen Reilly, “Putting industrial sludge on farmland is not responsible recycling.”