Presentation on theme: "Toxic Sludge is Good for Farmland Kelly Lavery and Ella Haley Athabasca University"— Presentation transcript:
Toxic Sludge is Good for Farmland Kelly Lavery and Ella Haley Athabasca University
Sustainable recycling of sewage sludge? Point 7a of the Earth Charter – “Ensure that residual waste can be assimilated by the ecological system”(1). Municipalities and industry call land application of sewage sludge ‘recycling’ However, according to the US Federal Clean Water Act, sewage sludge is a pollutant(2).
What are biosolids? The term “biosolids” is industry’s term for sewage sludge. The term “biosolids” is not in the federal US sewage regulations Part 503 or the Canadian Federal Fertilizer Act.
Halifax’s situation In the late 19 th century, sewers replaced outhouses. Halifax Regional Municipality (HRM) discharges its sewage directly into the Halifax Harbour with little treatment. Raw sewage destroys the aquatic environment The Habour Solutions Project involves the construction of three new wastewater treatment plants to treat sewage waste.
Adding Toxins to sewage sludge N-Viro is a US multinational corporation that processes sewage sludge for municipalities and industrial customers (1). N-Viro will mix Halifax’s sewage sludge with cement kiln dust or lime and dry the mixture. N-Viro plans to sell this sewage sludge mixture as Class A fertilizer.
Contaminants in sewage sludge 4 key categories of contaminants: pathogens, heavy metals, chemicals, pharmaceuticals Waste water treatment plants are not designed to remove heavy metals or toxic chemicals. They don’t do a very thorough job of eliminating pathogens either. In Canada, only 11 heavy metals are regulated: lead, mercury, copper, molybdenum, nickel, zinc, cadmium, arsenic, selenium, chromium and cobalt. Land applied sewage sludge is regulated province by province.
Nova Scotia Regulations Maximum Acceptable Metal Concentrations Biosolids (mg/kg of dry weight) MetalEQ QualityClass A/B Arsenic1375 Cadmium320 Chromium Cobalt34150 Copper Mercury0.85 Molybdenum520 Nickel62180 Lead150500
Nova Scotia Regulations Maximum Acceptable Metal Concentrations Biosolids (mg/kg of dry weight) MetalEQ QualityClass A/B Selenium214 Zinc
Ontario’s Slacker Regulations Metal Mercury Molybdenum Nickel Lead Selenium Zinc Maximum Concentration Mg/kg solids Typical Concentration Mg/kg solids
Processing sewage sludge sewage treatment plants reduce pathogens to a certain extent. E.coli can survive the treatment process and gets reactivated in soil (1).
Nova Scotia’s regulations for “biosolids” If the material is given away, the NS Dept of Env’t and Labour analyze soil samples to determine levels of pathogens and heavy metals. If the material is sold, the Canadian Food Inspection Agency randomly checks to see that the label is accurate.
Pathogens in sewage sludge “Exceptional quality (EQ) and class A biosolids” can contain a certain level of fecal coliform or salmonella. The accepted level of fecal coliform increases by 2000 times in “Class B biosolids.” What about all the other pathogens?
Industry PR The word “biosolid” was created by a PR firm for the sewage sludge industry(1) Industry and US EPA government officials have minimized the risk of sewage sludge Industry hired scientists are also being used to defend the safety of sewage sludge.
Dumping Sludge on Farmland is a cheap, quick fix US and Canadian municipalities have a history of dumping sewage sludge into waterways. To stop ocean dumping key US environmental groups supported the land application of sewage sludge.
Lack of Independent science Whistleblower Dr. David Lewis is a internationally known senior research scientist. Lewis used to work for the EPA until he started researching the health complaints and deaths associated with sewage sludge exposure.
Clip from Sludge Diet Dr. David Lewis
Precautionary Principle If we suspect that a practice or policy is an environmental health risk, than it is better to err on the side of caution in order to protect public health and the environment.
Reverse Onus The onus to prove that sewage sludge is safe for farmland should fall on government officials, and industries that are dumping contaminants down the sewer.
Safer sewage disposal Separating residential waste from industrial waste would make treating sewage waste much easier. Composting toilets
Environmental Justice Health Movements Sludge Watch-Maureen Reilly Farmers groups: Ottawa Citizens Against Pollution by Sewage, NS Federation of Agriculture, National Farmers Union The Concerned Citizens of RR#1 Truro
Policy Implications for Sustainability Activist scientists, environmental health justice groups and some policy makers are questioning the dumping of sewage sludge on farmland. Several European countries (Switzerland, Sweden) have banned the application of sewage sludge on farmland.
How does your community dispose of sewage sludge? Think about it the next time your flush the toilet