Nutrifor Explained – How biosolids become manufactured soil

Nutrifor – Building New Soil out of Biosolids from Metro Vancouver on Vimeo.

Learn how waste is transformed into a usable resource with this look at the creation of Nutrifor. Over 750,000 tonnes of biosolids have been transformed into this manufactured soil since 1990, and used in a variety of applications across our region.

Annacis Island Waste Water Treatment Plant operator Craig Meyer holds some black, lumpy material in his hands. It looks a bit like asphalt or some kind of sticky soil.

“I’m holding in my hands some Class A biosolids. This comes from the digesters. After the sludge has been cooked for twenty days it goes to the dewatering building. This is about 70% water and 30% solids. These biosolids are really rich in nitrogen and phosphorus and other nutrients. We use it for old mining site reclamation and forestry projects.”

Another place biosolids were used extensively was in the building of the Annacis Wastewater Centre, a facility for research and technology trials related to wastewater, situated adjacent to the Annacis treatment plant, which is Metro Vancouver’s largest wastewater treatment facility.

Metro Vancouver Biosolids Project Coordinator Tania Gheseger stands in front a small hill of dirt, not far from the research building. A front end loader dumps sand and sawdust into a large soil mixing machine, as a conveyor belt transports the material to the top of the slowly growing pile.

“Behind me we’re mixing the biosolids soil, using sawdust and sand. We’re utilizing materials that were brought originally for preparing the site. So, we are using the preload sand as a component in the biosolids soil mixture and we also using locally sourced wood products as well. The biosolids themselves come from the Annacis Island Wastewater Treatment Plant.”

Michael Van Ham, Senior Environmental Scientist and President of SYLVIS Environmental scoops up a shovel full of the manufactured soil, crumbling it in his hands.

“This is the final product — biosolids growing medium containing biosolids from the Annacis plant. The biosolids in a fabricated soil are very useful and very unique in that because they originate predominantly from materials that we consume, the nutrients that are in the biosolids — the nitrogen, the phosphorus, the boron, the potassium, they are all in the right ratios and they have the concentrations that make them ideal for growing food again. And so, as a result, this growing media that contains biosolids can be used to grow vegetables, fruits, crops that we would eat.”

Recovering biosolids and using them to enrich soils in a wide variety of applications is one way in which wastewater becomes a valuable resource.

2 thoughts on “Nutrifor Explained – How biosolids become manufactured soil

  1. What is Harmful in the Sludge?
    1.) Persistent Organic Pollutants: Industrial chemical compounds such as PCBs and dioxins cannot be degraded and “persist” in the environment. They can bioaccumulate up the food chain as they are taken up by plants, which are in turn eaten by animals, which are in turn eaten by other animals. Many POPs are known to be carcinogens and have been implicated in endocrine, reproductive, and immune disorders.
    2.) Heavy Metals: Heavy metals such as lead, mercury, molybdenum, cadmium, and thallium – a toxin hazardous to humans in very small doses – can be taken up by plants in neutral and basic soils and poison both animals and people.
    3.) Harmful Pathogens: Some pathogenic bacteria, viruses, parasites, and fungi survive sewage treatment and thrive in the nutrient-rich sludge. These can include salmonella, campylobacter, listeria, hepatitis, diarrhea-causing protozoa, and parasitic worms that can lead to neurological problems and nutritional deficiencies. Because of the antibiotic residues commonly found in waste, sewage sludge is the perfect way to select for extremely hardy and antibiotic-resistant bacteria, which can be deadly.
    4.) Nanomaterials: Nanomaterials are used in several cosmetics, such as sunscreen, and enter sewage treatment plants when washed off in the sink or shower. Nanomaterials are physically distinct from their bulk counterparts and act in ways that are not yet fully understood. Exposure to nanomaterials can cause potentially devastating plant and animal harms and should not be released into the environment until fully assessed.
    5.) Hormones: Pharmaceutical residues from hospitals, animals treated to promote growth, and people on prescription doses for various reasons can also be found in sewage sludge. These hormones can act as endocrine disruptors and interrupt reproductive cycles, in rare cases leading to premature puberty and cancer.
    6.) Prions
    7.) CEC’s Contaminents of Emerging Concern
    (taken from Center For Food Safety

    • Metro Vancouver has been using biosolids safely and responsibly since the program’s inception in 1991.

      A good source for scientifically verifiable information regarding biosolids and biosolids recycling is the North East Biosolids and Residuals Association (NEBRA) website. NEBRA tracks research, legislation and regulations and provides information to its members and the public .

      Should you be interested in discussing further, Metro Vancouver staff welcome the opportunity to meet directly with individuals to have a conversation about biosolids (604/451-6613).

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