As we know, when humans intake any source of food, the food will one day leave the body. Have you ever wondered what happens to the excreted waste? Most people probably just think that it takes a trip down the toilet, into some pipes, into the sewage and into a lake or river. This is true in some ways, but little do people know that some of the waste is actually being treated and recycled as fertilizer! GROSS…may be the first reaction of many. It does indeed sound very “gross”, however putting that aside, there are many benefits to the use of biosolids. Although that may not necessarily mean that there are no negative aspects, the benefits far exceed the negatives.
Cities in Canada u
sed to dump their raw sewage sirectly into the rivers, lakes and other bodies of water. In fact, some cities still do so today. This is very polluting to the waters and is extremely hazardous to the animals that live there. Also, our tap water/drinking water comes from these sources, so this is potentially harmful to humans as well. Canadian cities are now required to treat the wastewater by separating the water and the waste at wastewater treatment plants. Now that the water is safer to release into the waters, what happens to the solids left behind? In 2008, 41% of biosolids in Toronto ended up in landfills (look to the pie chart above). This takes up a lot of disposal space and can even be considered a waste, no pun intended.
In many parts of the world, biosolids are returned back to the environment for agricultural purposes. People of the western world may view this as unsanitary and disgusting, but that’s only judging a book by its cover. Biosolids have been proven to be, for the most part, environmentally safe. They are definitely less pollutant than animal manure and chemical fertilizers and so far have had no significant risks to the environment or human health. What can these biosolids do for our environment other than make more space for other landfills? The answer is ‘plenty’.
Biosolids actually contain rich nutrients such as nitrogen, phosphorus and many other micronutrients like copper, boron, zinc and iron. Due to the fact that our bodies do not absorb all the nutrients that enter, much of it is excreted through the waste. These nutrients are essential for plant growth and helps maintain the soils healthy. The organic material of biosolids serves as a conditioner for the soil, which promotes dense healthy roots and allows the plants to take up nutrients better. They also bind the soil particles so that there is better soil texture (reducing erosion) and better water holding capacity. The nutrients of biosolids are less water-soluble, so they are less likely to filter into underground or be carried away by surface waters. This way, they will stay with the roots and can be used up by the plants.
Although biosolids have been so far been labeled as safe, there are still potential do
wnsides. Due to the fact that biosolids are in fact human waste, there can be, although not so severe, health hazards. If, and I say if, these biosolids do indeed cause harm, their effects would not be reversible because once they are applied to the area, they cannot be taken out. As mentioned before, biosolids contain many metal elements, which cause another concern of these metals accumulating in the long-run. These long-term effects may be a big problem to the land as well as humans and animals who may consume the vegetation grown from biosolids. Lastly, one of the main reasons to why people oppose the use of biosolids is the odour. We all know how horrible human waste can smell, so how can we even imagine using it not as fertilizer for our food? Maybe even the thought of eating food grown from human waste can take away someone’s appetite.
These negative aspects of biosolids are just some major concerns of people. Since biosolids have already been approved by the Environmental Protection Agency, they shouldn’t be much of a problem. The pros of biosolids definitely outweigh the cons, so we should just put our negative thinking aside and give them a chance. Think about it, by using biosolids we get nutrient-rich fertilizer for our agricultural purposes, we can reduce landfills and save a whole load of money spent on disposing them in landfills and buying chemical fertilizer which isn’t even good for the environment at all. In the year of 2008, only 11% of Toronto’s biosolids have been returned back to the land (refer to chart above). I think our city can definitely do better than that!
Cities in Canada u
sed to dump their raw sewage sirectly into the rivers, lakes and other bodies of water. In fact, some cities still do so today. This is very polluting to the waters and is extremely hazardous to the animals that live there. Also, our tap water/drinking water comes from these sources, so this is potentially harmful to humans as well. Canadian cities are now required to treat the wastewater by separating the water and the waste at wastewater treatment plants. Now that the water is safer to release into the waters, what happens to the solids left behind? In 2008, 41% of biosolids in Toronto ended up in landfills (look to the pie chart above). This takes up a lot of disposal space and can even be considered a waste, no pun intended.
In many parts of the world, biosolids are returned back to the environment for agricultural purposes. People of the western world may view this as unsanitary and disgusting, but that’s only judging a book by its cover. Biosolids have been proven to be, for the most part, environmentally safe. They are definitely less pollutant than animal manure and chemical fertilizers and so far have had no significant risks to the environment or human health. What can these biosolids do for our environment other than make more space for other landfills? The answer is ‘plenty’.
Biosolids actually contain rich nutrients such as nitrogen, phosphorus and many other micronutrients like copper, boron, zinc and iron. Due to the fact that our bodies do not absorb all the nutrients that enter, much of it is excreted through the waste. These nutrients are essential for plant growth and helps maintain the soils healthy. The organic material of biosolids serves as a conditioner for the soil, which promotes dense healthy roots and allows the plants to take up nutrients better. They also bind the soil particles so that there is better soil texture (reducing erosion) and better water holding capacity. The nutrients of biosolids are less water-soluble, so they are less likely to filter into underground or be carried away by surface waters. This way, they will stay with the roots and can be used up by the plants.
Although biosolids have been so far been labeled as safe, there are still potential do
wnsides. Due to the fact that biosolids are in fact human waste, there can be, although not so severe, health hazards. If, and I say if, these biosolids do indeed cause harm, their effects would not be reversible because once they are applied to the area, they cannot be taken out. As mentioned before, biosolids contain many metal elements, which cause another concern of these metals accumulating in the long-run. These long-term effects may be a big problem to the land as well as humans and animals who may consume the vegetation grown from biosolids. Lastly, one of the main reasons to why people oppose the use of biosolids is the odour. We all know how horrible human waste can smell, so how can we even imagine using it not as fertilizer for our food? Maybe even the thought of eating food grown from human waste can take away someone’s appetite.
These negative aspects of biosolids are just some major concerns of people. Since biosolids have already been approved by the Environmental Protection Agency, they shouldn’t be much of a problem. The pros of biosolids definitely outweigh the cons, so we should just put our negative thinking aside and give them a chance. Think about it, by using biosolids we get nutrient-rich fertilizer for our agricultural purposes, we can reduce landfills and save a whole load of money spent on disposing them in landfills and buying chemical fertilizer which isn’t even good for the environment at all. In the year of 2008, only 11% of Toronto’s biosolids have been returned back to the land (refer to chart above). I think our city can definitely do better than that!
Sources:
Biosolids Benefits
<http://www.biosolids.com/benefits.html>
Biosolids: Fertilizer or Pollution?
<http://www.sencer.net/Outreach/pdfs/DCSymposium08/Posters/LUbiosolids.pdf>
Biosolids Management
<http://www.toronto.ca/water/biosolids/index.htm>
FAQ - Biosolids
<http://www.cwwa.ca/faqbiosolids_e.asp>
Commented on:
Jenny Yeung - Biosolids
Priscilla Chen - I'm all for recycling, but human waste?
