Stop! That poo can be put to good use.

In other parts of the world, biosolids (human waste) from sewage treatment plants are treated and used as sustainable agricultural fertilizer. Research the pros and cons of this method and take a stand on whether this can be a realistic alternative to our current agricultural practices. Who are the potential stakeholders in this issue? Are we influenced by the western view of human waste as an unsanitary and disgusting nuisance?

Have you given thought to where your personal waste ends up after you flush the toilet? I know I have. Sorry if that's too much information! Does our waste just end up in the middle of no where? Can you imagine a pile of real crap, collected, in the middle of flat land?How about in the oceans? That is one imagine that would be horrible to view. As citizens we need to know how waste water is treated, and how biosolids are created.

What are biosolids? That is the first question that needs to be answered before I can contribute my two cents for this bio-blog. Biosolids are nutrient-rich organic materials resulting from the treatment of domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth.

Any water that is flushed down the toilet, through the drain, or through the shower is classified as wastewater. The wastewater travels away from its original location through a series of underground pipes. These pipes have been organized and designed by the government to allow the water to go through a filtration process. Solids, chemicals, feces, and any other undesirable material is cleaned from the wastewater, before it enters Lake Ontario. These pipes stretch for about 9 000 kilometers in total. Without treating the wastewater, bodies of water, as well as drinking water will be contaminated.

Due to Ontario's vast and concentrated population four wastewater plant treatments plants are essential: Ashbridges Bay Wastewater Treatment Plant, Highland Creek Wastewater Treatment Plant, Humber Wastewater Treatment Plant, and as well as North Toronto Wastewater Treatment Plant. Through a series of physical and chemical processes water quality expectations are achieved.

Process of Water Treatment in Toronto
1) Water travels through a series of pipes with various bar screens, disabling large objects from passing through. Items such as tree branches or rocks will be stopped at this step. After water passes the bar screen, it slows down and enters a grit tank, where debris settles at the bottom of the tank. The waste that is divided through these steps is disposed of in a landfill.

2) Water is held in another tank for several hours where more waste in the water settles at the bottom.

3) Oxygen is added to a tank of water. This addition provides an environment allowing for the growth of micro-organisms. These micro organisms eat small bits of organics, resulting in a mixture of solids with micro-organisms. This mixture then travels to a clarifier, where solids settle to the bottom

4) The wastewater, which is hardly waste at this step is finally disinfected using chlorine. Chlorine is used to kill harmful pathogens before it enters Lake Ontario.

5) All the solids that have settled to the bottom of the water tanks are sent to the digester. Micro-organisms use organic material in the solids as food and convert it to methane gas which is used to produce electricity and heat at the plant. After 15 days, the biosolids (a wet soil-like material), high in organic content and nutrients, such as nitrogen, and phosphorous can be beneficially reused as fertilizer, incinerated or sent to landfill.

In learning about the water treatment in Toronto, I observed how biosolids (human waste) from sewage treatment plants are indeed treated and used as sustainable agricultural fertilizer. In conducting this bioblog, I had certain expectations, thinking that Toronto did NOT use biosolids. Through research it is clear that this is not that case.

195 000 tones of biosolids is generated from the users of the Toronto wastewater system. Seventy seven percent of Toronto biosolids are treated at the Ashbridges Bay Treatment Plant and the other twenty three at the Highland Creek Treatment Plant. Biosolids can be reused and disposed of in a variety of methods including at landfills, used for incernations, for land applications, pelletization, alkaline stabalization, as well as site remediation.

THE PROS
It is obvious that the use of biosolids is very useful in terms of effective fertilizers. Instead of storing the biosolids in a landfill site, the biosolids can instead benefit the environment and the soil especially. Biosolids are a possible substitute for chemical fertilizers, which will be extremely beneficial in regards to the environment. It is obvious that the health of our Earth is very fragile at the moment, so every precaution will make a difference. Farmers do save money by using biosolids, due to the elimination of chemical fertilizers. Excess application of chemical fertilizers do eventually seek through the ground into the groundwater, streams, lakes and eventually oceans thanks to the rain and irrigation, creating hazards. The excess application results in pollution and damage to the natural environment. It has been questioned whether or not the growth of agriculture is equivalent in using chemical fertilizers or biosolids, and it seems as if it is. After all, biosolids are rich in organic content and nutrients, such as nitrogen, and phosphorous. They also contain elements such as magnesium, calcium, copper, iron, manganese, sulfur and zinc. Biosolids are also sometimes applied to forest land and tree nurseries. Application to strip mines can also help reclaim and vegetate the land. Numerous studies completed over the years have shown that biosolids land application is safe and has significant benefits.

THE CONS

The cons of using biosolids include the odour that it gives off due to their composition of sulphur and ammonia, important nutrients for plants. The smell of biosolids is very distinct and may aggravate individuals. The smell can be toned down by managing techniques, but this will not fully rid the smell. Another con to the use of biosolids is the presence of metals that are seen in biosolids. Excessive amounts of metals will pose a dilemma in regards to the health of animals and plants. The presence of pathogens is a concern to health officials, as they can rupture the presence of diseases in communities.

Whose choice is it?

The stakeholders in this issue include government officials, farmers, and gardeners. Neither the Minister of Health nor the Minister of Environmental Concerns view biosolids as having a significant negative impact in the well-being of the community or the environment. Farmers decide on the techniques they use for the development of their agriculture. The same goes to gardeners. The bottom line is that each and every person is a steward of the Earth, and each and every one of us are privileged with a voice, a voice that should be used and put to work to benefit society.

Works Cited:
http://en.wikipedia.org/wiki/Biosolids

http://www.toronto.ca/water/biosolids/index.htm

http://www.cwwa.ca/faqbiosolids_e.asp

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