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 as to 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?
What are biosolids?
Biosolids, also known as sludge, is the organic by-product of sewage water treatment. They contain essential plant nutrients and organic matter, which allows it to be recycled and used as a fertilizer.
Pros
There are many benefits that come along with using biosolids as fertilizer. Sewage biosolids are rich in nitrogen and phosphorus, as well as important micro-nutrients such as copper, iron and zinc. These micro nutrients make biosolids a good fertilizer because it allows the pants to grow and the soil to be rich. Sewage biosolids are particularly good for growing crops such as corn, soy beans and canola. They also improve pasture. This in turn reduces the need for commercial fertilizers that can have harmful chemicals, reduces production costs and does wonders for the soil.
Biosolids, as mentioned before, improve the fertility of the soil, enhance the soil structure, moisture retention and reduce the chance of soil erosion and runoff. Not only do biosolids help the crops and soil, but it also helps the farmers. Instead of purchasing micro-nutrients, nitrogen, phosphorus and other resources needed to grow their plants; farmers can save money by using biosolids that naturally come with all those things. An additional benefit is that by using biosolids on agricultural lands, municipalities are able to recycle a treatment process by-product in a cost effective manner. Lastly, society in general gets to reap the benefits. As a result of biosolids as fertilizers, reduced pressure of costs to provide sewage treatment, revitalizing used up soil resources and keeping farmers in business are rewarded to society.
Cons
Although there are many obvious benefits from using biosolids as land fertilizers, there are still concerns surrounding the process. One small example is the public concern for the odor of biosolids. One other example is the concern about contaminants in biosolids. Many studies have identified heavy metals, organic pollutants and pesticides in many samples of biosolids. Also, although metals such as zinc and copper are necessary for plant growth, some metals in large quantities can cause problems with animal health and plant growth. Biosolids also contain nitrogen and phosphorus, which in excess can move into groundwater or surface water causing problems for animals. There are also concerns surrounding the amount of pathogens in biosolids. Pathogens are infectious agents, or germs, that cause disease to its host.
Regulations
There are many steps to be taken and requirements to be fulfilled before sewage biosolids are allowed to be used for land application. One of the many examples is the regulations and protocols under the Nutrient Management Act. This act describes the standards that must be fulfilled in order to use sewage biosolids as a land fertilizer.
• Government approval of the treatment processes
• Laboratory analysis of the sewage biosolids
• Receiving soils to ensure that they meet the standards
• Government approval of the fields that receive sewage biosolids and the application procedure
• Government certification and licensing of persons involved in preparation and land application
• Detailed record-keeping
Conclusion
I think that sewage biosolids is a realistic alternative to current agricultural practices. Personally, I think that the benefits of sewage biosolids outweigh the disadvantages. Yes, there are risks, but what doesn’t come with risks. Using biosolids as a land fertilizer is not only better for the land, but for society as well. It allows farmers to stay in business and make a living and helps society. Although there are many concerns surrounding this subject, I think it is a safe method. There are many steps that go into using biosolids as a fertilizer. There are tests, licenses, certificates, approvals and standards that must be met. They are only permitted to be used a fertilizer if it is proven that it is safe and does not contain any contaminants and pathogens. Therefore, I think sewage biosolids should be used as fertilizer. Although it may seem unsanitary or disgusting to use biosolids as fertilizer, we have to look past the first thing that comes to mind and actually think about the benefits.
www.atlantawatershed.org/glossary/glossary.htm
http://www.omafra.gov.on.ca/english/nm/nasm/sewbiobroch.htm#1
http://www.durhamsap.ca/works.asp?nr=departments/works/sewer/biosolids/biosolids1.htm&setFooter=/includes/biosolidsFooter.inc
http://pubs.caes.uga.edu/caespubs/pubcd/SB27/SB27.html
