Biosolids!

So what are biosolids?

Biosolids are mostly organic solids resulting from the treatment of wastewater that have undergone additional treatment to kill pathogens and that have been approved by the EPA for land application as a fertilizer and soil amendment. It involves such nutrients as ni trogen and phosphorus and contain other micronutrients for plant growth. Opponents refer to this as treated sewage sludge or human waste.

Are biosolidssafe?

Answer: The National Academy of Sciences has reviewed current practices, public health concerns and regulator standards, and has concluded that "the use of these materials in the production of crops for human consumption when practiced in accordance with existing federal guidelines and regulations, presents negligible risk to the consumer, to crop production and to the environment. The Water Environment Association of Ontario produced a comprehensive report in 2001 which indicated that, at least in Ontario, the practices are sufficiently conservative and if followed properly show no significant risk to the environment or human health

Who regulates biosolids?

Answer: Biosolids are regulated at both the federal and state level. Biosolids must first meet several quality standards and regulations in order for them to be applied to land. These standards contain limits for metals that may exist in biosolids, site rules and regulations, pathogen standards, record keeping rules and soil monitoring requirements. 

Why do we have biosolids?

We have biosolids as a result of the wastewater treatment process. Wastewater treatment technology has made our fresh waters safer as sources of drinking water, for recreation and as fish habitats; it has also improved marine water quality for recreation and seafood harvesting. In the past, many hundreds of Canadian cities simply dumped their raw sewage directly into the nation's rivers, lakes, and bays - some still do, although this is being addressed through environmental and infrastructure programs. Through regulation of this dumping, municipalities are now required to treat wastewater and to make the decision whether to recycle biosolids as fertilizer, incinerate it, or bury it in a landfill.

Do biosolids affect water quality?

About 95% of the nitrogen in biosolids exists in an organic form that has a slow release rate, which makes it much less likely to run off into streams. 

Pros

•Creates jobs

• It is a cost effective method of

disposal

• Recycles versus filling landfills

• Promotes farming

• Reduces emissions from

transportation to landfills

• Good free fertilizer

•Land Reclamation

•It’s regulated according to EPA

law 503

Cons

• Potential health hazard

• Effects irreversible

• Contamination resulting from

accumulation of industrial waste

• Its true composition is unknown

• May contain hazardous

chemicals

• Possibly transferable to crops

• Decreases property value

•Not sufficiently regulated

•Odor

The stakeholders supporting the Biosolids Partnership believe in and seek the active participation by federal, provincial and territorial government departments and agencies since we have a common goal that residuals of wastewater services (whether municipal or industrial) represent an untapped environmental resource which can be managed to support our collective sustainable development objectives in a manner that protects public and environmental health and safety. The many potential uses for these biosolids residuals in current practice include: land application for agriculture and reforestation; mine tailing site reclamation, energy recovery, and compost production. Other uses such as cellulose-based ethanol production have not yet reached Canada or are at a bench scale stage, e.g. phosphorus recovery.

Among their benefits, the use of biosolids can:

• Improve crop production

• Reduce soil erosion and protect water quality

• Provide topsoil for recreational uses

• Reclaim strip-mined lands

• Enrich forestland

• Conserve landfill space

• Provide economic incentives 

What happens to Toronto Biosolids?
Toronto's biosolids are all treated at the Ashbridges Bay Treatment Plant (77%) and the Highland Creek Treatment Plant (the other 23%). Throughout the world, biosolids are returned to the environment in a variety of ways. Some methods require little or no processing, while others use sophisticated technology. Although the City continually pursues beneficial reuse options, we currently use a combination of methods to manage biosolids. The table below shows where our biosolids went in 2008:

2008 Biosolids Reuse/Disposal Methods

Management	Percentage
Landfill	41%
Incineration at Highland Creek	23%
Land Application	11%
Pelletization	16%
Alkaline Stabilization	5%
Site Remediation	4%

Students who are undecided or against biosolids are concerned about the long-term effects and want to see more research on the subject. Students who support biosolids believe that if it is applied properly, biosolids are a viable alternative for fertilizers and good way to recycle.

Sources:

http://www.cwwa.ca/cbp-pcb/pdf%20files/EPPC%20Proposal1.pdf

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

http://www.biosolids.com/benefits.html

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