Presentation to the CRD’s Core Area Liquid Waste Management Committee on November 24th 2010
by Dr Shaun Peck
Thank you for the opportunity to speak to you again.
I will address to-day agenda items # 5 Resource Recovery use plan and #7 The Macaulay and Clover Point Wastewater and Marine Environment Annual Report. I would like to complement staff on these two excellent reports. The first one answers many questions that have been in my mind since hearing from your consultants. Many of the concerns that I had are addressed in the summaries or may be included in contract documents. The agenda items can be accessed via:
You have been informed by your consultants that you may expect to receive revenues of $2 Million per year from sending dried sewage sludge to cement kilns. This I have determined is far from the truth. I personally spoke to LaFarge and they informed me that a) they would not consider receiving the biosoldis unless there were other sources to make it economic and b) Paying for the sludge was just not on the cards – they would need to be paid. I am glad to see that this error is not in to-day’s report. It does mean that the current advertised annual revenue of $3.1 Million needs to be reduced to $1.1 Million. The potential revenue generation from disposal of the biosolids is hypothetical.
On November 10th you were informed by your consultants that sewage treatment plants create a noxious, odourous concentrated sludge that is considered a dangerous material and is a Public Health risk to sewage plant workers. (This I completely agree with). Therefore you need to put in extra treatment to treat something you did not need to create in the first place. The consultants are therefore recommending thermophilic anaerobic digesters to produce pathogen free biosolids. This will require a great deal of energy as it does in the present Saanich Peninsular Sewage Treatment plant.
Off Victoria the Ocean treats the screened effluent naturally by biologic and chemical processes after passing through the deep sea outfalls with their diffusers. (It is not dilution – there is an active biological and a chemical process that occurs). On land the treatment plants concentrate the effluent into this noxious, odourous substance. A great deal of energy is later used to dewater the sludge or biosolids as it is planned that they will be thermally dried to increase the solids content to about 95%. The dried biosolids will weigh about 15 tonnes/day.
There have been recent developments in the US related to the treatment of sludge. In the US (whose regulations do not apply to Canada but are often adopted in similar form) the Environmental Protection Agency has released proposed Air Emission Standards Impacting the Management of Sewage Sludge Nationwide. They will have a major impact on the limited options local governments have for the management of sewage sludge.
Rather than encouraging upgrades to newer, cleaner incinerators paired with energy recovery that can offset a significant amount of the energy needs for treating wastewater, the proposed standards will result in many of the US’s wastewater utilities abandoning their significant capital investments and simply sending an energy-rich secondary material for disposal in a landfill.
At this time due to the limited space available for curing of biosolds at the Hartland landfill, the production of PenGrow is limited to about 180 tonnes per year, which represents only 5% of the 3,500 tonnes of residual solids produced annually by the Saanich Peninsular Treatment Plant.
Another issue I would like to draw to your attention to again, is carbon offsets. A University of Victoria Scientist has informed me that:
“There are very clear standards for claiming offsets. You can only claim an offset if a technology is introduced that is replacing an existing technology that is producing emissions. You also cannot claim an offset if you planned to do something anyway.”
Let us be more honest about the carbon footprint. Offsets are being claimed but this is a sham as it does not reduce the original carbon footprint. The annual emissions prior to claiming any offsets, based on one set of calculations from a previous report that you have received, will be the equivalent to the C02e put out by 7,736 automobiles per year.
By building these land based sewage treatment plants there will be an adverse effect on the land (terrestrial) and global environments.
Speaking briefly to Agenda #7. The report reinforces the fact that with the current two deep sea outfalls treating Victoria’s sewage naturally there is no measurable public health risk and a minimum effect on the Marine Environment.
- · predicted wastewater concentrations in the marine environment met receiving water quality guidelines for the protection of aquatic life,
- · the potential for sea surface human exposure to wastewaters from the outfalls is low (public health officials have said not measurable), and
- · there are some limited effects on marine organisms which are restricted to within 100m at Clover Point and within approximately 200m east of the Macaulay Point outfall diffuser. Overall monitoring results…………indicate that the effects of the outfalls are not expanding or increasing over time.
Dr Shaun Peck, Public Health Consultant
Member of Responsible Sewage Treatment Victoria www.rstv.ca
Board member of the Association for Responsible and Environmentally Sustainable Sewage Treatment. www.aresst.ca