Too many uncertainties in sewage treatment.
With a June 30 deadline approaching, we still don't have all the answers.
David Anderson, Special to Times Colonist - June 11, 2008
With weeks to go before the provincial government's June 30 deadline for the Capital Regional District to decide on a liquid-waste plan,residents are farther than ever from a clear direction in which to proceed. This uncertainty starts with whether treatment beyond the present outfall system would bring any appreciable benefits. Since the province required the CRD to propose a plant, two groups in particular have provided analysis that cannot be lightly brushed aside.
The first are six present and former public health officers of the region, who have concluded that further treatment provides, on balance, no increased health benefits.The second is a group of 10 University of Victoria academics in the marine sciences, who have concluded that on balance further treatment would provide no appreciable benefits to the marine environment. Their views remain the most credible expert advice put forward on the issue.
The question of whether further treatment has benefits that justify the cost is raised by another recent report, commissioned by the provincial government, which focuses on the concept of integrated resource management. It proposes some 33 small treatment plants rather than the four larger plants originally proposed in the CRD's June 2007plan, "The Path Forward." This radical change in the proposed approach casts further doubt on the merits of the original thinking calling for treatment.
The difficulties raised by the recent report go further. The concept of integrated resource management, in this case considering waste water a resource for the nutrients, heat, and water it contains, is logical, not new and CRD officials have made clear they support it.The issue is how practical the concept is in implementation. The devil is in the details, and on the details the report is thin. For example, why 33 resource recovery locations? The LEED Platinum Level house I visited recently extracts the heat from the waste water in the basement, where the wastewater is at its hottest, recovery efficiency is greatest and the distance (and thus heat loss) to the point of reuse is least. (For those interested, the technology is straightforward and cheap. A slightly flattened copper pipe is wound around the cast iron waste water pipe, which transfers the heat from the exiting waste water to the incoming water in the copper pipe to preheat the water going to the home water heater.) Why send wastewater down the sewer pipe for hundreds of metres, losing heat all the way, to one of those 33 collection centres, and then move the heat back to the home, hospital, hotel, or office building? Might it not be better to have the recovery and reuse done in an energy-efficient manner in the basement of the individual building? Another factor should be noted. We are not short of geothermal heat,even in Victoria. The heat is underground and it is feasible to recover it. What are the costs of heat recovery from waste water, when compared to a geothermal system? Cost estimates, both environmental and in dollars, are needed to find out whether heat recovery from waste water is more sensible than heat recovery from ground water. How can we make informed decisions when we have not been given such basic information?
Turning to the question of water recovery, why mix water from the sink with sewage water at the house and then treat the water later in those 33 plants so that it can be returned to individual homes for use in the toilet tank or in the garden? Why not keep the sewage water separate from shower water at the home and allow the shower or bath water to go directly to water the garden, where this can be done without health or environmental risks? Again, a simpler, local, system might be superior to what is being proposed. This can only be determined if the study is comprehensive. Some of these questions were considered by the technical review team hired by the provincial government to comment on the integrated management report. The review team's conclusion was that they are highly skeptical about the potential value of a sewage-treatment system based on those 33 plants.
This contradictory view casts further doubt on the wisdom of the decision to proceed with the CRD treatment plan. There are just too many uncertainties, and every time a review takes place to dispel uncertainties, further differences of opinion surface and uncertainties increase. Before making multi-hundred-million dollar decisions that will lock us in to specific and expensive technologies for decades, with an expected cost of $500 to $700 per household per year, the CRD should have these questions answered. If this cannot be done by the June 30 deadline, then good public policy requires that deadline be dropped and adequate time taken to get this right. - David Anderson was MP for Victoria from 1993 to 2005 and was federal minister of fisheries and oceans and minister of environment between 1999 and 2004.