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Getting to the bottom of sewage treatment debate

Throughout the planning process the CRD looked for the least cost option

In Dr. Maler’s letter of Dec. 24, he attempts to assure me and by extension, the public, that there’s no need to lose any sleep over cost overruns because he is fully confident that the new plan will cost less than the now defunct McLoughlin Point Plan. He provides new information in support of his assurance. Unfortunately, his letter once again illustrates the lack of expertise of Dr. Maler and the RITE plan advocates on sewage treatment.

Dr. Maler asserts ‘the processes incorporated in the proposal for McLoughlin … are just enhancements to this old process (activated sludge treatment)’ comparing it ‘to putting lipstick on a pig’. Yet at the core of membrane bioreactor plants (MBR) is activated sludge treatment.

This is followed by an advanced ultrafiltration system, namely membranes, which act as a physical barrier to bacteria and most viruses, removing them from the effluent. Development of the membranes has allowed tertiary plants to be constructed with a much smaller footprint than conventional filtration methods, but at the expense of comparatively high capital and operating (energy) costs.

The new technologies used in the CRD’s indicative design (biological aerated filters) and in the final design (moving bed bioreactors) have also enabled more efficient secondary treatment designs with a smaller plant footprint. With the addition of ultraviolet and ozone disinfection, as proposed, high levels of contaminant removal would be achieved.

Dr. Maler next contends that eight, presumably MBR, treatment plants can be built at significantly less cost than a single plant with the same total capacity based on ‘extensive research data analyzed by the RITE plan advocates’ a group of well-meaning but unqualified members of the public, who have refused to make public the details for public scrutiny. The CRD has had two separate consulting groups come to the conclusion that multiple plants will cost more to build and operate than a single plant. The Comox Valley Regional District’s Sanitary Sewage Master Plan evaluated a distributed treatment system as one of its options reached the same conclusion. It is also not clear if Dr. Maler’s estimate of $400 million includes administration costs, public consultation, site selection, property purchases, engineering design, project management, interim financing, inflation etc., which can easily amount to 20 – 25 per cent of project costs.

So we’re left with a choice – do we accept the opinion of three groups of experienced consultants who independently came to the same conclusion or that of Dr. Maler and the RITE plan advocates who came to the opposite conclusion?

Finally, to make use of reclaimed water a network of pipes is required along with pump stations and possibly balancing reservoirs to meet peak demands. Watermain construction is expensive, costing $300-$400 per metre depending on the pipe size. A standard 19 mm connection to a residence, including a water meter, physical separation of the potable and non-potable water supplies, will cost in the $4,000 - $5,000 range.

If Colwood, for example, can’t afford to expand its sewer network to existing homes and businesses, how is it going afford a second water distribution system for reclaimed water? Certainly not unless residents were forced to pay whether or not they connected to the system.

Throughout the planning process the CRD looked for the least cost option that met the provincially approved core area liquid waste management plan and federal regulations. If the multiple MBR treatment plant option had been the least cost then that’s what the CRD would have selected. Will the new approach cost less? Only time will tell.

Jack Hull

Oak Bay