Re: “For now, mainland favoured for scraps,” June 25.
This focus on composting organics suggests there are some misperceptions on the natural processes involved.
My recollection is that composting refers to oxygenated metabolic processes in the formation of new cellular structures that produce between 25 and 40 per cent more cellular material than is fed in. The alternative is digestion, catabolic processes that break down existing cell structures under anaerobic conditions. Digestion comes about naturally and the trick is to manage the gases that come off, mainly methane, carbon dioxide and reduced sulphur and nitrogen compounds (stinky bits). The conversion to these gases translates into a reduction of solids of up to 50 per cent, but this is seen as the source of bad smells.
The simple solution to this problem embraced by our engineering community is to pump through more air. However, as recent history in Central Saanich shows, this is easier said than done. Digestion cannot be avoided, no matter how sophisticated the added bells, whistles and pumping systems.
By working with what is the natural order, digestion systems are less complex, less energy-intensive and much less expensive. They can be scaled to virtually any application, as demonstrated globally, to produce effective waste treatment, net energy gains (biogas) and reduced solids.
Using our local organic wastes — including food scraps, garden waste and sewage — to best advantage, a distributed, integrated organic-waste management system could produce substantial amounts of natural gas, reduce the need to despoil McLoughlin Point and present a cost-effective showcase of local innovation.
Geoff Krause
Brentwood Bay
