Tuesday, 7 June 2011

Worms of Endearment

Those of a delicate disposition look away now, this entry is all about cutting the crap.

According to HG Wells, "…our microscopic allies, the humblest things upon the Earth, minute, invisible, bacteria!" scuppered the Martian’s invasion to take over our planet. These same micro-organisms almost brought our own master plan to a halt as well.

As I’ve mentioned before, a waste system independent of a town sewerage network is mandatory for living in the country. This mainly takes the form of a septic tank, which processes waste with anaerobic bacterial activity then filters the resulting effluent, which is dispersed underground via irrigation drip lines.

As much as we love ‘little bush’ it can be a very wet piece of land in the winter months. Surface water makes its way down from the Tararua foothills, and from the more elevated blocks of land on either side of us. An alluvial pan, a dense layer with the appearance of wet concrete, lurks half a metre below our topsoil, and this slows the natural draining of surface water. Add to this the fact that we have two streams running through our property – both with the potential to overflow during particularly heavy rainfall, and we have a piece of land very unsuited to the standard septic system. Unable to drain away into the saturated ground, the discharge from the tank would be more likely to rise to the surface and, well, we’d lose friends and effluence people.
Rose found and hired a consultant who recommended, (and the South Wairarapa District Council insisted upon), a secondary aerated treatment system. Essentially this uses tanks and filters to establish huge colonies of bacteria which feed on the waste outflow from the septic tank; further processing it to such a degree that the resulting outflow is as clean as is possible to obtain (given the original raw material).
The problem lay with the word ‘aerated’. In order for the bacteria to keep their appetite for the all-you-can-eat banquet we’d be serving them, they require a large amount of oxygen, which needs to flow constantly using electrically-driven pumps.
In other words, it’s no longer a passive system power-wise, and would continually draw on our precious, self-generated electricity - a demand which we wouldn’t have the capacity to supply. Unless we could keep the germs happy our entire off-grid dream was looking as doomed as H G Wells’ Martian invasion.

Only slightly daunted, Rose kept in constant contact with local ‘waste water system suppliers’ and together they all tried to find a system whose air pump would have the smallest possible draw on our electricity. We were considering regular power black outs just so that our bacteria could breathe easy when the answer arrived out of the blue. Our perhaps out of the ground, is more appropriate because we were rescued by earthworms.
 An Australian company called Biolytix had just become based in New Zealand, and they brought with them the gift of the Biopod ‘worm farm’ system to mankind. Essentially worms living in a tank convert the sewage into hummus, naturally aerating it as they create kilometers of tunnels. This ultimate worm residential estate becomes the ideal environment for the bacteria-fueled aerobic decomposition – eventually producing filtered, odour-free ground water. All of this through completely natural processes and using 95% less power than any other system. We were hooked, but now had to sell it the South Wairarapa District Council. To our further astonishment, the Building Control Officer practically gushed, having come across the system many times in Northland:
"In my opinion it is the best system with the most proven service history", he emailed enthusiastically, "there would be no problem with consenting the Biolitix system."
At the time of writing, our house plans are now with the council and going through the consent process. The energy-producing and waste-processing systems which we’ve spent so long researching will be coming under scrutiny, but we’re feeling confident.

Having started by invoking HG Wells, I’ll now finish by quoting Charles Darwin:
"It may be doubted whether there are many other animals which have played so important a part in the history of the world as the worm."

Our current, temporary 'waste water system' - definitely not bigger on the inside.

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