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permaculture - Re: [permaculture] - Willow Wastewater Cleaning Facility

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  • From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: Re: [permaculture] - Willow Wastewater Cleaning Facility
  • Date: Thu, 15 Jul 2010 23:53:17 -0400

On 7/15/2010 11:10 PM, Lawrence F. London, Jr. wrote:

I am going to make a foray into the Permies.com threads Paul referenced
and Xpost interesting material into this thread.

Reading through the dry system thtead gave me a few ideas about plant material with the capacity to absorb large quantities of nitrogenous waste, raw or partially composted: pines (loblolly, virginia, shortleaf,
not white in southeastern US), eastern red cedar, river birch, poplar, willow, winterberry holly (ilex verticillata or ilex decidua), inkberry holly/ilex glabra, Black chokeberry/aronia melanocarpa, eleagnus, elderberry, viburnum [arrowwood viburnum, other native varieties seen growing on creekbanks with roots near water), cattails, papyrus, water lillies, water hyacinth and duckweed, azolla where it will grow.

I am thinking of a land based system with carefully formed terrain
using ditches, swales, berms, flatland and water impoundments that are part of ditch systems in wide deeper spots and individual ponds.

Another idea is to build a Hugelculture system and channel effluent through it before dumping it into a meadow/fallow field on a slope
where weeds of all sorts are allowed to grow; as species become established (i.e. grasses and clovers, plantain and dock) hardy shrubs and woody perennials could be planted to increase year round nutrient absorption.

The Tree Bog concept from Biologic Designs (see previous posts about their demo site):

https://secure.wikimedia.org/wikipedia/en/wiki/Tree_bog

History

The tree bog was invented by Jay Abrahams of Biologic Design in the UK after he observed that the trees around the place where faeces were deposited were particularly vigorous. Tree bogs can be considered examples of permaculture design.

The tree bog is a simple method of composting wastes, and since its introduction by Biologic Design in 1995 over 500 tree bogs have been built in Britain[citation needed]. They have been on sites ranging from fruit farms[citation needed] and pick-your-own enterprises[citation needed], campsites[citation needed] and an angling lake to annual festival sites[citation needed], remote/low impact dwellings[citation needed] holiday cottages[citation needed] and churches[1].

A tree bog can be created if one is on the mains but wishes to lower the environmental impact of sending wastewater to the sewage works.

The tree bog has attracted the attention of NGOs[citation needed] and aid workers who hope to develop its potential for shanty towns or refugee camps[citation needed] - anywhere that water is scarce and the population pressure on resources is high. Most regions have vigorous and useful plants which, if willow is not available, can be used (e.g. Gliricidia sepium or ‘Quickstick’ in the subtropics).


Workings

A tree bog is simply an uncontrolled compost heap whose function has been enhanced by use of moisture/nutrient-hungry trees. Tree bogs use no water, purify waste as they create willow as a biomass resource, and also contain the organic waste, thus preventing the spread of disease - all whilst creating soil. A seating platform/cubicle is mounted at least one meter high. The area beneath the seating platform should be enclosed by a double-layer of chicken wire - this acts as an effective rodent/small animal and child proof barrier, but allows air to circulate through the compost heap.

The space between the wire should be stuffed not too densely with straw which acts as a wick to help sop up excess urine preventing the likelihood of odour problems due to incomplete biological absorption of the nitrogen from the urine. The straw filled wire also enables the pile to be well-aerated whilst acting as a visual screen for the first year’s use. The structure is then surrounded by two closely planted rows of osier or biomass willow cuttings; this living wall of willow can then be woven into a hurdle-like structure and its annual growth can be harvested.

Tree bogs can also be sited on the edge of existing stands of trees, woodlands or hedges: the mature tree roots will soon find the additional source of nutrients, so that the willow may be unnecessary, - or indeed, in the middle of a mature woodland, pretty well impossible due to shading.

The tree bog combines resource production and waste disposal. The tree bog functions by transforming faeces and urine into growing trees and organic soil. The roots of the trees are host to soil micro-organisms which decompose and mineralise the materials in the heap, making the nutrients available to the tree roots. Thus the willow are able to grow more vigorously as these added nutrients become available.

Outputs/Benefits

Benefits include:

* Disposal of waste without using water.
* Soil is both generated & regenerated.
* Earthworms proliferate within and around the compost contained within the tree bog.
* Leaf mould from willow leaves.
* Comfrey bed on leach field for nitrate/phosphate absorption.
* Leaf matter and twigs for stock fodder.
* No odour or fly problems.
* Willow wands for baskets, fuel or structural use.

The tree bog is a simple means of taking responsibility for wastes produced in everyday life. It involves no secondary handling (except the poking with a pole) of waste matter. Management is minimal, being an annual winter cutting and weaving of the willow. The wands can be used as polewood, for basket or hurdle making, or chipped for use for animal bedding or cut and bundled as fagots to use as fuelwood.

Willow planting

Although not required for an effective tree bog, planting the willow wands at least one growing season prior to the tree bog being used has advantages. This way the willow roots are mature and the wands have grown up to a reasonable height before the platform is constructed - as the platform shadow can hinder the growth of the planted willow sets on the shade side.

The best time to plant out the willow for a tree bog (in the northern hemisphere) is from October to March, as then the willow has a chance to get established before the onset of summer. However it is possible to construct and use a tree bog at any time and then plant it out at the appropriate time of year. The straw acts as the visual screen for the compost pile until the willow is in place and growing.

Vigorous varieties of unrooted willow sets/cuttings work best, and if they are planted out after the middle of April they should be well mulched and watered every day for the first month or they will not take (i.e. the roots will not develop and they will wither away). If possible use named osier or biomass types since these will grow vigorously and can tolerate the annual coppicing as well as being suited for use in basketry and hurdle making. If you are gathering local wild osier or other willow to plant your tree bog, use willow that has been coppiced or pollarded recently, because young wood makes the best cuttings.

Willow management

The willow can be coppiced annually or left to grow for more than one year, though you will find it grows quite large. Cut the willow between November and early March and don’t be afraid to cut it right down to the ground or to the top of your living woven willow hurdle - as long as it is not smothered with weeds and has sufficient sunlight it will regrow vigorously, using the nutrients and moisture within the tree bog.




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