What does the system look like?

Whether your system is located under the floor of a building or next to the building or in the garden, all you will see is the top of a small pumpwell protruding to just above the soil surface. If you don't have the slope to configure a gravity drain to your garden irrigation system, then the top of the pumpwell would have a small 12 volt solar powered pump, mounted on it. Below is an Xray diagram of a typical setup for a one person system.

For a 10 person system the total length of trencharch needed would be 30m instead of the 3m shown here. This is a truly open source collaborative project and so the sketchup files for all components are freely available to use or modify. Just email info@gosep.org for the link access so we can manage version control.

PS We desperately need a Sketchup expert to update/fix all of our model files as we are Sketchup novices!

How does a GOSEP system work?

Summary of Design principles

• Fully enclosed treatment chamber to eliminate disease vectors

• Soil ecosystem based treatment not aquatic

• Biological breakdown using a diverse ecosystem of earthworms, nematodes, arthropods, mites, fungi, protozoa and bacteria

• Exposed to air aerobic treatment (only temporary anoxic micro sites within soil and humus layer)

• Temperature stability using thermal mass energy stored in the soil

• Gravity drainage flow through the treatment stages for reliability

• Odours adsorption by humus produced by organic breakdown

Description

• The GOSEP concept uses conventional household plumbing with toilet water traps to eliminate fly and insect vectors from entering the home or facility as they do with composting and pit toilets.

• GOSEP entirely eliminates the septic tank pretreatment stage and all the associated costs and logistical barriers entailed.

• All wastewater goes directly into a soil enclosed trench arch chamber installed above a sandy loam topsoil layer at least 400mm deep

• The solid portion of the raw sewage inputs are very rapidly separated from the liquid component before the water has a chance to go anoxic or anaerobic.

• A rich and diverse soil surface ecosystem is seeded into the chamber and converts the raw waste to humus. https://www.youtube.com/watch?v=u6RtbdyKb6Q

• The humus produced from organic breakdown is structured by the ecosystem into a porous filtration medium with a massive surface area for oxygen exchange and a high cation exchange capacity and as a serendipitous bonus it absorbs odours!

• Earthworms in particular, process and move the raw wastes laterally and along the surface of the trench arch chamber and into the soil below this surface organic zone.

• Incorporation of the humus into the soil improves soil porosity, aerobic capacity and infiltration surface area.

• The water component of the wastewater is filtered by the soil layer where virus, bacteria and pathogens are quickly removed and consumed by a dynamic infiltration surface ecosystem of other bacteria, fungi, free swimming protozoa, vorticella, rotifers, slime moulds, nematodes, and more which are in turn grazed by tardigrades, beetle mites, springtails, mites, larger nematodes, pill bugs, moth flies, cockroaches and other insects, and earthworms.

• Higher trophic levels of predator organisms like centipedes, isopods, staphylinid and other beetles, earwigs, spider mites, spiders, and even lizards and frogs keep the treatment ecosystem diverse and healthy.

• Purified water emerging from the soil layer is either collected for reuse in a geofabric separated airspace below the soil layer and in the base of the pumpwell or directly wicked by capillary action onto the surrounding native soil. (One of the risks we need to mitigate with the lower cost capillary irrigation configuration is aggressive tree roots invading the trencharch lumen where there is abundant water and nutrients, so attention will be focused on this through our Design Optimisation Team - please apply to join if you have any brilliant ideas to solve this potential problem)

• Plant roots in and around the irrigation zone take up the nutrients and salts leached out of the treatment layers by the water flow.

• If sized correctly the system should require no ongoing maintenance for at least 25-30 years.

• GOSEP is more compact than all aquatic treatment systems and can even be installed below the floor or basement of a typical dwelling (especially relevant in very cold climates).

• GOSEP is superior to and more reliable than centralised sewerage treatment and is implemented at a fraction of its cost.

• GOSEP closes water and nutrient cycle loops in a simple to construct low cost onsite solution. There is no point exporting organic matter, water and nutrients when urban gardens need all three to thrive!

What are the specifications?

GOSEP Performance specifications

• Must treat used water and human wastes including food waste

• Must operate with

  • intermittent loading and

  • typical household chemical inputs

• Use a robust soil based ecosystem to power the waste degradation and water purification process

• Separate organic matter in wastewater from the water within minutes

• Use only passive natural ventilation for oxygen supply

• Treatment process must operate without electricity

• Produce no detectable odour

• Can be installed in high density informal settlements

  • if necessary below the floor of the dwelling

• Installed cost of less than $360/person serviced

• Can be installed with hand tools (pick and shovel)

• Treatment process can operate for at least 25 years with no maintenance

• Trench-arch chamber accessible from one end for inspection, monitoring or compost sample extraction

• Can be configured to recover purified water suitable for drip irrigation of food crops and toilet flushing

  • plastic membrane liner required for effluent recovery

• Key components either readily available off the shelf or can be manufactured locally

• Eliminates human pathogens

• Requires no lime, sawdust or chemical additives

• Removes nutrients using food plants

• Produces no sludge or toxic byproducts

How much does it cost to install A GOSEP system?

The cost per person serviced comes down based on the number of people sharing the pumping infrastructure as only one solar pump is required per system. The chart below shows how this affects the price/EP for a single person system and a email person system.

docs.google.com/spreadsheets/d/1Aw1sLNavPpyRZX98ouCOmH7JTZKQCjgwBdGrVfm34Pc/edit?usp=sharing

If economic analysis is your thing please email us as one of our project objectives is to complete a rigorous economic comparison against alternative treatment approaches - including no treatment, to clearly quantify the empowering benefits of GOSEP

What kind of soil is best in a GOSEP?

What we know works well from informal prototype trials conducted over 20 years is sandy loam. It is readily available in developed countries from landscape suppliers. What we don't yet know if this can be improved on. Sandy loam has mostly sand with some clay mixed in. The sand makes it more free draining than clay based soils. The loam increases the soil water holding capacity and also improves the cation exchange capacity so this may be an advantage. Given fine high cation exchange organic colloids which also retain more water in the soil are continually produced by the breakdown of the organic matter in the humus layer, sand may be just as effective in the long run. We don't know yet until we complete the soil optimisation trials. Also modifying the soil by adding biochar may have some big advantages too because it is known to reduce leaching of nitrogen from the soil and increase the aerobic capacity of the soil. Generally keeping the nitrogen in the irrigation water is a good thing if it is all taken up the plants in the garden so retaining nitrogen in the soil may not be an advantage and it is likely that no matter how much biochar is added to the soil it will eventually become saturated with nitrogen and only be beneficial for is ability to hold more oxygen in the soil. Only time will tell. We actually also don't know if retaining more water in the soil column is even a treatment advantage. Virus removal may be just as good at higher hydraulic flow rates provided the colloidal exchange sites are still high enough to capture them and still allow microbes that consume or degrade them.

If soil chemistry or microbiology is your thing, please consider joining our Optimisation Design Team and help us more quickly answer these questions and come up with the ideal soil configuration.

How do you start off the ecosystem in the GOSEP system?

When we take samples of the mature sponge-like humus matrix in a wet vermicomposting filter system we find that the key organism by weight is worms, but not far behind them as far as biomass is beetle mites, beetles and springtails. Even though the beetle mites and springtails are tiny there are literally millions of them in a kg of humus and their biomass total is not far behind that of the worms. The worms are the keystone organism in the ecosystem however because they create aerobic channels and pores through the matrix that allow water to drain quickly through and fresh air to be drawn in behind it. This gravity powered air pumping keeps the whole system aerobic and teaming with life. In practice if you seed a start up system with just a handful (about 1 kg) of worms and matrix from a mature system that is all that is needed to create a healthy moist soil ecosystem. Cockroaches and many other creatures will cryptically end up in the system, attracted most likely by the smell of their favorite foods.

If soil ecology or entomology is your thing, please get in touch soon as we have trials planned on the GOSEP ecosystem dynamics and at this stage we need to recruit honours or Phd students conduct these trials.