Composting Toilets & Urine Treatment

Composting Toilets

Looking for a sustainable way of treating toilet waste? Look no further than composting toilets. With Irish planners looking more closely at ground and stream pollution caused by septic tank run-off, composting toilets are one way to tackle these concerns as part of your planning application.

Standard Toilets and Aquatron

Herr Ltd is the official distributor of Aquatron systems in Ireland. This system separates solids and liquids from a conventional toilet. From there, solids can be composted safely with earth worms and liquids can be diverted to a reed bed or stored for further treatment.

This separation process—unlike standard septic tanks—avoids making sewage sludge that would otherwise have to be collected and taken away by tanker. Since in this situation there will be no diesel truck required to transport sewage sludge over long distances, there will be a considerable avoidance of greenhouse gas emissions and avoids the added cost as well.

No electricity or energy is required for the toilet solids separation process or for the composting process itself.

By avoiding septic tank run off, phosphorus is prevented from entering local streams that would otherwise harm wildlife and contribute to algal blooms.

Waterless Toilets

Porcelain waterless toilets are also available. These are hygienic, clean and odorless. These waterless system reduce mains water demand and water charges by 25%. Every month the semi-dry toilet solids are removed to an outside bin for composting with earth warms in the same way as the separation design. The urine can be used as a natural fertiliser.

This system also prevents harmful natural pollutants from domestic sewage being released into the environment, effecting our lakes and waterways. Farmers can also use the separated urine to recycle the phosphorus and grow crops in a sustainable way.

Dry Toilet and Raised Beds

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Due to climate change, summer droughts may become more frequent. With efficient low water-use flushing urinals and the use of this almost waterless toilet, a relatively small rainwater harvesting system might be sufficient. If however a much larger rainwater harvesting system is installed then the extra available rainwater can be used for clothes washing.  With ultra violet lamps used to sterilize the water then the rainwater can also be used for dish washing and other uses.

Dublin’s water supply system at present is particularly vulnerable to long summer droughts. Hose pipe bans and temporary water shut off may happen over the coming summers. Significant reductions in mains water use could be achieved if everyone in Dublin installed water saving measures and had very low water-use toilets.  

Another important long term goals is the protection of  our ground water and nearby streams from pharmaceutical, nitrogen and phosphorus pollution. New homes in Dublin could do their bit in reducing the overloaded Ringsend Sewage Treatment Plant.  

More Information

If you want to learn more about composting toilets, check out our case study on the WISER Life project in Ballymun, Dublin.

For more information about Aquatron systems or bespoke reed bed/composting toilet designs, get in touch.


Urine Treatment

Nutrient pollution from sewage making its way into ground water and surface waters not only harms our fresh water supply and impacts fresh water ecosystems, it is also wasting a valuable resource.

With the inevitability of future resource restrictions and to ensure or food security, big changes will have to happen for domestic and municipal wastewater treatment systems. Nitrogen and Phosphorus are key resources that mankind needs to manage better from now on, they are freely available for recycling from human excrement. 

For single house wastewater systems, a paradigm shift must occur with the separate treatment of human urine and the use of toilet composting systems. To avoid pharmaceutical pollution in surface waters and to end the wasting of phosphorus and nitrogen from septic tanks, the growing of non-food plants such as flowers will eventually be regarded as the most economic, and ecologically effective method. Almost half of the food we eat around the world is grown with synthetic nitrogen fertiliser that is made using natural gas and coal. Map of synthetic nitrogen. We therefore should not be so wasteful of nitrogen from septic tanks. 

The present system where all domestic wastewater is first passed through a septic tank is very wasteful of important nutrients which are vital as fertilizer within the global food supply chain, and will eventually have to end.  Low cost mineral-based phosphorus and synthetic nitrogen will be in short supply as the resources to make synthetic fertilisers become restricted or depleted in future, on the global market. 

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Instead we must recover and recycle Nitrates and Phosphates. Single houses in future will be encouraged to consider the use of composting toilets and urine hydroponic systems. The diagram below shows how this can be done while continuing to have hygienic and odourless toilets. 

Outdoor plants will thrive in the summer sun but can die back with cold outside winter temperatures. Flowers in glazed rooms however, that enjoy indoor warm house temperatures and artificial light in the evenings can continue to grow throughout the full year. 

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The flower growing system shown below is in an attached greenhouse. The hydroponic growing of flowers and plants using separated human urine is happening without odours. The flowers are forced to bio absorb any pharmaceuticals, phosphorus, and nitrogen in the urine. The photograph taken in September shows a vertical flower wall that bio accumulates the nutrients in urine. 

Why does urine treatment and recycling matter?

  • Half of the global population depend on synthetic nitrogen fertiliser to grow food crops 
  • The remaining global reserves of natural gas and coal to make synthetic nitrogen fertiliser will eventually become expensive and diminish.  
  • There are urgent calls from the International Panel on Climate Change to keep within the carbon budget end the use of fossil fuels over the next decade 
  • There are calls from the EU to begin the recycling phosphorus from wastewater and organic waste streams 
  • Septic Tanks are so wasteful of nitrogen and phosphorus, we must end nutrient pollution that causes algal blooms and surface water pollution.  
  • The global food system emits so much greenhouse gases, we will need to make compost from human excrement to grow vegetable crops more locally or in gardens. 
  • With unsustainable farming and climate change the world is rapidly losing its top-soil. This flower growing method will make compost to make your own home garden more fertile.

Human urine contains about 70% of the nitrogen in wastewater. We must start now to direct human urine to grow flowers. We must compost the flowers afterwards and return the compost to our gardens.