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Why it’s time to put toilets centre stage

Virginia Gardiner, Chief Executive Officer of Loowatt, explains how anaerobic digestion is helping ‘waterless’ toilets tackle the global sanitation crisis while fighting climate change.

Toilets play a central role in the human habitat. They are where we have our most regular, private and personal interaction with waste. In countries where flush toilets are widespread, people complete these moments by contaminating clean water – a flush-and-forget moment in which wastewater rushes away to unseen infrastructures. In places where there are not sewers, which comprise approximately 65% of built environment, toilets are mostly latrines that lack any treatment apart from environmental degradation. 80% of human waste today is dumped untreated. Diseases from faecal sludge contamination cause thousands of deaths each day, and many other negative impacts, including the stunting of children.

But toilets have not taken centre stage in the conversation on reducing carbon emissions. Why rethink the toilet when we can reduce CO2e more by changing other aspects of life, such as reducing air travel, riding public transport, and eating less meat? In fact, untreated human waste has a sizable footprint. Non-CO2 emissions from untreated wastewater (primarily methane) are projected to contribute ~4.7% of global emissions from non-CO2 greenhouse gases from 1990 to 2030. even more problematic might be the wasteful state of mind we embrace when we flush the toilet with drinking water, and our ostrich-like tendency to ignore tough systemic challenges such as the Global sanitation Crisis – especially when they involve taboo subjects like our own faeces.

Loowatt has been developing waterless sanitation technology since 2010, taking a bums-on-seats approach to product design and development: testing products extensively in our own backyard before we began to commercialise the technology through services. Our products provide a high-quality waterless toilet experience for users and servicers and send toilet-derived feedstock to anaerobic digestion systems. since 2016, we have processed over 300 tons of waste into utility-run anaerobic treatment systems, including those operated by Thames Water, right here in the UK. Loowatt is also working with Thames Water to characterise its organic waste stream in comparison to combined sewage and chemical toilet waste. early results indicate that because Loowatt waste has no dilution from water and no inhibiting chemical additives, the high COD nature of our waste offers valuable input for anaerobic digestion at their sites.

ADBA is addressing one of our greatest 21st century challenges, methane emissions, by supporting the infrastructure solutions that convert biogas to power. We at Loowatt are working to bring into focus the exciting opportunity that anaerobic digestion offers when providing decentralised waste treatment for municipal sanitation. This is happening right now, as we are expanding our Madagascar operation – a household toilet service for paying customers in the capital, Antananarivo – in partnership with the municipal waste utility, SAMVA. Between 2014 and 2016 Loowatt designed, specified and commissioned a 30m3 anaerobic digestion facility for our Madagascar operation. The facility co-digests toilet and food waste and produces liquid fertiliser that is pasteurised with heat from biogas and sold locally. By the time Loowatt’s facility was commissioned in 2016, the city had built two more digesters funded by NGOs and again operated by SAMVA. There are now six digesters in the city – enough treatment capacity for over 5,000 toilets – and several more are under construction. And our strategy for further expansion has evolved into a collaboration with the utility, who offers us access to these facilities.

From the standpoint of both logistics and technology, Loowatt’s work in Madagascar embodies our vision for 21st century sanitation: linking up urban waste collection to waterless toilets and creating energy and fertiliser from co-digested organic household waste. With the right mix of logistics and technology, waste from waterless toilets and other organic waste from households can together be treated in utility-run systems that generate value – providing toilets people love, while working towards a cleaner future for our people and planet.

  • Virginia Gardiner will be speaking on Day 1 of the World Biogas Summit, being held at the Birmingham NEC alongside the UK AD & World Biogas Trade Expo on July 3rd and 4th. Register for free here: https://biogastradeshow19-summit.reg.buzz/
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