This article, the second in our series ‘Hero of the Month’, is born out of the frustration generated by Italy’s plumbing systems.

Not Italy’s ancient plumbing systems, the latrina (toilet) or forica (public baths) so exquisitely analysed in Koloski-Ostrow’s research, (detailed by our new favourite website toilet-guru.com – explaining all things toilet across the globe).
Our issue is instead with Italy’s contemporary plumbing, actually with Europe’s, the USA’s, most of the modern or Western world’s plumbing. Across these regions, plumbing systems most commonly use clean water (also known as ‘blue water’) to flush our toilets. Potable water. Drinkable water flushes our loos, about 11 litres per flush to be precise, down the drain.

To briefly state some relevant facts:

Only 0.5 per cent of water on Earth is usable and available freshwater. Climate change and pollution are dangerously affecting this supply, both in terms of quantity and quality.
– The biggest demand for freshwater is from the agricultural sector – we need fresh water to produce our food.
– Approximately 80% of the world’s population already suffers from high levels of threat to water security.
– A sharp increase in water scarcity is projected in most areas of the globe.

A dry river. Source: Meteogiornale 06/2022

Maybe we’re pernickety, but it seems to us that to flush our toilets, several times a day, with drinkable, fresh water, is obscene. To flush away litres of freshwater everytime we need a tinkle is to spit in the face of the two billion with limited access to freshwater, to deny the arriving onslaught of water difficulties, to poke the climate bear.

Ancient Roman foricae were cleaned with water flowing from the baths, latrinae were likely flushed with household water. This water, previously used, containing some impurities but relatively clean, is called greywater. And its use is what we want to talk about today.

Water Reuse Technologies (also known as water recycling and water reclamation technologies) are somewhat self-explanatory. They seek to reuse water, to apply technological solutions that allow us to get the most out of the resource.

Finding secondary uses for water, or ways to use greywater is, in our opinion, the most valuable, though overlooked, frankly very cool, form of recycling.

In the hope that piquing curiosities stimulates demand and encourages tech development, the second publication in our Hero of the Month series, is about Water Reuse Technologies (WRTs). This is a series dedicated to our heroes, love letters to products, species, things, that are all-round champions in the fight against climate change.

Ancient foricae. Source: Lawrence OP via Flickr.

Seeing as we opened with a discussion of toilets, our first WRT is Hydraloop.

Hydraloop is a Dutch company that allows homes, hotels, businesses, large buildings, to “use water twice”. Their water recycling units, once installed, collect and treat water from showers, baths, washers, dryers, heat pumps and air conditioning units. Their tech is able to save up to 45% of water for reuse in laundry, for watering your garden, filling up swimming pools, and most gloriously, for toilet flushing. An innovative, modernised foricae → latrina system.
Hydraloop’s technology is not only designed for dense urban, or wild rural areas but can also be effectively used in off-grid situations. Where water supply is scarce or unreliable, this tech is, for want of a better word, revolutionary. Hydraloop units have been installed throughout Europe, the Middle East and parts of Africa, (and hopefully one day, my dream house).


© Hydraloop

A second, nature-focused example of WRT is porous pavement.

Porous pavement, often incognito, looks like regular pavement, but rather than being impermeable, it allows water to trickle down through to the soil. This might not seem imminently important (why would you want to water the soil under a street or a sidewalk), but the problem with non-porous pavements is becoming increasingly clear: in periods of prolonged or sudden, heavy rain, storm drains often become overloaded, creating flooding, dangerous road conditions, and even damaging stormwater and septic systems (which, in turn, risks contaminating fresh water infrastructure).

Source: John Harrison via Massachusetts Clean Water Toolkit.

Storm drains also carry stormwater – often unclean water, polluted by salt, chemicals, car exhausts and general urban grime – into oceans and rivers. An answer to this issue is porous pavement, or, as best put by the journal ‘Soils Matter’, to “reconnect precipitation to the soil”. This poetic concept really just requires the installation of porous technology, whether concrete, asphalt or paving stones, which allows rainwater to move freely down into the soil below. Not only does this protect fresh water systems and storm drain infrastructure from being overwhelmed, but it also helps to replenish local groundwater sources. Topping up aquifers and springs with rain is, in essence, the OG reuse of water. Porous pavement thus becomes nature’s very own WRT.

© USA Environmental Protection Agency.

Another similar example is green roofs.

Take the SkyWater Concept. Developed by Sonoma, this technology installs smart green roof irrigation, allowing biodiverse plants and flowerbeds to reuse rainwater, and preventing buildings’ storm run-off from overwhelming draining systems. Sonoma’s green roofs seek to achieve a “zero-rainwater-discharge level”: they’re also designed to store excess rainwater, to irrigate the greenery in dryer weather.
An extra plus, green roofs help to mitigate what’s known as the “urban heat island effect”: they cool the buildings’ surroundings and maintain fresh temperatures inside, lowering demand for air conditioning. This is due to the plants’ evapotranspiration, aka, releasing water vapour back into the air. The company is further developing an add-on cleaning tech for the green roofs: a phyto-purification process to allow the greywater to be filtered and reused throughout the building itself. A powerhouse WRT.

An urban green (or ‘climate) roof. © Zinco.

Perhaps the most high-tech example of WRT is desalination plants.

Desalination produces freshwater by removing salt and other mineral components from seawater. It quite literally turns saltwater into drinking water (as well as various other less quality-stringent uses, such as irrigation, or, as mentioned before, toilet flushing). Desalination technologies are being developed worldwide, particularly in coastal countries that suffer from water scarcity and hot dry summers (imagine Israel, Spain, ecc.) There are two desalination processes, reverse osmosis (removing salt and impurities by transferring water through a series of semi-permeable membranes) and thermal desalination (changing salt water into vapour, and back into now pure water). MIT researchers recently built a portable desalination unit that generates clean drinking water without needing filters or high-pressure pumps. A huge achievement, the size of a suitcase. Whilst this, and many other desalination technologies require significant investment (most importantly to bring down operating costs and prevent damage to marine ecosystems), the scalability factor is immense – might we add that 70% of the world’s surface is covered in salt water. Perhaps the most exciting WRT to watch expand. 

Adelaide Desalination Plant. Source: ACCIONA.

Whilst not exactly an WRT, we wanted to close the article with a shout-out to nasoni or drinking fountains.

Whilst some would assume that they waste water, this is a myth. Fountains allow urban areas to continue to circulate water supply, rather than having it lie stagnant. This maintains water pipes and prevents water from breeding bacteria. Whilst it’s a circulation more than a ‘reuse’ of water, they help us to maintain water quality, to preserve it. To make the most of these in the scorching summer heat, Waidy WoW designed an app for Italian cities mapping the different (and it should be added FREE) water sources throughout the city. A bit more old-school but still functional, here’s a hyper detailed map of the active state of all drinking fountains in Rome.

Source: Lalupa via Wikipedia.


‘The Big Short’, Adam McKay’s award-winning film on the 2008 global financial crisis ends with a bone chilling statement. Dr Michael Burry, the derided genius who first predicted the housing market collapse and made nearly $1 billion by betting against it, “now focuses all of his trading on one commodity: Water”.
There is a reason why water is increasingly referred to as ‘blue gold’. It is a near priceless resource, that will dwindle in supply and increase in demand as we move towards 2030 and beyond.

Any and all ways to safely conserve and reuse water must be employed. WRTs are some of the most exciting and essential technologies we have to tackle future scarcity.