The new wave of body disposal: alkaline hydrolysis

In Hobart’s industrial area, nestled between a karate school and a food and beverage distributor, is Australia’s newest body disposal provider. (Some people prefer the term ‘disposition’, but I call a spade a spade.) Co-founders Luke Cripps and Brendan Cooper opened their doors to me last week.

‘Alluvium Water Cremations’ uses the process of alkaline hydrolysis. It’s something that’s becoming common in the USA, with about 12 states offering the method so far. It’s available in Canada, South Africa and Ireland too. It’s been quietly available in Australia for more than a decade. Alkaline hydrolysis is available for pets too, and it’s been used in agriculture for decades (known as tissue digestion).

How does it work?

Alkaline hydrolysis breaks down the building blocks that make up the human body – the proteins, lipids/ fats, nucleic acids, carbs, etc. In this Tasmanian operation, the body is broken down using water and potassium hydroxide, an alkaline solution with a high pH that is washed repeatedly over the body.

Let’s break Luke and Brendan’s process down, step by step.

• The body, wearing or covered with natural fibres that break down just like the body, is laid in the tray of a big stainless-steel chamber. (Yes, no coffin is needed.)
• About eight kilos of potassium hydroxide in granular form is added to the tray.
• Chamber is closed and filled with about 800 litres of water (which does not fill the whole chamber)
• The machine is tilted upwards to about 34 degrees to ensure the water covers the whole body. This also ensures the bones are concentrated at the bottom end after the process.
• Water is heated to 93 degrees
• For the next 10-12 hours, the water flows backwards and forwards over the body. It’s this flow movement that is instrumental to the process. Time and temperature can be adjusted, depending on size of the body, and body composition (fat vs skinny, big boned vs not, for example).
• Carbon dioxide (gas) is pumped into and dissolved in the used water. This lowers the pH to about 8. (It works by the CO2 releasing hydrogen ions in carbonic acid to lower the pH. It’s at this point I wish I’d finished my Medical Laboratory Science degree at QUT in the 90s.) 
• The nutrient-rich, CO2-treated water is stored in an IBC (bulk container), ready to be taken away by TasWater, for more wastewater treatment. (UPDATE: 10/1/25 – A trade waste agreement with TasWater did not go ahead. TasWater told me that “Alluvium manages their own waste generation, treatment, and disposal. they do not hold a trade waste agreement with TasWater and don’t discharge any trade waste into our sewerage infrastructure.”) 
• Bones are removed from the tray, dried, then crushed into a fine powder.

What’s left?

Once the chamber is drained, what’s left is quite amazing – very white, soft bones that are then ground down into a very fine white powder. When the remains (cremains) are ground down after a fire cremation, they’re coarse, grey, and granular-like.

(Screen shot from Vice Asia)

Everyone offering alkaline hydrolysis will tell you that it’s more environmentally friendly than the ‘LPG gas guzzling’ and ‘greenhouse gas emitting’ fire cremation. (Fire cremation uses gas to heat the furnace to around 900 degrees Celsius for about 90 minutes.) Without accessible, peer-reviewed data, consumers are left to the mercy of PR messaging.

In this Tassie version of alkaline hydrolysis, the main energy use happens at the start of the process when the water, about 800 litres of it, is heated to 93 degrees. It remains at that temp for 10-12 hours. After the body has been broken down, carbon dioxide (the gas cylinder you can see in the video) is pumped through the water, decreasing its pH from 11 to 8. This is the first step in making the water suitable to be released back into the water cycle or sewerage system.

Because a body is rich in nutrients, it makes sense that the water is very nutrient-rich at the end of the process. Operators claim that there is no DNA in the remaining water and that the water is sterile. Alluvium initially claimed that the local water authority, TasWater would take the water away and treat it like it does its other wastewater; however, TasWater told me in January 2025 that this wasn’t the case and that Alluvium manages its own waste generation, treatment, and disposal.)

Not Australia’s first aka ‘same same but different’

There are three other alkaline hydrolysis providers in Australia (one is Vic-based with a facility at Moama in NSW, just over the Victorian border, and another in Townsville and Mackay in north Qld). All three operators offer a similar outcome with different machines/technology.

Update: 20/6/24 – Alkaline hydrolysis will be available in Brisbane before the end of the year. It’s also planned for the Sunshine Coast and Rockhampton, with other locations including the Gold Coast, Cairns and Sydney being explored.

Writing down your wishes

It’s great that families have more choice. Once you’ve decided how you’d like your body dealt with (conventional or natural burial, fire cremation, water cremation), make sure you tell your family or write it down in The Bottom Drawer Book: the after death action plan. Then, at a time of grief, your family will have one less thing to worry about: they’ll know exactly how you’d like to be farewelled.

No regulation

Like the rest of the funeral industry in Australia, there is very little regulation of providers in the business of death. Some funeral directors are screaming out for regulation, others don’t want a bar of it.

Alkaline hydrolysis providers have had to jump through hoops to meet the operational requirements of both state and local governments. If you’re keen to utilise alkaline hydrolysis, go and meet the operators and check out their facilities and equipment to find out if their version of the process is for you. If you’re specifically keen to use it for its environmental credentials, do your homework. And that’s hard to do because the claims of being environmentally friendly are uncontested, with no peer-reviewed studies and data available.

Perhaps start by asking your chosen provider how the remaining nutrient-rich and high-alkali water is treated and where it ends up.

It’s all about making an informed decision that’s right for you or your loved one, whether it’s water cremation or the more traditional methods of burial or fire cremation.

And remember, you are welcome to shop around funeral providers to find the right one for you. And …

“If a funeral business does not show you behind the scenes on request, find another funeral provider. What don’t they want you to see?”

Me, Lisa Herbert