A guide to water cremation

Water cremation, or alkaline hydrolysis, is a process that uses water, heat, and chemicals to break down human remains. In this article, we’ll cover how it works, why you might choose it, and where in the world it’s available.

It’s an alternative to burial and cremation that people are slowly adopting around the world. Its biggest benefit is that it’s very environmentally friendly. It requires no land space, and creates very few carbon emissions.

Water cremation has a few different names

You might have heard it referred to as:

  • Alkaline hydrolysis

  • Liquid cremation

  • Hydrocremation

  • Biocremation

  • Resomation

  • Aquamation

Resomation and Aquamation are brand names, created  by the companies who’ve developed the technology. Resomation is the most widely adopted technology for water cremation in the world to date. The main difference is that Resomation takes 4 hours, whereas Aquamation takes around 14. 

The process has also been referred to as ‘flameless cremation’ and ‘green cremation’.

Water cremation breaks down natural tissues in around 4 hours

It’s much quicker than the eight to twelve years it takes for bodies to break down in graves. 

The process involves placing the body in a large water chamber, which is then filled with hot water and potassium or sodium hydroxide (these compounds are commonly referred to as lye - they are very similar and used interchangeably). Temperatures reach 160℃, but the pressure in the chamber prevents the water from boiling. The combination of water, heat, and chemical compounds causes the natural tissues of the body to dissolve.

This just leaves the bones, which emerge from the process as pure calcium phosphate. They will be very white, soft, and brittle. They are usually powdered and returned to the family of the person who’s died. They can be treated in much the same way as ash - kept in an urn, or scattered in a meaningful place.

You can decide what to do with the remains

After a water cremation, the bones, the fluid, and any dental fillings, prosthetics, and implants the person had will be left over. They will have been naturally sterilised during the alkaline hydrolysis process. 

These items are usually returned to the family of the person who’s died, or the facility can handle them for you. 

The resulting fluid is sterile or ‘clean’

The fluid that results from the process is composed of the natural proteins (specifically amino acids), peptides, sugars, and salts that make up the human body. The family can decide what to do with the fluid. 

Some choose to place it in a garden of remembrance, or at a site that was meaningful to the person.

An old technology with a new, green use

Alkaline hydrolysis dates back to the 1880s. Historically, it’s been used:

  • In the processing of animal bodies

  • As an alternative to pet cremations or burials

  • In the disposal of bodies used for medical research, and by the Mayo Clinic in the US

Following the BSE epidemic of the 80s and 90s (commonly known as mad cow disease), alkaline hydrolysis was found to be a much more efficient and environmentally-friendly way of disposing of the many cow carcasses that were usually burned. It was also extremely effective at destroying the pathogens that caused the disease, which flame cremation didn’t guarantee. 

Alkaline hydrolysis was then adapted for human cremations

Sandy Sullivan, a Scottish biochemist, developed the first water chamber for human water cremation in 2009. He termed the system the Resomator, and the process ‘Resomation’.

Water cremation is slowly being legalised and adopted around the world

In North America, alkaline hydrolysis is currently legal in 18 states, with laws being reviewed in a further 5 states. By the end of 2019, 5000 people in America had opted to have a water cremation.

The process is also starting to be adopted in Canada, Australia, Mexico, and the Netherlands. 

It’s not yet available in the UK, but that may change

There are no laws against water cremation or alkaline hydrolysis in the UK. However, the process needs very specific facilities which cost over £300,000 to install. UK councils and cremation services have yet to purchase any. 

In 2017, Sandwell Council (in the Midlands) attempted to partner with Leeds-based Resomation Ltd to install a Resomator. It was blocked by Severn Trent Water due to concerns over liquefied remains entering the water system. 

Resomation Ltd argued there is no more risk to water safety than that of  fluids from hospitals and funeral services (like embalming fluids). The founder of Resomation Sandy Sullivan says  that the waste water doesn’t contain any human DNA - just amino acids, peptides, sugars, and salts.

Promising studies conducted throughout 2019 showed that water cremations don’t pose a risk to wastewater treatment or sewer systems. As a result, Yorkshire Water is likely to allow Resomation Ltd to start developing. Plans to upgrade a crematorium in Bradford with a Resomation facility are also being discussed.  

Read our guide for more information on cremations

If you need to organise a cremation, or want to know more about traditional cremations in general, our what happens at a cremation guide will explain exactly what it involves and how much it costs.

Water cremations come with several advantages

They don’t take up space

In cities with dense populations, burial space is limited. Liquid cremation is emerging as a new option that doesn’t take up space.

They have a lower environmental impact

When bodies are buried, chemicals like embalming fluids and chemotherapeutic agents make their way into the soil. When they’re burned, carbon emissions are produced. 

There are no mercury emissions

Mercury is released into the atmosphere when people with dental fillings are cremated. Water cremation is less harmful to the earth and to the ozone layer. 

Water cremation doesn’t require a coffin

Coffins use natural wood resources to build, and take a long time to decompose. They can also be expensive, and some families of people who’ve died feel pressure to purchase an ornate or expensive one. In a water cremation, the body will be placed directly into the water chamber.

You can still hold a traditional funeral or wake with water cremation

If someone close to you has died, or you’re in charge of funeral arrangements, it’s up to you how you say goodbye. As and when they become available in the UK, water cremations will likely be conducted in a similar way to traditional or ‘flame’ cremations. 

This might mean organising a ceremony at the facility or crematorium. It might be a small or closed ceremony, or a traditional funeral proceeding that’s open to anyone who wants to attend.

Alternatively, you might choose not to have a funeral service, but to host a wake afterwards. Or you might choose to just have a private water cremation without a funeral or a wake.

Speak to us about making arrangements

If you’re unsure about the type of arrangements you should make for someone who’s died, you can speak to us to discuss the different options. You can also read our guide on organising a simple funeral service.

Costs for water cremation might be similar to traditional cremations

Because water cremation is not yet available in the UK, it’s difficult to say how much it will cost. Resomation facilities are very expensive for councils and crematoriums to buy, so costs might be higher than the average burial or traditional cremation

However, it might be that costs will eventually fall in line with flame cremations as the process becomes more widely used.

Water cremation might be a good option for eco-conscious people

If you’re considering water cremation for someone who’s died, the option might suit their wishes if they were particularly concerned about the environment. It’s nice for some people to know their death will be as gentle as possible on the earth. 

It can be a comfort for friends and family to have ashes to scatter, which forms a familiar and traditional part of the ritual of saying goodbye. 

Our choices about what will happen to our bodies after we die are very personal. Some people don’t like the idea of flame cremations, and some don’t like the idea of being buried. Water cremation will likely present another option in the not so distant future.

Article reviewed

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