What is “aquamation”, the method of cremation with water and alkaline chemicals that allows a corpse to be disposed of in an ecological way in three hours

At his death, at the end of December, having just turned 90, Archbishop Desmond Tutu he had become an anti-apartheid hero, a religious leader and a strong advocate for environmental protection, a voice heard and respected halfway around the world. Regardless of who he was or what he did, his death was news too for how Tutu decided to say goodbye to this world.

Instead of a conventional burial, with his body resting in a tomb, underground, or a cremation to use, with fire, the archbishop decided that his corpse should undergo a process of “aquamation”, the also known —and this is the way recommended by the Fundéu and the RAE— “cremation with water”, an alternative that its defenders defend as more ecological.

What exactly? Broadly speaking —and as its name suggests—, “aquamation” consists of undoing the remains of the deceased with water instead of flames. The body is immersed in a pressurized, airtight metal cylinder filled with a liquid solution of water and alkaline chemicals, which is heated to a temperature ranging from 90 to 150°C. One of the “ingredients” often used is potassium hydroxide. Over time, the bonds between chemicals in the body break down in a process called hydrolysis, and the organic matter liquefies. Everything except the bones, which are later processed and reduced to powder. Once prepared, the remains are deposited in an urn and delivered to the family of the deceased.

A greener goodbye

In addition to heat, water and chemicals, sometimes the process also requires pressure and agitation. “The decomposition that occurs in alkaline hydrolysis is the same as during burial, only considerably accelerated by chemicals,” specifies the North American Cremation Association (CANE). The resulting liquid, the effluent, is sterile and contains salts, sugars, amino acids, and peptides. “There is no tissue or DNA left when the process is complete,” clarifies the association, which explains that the effluent is disposed of along with the rest of the wastewater.

The pressurized chamber used in the process contains about 450 litres, although —as CANA details— the volume largely depends on the sex, body mass and weight of the deceased. The entire process takes between three and 16 hours. The North American institution defends that the effluent is “much cleaner than most” of the waters in the waste collection system and is disposed of in compliance with the regulations that apply in each region. “In some cases, the water is diverted and used as fertilizer due to the potassium and sodium content,” he adds.

It is not the only advantage that its defenders highlight. The American company Bio-Response Solutions, specialized in “acuamación”, ensures that throughout the process “90% less energy than flame cremation”, and adds: “It does not emit harmful greenhouse gases”. Resomation, another firm in the sector, based in the United Kingdom, estimates that throughout the process five times less energy is used than fire and that the system reduces harmful gas emissions to the atmosphere of a funeral by about 35%.

As for the deceased, CANA ensures that at the end of the treatment, 32% more cremated remains than with cremation. Being a green alternative was, in fact, what led Desmond Tutu to opt for a process that is not yet regulated in some countries. “It was what I aspired to as an environmental activist that I was,” came to detail his friend Michael Weeder.

Although the origins of water cremation date back to the late 19th century, when Amos Herbert Hanson developed it while looking for a way to make fertilizer from animal carcasses, its implementation at a commercial level among humans is recent.

CANA details that it was not used in the funeral industry until 2011, when it was released by Ohio and Florida. To this day, there would still be US states where the system is still being evaluated. Countries like the United Kingdom, Canada or the Netherlands have also been legalizing it over the years. In Spain, however, legislation does not yet allow the technique to be adopted.

Cover Image | Israelress (Wikimedia)