Is water cremation the same as aquamation and resomation?

Yes. Water cremation, aquamation, resomation, bio cremation, and green cremation all refer to the same process. Its technical name is alkaline hydrolysis. Resomation and bio cremation are trademarked brand names for the method.

What is left behind after water cremation?

Two things remain: soft white bone fragments that are pulverized into a fine, pure-white ash returned to the family, and a sterile, non-toxic liquid made up of peptides, soap, sugar, and amino acids that is disposed of through the sewer system.

How is it better for the environment than flame cremation?

Water cremation uses about one-seventh of the energy of flame cremation, around 300 degrees versus roughly 1,800 degrees Fahrenheit. It releases far less carbon dioxide and, because it runs cool, does not vaporize the mercury in dental fillings.

How much does water cremation cost?

Most facilities charge about the same as a traditional cremation, roughly $700 to $3,000. The chambers themselves cost providers between $90,000 and $450,000, which is part of why availability is still limited.

Is water cremation legal in my state?

It depends on where you live. Minnesota was the first state to legalize it in 2003, and as of 2026 it is legal in 26 states, though New Hampshire explicitly bans it and a few states that permit it don't yet have an operating provider. Check with a local provider to confirm availability where you are.

Can pets be water cremated?

Yes. Units are built specifically for pets, some with separate compartments so multiple animals can be processed without mixing their ashes. Costs run from about $150 for small pets to $400 for large animals, plus optional fees for pickup, mailing, or delivery.

Guides

Water cremation: how aquamation works, costs, and the eco case

Water cremation is widely seen as a gentler, greener alternative to flame cremation. You may also hear it called resomation, bio cremation, green cremation, or aquamation, and its technical name is alkaline hydrolysis. This guide explains how the process works, what the remains look like, how much it costs, where it's legal, and how it stacks up against traditional cremation, including options for pets. Some of the details below are of a sensitive nature.

What water cremation is and where it came from

Water cremation uses water, heat, pressure, and an alkaline solution rather than fire to reduce a body to bone fragments and a sterile liquid. Supporters point to it as one of the most environmentally friendly options available for end-of-life care.

The technology was first developed in Europe in the 1990s during the mad cow disease outbreak, where it was used to dispose of infected cattle. Through the mid-2000s, medical schools also adopted the method for handling human and animal remains before it began moving into the funeral profession.

Resomation and bio cremation

The name resomation is used frequently because it was first trademarked by Resomation Ltd, and the term bio cremation has also been trademarked. These are brand names for what is generically called alkaline hydrolysis.

Minnesota became the first US state to legalize the process in 2003, and as of 2026 the process is legal in 26 states, with more considering legislation. In a handful of those states it is legal but not yet offered by a licensed provider, so availability can lag behind the law.

Why it isn't legal everywhere

Legalization has rolled out unevenly. Many states have approved water cremation while others are still working through legislation, and the pace of acceptance mirrors the slow road that flame cremation once traveled.

Much of the resistance appears to come from unfamiliarity rather than any practical problem with the method itself. Supporters argue that the process gets a bad name largely because the public doesn't understand it, a perception not helped by the insensitive way it is sometimes depicted online and in print.

The icky factor

You'll repeatedly see water cremation described as having an icky factor. The liquid that remains after the process has the color of coffee, a syrupy consistency, and an ammonia smell, and it is disposed of through the sewer system.

Because of that, some people feel it amounts to pouring a loved one down the drain. In reality it is a sterile, non-toxic solution, and the disposal is comparable to how blood and fluids are handled during embalming.

Religious resistance

Religion has also slowed adoption, with some leaders viewing the process as disrespectful to the deceased. This echoes the long resistance to flame cremation, which took decades for religions and the wider public to accept.

The Catholic Church did not change its views on conventional cremation until the 1960s, and it has voiced similar objections to alkaline hydrolysis, with religious leaders opposing the procedure in a number of states.

How alkaline hydrolysis works

Alkaline hydrolysis mimics the natural decomposition a body undergoes when buried, but compresses what would take many years in the ground into just a few hours. Like flame cremation it relies on heat and pressure, but it does this without fire.

The body is placed into a sealed metal chamber along with a mixture of water and potassium hydroxide. The chamber is heated and put under very high pressure, and over roughly two to three hours the body is broken down into its basic chemical elements.

The machine

The process takes place inside a stainless-steel alkaline hydrolysis chamber. Resomation Ltd designed and patented the first commercial unit in 2007, naming it the Resomator.

It was the first commercial equipment built to dissolve a human body safely. The pressurized chamber is completely sealed and heated to a temperature high enough to sterilize its contents.

What happens during hydrolysis

Dressed or wrapped in a natural fiber such as silk or wool, the body is placed into the unit, which is then filled with about 80 gallons of water containing potassium hydroxide, an ingredient commonly found in the liquid soap we use at home. The mixture runs roughly 95% water to 5% potassium hydroxide.

The solution is heated to between 300 and 350 degrees Fahrenheit, hot enough to destroy any bacteria, and over the cycle the soft tissue of the body dissolves.

What the remains look like

After the process, soft white bone fragments remain. These are pulverized into a pure white, dust-like ash, noticeably finer than the gritty cremains left by a flame cremation.

The liquid left from the soft tissue is a non-toxic solution made up of peptides, soap, sugar, and amino acids.

Where the liquid remains go

The liquid is sterile and can be safely disposed of through the sewer system. This is the step that unsettles many people, conjuring images from movies in which a body is liquefied and poured down the drain.

In practice it is much the same as the routine disposal of blood and fluids that occurs during the embalming process, and the solution itself poses no hazard.

Benefits compared with flame cremation

Many of water cremation's advantages overlap with those of conventional cremation. Both take roughly the same amount of time to complete, both ease the strain of crowded cemeteries and shrinking burial space, and both spare the earth the tons of metal, wood, and embalming fluid that go into the ground with full-body burials each year. In both cases, the family can still receive the ashes afterward to keep, scatter, or memorialize as they wish.

A much lower energy footprint

Water cremation uses about one-seventh of the energy of a flame cremation. Fire-based cremation requires heat of around 1,800 degrees Fahrenheit, while water cremation needs only about 300 degrees.

Fewer carbon and mercury emissions

Although most flame cremation facilities use filters to keep carbon dioxide output low, the process still releases far more into the atmosphere than alkaline hydrolysis.

The intense heat of flame cremation also dissolves dental fillings, releasing mercury vapor. At the much lower temperatures used in water cremation, fillings stay intact.

Implants and metal are recovered

Because the process runs cool, items such as dental fillings, breast implants, and metal hardware like artificial hips, plates, and screws are not destroyed.

These are simply separated out after the cycle finishes. For these reasons, supporters consider water cremation the most environmentally friendly disposition method available.

What water cremation costs

For providers, the equipment is a major investment. Alkaline hydrolysis chambers have sold for anywhere from $90,000 to $450,000, which has slowed how quickly facilities adopt it.

For families, most facilities charge about the same as a traditional cremation, which can range from roughly $700 to $3,000. As the method becomes more widely used, prices are expected to level out and may come down over time. If you are weighing your options, our guide to cremation costs and a direct cremation can help you compare prices in your area.

Water cremation for pets

Alkaline hydrolysis units are now manufactured specifically for pets, and companies such as BioResponse build machines for both humans and animals. The process works the same way it does for people and offers families the same gentle, low-impact alternative to flame cremation.

Some pet units are built with multiple compartments so several animals can be processed at once without their ashes mixing, and containment bags serve the same purpose, ensuring a family receives only their own pet's remains. A single-chamber unit can handle an animal up to around 400 pounds, such as a horse, though capacity is lower when multiple pets are processed together.

Cost of pet water cremation

Pricing scales with size, running from around $150 for small pets up to 15 pounds to about $400 for large animals over 100 pounds.

Providers often add extra fees on top: roughly $75 to $150 for pickup depending on size, $25 to $75 for mailing the ashes, up to $100 for after-hours or weekend service, and around $50 to hand-deliver the ashes.

The future of water cremation

As with flame cremation before it, the stigma around water cremation is likely to keep fading as more people understand the process and more states approve it. Acceptance tends to grow with familiarity.

For anyone already planning on cremation, resomation is worth considering, and it may especially appeal to those who want their final choice to leave the lightest possible footprint on the earth.

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