Alkaline Hydrolysis (Water Cremation) Explained: Process & Legality


Are you interested in cremation for yourself or a loved one? In past decades, it’s been a cheaper alternative to underground burial. But personal preference, religious views, and cost all play an important role in your end-of-life planning decisions. 

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There’s a new type of cremation that is an environmentally friendly alternative to traditional cremation — alkaline hydrolysis. It may be exactly what you’re looking for. Here’s what you need to know. 

What’s Alkaline Hydrolysis in Cremation?

When loved ones bury your body underground, your body undergoes the natural process of decomposition. This can take a long time. As evidenced by archaeological discoveries, bones can last for thousands of years under the right conditions. Alkaline hydrolysis — also known by other terms, such as resomation or aquamation — merely speeds up that process through flameless cremation. 

Cremation by water reduces your human remains to bone fragments. These fragments are pulverized and mimic traditional cremation. Afterward, you or your loved ones can store these remains in an urn, a mausoleum, or in any other way you choose. 

The process itself uses water, heat, and alkaline chemicals to accelerate decomposition. This solution reduces the body to organic compounds, just like natural decay.

Difference between alkaline hydrolysis and traditional cremation

First, you’ll have to understand how traditional cremation works. Traditional cremation requires flames and extreme heat to reduce a body to ashes. Temperatures range from 1,400 to 1,600 degrees Fahrenheit. Once the severe heat and flames reduce the remains to bone fragments, these are pulverized and stored in an urn. 

Flame-based cremation relies on a machine called a cremator. In the first half of the process, primary combustion burns off the casket, tissues, organs, and fat. This occurs in the cremator’s first chamber. 

Afterward, this waste transitions to a secondary chamber. All bone fragments remain in the first one. Gases produced by combustion go outside through a chimney in the building’s roof. 

Cremation by water doesn’t rely on flames or extreme heat. Rather than artificial decomposition through flame, alkaline hydrolysis is very natural. Your body is placed in an airtight, watertight chamber and the chamber is filled with a solution of water and alkaline chemicals. 

Pressure and agitation are sometimes used to speed up the process. Heat is more often used. The liquid solution reaches a temperature between 199 and 300 degrees Fahrenheit. 

There’s no combustion involved or emissions that contribute to greenhouse gases in aquamation. For these reasons, water cremation is an interesting option if you’re interested in the impact your end-of-life planning has on the environment. 

What do you do after someone dies?

Follow the guidance of our post loss checklist.

How Much Does Alkaline Hydrolysis Cost? 

The equipment required, especially an alkaline hydrolysis machine, carries a hefty price tag but you may not notice a financial difference compared to traditional cremation. For both cremation types, the cost ranges between $700 and $3,000.

Traditional burials tend to cost much more. The cost of a headstone, a gravesite, a casket and a gravedigger’s fee usually costs over $5,000. Green burial options are cheaper and gaining popularity but they still cost more. By contrast, factors involved in alkaline hydrolysis are simple. 

The state you live in, the size of your body, and personal preferences all play a role. The type of memorial service you choose will factor into total costs. If cost is a primary factor, cremation has traditionally been the way to go. A less intensive, environmentally-friendly option, alkaline hydrolysis may be attractive to you for those reasons. 

How Does it Impact the Environment?

Resomation is gaining ground for many reasons  — not to mention, it’s nice to be able to have another burial option. One primary reason is its minimal impact on the environment. 

A primary concern with traditional burial is that the earth is running out of room for more people to be buried in cemeteries and so many caskets in small spaces negatively impact the local environment. 

This is why many people prefer cremation. Unfortunately, traditional cremation utilizes natural gas, which releases harmful emissions and greenhouse gases into the environment. It also requires a significant amount of energy to reach temperatures above 1,400 degrees Fahrenheit. 

Flameless cremation uses one-seventh of the energy required by traditional cremation. It also eliminates metal, wood, and embalming fluids from being buried in the earth and there’s also no release of toxic greenhouse gases. Cremation by water leaves a very small footprint. 

Where is Alkaline Hydrolysis Legal?

Water cremation is legal in many states. However, it’s faced the same opposition as traditional cremation by religious authorities. Acceptance is slow, mainly because it’s a different way to deal with human remains, and many people aren’t comfortable with the concept yet. 

Aquamation is currently legal in the following states: Washington, Oregon, Idaho, Wyoming, Colorado, Nevada, Utah, Kansas, Missouri, Minnesota, Illinois, Alabama, Georgia, Florida, North Carolina, Delaware, Maryland, Washington, D.C., Connecticut, Vermont, and Massachusetts. It is also legal in parts of Mexico, the U.K., Australia, and Canada.

Alkaline Hydrolysis Process 

After death, your remains or those of a loved one will be transported to the funeral home. Then, the body will be placed in an alkaline hydrolysis machine, which can hold 100 gallons of liquid. 

What’s in the Liquid Solution?

Alkaline chemicals and water compose the liquid solution. Exact ratios are determined by unique factors, such as gender and weight. The body will be placed in the chamber, and it will fill with that solution. 

Sometimes, pressure and agitation are used. This depends on the provider and the equipment available. Usually, mild heat is used to accelerate the process. 

How are Remains Treated?

Once the alkaline hydrolysis machine has completed the process, bone fragments and liquid are left. It’s usually the liquid part that raises controversy. 

As soon as that part of the process is described, loved ones are rightfully concerned that part of the deceased’s remains are being “poured down the drain.” This isn’t the case! In natural decomposition, fat and tissues eventually revert to their original form. This equals basic organic compounds. 

That includes salt, sugars, amino acids, and peptides. These organic compounds are what make up the leftover liquid. After the process is over, that liquid is released to wastewater treatment plants. Usually, this liquid — referred to as effluent — is cleaner than most wastewater released into the plant daily. 


The remaining bone fragments are allowed to dry. After that is complete, fragments are pulverized into ashes. The process differs from flame-based cremation — which means you should account for 32% more cremated remains. Flame-based cremation leaves less ash. 

Once the bone fragments are pulverized into ashes, they’re stored in a strong plastic bag. This bag is placed in an urn and given to a loved one. 

You can determine what you’d like to have happen after your ashes have been stored properly. Some people want to remain in an urn that loved ones can keep nearby. Others want their ashes scattered in a special location. Think about what’s right for you, so you can make a confident, comfortable decision. 

Is Resomation Right for Me?

Cremation by water is a gentle, environmentally-friendly approach. It’s a great alternative to flame-based cremation and can even be considered a more natural burial. Resomation also accounts for concerns about toxic emissions and limited burial space. 

For these reasons, flameless cremation may be right for you. No matter what choice you make investigate your options and make sure that your loved ones know you’d like to use this method of burial. That way, your future wishes are known and there’s no question what will happen once you die.

Think about your preferences, investigate options, and communicate them to your loved ones — it all takes time and may even be emotional. However, end-of-life planning is much harder to do when you or a loved one are in mourning.


  1. “Alkaline Hydrolysis.” Cremation Association of North America,
  2. “Water Cremation: Is Resomation a Green & Bio Friendly Solution?” Cremation Institute,

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