What Is Water Cremation?

Water cremation — also known as aquamation or alkaline hydrolysis — is an alternative to flame, or fire, cremation.

Like flame cremation, water cremation is a process that reduces human remains to bone fragments. But instead of flame, it uses water and an alkali solution of potassium hydroxide that, when heated, dissolves the body, leaving behind bone fragments and a sterile liquid. Alkaline hydrolysis accelerates the natural decomposition process from the decades required of a conventional casket burial to hours.

During the process, the remains are placed in an airtight capsule with alkalized water, and through gentle water flow, all organic material is broken down. When the process is complete, the bone remains are collected, dried, and processed before being returned to the family.

Environmentally speaking, it’s estimated that water cremation can cut energy use by 90 percent and greenhouse-gas emissions by 35 percent. (Flame cremation produces about 1.04 billion pounds of carbon dioxide each year in the United States.) The effluent is returned to wastewater for processing, so the water is not wasted.

Environmentally speaking, it’s estimated that water cremation can cut energy use by 90 percent and greenhouse-gas emissions by 35 percent.

From a financial perspective, water costs about the same or slightly more than flame cremation.

The aquamation process yields about 20 to 30 percent more ashes. These are typically white or tan, while the ashes from flame cremation are grayer in color.

Water cremation is legal in about half the states, and even where it is legal, few facilities offer the service, making access an ongoing issue.

As such, it’s worth noting that alkaline hydrolysis is the greener cremation option, but fire cremation is considered more eco-friendly than conventional burial. Moreover, there are environmentally conscious steps you can take to make fire cremation an even greener option. (Again, “green” exists on a spectrum.)

The Order of the Good Death, a nonprofit dedicated to “building a meaningful, eco-friendly, and equitable end of life,” offers the following tips to green your fire cremation:

• Choose the crematory closest to you that has the newest equipment.
• Buy carbon offsets yourself or find a funeral home that purchases these for every cremation.
• Don’t buy funeral products that insist they are going to make a tree out of the ashes.