Alkaline hydrolysis — also referred to as aquamation, water cremation, or flameless cremation — is a gentle, environmentally friendly alternative to traditional flame cremation and burial. Using a combination of water, alkaline chemicals, heat, and gentle pressure, the process accelerates the natural decomposition of the body, returning it to its essential organic elements in a matter of hours. With a carbon footprint that is up to 90% lower than traditional flame-based cremation, aquamation is rapidly gaining traction as a premier choice for eco-conscious families.
The Science of Alkaline Hydrolysis
Despite the term 'water cremation,' the process is actually an acceleration of natural decomposition. When a body is buried in the earth, it eventually breaks down through alkaline hydrolysis over several years. The aquamation machine accomplishes this same chemical breakdown in just 3 to 16 hours.
Here is how the scientific process works:
- The Solution: The body is placed in a stainless-steel pressurized vessel. The vessel is filled with a solution consisting of 95% water and 5% alkaline chemicals (typically potassium hydroxide and sodium hydroxide).
- Heat and Pressure: The solution is heated to approximately 300°F (150°C), but the vessel is pressurized to prevent boiling. The combination of heat, alkalinity, and gentle circulation dissolves the chemical bonds holding the body's tissues together.
- The Result: The process breaks down proteins, fats, and nucleic acids into a sterile liquid solution of amino acids, peptides, sugars, and salts. Only the inorganic bone minerals (calcium phosphate) remain.
- Processing the Remains: The sterile liquid is safely disposed of through municipal wastewater systems (or used as fertilizer), and the remaining soft bone fragments are dried and processed into a clean, white powder similar to traditional ashes.
Environmental Benefits: Water vs. Flame
Alkaline hydrolysis is widely considered the greenest form of final disposition available. Compared to traditional flame cremation, it offers significant environmental advantages:
- No Direct Emissions: Aquamation produces zero direct greenhouse gas emissions. Traditional cremation releases roughly 540 pounds of carbon dioxide per body, along with mercury vapor from dental fillings.
- Energy Efficiency: The process uses roughly 90% less energy than flame cremation, which requires sustained temperatures of 1,600°F–1,800°F for several hours using natural gas.
- Mercury Containment: Any mercury from dental fillings remains intact in the vessel and is safely recovered for recycling, rather than being vaporized into the atmosphere.
- Preserves Land: Like flame cremation, the resulting ashes require no permanent cemetery land, though they can be buried in a small plot or columbarium niche if desired.
Is Aquamation Legal in Your State?
As of 2026, alkaline hydrolysis is legally approved for human disposition in over 25 states. These include:
- California, Colorado, Florida, Illinois, Minnesota, Missouri, Nevada, North Carolina, Oregon, Washington, and many others.
However, even in states where the process is legal, finding a local provider can be difficult. The equipment is expensive to install, and local zoning laws or municipal wastewater regulations sometimes delay funeral homes from offering the service. Always call local providers to confirm availability.
What Do the 'Ashes' Look Like?
Families who choose aquamation receive the remains in an urn, just like traditional cremation. However, there are visual differences:
- Color: The remains from aquamation are typically clean, uniform, and white. Flame cremation remains are often darker grey or off-white due to carbon soot.
- Volume: Aquamation yields approximately 20–30% more remains than flame cremation. This is because the process preserves all bone minerals without burning any off. You may need a slightly larger urn to accommodate the remains.
- Texture: The processed remains have a fine, powdery texture, whereas flame-cremated remains are often coarser and contain small bone shards.
Comparing Costs
The cost of aquamation is generally comparable to a traditional funeral or high-end flame cremation, typically ranging from $2,500 to $5,000 depending on the provider and region. While more expensive than direct flame cremation (which can be found for $1,000–$2,000), many families find the environmental benefits and gentle nature of the process well worth the additional cost.