Water Cremation: How Alkaline Hydrolysis Works and Where It's Legal

Water cremation dissolves a body in a heated solution of water and alkali instead of burning it. The technical name is alkaline hydrolysis. Funeral homes sell it as aquamation, resomation, bio-cremation, flameless cremation, green cremation, or liquid cremation.^[3] Six names, one process. If a provider uses any of them, they are describing the same chamber, the same chemistry, and the same result.

The chemistry is old. Amos Herbert Hobson patented it in 1888 as a way to process animal carcasses into fertilizer. The Mayo Clinic has used it for its donated-body program since 2005, and Minnesota became the first state to authorize it for human disposition in 2003.^[2] What is new is availability. Over the past two decades, a slow march of state legislation has made it a legal option for roughly half the country, and the number of states keeps climbing.

Why does anyone pick it? Three reasons come up again and again: it uses far less energy than flame cremation, it releases nothing into the air, and it feels gentler to some families than fire. Whether those reasons hold up is what the rest of this guide is for.

One correction to the most common misunderstanding: this is not dissolving a body in acid. The process uses the opposite of an acid, a strong base, usually potassium hydroxide.^[2] It speeds up the same decomposition that happens to every buried body over decades and compresses it into hours.

Here is what happens, step by step.

• The body goes into a stainless steel chamber. Most providers place the person who died in a biodegradable pouch or on a metal cradle first. No casket. No embalming required.
• The chamber fills with roughly 100 gallons of solution. About 95 percent water, 5 percent alkali, usually potassium hydroxide, sometimes sodium hydroxide.^[1][3]
• The solution heats to between 199 and 302 degrees Fahrenheit. Some systems add pressure and gentle agitation.^[1]
• The cycle runs 3 to 16 hours, depending on the equipment and the size of the body.^[1] High-pressure systems run hotter, around 320 degrees, and finish in 4 to 6 hours. Low-pressure systems run near 208 degrees and take 14 to 16 hours.^[2]
• Soft tissue dissolves. The skeleton does not. At the end of the cycle, the chamber holds bone and liquid, and nothing else.

Compare that to flame cremation, which burns the body in a gas-fired furnace. We cover that process, and its real prices, in our guide to how cremation works and what it costs.

Two things remain after alkaline hydrolysis: bone and liquid.

The bone. The skeleton comes out of the chamber intact, softened, and pure white. The fragments are dried and reduced to a fine powder, then returned to the family in an urn, exactly as flame-cremated remains would be. One practical difference: alkaline hydrolysis returns about 32 percent more remains than flame cremation, because the process does not burn away any of the bone. Families sometimes need a larger urn.^[1]

The liquid. This is the part people ask about, so here it is plainly. The water and dissolved tissue become a sterile solution of salts, sugars, amino acids, and peptides.^[1] A full cycle produces roughly 120 to 300 gallons of it per 1,000 pounds processed, and the solution ends at a pH around 11.^[2] The liquid is disposed of through the sanitary sewer system, the same route a hospital or embalming room uses, or in some cases applied to a garden or green space.^[2]

Some people find that disturbing. Others point out that flame cremation sends the same material up a smokestack instead. Neither option keeps the body intact. That is what disposition means, and you should decide how you feel about the liquid before you sign, not after.

As of March 2026, alkaline hydrolysis is legal for human disposition in 26 states, according to the Cremation Association of North America.^[1]

Those states: Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Idaho, Illinois, Kansas, Maine, Maryland, Minnesota, Missouri, Nevada, North Carolina, Oklahoma, Oregon, South Carolina, Tennessee, Utah, Vermont, Washington, West Virginia, and Wyoming.^[1]

Industry reporting says New York finalized its regulatory guidelines in early 2026, which would allow funeral providers there to install the equipment.^[6] CANA's official list did not yet include New York as of March 2026, so if you live there, call the state Division of Cemeteries or a local funeral home and ask directly.

Two warnings about that list.

Legal does not mean available. A state can authorize the process years before any funeral home installs a machine. The equipment is expensive, so providers are concentrated in a handful of metro areas even inside legal states. Many funeral homes that advertise aquamation do not perform it on site. They transport the body to a facility that does, sometimes hours away.^[3] Ask.

Illegal in your state does not mean impossible. Funeral homes transport bodies across state lines routinely. If water cremation matters to you and your state has not authorized it, ask providers in the nearest legal state whether they accept out-of-state transfers, and what transport adds to the bill.

The rest of the world is moving slower. Ireland became the first European country to offer the service, in 2023. The United Kingdom has refused permits so far, in part because no water-industry standard exists there for releasing the effluent into sewers.^[2] The regulatory fight, everywhere, is about the liquid, not the bones.

You will see the figure "$2,000 to $3,500" quoted around the internet. Current tracked pricing runs higher in most markets, so budget from real numbers, not old blog posts.

Based on May 2026 pricing data from US Funerals Online, a standard water cremation in the United States runs $2,500 to $4,500. A direct arrangement with no ceremony, just transport, the process, and the return of remains in a simple container, starts lower: the cheapest tracked provider charged $1,075 in Las Vegas, and low-cost markets cluster between $1,000 and $1,500. Full-service arrangements with a viewing reached $5,000 at the high end.^[4]

That makes water cremation typically $500 to $1,000 more per arrangement than flame cremation, though the gap is narrowing as more facilities open.^[4] Against a conventional burial with a casket, vault, plot, and headstone, water cremation is typically $4,500 to $10,000 cheaper.^[4]

The premium exists because the machines are scarce. Prices vary sharply by state, and a provider with the only machine in the region has little reason to discount. Get quotes from more than one provider, and remember that federal law requires funeral homes to give you prices over the phone.^[5]

The environmental case is the reason most people consider water cremation, so the numbers deserve scrutiny. The honest answer is that the published figures vary by study and equipment, but they all point the same direction.

• A typical alkaline hydrolysis cycle uses about 90 kilowatt-hours of electricity, roughly one quarter of the energy of a flame cremation.^[2]
• Hawaii's authorizing legislation cited about one-eighth the energy use and a 75 percent reduction in carbon emissions compared to flame cremation. A Pennsylvania legislative analysis put energy use roughly 90 percent lower.^[3]
• The process produces no direct emissions. Nothing goes up a stack, including the mercury from dental fillings that flame cremation vaporizes.^[3]

No direct emissions does not mean zero footprint. The electricity that heats the water comes from somewhere, and potassium hydroxide has to be manufactured. But burning a body requires holding a natural gas flame for hours; heating water to 200 or 300 degrees does not. Whichever figure you trust, water cremation uses a fraction of the energy.

If your priority is the smallest possible footprint, compare it against burial without embalming or a vault. We break that down in our complete guide to green burial.

There is no national water cremation directory that covers everyone, and providers hide under six different names. Here is the practical path.

• Search all the names. Try "aquamation," "water cremation," and "alkaline hydrolysis" plus your city or region. A provider two hours away may still serve your area; most quote transport as a line item.
• Ask the on-site question. "Do you perform alkaline hydrolysis at your facility, or do you transport to another provider?"^[3] The answer affects the timeline and the price, and you are entitled to know where the body will go.
• Use your Funeral Rule rights. Federal law requires funeral homes to give you price information over the phone, hand you an itemized general price list, and let you buy only the goods and services you want.^[5] No provider can force a package on you. We cover the full law in our guide to the FTC Funeral Rule.
• Get the quote itemized. Transport, the process itself, the container, the urn, death certificates, and return of remains. The $2,500 quote and the $4,500 quote often differ only in what is bundled.
• Planning ahead? Put it in writing. If you want water cremation for yourself, name it in your disposition instructions and tell the person who will make the arrangements. A preference nobody knows about is a preference that does not happen.

Water cremation is legal in 26 states, costs a few hundred dollars more than flame cremation, and uses a fraction of the energy. If those trade-offs work for you, the only remaining task is finding the machine. Start with the phone calls now, not at 2 a.m. on the worst night of your year.