Water Cremation in Washington State: Alkaline Hydrolysis Laws and Providers

Water cremation — known legally as Alkaline Hydrolysis (AH) and informally as aquamation — is fully legal in Washington State and has been for years. Washington was among the earliest states to recognize it as a legal form of final disposition, and it remains one of the more established markets for the service in the country.

If you're considering it for a loved one or pre-planning your own arrangements, here's what you need to know about how the process works, what the law requires, and how it compares to the alternatives.

What Alkaline Hydrolysis Actually Is

Alkaline hydrolysis uses a combination of heat, pressure, water, and a base chemical agent — typically potassium hydroxide — to accelerate the natural decomposition process. Over the course of a few hours in a pressurized stainless steel vessel, soft tissue dissolves completely. What remains are bone fragments and a sterile liquid effluent.

The bone fragments are processed into a fine, ash-like powder — similar in appearance to conventional cremation remains — and returned to the family. The effluent, which is sterile and meets safe harbor standards for wastewater discharge, is released to municipal water systems at licensed facilities.

The family receives the bone powder, which can be placed in an urn, scattered, or handled in any of the same ways as conventional cremated remains. Washington law treats AH remains identically to flame cremation remains for all legal purposes.

Legal Status Under Washington Law

Alkaline hydrolysis is explicitly legal in Washington under RCW 68.50.110, which defines "cremation" to include multiple processes of reduction, including alkaline hydrolysis. The Washington State Department of Licensing (DOL) regulates AH facilities under the same licensing framework as conventional crematories.

Operationally, AH requires the same documentation as flame cremation:

1. Death certificate filed within five days of death, using the state's WHALES electronic registration system
2. Burial-transit permit issued by the local health registrar after the death certificate is accepted
3. Written authorization from the legally recognized next-of-kin or designated agent, following the hierarchy established under RCW 68.50.160

There is no additional permit, no separate regulatory filing, and no waiting period beyond what's required for documentation. The process itself takes approximately six to twelve hours, compared to two to three hours for flame cremation.

How It Compares to Flame Cremation

Environmental impact: This is the most common reason families choose AH. Flame cremation emits greenhouse gases directly — primarily carbon dioxide and carbon monoxide — and releases small amounts of mercury if the deceased had dental amalgam fillings. Alkaline hydrolysis produces no direct emissions and uses roughly 85–90% less energy than flame cremation. No greenhouse gases are released during the process.

Remains: The bone powder returned to the family tends to be slightly more voluminous than flame cremation ash, often a lighter color. The feel and appearance are otherwise similar.

Timeline: The AH process itself is longer than flame cremation, but total elapsed time from death to receiving remains is often comparable, as scheduling and documentation processing time dominate the overall timeline.

Pricing: Water cremation typically costs more than direct flame cremation but less than traditional full-service burial. Expect a range of $3,000–$5,500 in Washington depending on the provider and region. Some providers offer pricing comparable to mid-range flame cremation.

Availability: AH is not available at every funeral home in Washington. It requires specialized equipment. Currently, a limited number of licensed providers in Washington offer the service, primarily in the Seattle-Tacoma metro area and larger population centers.

How It Compares to Natural Organic Reduction (NOR)

Washington also legalized Natural Organic Reduction — commonly called human composting — making it one of only a handful of states to offer both ecological alternatives. The two are distinct:

Both are regulated by the DOL. Both require the same death certificate and permit documentation. The choice comes down to personal and environmental values, budget, and what the family wants to do with the remains.

Authorizing Alkaline Hydrolysis: The Next-of-Kin Rules

The same authorization rules that apply to flame cremation apply to AH. Under RCW 68.50.160, the authority to authorize any form of cremation — including alkaline hydrolysis — follows this hierarchy:

1. A designated agent named in a written, signed, dated, and witnessed pre-death directive
2. Surviving spouse or state-registered domestic partner
3. Majority of surviving adult children
4. Surviving parents
5. Majority of surviving siblings
6. Court-appointed guardian

If the deceased left a written directive specifying alkaline hydrolysis, that directive controls and supersedes family preferences. If no directive exists, the appropriate tier of the hierarchy must authorize. When multiple people share authority (multiple adult children, multiple siblings), a majority is legally required — one person cannot unilaterally authorize against the others' objections.

Disputes over whether to choose AH, conventional cremation, or burial are among the most common family conflicts that arise after a death. If no designated agent was named and family members disagree, Washington's Trust and Estate Dispute Resolution Act (TEDRA) provides a non-judicial pathway to resolution. TEDRA can produce a binding agreement without going to court, avoiding the cost and delay of probate litigation.

Pre-Planning for Alkaline Hydrolysis

If you want to ensure your remains are processed via alkaline hydrolysis, the most legally reliable way to do that in Washington is through two mechanisms:

1. A written designated agent directive: Under RCW 68.50.160, you can appoint a designated agent to carry out your specific funeral wishes. The directive must be in writing, dated, and signed by you in the presence of a witness who also signs. The directive can specify the method of disposition — including alkaline hydrolysis — and name the agent authorized to carry it out.

2. A prearrangement contract with a licensed AH provider: Under RCW 18.39.250, preneed funeral contracts are legally binding. The AH facility must deposit at least 90% of the funds into a regulated trust account within 20 days. If you change your mind within 30 days of signing, you're entitled to a 100% refund.

A verbal statement, a letter not meeting the legal requirements, or an informal note is not enough. Washington probate and funeral law requires the designation to meet specific formalities to be enforceable against a family member who disagrees.

Finding a Licensed Provider in Washington

Before engaging any provider, verify their license at dol.wa.gov. Washington's DOL maintains a publicly searchable database of licensed funeral establishments and crematories. An AH facility must hold a specific license to operate the process legally.

When contacting providers, request the General Price List (GPL) — federal law requires any funeral home to provide one on request, and it must include AH pricing if the service is offered.

Questions to ask:

• Is alkaline hydrolysis performed at your facility, or is it contracted to a third party?
• What is the timeline from authorization to return of remains?
• What does the process include — documentation, transportation, and return?
• What container or urn options are available?
• What happens to the effluent after processing?

Families who have pre-planned or are arranging AH and want to understand the full scope of Washington disposition law — including the designated agent directive form, the preneed trust rules, and what to do if family members object — can find all of it in the Washington Funeral Laws & Consumer Rights Guide.

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