The Hidden Costs and Environmental Impacts of Water Cremation Compared to Fire Cremation

Water cremation, also known as alkaline hydrolysis or resomation, is often promoted as a greener alternative to traditional fire cremation. It promises a gentler, more environmentally friendly way to handle human remains. But beneath the surface, water cremation carries hidden costs and environmental impacts that are not always clear. When comparing it to fire cremation, the idea that green deaths are always better for the planet can sometimes be more about greenwashing than real sustainability.

This article explores the environmental footprint of both water and fire cremation, revealing the less obvious consequences of each method. It also examines how the green death movement can sometimes oversimplify complex issues, leading to choices that may not be as eco-friendly as they seem.

What Is Water Cremation and How Does It Work?

Water cremation uses a process called alkaline hydrolysis to break down the body. The body is placed in a pressurized chamber filled with a mixture of water and potassium hydroxide or sodium hydroxide. This solution is heated to around 160°C (320°F) but under pressure to prevent boiling. Over several hours, the body dissolves into its chemical components, leaving behind bone fragments and a sterile liquid.

The bone fragments are then dried and returned to the family, similar to ashes from fire cremation. The liquid, which contains amino acids, peptides, sugars, and salts, is typically disposed of through the wastewater system.

Environmental Benefits Often Cited for Water Cremation

Water cremation is often praised for several environmental reasons:

• Lower energy use: It uses less energy than fire cremation because it operates at lower temperatures.

• Reduced emissions: It produces no direct air pollution such as mercury or carbon dioxide from burning fossil fuels.

• No harmful chemicals: It avoids the release of toxic substances like dioxins and furans that can come from burning embalmed bodies.

• Water recycling potential: Some facilities treat and recycle the water used in the process.

  
  

These points make water cremation appear as a clear winner for eco-conscious consumers.

The Hidden Environmental Costs of Water Cremation

Despite these benefits, water cremation has environmental drawbacks that are less visible:

Energy and Water Consumption

While water cremation uses lower heat, it requires large volumes of water and energy to maintain pressure and temperature for several hours. The water used is often fresh and not always recycled, which can strain local water supplies, especially in drought-prone areas.

Wastewater Disposal Concerns

The liquid byproduct contains organic compounds and minerals. Although it is sterile, it can still impact wastewater treatment plants and aquatic ecosystems if not properly managed. Some regions lack clear regulations on how to handle this liquid, raising questions about potential pollution.

Infrastructure and Equipment Impact

Water cremation requires specialized equipment made from metals and plastics. Manufacturing, maintaining, and eventually disposing of this equipment has its own environmental footprint. The chemicals used in the process also require safe handling and disposal.

Limited Availability and Transportation

Because water cremation facilities are less common, bodies may need to be transported longer distances. This increases carbon emissions from vehicles, offsetting some of the environmental gains.

Fire Cremation: Environmental Impact and Hidden Costs

Fire cremation has been the standard for many decades and is often criticized for its environmental impact. Yet, it also has some advantages and less obvious costs:

Energy Use and Emissions

Fire cremation requires very high temperatures, typically around 870°C to 980°C (1600°F to 1800°F), consuming significant amounts of natural gas or propane. This results in carbon dioxide emissions and other pollutants, including mercury from dental fillings.

Advances in Emission Controls

Modern crematoriums often use filters and scrubbers to reduce harmful emissions. Some places have strict regulations requiring mercury abatement technology, which helps limit environmental damage.

Land Use and Resource Efficiency

Unlike burial, cremation does not require land for graves, reducing land use and the environmental impact of cemetery maintenance. It also avoids the use of embalming chemicals and caskets, which have their own environmental costs.

Transportation and Accessibility

Fire cremation facilities are more widespread, often reducing transportation distances and related emissions.

Comparing Water Cremation and Fire Cremation: What the Numbers Say

Several studies have tried to quantify the environmental impact of both methods:

• A 2019 study by the University of Minnesota found that water cremation uses about 90% less energy than fire cremation but consumes significantly more water.

• The same study noted that water cremation produces no direct air emissions, but the impact of wastewater disposal varies depending on local treatment systems.

• Fire cremation emits roughly 540 kg of CO2 per body, while water cremation’s carbon footprint depends largely on electricity sources and water treatment.

  
  

These numbers show trade-offs rather than clear winners.

When Green Deaths Are Greenwashing

The green death movement promotes alternatives like water cremation, natural burial, and tree planting memorials as eco-friendly choices. While these options can reduce some environmental harms, they sometimes oversimplify complex issues:

• Marketing vs. reality: Some providers emphasize water cremation’s lower emissions but downplay water use and wastewater concerns.

• Regulatory gaps: Lack of consistent rules for wastewater disposal can lead to environmental risks.

• Consumer awareness: Families may choose water cremation thinking it is the best green option without understanding the full impact.

• Infrastructure limitations: Limited access to water cremation facilities can increase transportation emissions.

  
  

This means that not all green death options are equally sustainable, and some may be more about appealing to eco-conscious consumers than delivering real environmental benefits.

Water cremation chamber showing equipment and pipes

Water cremation chamber with control panel and pipes used in alkaline hydrolysis process

Practical Considerations for Choosing Between Water and Fire Cremation

If you are considering cremation options with the environment in mind, here are some points to weigh:

• Local water availability: In areas with water scarcity, water cremation may not be the best choice.

• Facility proximity: Choose the option with the least transportation impact.

• Regulations and treatment: Check how wastewater is handled in water cremation facilities.

• Energy sources: Fire cremation powered by renewable energy can reduce carbon emissions.

• Personal values: Consider what environmental trade-offs you are willing to accept.

  
  
  
  

The Future of Sustainable Cremation

Both water and fire cremation technologies continue to evolve. Innovations include:

• Improved water recycling and treatment systems for alkaline hydrolysis.

• More efficient cremation furnaces with better emission controls.

• Development of new methods like recomposition (human composting) that may offer lower environmental impact.

  
  

Choosing truly sustainable death care requires ongoing research, transparent information, and thoughtful regulation.