Compost Toilets And Flush-Vaults, A Head To Head Comparison

Composting toilets, in theory, are almost miraculous.

Compost toilets convert 95% of human waste into carbon dioxide. The remaining material, in theory, can be used as fertilizer. Thousands of composting toilets have been installed over the last twenty years in remote locations without utilities. Another option in these locations is Flush-Vaults™ which are vault toilets equipped with flush toilets.

Which is the better choice for you? Here’s how they compare:

Advantages of Flush-Vaults

  • The public universally prefers restrooms with flush toilets to any other system.
  • They have sinks that allow the visitors to feel clean afterwards.
  • They never smell.

Disadvantages of Flush-Vaults

  • They require water to be delivered and sewage to be hauled away.
  • They have a few moving parts that may break.
  • They have sinks and flush toilets which need to be cleaned.


Advantages of Composting Toilets

  • Compost toilets do not require water to be delivered, or sewage to be hauled away.
  • Composting toilets have no moving parts to break down.
  • Since compost toilets have no sinks or flush toilets, cleaning frequency may be less.

Disadvantages of Composting Toilets

  • Maintenance employees may be exposed to pathogens.
  • Compost toilets are expensive to maintain. Frequent servicing includes:
    • Knocking down the fecal cone as it forms
    • Frequently adding bulking agent
    • Removing materials that are thrown down the riser
    • Removing excess liquids
  • Failing to maintain a disciplined maintenance regime may lead to:
    • Terrible odors
    • Failure to compost fecal matter
    • Septic conditions in the compost chamber
    • Closure, abandonment, or removal of the building

Closure, conversion, or removal of compost toilet buildings is not infrequent among those that are over 10 years old. For example, most of the composting toilets installed on the White River National Forest in the last 20 years have been decommissioned, removed, or converted to flush restrooms with sewage treatment facilities. The restroom pictured below was converted from a compost restroom to a flush restroom at great expense due to complaints about foul odors and maintenance headaches. For a more municipal story, CBC News in Vancouver wrote a piece on one of their local examples of a compost toilet not working as desired.

For more detailed information on this subject please see our other blog article “A Few Things You Should Know Before Considering a Composting Toilet”.

Contact Green Flush at (360) 718-7595 to talk to one of our experts!
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