A better bathroom: Green and Flush

greenflush1When I made the case for better bathrooms at a Berkeley City Council work session a couple of months ago, council member Laurie Capitelli offered the suggestion that the city should look into alternative bathroom designs.  He had looked on the web at installations in use in Europe.

It turns out that there is a vendor much nearer than Europe, namely in Vancouver WA (just across the river from Portland OR) with an alternative product that is worth looking at for Cesar Chavez Park.  The company is called Green Flush Technologies, and their design is called “flush-vault.”   I’ll let their blog explain:



What are Flush-Vaults?


As the name suggests, Flush-Vaults™ are flush restrooms built over vaults that contain the sewage.

Vault restrooms are typically installed in areas not served by sewer or septic systems. They utilize a subterranean containment chamber below the building (the vault) to hold waste. Most vault toilets constructed in recent years are built to meet the “Sweet Smelling Toilet” standards promoted by the U.S. Forest Service. When built to these standards, odor is reduced, but may still be present when there is limited air flow around the building or in locations where there is very heavy use. Vault toilets are equipped with a toilet seat mounted on a fiberglass riser located over a hole in the floor. The contents of the sewage vault are easily seen when looking down the toilet riser. This causes many visitors to think of vault toilets as revolting and unsanitary and many visitors totally avoid vault toilets for these reasons.

From the floor down, a Flush-Vault™ is the same as a vault toilet. However, with Flush-Vaults™ the toilet riser is replaced with a flush toilet. If a public water supply is not available, a water storage tank is installed in a mechanical room. A hand wash sink is typically installed, something you won’t find in a vault toilet. The result is a vault toilet system that the public recognizes as a flush restroom without the unpleasant odors or visuals.

This method is made practical by using toilets designed to use very little water (typically about 1 quart per flush). The capacities of the water tanks vary from 2,500 to 5,000 uses. The vault capacities vary from 4,000 to over 20,000 uses. Like vault toilets, Flush-Vault™ restrooms are built over coated and sealed precast concrete vaults that contain the sewage until it can be pumped and hauled away.

Since these restrooms are not limited by the “Sweet Smelling Toilet” design principles that normal vault restrooms must adhere to, a cabin can be equipped with more than one commode. A Flush-Vault™ can have any number of toilet stalls with no odor problems.

Where potable water is not available, flush water is processed through a high-efficiency filter and can come from irrigation, harvested rainwater, or from another non-potable water source.

Another problem with Vault toilets is that waste disposal can be a pain. Have you ever seen a sign in a vault restroom that says “never throw garbage down the hole because it’s extremely difficult and expensive to remove”? Vault risers have large holes to throw things into. But a flush toilet cannot pass anything larger than 2” in diameter. This eliminates the garbage problem. The use of water for flushing also means the sewage is only 10% solid, which also makes the job of pumping the vault easier.

Flush-Vaults™ can go anywhere there is vehicle access, just like a Vault toilet can. Currently, Green Flush Technologies is the only American company offering Flush-Vaults™.   They are being offered at prices comparable to vault toilets.

Vault toilets, as the blog explains, are the kind in use in many remote parks, such as the Point Reyes National Seashore.  There are also a couple of them nearby, on the east side of the Pt. Isabel dog park.  The blog is absolutely correct when it says that these are stinky, disgusting to look into, and hard to keep clean.  The openings are so big that little kids could fall in.  Vault toilets are like permanent porta-potties.  The difference is that the building won’t blow over in a hard wind, and the stinky stuff is down a couple of feet instead of a few inches.  But they’re cheap to build and (provided nobody throws beer cans down the hole) cheap to maintain.

Green Flush units, “being offered at prices comparable to vault toilets,” offer big advantages.  They flush!  (One quart of water per flush.)  There’s absolutely no odor, the manufacturer claims.   There’s no fecal panorama to look down at.  There’s a no-water urinal.  There’s a low-flow sink for washing hands.  And the cost to pump them out is the same as vault toilets.

The city ought to be looking at this innovative and economical design.

We’ve been told that restrooms in the Marina are astronomically expensive ($600,000 for the proposed windsurfer bathroom) because ditches have to be dug to connect with sewers.  (OK, that’s some of the most expensive ditches in history, but never mind.)  The Green Flush toilets don’t require sewer hookups at all.  The same company that now pumps out the porta-potties could pump out the Green Flush units.

As for water, Green Flush offers the option of a clean water storage tank that can be refilled by truck, but that isn’t necessary at Cesar Chavez Park.  The park is already plumbed for water at numerous fire hydrants and several drinking fountains; a water supply pipe runs along Spinnaker Way, a few feet from the current restroom locations.  The GFT toilets use one quart of water per flush, compared to 1.6 gallons for conventional “low-flow” toilets.

Electric lighting is also not a big problem; the park is already wired.  Wiring runs underground all the way out to the flare station in the center of the park.

Parks and Waterfront Department, are you listening?

P.S.  The Green Flush Technologies blog has some interesting comments on composting toilets, which were Capitelli’s original suggestion.  If properly maintained, they can be great; but proper maintenance involves frequent, skillful, timely, and labor-intensive stirring and conditioning of the fecal cone — or the result is an unmanageable mess that takes the installation out of service.   If you’re interested, read the GFT blog item, “Compost Toilets and Flush-Vaults, a Head to Head Comparison,” and “A Few Things You Should Know Before Considering a Composting Toilet.”


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