October 2010 - Parks & Recreation - 86

Introducing the New Eco-Restroom
Composting toilets do more with less for less money
By Andrea Lynn

Julie Larsen Maher ©wildlife conservation society

n the island of Kauai
in Hawaii, there came a
point when park officials
and community members agreed that the existing sewage treatment in the Haena
State Park was desecrating the cultural
resources beneath it. The solution was to
install composting toilets instead. Also
referred to as " comfort stations, " these
compost toilets rely on an individual
wastewater system using a constructed wetlands form of sewage treatment.
The Hawaii park system has composting
toilets in a few other locations, including the Na Pali Coast State Wilderness
Park and Manuka State Wayside in south
Hawaii.
" Our Division of State Parks uses
composting toilets to provide a self-contained sanitation facility in remote locations where it would be impractical to
install infrastructure (such as water or
electricity) to support a sewer system
that could pump out the sewage, " says
Public Information Officer Deborah
Ward. " We may also put in a composting toilet if we lack adequate space to put
in a sewer system. "
With the composting toilets, the waste
is transferred to an elevated tank and
biomatter, such as leaves and grass, is
added to the sewage. These materials
are blended and over time decompose
into compost, which is then recycled into
the ecosystem in an area not accessed
by the public, Ward explains.
In 2007, when the Bronx Zoo in New
York City was renovating its restrooms at
the Bronx River Gate, it chose to go the
eco-friendly route, in keeping with the
zoo's overall conservation mission. The
eco-restroom with compost toilets and
energy-saving techniques is used by 60
percent of the zoo's two million visitors

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Bronx Zoo officials use the facility's composting toilets as opportunities to
teach visitors about sustainability, as well as signs explaining how water from
handwashing goes to help water the zoo's gardens.

per year. " The 1,200-square-foot 'green'
restroom incorporates sustainable design strategies, such as maximizing the
use of daylight and minimizing electrical use, as well as utilizing environmentally friendly materials and composting
toilets, " says Susan A. Chin, AIA, Wildlife
Conservation Society's vice president of
planning and design and chief architect.
" The odorless composting units require
very little water and produce clean and
viable compost. "
The way the compost toilets at the
Bronx Zoo work, visitors f lush with
foam before and after use, and the
waste goes down into the composter,
which contains organisms that help to
break it down. These foam-flush toilets
use just six ounces of water per use,
says Amy Galvin, marketing coordinator for Clivus Multrum Inc., the company that installed the facility. Compared
to conventional low-flow toilets, that's a

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97 percent savings. " Composting toilet systems eliminate the need for sewer connections and septic systems and
the land that needs to be sacrificed for
these things, " Galvin says. Because of
this, compost toilets can be placed in locations where other waste treatment systems cannot.
Logistically, for a facility to install
composting toilets, there must be sufficient space beneath the toilet to accommodate a composting tank, since gravity
is the primary transfer mechanism for
the waste. " Either a restroom must have
a basement area or the tanks can be set
on the ground level with toilets on an upper floor, " she says. She maintains that
composting toilets have no more a yuck
factor in terms of maintenance than a
conventional toilet. " There is no f lush
and therefore no spray or splash from
water in the bowl. The ventilation system
pulls all odors down through the toilets

October 2010 - Parks & Recreation

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