At Clay Hill Memorial Forest we make every
effort to demonstrate novel, new or alternative technologies in our
buildings and exhibits. We are located several miles from
the nearest municipal sewer line. Most of Clay Hill's neighbors
treat domestic wastewater using septic tank drainage field systems.
Such systems release effluent below the surface of the ground, and this
can result in contamination of groundwater. Subsurface drainage
fields, although the most commonly-used household system, are often not
the most environmentally sound method for treating wastewater. We
typically host thousands of school children each year and expect the
number of people visiting Clay Hill Memorial Forest and the Joan White
Howell Environmental Education Center will continue to grow. We
needed an environmentally sound way to treat wastewater and found it in a
We clean our "wastewater" with
an above ground constructed wetland using natural processes.
Nutrients are removed from the water by plants such as cattails, rushes
and irises as the water passes slowly thorough a series of rubber-lined,
gravel-filled beds. These plants along with bacteria and other
microscopic organisms remove the nutrients from the water and utilize them
for their own growth. The water travels very slowly through
this system but eventually reaches a sump. From here it is pumped
into our greenhouse where we have three tanks with tropical floating
aquatic plants such as water hyacinth and African water lettuce.
These plants remove any remaining nutrients and remain active in winter
months when the cattails are dormant. The finished water is pumped
from the greenhouse into a large aquarium in the Joan White Howell
Environmental Education Center where children learn that water is a
recyclable resource. Overflow from the aquarium is returned to the
wetland system to be cleaned and used again. No water is ever
released below the surface of the ground. Children who visit Clay
Hill learn that "wastewater" can be recycled to the extent that
it is pure enough to supply water to fish tanks or water for human
consumption. Water is a recyclable resource!