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Environmental Studies
Yucca Mountain reclamation programs
Department of Energy (DOE) scientists and technicians are
studying Yucca Mountain, Nevada, to determine whether it would be
safe to house a repository for spent nuclear fuel and high-level
radioactive waste. While performing these studies, they must drill,
trench, or clear some parts of the Yucca Mountain area. Scientists
are trying to keep damage to plant and animal habitats at Yucca
Mountain to a minimum while doing this work. However, in the course
of its activities, DOE may disturb some of these environs and has
promised to reclaim Yucca Mountain by restoring as much of the
disturbed areas as practicable to their former conditions.
To reclaim the mountain, DOE scientists must repair any damage to
soils that have been disturbed. They also must develop the means to
plant over any sites that have been disturbed. Because so little is
known about restoring a desert environment to its natural state, DOE
follows an extensive Reclamation Feasibility Plan during the course
of its work at Yucca Mountain. The plan’s purpose is to ensure that
all appropriate steps are taken to restore Yucca Mountain to its
former state whether or not the mountain proves suitable as a
repository site. Some of the elements of the Reclamation Feasibility
Plan are soil and plant surveys, site clearing, topsoil storage and
management, erosion control, drainage control, recontouring,
replanting, and post-reclamation monitoring.
Soil and Plant Survey
Scientists have studied the soils and plants at Yucca Mountain,
and Yucca Mountain Project botanists and soil scientists have
reviewed the findings of these studies. At some sites, though, they
must still catalog and analyze plant and soil characteristics to
provide answers to specific problems associated with this
reclamation. For instance: Does the area contain plant and soil
resources that can be preserved for later use? What, if any, species
(endangered or otherwise) will be affected by the Project? What is
the area’s significance as a natural habitat? How can scientists
lessen the negative effects of removing topsoils, which contain
organic material important as a growth medium for plants? What other
soils can scientists use during reclamation to replace topsoils?
What kind of native plants can survive on reclaimed plots, and what
do they need to thrive?
Clearing a site
Site clearing is the removal and preservation of resources from a
disturbed area so they can be used later to help reclamation. These
resources could include plants, soils, and other organic materials.
Project scientists tailor their efforts to fit each site where they
move earth or otherwise disturb the soil. In their efforts, they
consider the location, size, and type of disturbance. Also important
are the type and density of plants present, the amount of topsoil,
and the best places available to store and preserve soil for later
replacement.
Storing and managing topsoil
If topsoils are to be removed and put back later, biologists have
to develop proper storage methods. They must protect soils from
erosion and from the loss of the nutrients they contain. The
best-known way to replace topsoil is to move freshly removed topsoil
to another site that needs its own topsoil replaced. Unfortunately,
this is not feasible for the Yucca Mountain Project. Scientists,
therefore, have to find a way to stockpile their topsoils for short-
(up to six months) and long-term storage.
Over the short term, Project botanists preserve their stored
topsoils by spraying them with soil stabilizers to prevent erosion.
Over longer periods, they plant over their stockpiles to provide
additional protection. Botanists maintain their stockpiles in
locations that offer maximal protection from erosion and other
disturbances.
Controlling erosion
Erosion is a natural process. It is not the Project’s intent to
eliminate erosion in disturbed areas but to control it to the extent
possible to minimize any harmful effects. Minor grading and shaping
of disturbed sites (to preserve rainfall) are combined with a number
of approaches to control erosion. For instance, temporary plants are
placed to provide ground cover, and agents that hold the soil
together are applied to ensure their continued safekeeping.
Controlling drainage
Project scientists have had to develop ways to minimize their
effects on the quantity and quality of water in surface and
groundwater systems in those areas disturbed by their studies. For
instance, channels, ditches, culverts, and other structures divert
water flowing from undisturbed areas away from disturbed areas to
control drainage.
Recontouring
Recontouring is the act of grading or rearranging a disturbed
site so it blends in with the surrounding landscape. This grading is
done at Yucca Mountain to restore natural drainage patterns and
maintain the original degree of steepness. Recontoured surfaces are
roughed by ripping or disking with various machines to permit better
contact and stability between the surface and soil materials applied
to topsoil.
Replanting
Replanting disturbed areas is a complex process dependent on
natural conditions not easily controlled. Rainfall becomes a vital
factor in desert revegetation, and scientists must take measures to
optimize available moisture. Whenever possible, they only replant
plants native to the region. Presently, a series of field programs,
coupled with an ongoing review of existing revegetation studies, is
used to ensure proper replanting.
Monitoring after reclamation
DOE scientists will develop a set of criteria to measure the
success of all reclamation efforts. They will look at several
different parameters such as the percentage of plants growing as
ground cover and the soil’s ability to sustain plant life.
Scientists will visit and test reclaimed sites periodically
according to these parameters.
This factsheet is available to download in PDF
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Update June 2000 | 
