Annual Report 3 - New Mexico - Energy, Minerals and Natural ...

ACCOMPLISHMENTS
ADVANCES IN MINE RECLAMATION: One of the continuing goals of MMD is to focus
on making New Mexico a leader in mine land reclamation. Over the past eight years, MMD has achieved success in
advancing reclamation through partnering with industry, technical experts, environmental groups and others.
Promoting a progressive approach to reclamation has consistently resulted in high quality reclamation projects over
many years. Even as far back as 2004, the BHP San Juan Mine received the U.S. Department of the Interior’s “Best of
the Best” national award for innovative regrading and channel design techniques. This was the first major application
of a new reclamation technique known as “geomorphic reclamation.” Geomorphic reclamation is, quite simply,
re-establishing land slopes with the same characteristics as the undisturbed lands. This new reclamation technique
replaces the old terrace and down-drain style of slope construction. The geomorphic technique has so far proven to
require less maintenance than the old style and creates a more diverse and natural looking wildlife habitat.
Using a design process based on fluvial geomorphic principles, the reclaimed topography is more stable, diverse
and resistant to damage from flash flooding than traditional reclaimed land in this arid environment. Techniques
that help minimize erosion include a combination of highly scalloped slopes which create drainage density, sinuous
drainages which reduce gradient and concave slope shapes which slow the water velocity near the bottom of slopes.
All these practices mimic the shapes that nature creates in hill slopes that are lacking bedrock control.
BHP followed the success at the San Juan Mine with a more comprehensive reclamation plan at the La Plata Mine
using these techniques. This new reclamation grading practice passed a significant early test when the mine received
over two inches of rainfall within a two-hour period in 2006. This is equivalent to a storm with an approximate
recurrence interval of 200 years! Much of the reclamation was new and had no vegetation, but because of the
innovative reclamation techniques used, there was astonishingly little erosion.
Today, the 1,700 acres of coal pits are gone. In their place rest rolling hills and valleys with native vegetation grown
tall enough to touch the knees of passers-by. With native vegetation growing strong, the simulated topography also
has helped reduce erosion of the reshaped land. Although wildlife habitat rehabilitation often is a slow process, the
site has begun attracting deer, elk, bobcats and a variety of raptors back to the area. The U.S. Department of the
Interior recognized BHP Billiton with the 2009 Excellence in Surface Mining Reclamation Award for its geomorphic
reclamation efforts at the La Plata Mine.
One of the challenges of reclamation is matching the existing undisturbed landscape. INTERA Inc., was presented
with the 2010 Excellence in Reclamation award for its work at the JJ No. 1 Mine. A number of the vent shafts in the
mine area were not located on terrain that allowed for blending the vent shaft closures into the existing topography
without requiring excessive fill or steep slopes. The closure method, termed “hardscaping,” involved placing natural
rock from the mine area over the vent shaft concrete slabs to simulate natural rock outcrops in the surrounding
landscape.
ANNUAL REPORT 2010
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