| Reclamation of Surface-Mined Lands via Waste Management Techniques |
| Initiation Date: |
1979
New federal law required mining companies to restore specific vegetation to their mine
sites within 5 years AFTER finishing the surface mining.
About $1 million to date has been spent on the research aimed at revegetation techniques. |
| History:
 |
| Sludge being applied as an ammendment to surface-mined soils. |
|
The law required each company to post a bond of $10,000/acre PRIOR to mining to insure that
there would be monies available to have the land restored following mining. If the companies
successfully complete restoration, the money is returned to them. But mine sites provide big
challenges to plants and there were few known methods to achieve successful restoration.
Of the many people who became involved in the project, Dr. Lee Daniels' role was to investigate
ways to restore pasture land and forests from a soils perspective, working along with Jim Burger
of Forestry. To start out, it is important to understand the nature of soils exposed by surface
or strip mining: these soils are subsoil in nature with no topsoil left. They are often very
acidic and possess large quantities of elements which can be toxic to plants at such high levels.
Daniels wanted to restore diverse plant life to the sites by first amending/improving these
inhibitory soils so they could once again support plant life, preferably using materials recycled
from other processes. So in the early '80s, he started to examine the effects of adding several
by-products to existing mine soils: topsoil, sawdust (organic waste from lumbering), sewage sludge
(a human waste product high in Nitrogen, Phosphorus, and some metals), or coal flyash (a powdery
residue remaining after coal combustion) to the exposed soils. |
Contemporary Impact of the Work:
 |
| A previously surface-mined area restored with sludge and successfully
revegetated. |
|
Sewage Sludge
His initial observations indicated that the natural succession of primarily wild herbaceous
plants was encouraged when sewage sludge was added. Compared to untreated mined areas where
only 4-5 plant species would grow naturally, sludge-ammended soils supported dozens (= increased
botanical diversity). These positive results were initially met with great excitement. Afer all,
here was a material that was truly a waste product which ordinarily went into landfills or had
to be incinerated. Furthermore, sludge was free and wouldnÕt cost the mine owner anything to
use on the exposed soils during closure; in fact, cities often pay someone to remove it!
Although about 20,000 acres of Virginia farmland have had sludge applied, this feasible solution
for land reclamation has never fully materialized; primarily because no one anticipated the
subsequent negative public reaction to sludge applications. Residents of rural mining regions
looked at this as simply a way for the urban areas to ÒdumpÓ their wastes on them. They also
rejected any idea of the safety of sludge as an amendment because it is "sludge" (therefore it
must be toxic!) in their "backyard!" In fact, the ensuing public outcry when large scale sludge
use was being investigated virtually killed the idea for further use in Virginia. You see, the
law made no restrictions on the use of the same land after the 5 year period of reclamation; it
could be left alone, farmed (exept for root crops), developed, and even strip or deep mined again.
There may even be a bill introduced into the Virginia General Assembly to formally outlaw the use
of sludge to reclaim surface mined soils. |
Coal Flyash
This material is basically the particulate waste left in smokestack filters following coal burning.
Of primary importance to plants, flyash contains calcium, magnesium, and traces of several metals;
and tests proved it to be just as effective as sludge as a mine soil amendment...but its use is
still controversial.
In both instances, there is an inextricable link connecting Science, Politics, and Sociology.
Experience has also shown that for waste management to be effective in solving other problems, all
three factors must be considered. |