Introduction - Coal Waste Impoundments: Risks, Responses, and Alternatives - page 10

search for alternative disposal technologies (e.g., thickened [60 percent solids]
high-density residue stacking), as well as for processing and utilization of the
red mud, have been underway for some time (Wagh and Desai, 1987).
The disposal of the tremendous volume of waste sand and clay in the
beneficiation process of phosphate mining is another example of these
problems. The clay is pumped to a settling area in a dilute stream (3 percent
solids) or sent to a thickener to increase the solids content (15 percent solids)
(Garlanger and Fuleihan, 1983). Fine sediment disposal also is a problem in
base metal mining and smelting operations.
COAL WASTE IMPOUNDMENT FAILURES
Coal waste facilities have been involved in several accidents or incidents
since 1972. The incidents reviewed here demonstrate the range of the types of
failures that can affect coal waste impoundments and of impacts of such
failures. They are not a complete list of incidents. The first event was the
Buffalo Creek accident ( Sidebar 1.3 ), the most serious because it resulted in the
loss of 125 lives and extensive damage to property downstream of the refuse
piles and impoundments. Following that accident, regulations were promulgated
to govern the design of the embankment structures used in future
impoundments. Since then, no engineered embankments have failed, although
other incidents and accidents have occurred. Sidebars 1.4 to 1.12 describe
selected events.
SIDEBAR 1.4 AUGUST 14, 1977: ISLAND CREEK COAL
COMPANY, BOONE COUNTY, WEST VIRGINIA
An embankment under construction failed at Island Creek Coal
Company's impoundment in Boone County, West Virginia, on August 14,
1977. Heavy rainfall overflowed a temporary diversion ditch, causing the
water level in the impoundment to rise. Because the embankment was still
under construction, storage capacity had not yet reached the required
minimum, and the sudden influx of additional water overtopped the
embankment. Meanwhile, the water eroded the embankment, reducing its
height 23 feet during a two-day period. During this time, 6.8 acre-feet of
material was released, which clogged a drainage pipe downstream.
SOURCE: Owens, 1977.