MathBench > Environmental Science

The Case of the Missing Mountaintop


How to destroy stream habitat

In the 15 years between 1985 and 2001, over 700 miles of stream were buried by valley fill. Scientific studies suggest that regrading and revegetating are not enough to "rehabilitate" these streams. Instead, habitat for endemic and endangered species (not to mention many other species) is irretrievably lost. How does this happen?

First, the surface of the streams are buried and destroyed. Even if streams are not completely buried, sediments are very harmful for organisms that live in the stream -- they stop fish and insects from breathing, and bury their eggs. In short, adding sediment to the waterways ruins aquatic habitat.

In addition, large-scale earth-moving operations can also expose minerals and chemicals that were buried deep underground. Once they are brought to the surface, these chemicals can enter the waterway, a phenomenon called "acid mine drainage".  In large amounts, these chemicals they can poison aquatic organisms. They can also cause cancer, liver, and kidney problems for humans who drink or come into contact with contaminated water.

People who live near coal wastes storage sites ("sludge impoundments") are at higher risk of cancer and damage to kidneys, liver, and the circulatory system.  This is because there are higher concentrations of arsenic, lead, cadmium near these storage sites, and it will seep into drinking water. 

Martin County creek after the coal sludge spill

Occasionally a sludge impoundment fails. This happened in Martin County, Kentucky, in 2000, when a dam broke and 300 million gallons of sludge (30 times the volume spilled by the Exxon Valdez) created a spill five feet deep in places. The spill covered people's backyards, polluted over 200 miles of river, contaminated the water supply for almost 30,000 people, and killed all aquatic life in two creeks. These sludge spills happen at the rate of about 2 to 3 per year.

Sludge impoundment failure is the subject of the documentary SLUDGE, by Robert Salyer. Watch the trailer here: