NETL: Educational Initiatives

ENVIRONMENTAL MANAGEMENT:
STREAM ANALYSIS WITH RELATION TO ACID MINE DRAINAGE

What is Acid Mine Drainage (AMD)?

A watershed is the line of division between two adjacent rivers or lakes with respect to the flow of water by natural channels into them and the natural boundary of a basin. The Clean Water Action Plan was established to monitor and remediate the quality of water in our nations watersheds. It establishes standards for a watersheds nutritional and dissolved metals content and if these are exceeded the waterway must undergo immediate remediation.

Dissolved metals suspended in solution such as ferric iron and ferrous iron, (the orange pollution you sometimes see) as well as aluminum, and manganese all contribute to water pollution. Aluminum ranks third in the Earth’s abundant elements and is the most abundant metal in the Earth’s crust. Dissolved aluminum remains suspended in water between the pHs or 3 and 4. Due to its strong affinity to oxygen, aluminum rarely occurs in its natural metal states near the surface. Instead it forms many alloys with zinc, copper, manganese, magnesium and other elements with similar chemical properties. This same property is responsible for the classification of aluminum as a contaminant and neurotoxin. When introduced to aquatic environments (i.e. rivers, streams, and wetlands) aluminum attaches onto plant roots and inhibits the intake of oxygen. Physical abnormalities in humans and animals associated with aluminum poisoning include memory loss, tremors, muscle twitching, and several types of dementia. These apparent threats to the environment and its inhabitants are why aluminum leaching and contamination should be controlled.

Acid mine drainage is water containing iron and sulfate and sometimes other metals, such as, manganese and aluminum. It is often acidic (low pH) and is commonly referred to as acid mine drainage or AMD. AMD forms through a series of chemical and biological reactions that occur when the pyrite (iron sulfide, a.k.a. fool’s gold) found in coal and other rock strata is disturbed and exposed to oxygen and moisture as a result of mining operations. AMD may contaminate surface and ground water.

Why is it Important to Sample Streams?

To identify sources of mine drainage so that the quality of water can be improved. This is important to wildlife, aquatic (fish & frogs) and mammals (such as deer and small animals) so that they can flourish in their environment. Clean water is also important to people who use the rivers and streams for drinking water as well as for recreational uses. Water is an essential ingredient for boaters, swimmers, fisherman, and hunters.

OBJECTIVE

Helpful hint: sampling must be done starting at the mouth so that you do not collect turbid water. Be careful not to stir up sediment when collecting your samples.

Helpful hint: Where tributaries flow into main stream, the sample should be taken approx. 10 feet up the tributary. The main stream should be sampled approx. 10 feet up stream infront of the tributaries entrance.

Create your own Acid Mine Drainage, and neutralize it the way industry would when reclaiming a mining site.

(Note: A green color change should be observed immediately, if allowed to sit for several days the green sludge will change to an orange sludge – this is the iron coming out of solution. Relate this to students as the orange colored creeks they may have seen before which are most prevalent in old mining towns.)

Vocabulary Words

Alkalinity
pH Scale
Tributary
Wetland
Cattail Reeds
Limestone Bed
Graphing
Base Solution
Calibration
Spoils Pile

Coal
Strip Mining
Remediation
Geologist
Diversion Well
Ferrous Iron
Ferric Iron
Pyrite
Turbid