Acid Mine Drainage

Acid Mine Drainage

Visual Environmental Education Guide Acid Mine Drainage 1The Problem Basic definition: -The overflow of acidic water from abandoned coal mines (Websters Dictionary)

Image from: http://mw2.google.com/mw-panoramio/photos/medium/42656972.jpg 2Examples of Acid Mine Drainage

Image from: http://www.aeepartnership.org/acid_mine_drainage.php Image from:http://chemcollective.org/AMD/Amd.html

3Overview of Chemical Reactions Occurring Main chemical reaction: the oxidization of pyrite (FeS2)The 3 main chemical products formed in acid mine drainage reactions are: Ferrous iron and sulfuric acidFerric ironEventually turns into iron hydroxide Sulfuric acid is the cause of the distinct egg smell that acid mine drainage produces. Insoluble iron is mainly responsible for loss of habitat for aquatic species, while iron hydroxide is what makes the water source turn the red-orange color typically associated with acid mine drainage.

4First Chemical Reaction:Oxidization of Pyrite

+2FeS2 + O2 + H2O > Fe + H2SO4or (pyrite + dissolved oxygen + water) -> (ferrous iron + sulfuric acid) In this reaction pyrite is being oxidized and reacting with water from the stream. This reaction produces ferrous or soluble iron and sulfuric acid, which is the distinct smell that can be associated with acid mine drainage. Ferrous or soluble iron is the first main product in acid mine drainage and it starts to make the stream too acidic to support aquatic life. Sulfuric acid is what gives acid mine drainage such a distinct smell that is often unpleasant for humans. 5Second Chemical Reaction:Oxidization of Soluble Iron

+2 + +3 Fe + O2 + H > Fe + H2Oor (ferrous iron + oxygen +hydronium) -> (ferric iron + water)

In this reaction oxidation of ferrous iron is occurring and this produces ferric or insoluble iron. This is the reaction that begins to coat the stream floor and actually ruin habitat for aquatic life. It is this reaction that can make the effects of acid mine drainage so extreme. 6Third Chemical Reaction:Precipitation of Insoluble Iron

+3 + Fe + H2O > Fe(OH)3 + H or (ferric iron + water) -> (iron hydroxide + hydronium )

Image from: http://www.facstaff.bucknell.edu/kirby/AMD.htmlThis final reaction is the precipitation of the ferric or insoluble iron and this is the reaction that is visible to the human eye because it turns the stream a red-orange color, as is seen in Shamokin Creek. This reaction can only occur if the pH of the stream is around 3.5 and this is extremely low for supporting aquatic life.7The Importance of the pH of WaterWaters average pH is 7, which is basic Acid mine drainage can make waters pH as low as 2.5

Image from: http://pa.water.usgs.gov/projects/energy/amd/images/fig3b.gifKeeping water pH neutral or almost neutral is important for aquatic ecosystem health.

The bar graph shows the pH of streams of acid mine streams in Pennsylvania. The most popular pH is 3.5 and most streams have a pH between 3.5 and 6.5. Very few streams have a pH of 7 or higher. 8Possible Forms of TreatmentPassive TreatmentArtificial Wetland Construction Active Treatment Chemical additivesLimestone or carbonate neutralization

Image from: http://ots.blogs.bucknell.edu/files/2010/09/IMG_33691.jpgArtificial wetlands are built separately from the affected stream and use limestone gravel and soil to neutralize the acidity from the hydronium ions and this makes the streams more livable for aquatic life (Carl Kirby) Passive systems can still produce active chemical reactions. Active water treatment programs use direct chemical treatments or additives to neutralize the acidity of water affected by acid mine drainage.

The picture is of an artificial wetland near Shamokin.

9Mining Practices in the Susquehanna Valley Region

Image from:http://www.dep.state.pa.us/dep/deputate/minres/bmr/annualreport/2010/Photo_Coming_out_of_the_mine.jpg Image from:http://www.airphotona.com/stockimg/images/00478.jpg

10Map of Rivers/Streams Affected by Acid Mine Drainage in Pennsylvania

Image from:http://pa.water.usgs.gov/projects/energy/amd/images/amdmap.gif

Acid mine drainage has contaminated more than 3,000 miles of streams in Pennsylvania and other states (PA USGS website).

The blue lines show the rivers/streams that are affected by acid mine drainage, but still have some aquatic life. The orange lines show streams that are affected by acid mine drainage, but have no aquatic life.

As you can see, the problem is state-wide.

11Regional Treatment Programs

Image from: http://epcamr.org/home/

Image from:http://www.wpcamr.org/ Both of these are examples of regional programs.

The first regional coalition that was founded was the Western Pennsylvania Coalition for Abandoned Mine Reclamation or (WPCAMR)- started in 1982 - currently works with volunteers, technical experts, and government agencies to try to reclaim mines and streams polluted by coal mining- encompasses 24 counties in Western Pennsylvania - focuses on education and reclamation at the local level (WPCAMP website).

The Eastern Pennsylvania Coalition for Abandoned Mine Reclamation or (EPACMR)- It started in 1995- is a coalition of watershed organizations and reclamation partners focused in Eastern Pennsylvania counties- includes Northumberland County, which is where part of the Shamokin Creek watershed is located- Their main projects and initiatives include: mapping abandoned mines, GIS development, and acid mine remediation (EPCAMR website)

12The Shamokin Creek Story

Image from:http://farm4.staticflickr.com3591/3502701636_db54cf068f_z.jpg Shamokin Creek is an example of a stream that has been severely impacted as is visible by the red-orange color that is typically associated with the precipitation of ferric iron. Due to the large amount of abandoned anthracite coal mines along Shamokin Creek there is high volume of acid mine drainage in this watershed area. Shamokin Creek is even devoid of aquatic life in some places. This is especially dangerous for overall aquatic ecosystem health because Shamokin Creek eventually flows into the Susquehanna River, which flows to the Chesapeake Bay and eventually the Atlantic Ocean.

The image is of an abandoned mine on the Shamokin Creek. 13The Shamokin Creek Watershed Map Image from: http://www.facstaff.bucknell.edu/kirby/WshedMap.html

This is a map of the Shamokin Creek Watershed. The red dots represent treatment systems and the yellow dots represent sites where acid mine drainage is occurring. There are many untreated sites. 14Example of a Local Resource:Shamokin Creek Restoration Alliance

Image from:http://www.facstaff.bucknell.edu/kirby/0SCRAnewHome/SCRAhome.htmThe SCRA started in 1996 by local individuals who wanted to restore the Shamokin Creek back to its original state. They emphasize the importance of local knowledge of the mining industry for treating its environmental effects, while also admitting to its downfalls for some local ecosystems (SCRA website). Are responsible for the main acid mine drainage treatment sites around Shamokin and have more programs planned for the future. 15Sourceshttp://pa.water.usgs.gov/projects/energy/amd/http://www.dep.state.pa.us/dep/deputate/minres/districts/AMDPostMortem.htmlhttp://epcamr.org/home/current-initiatives/http://www.wpcamr.org/http://www.shamokincreek.org/http://www.facstaff.bucknell.edu/marsh/susquehanna/ehga.pdfhttp://reclamationresearch.net/publications/Final_Lit_Review_AMD.pdfhttp://www.facstaff.bucknell.edu/kirby/AMDPrimer.html16