MTR in PLA

Background

In 2014, coal supplied 18% of all US primary energy and 42% of electric power [1]. In West Virginia over 95% of our electricity comes from coal-fired power plants [2]. Nationally, there were 74,931 coal mining jobs in 2014 with 18,330 of those jobs within West Virginia [3]. Much of the coal mined to provide our energy is obtained from surface mining. In West Virginia about 27% of all coal produced in 2014 was surfaced mined [4]. In West Virginia and the rest of Appalachia surfacing mining often take the form of mountaintop removal (MTR).

Mountaintop Removal and the Changing Contours of Appalachia

The Surface Mine Control and Reclamation Act (SMCRA) of 1977 requires post-mining reclamation of surface mines to restore the “approximate original contour (AOC)” of the pre-mined land [5]. However, restoring the AOC of MTR mines is impossible. There is no practical way to restore 100s of feet of overburden once the coal seam underneath is removed and the overburden has been pulverized by explosives. So exemptions to the AOC rule are granted allowing conversion of mountain ridges to plateaus or gently rolling contours. Such exceptions often require the miner to propose industrial, commercial, residential, or agricultural post-mining uses for the land that constitute an equal or better economic or public use of the land compared to pre-mine use. Interestingly a 2009 report found that less than 5% of reclaimed MTR sites in West Virginia have actually been economically developed challenging the process by which exceptions to the AOC rule are made [6]. Another name for MTR is valley fill (VF) mining as much of the overburden is dumped into valleys. The US EPA estimates that this practice has buried 1900+ km of ephemeral and perennial headwater streams [7]. Coal is an important source of jobs in West Virginia and throughout Appalachia and it is an important component of our energy mix. Nevertheless, the practice of MTR/VF mining is dramatically changing the landscape of Appalachia. One goal of the MTR in PLA project is to help communicate these changes to a wider audience.

NASA Earth Observatory image of the Hobet Mine, WV in 2015.

Mountaintop Removal to Polylactic Acid – MTR to PLA

The MTR to PLA project aims to add 3D printed models of MTR/VF sites to the collection of mapping tools available to study and disseminate knowledge of mountaintop removal. The tactile nature of the models is particularly impactful. We use satellite-obtained elevation data and 3D CAD software including 3DS Max and Cura to make the models. We make the models freely available. They can be downloaded, shared, and manufactured by anyone with a suitable 3D printer using the Creative Commons Attribution-ShareAlike 4.0 International License. We manufacture the models on a Printrbot Simple Metal hot-end-extrusion-based 3D printers using PLA plastic filament. PLA plastic is preferred since it is a biodegradable bioplastic made from corn starch. Files for modeled mine sites are linked to below.

Acknowledgements

This work was facilitated by the 3D topographic map work of the Mansfield University Earth Lab.

Current Project Status

This project is a work in progress. New models will be added as they are completed. Also, the models posted thus far are great instructional tools, but they should not be considered cartographically precise. We are working on our workflow to figure out how to quantify the horizontal dimensions of each mountain modeled and also the z-scale utilized. We are also working on tutorials to explain how data is extracted from ArcMap and how this data is converted to 3D models. Check back later for updates.

Time-Lapse Video of Mountaintop Removal Site Being Printed