Grading contractor uses automated grade control to guide construction of passive water treatment system for Pennsylvania acid mine drainage remediation project, Industrial WaterWorld magazine, by Don Talend, brand storytelling, content management and demand generation expert. Water engineering, construction, and geospatial technology industries

1. by Don Talend
Contractor relies on GNSS – an advanced global positioning system (GPS) – for efficient
reclaiming of land and water impacted by abandoned coal mines in Pennsylvania
It may be that something is getting lost in the midst of recent highly publicized debate about the
Earth's environmental future: Technology can preserve precious resources such as water – not just
adversely affect those resources.
An example of technology as an environmental steward is recent use of a Global Navigation Satellite
System (GNSS) in constructing acid mine drainage systems and reclaim abandoned coal mine sites
near Benezette, a town in rural northwest Pennsylvania. Since a coal mining boom ended there years
ago, elk viewing and hunting and all-terrain vehicle (ATV) sightseeing are what bring tourists to
Benezette and boost its economy.
While the dozer in the foreground rough
grades the abandoned strip mine, a
GPS Assists Major Mine Cleanup - WaterWorld http://www.waterworld.com/articles/iww/print/volume-9/issue-2/column...
1 of 5 6/18/17, 8:17 PM

2. second in the distance – which is
equipped with a Topcon HiPer Light rover
system – does the rough grading with the
aid of Global Navigation Satellite System
technology.
Click here to enlarge image
In early 2008, Jim Irey, a civil engineer and vice president of Berner Construction of Gap, PA, located
about 4-1/2 hours to the southeast, completed his fifth coal mine reclamation project in the area in the
past two years. Berner Construction began using a GNSS system from Topcon Positioning Systems
for site preparation and construction machine control in 2007.
Dangerous Legacy
Like much of the state, the area has numerous abandoned coal mines with a great deal of sulfur
residue. Sulfur reacts with air and pyrite to form sulfuric acid that contaminates water flowing through
the mines. The acidic water, which cannot support aquatic life, finds its way to Chesapeake Bay to the
east, where it adversely alters the bay's ecosystem – not to mention those of watersheds en route.
Improving water quality in Chesapeake Bay is a priority of the U.S. Environmental Protection Agency
and one that's united various entities in the respective states surrounding it under auspices of the
Chesapeake Bay Program, a watershed management group that coordinates with multiple agencies
and stakeholders. Certainly, Pennsylvania isn't the only state with coal-mining legacy problems, but its
problems are generally considered more widespread than states such as West Virginia and Ohio.
Jim Irey's Topcon field
monitor displays the slope
that Berner Construction is
leveling out as well as a high
calcium limestone-lined
channel to be constructed,
which is represented by the
lines that look like railroad
tracks.
Click here to enlarge image
GPS Assists Major Mine Cleanup - WaterWorld http://www.waterworld.com/articles/iww/print/volume-9/issue-2/column...
2 of 5 6/18/17, 8:17 PM

3. The Pennsylvania Bureau of Abandoned Mine Reclamation estimates the state has about 250,000
acres of abandoned surface mines in 45 of its 67 counties with dangerous high walls – a safety
hazard to ATV and snowmobile riders. A more widespread safety hazard is the roughly 24,000 miles
of streams in the state that don't meet water quality standards due to drainage from abandoned
mines. In late 2007, the U.S. Office of Surface Mining provided Pennsylvania with the first installment
of $1.36 billion that the federal government is giving the state over 18 years to reclaim 184,000 acres
of abandoned mines on 5,100 sites. The state calls acid mine drainage its biggest water pollution
problem.
This high-calcium limestone is used to line
the mine reclamation channels and lower
the acidity of sulfuric acid-contaminated
water flowing out of abandoned mines.
Click here to enlarge image
Passive treatment systems can correct this problem on a wide scale. A typical passive system
consists of channels lined with high-calcium limestone to lower the acidity of the sulfuric
acid-contaminated water flowing over it, as well as basins lined with compost and wood chips that
impart bacterial activity to the water – lowering the pH and forming the biological building blocks that
support aquatic life.
Earthmoving Experience
During one of Berner Construction's mine reclamation projects, a Topcon HiPer Light+ base receiver
located on high ground receives satellite positioning signals. These signals are transmitted to a HiPer
Light rover system and used to create a three-dimensional survey model of the site. The dozer
operator views the 3-D model inside a monitor mounted in the cab and the base station transmits
signals to the rover – which, during earthmoving, is mounted on front of a dozer used for finish grading
– while the site is graded. The GNSS data, information drawn from Topcon's dual-constellation
system, that uses both U.S. GPS and Russian GLONASS satellites for constant reception, indicates
to the operator how near to specification the dozer blade is at any given moment, allowing precise,
continuous grading adjustments.
GPS Assists Major Mine Cleanup - WaterWorld http://www.waterworld.com/articles/iww/print/volume-9/issue-2/column...
3 of 5 6/18/17, 8:17 PM

4. On one abandoned mine site outside of Benezette, Berner Construction has multiple objectives: level
out a ridge formed by deposits of soil previously overlying a coal seam, create a downward slope to
facilitate acid mine drainage, line the slope with high-calcium limestone and eliminate 50-foot high
walls.
Irey accesses the same 3-D model on his handheld Topcon FC-100 field monitor that the fine-grading
dozer operator sees on his in-cab monitor. He can even see a black line on his field monitor indicating
where a high calcium limestone-lined drainage swale will be dug to channel acidic runoff from the
slope.
“This is the entire jobsite – it's about 8,000 feet from end to end,” Irey says, pointing to the crescent-
shaped model on his field monitor. Then he turns to the charcoal-colored stockpiled limestone to be
placed after grading is complete. “This material is a byproduct that we use,” he says. “It's waste
material from a quarry that met the specification for high-calcium limestone material. The quarry had
400,000 yards of it and we got it approved through the state as a beneficial waste material. They sell it
to us for a reduced price.”
Productivity Enhancers
The real benefit of GNSS in this situation is productivity. The company essentially does its own
surveying and site preparation, keeping its machines moving dirt as much as possible.
Irey took note of how use of GNSS is changing surveying and site preparation methods. “There are
fewer and fewer people who can do traditional survey work,” he says. “But it will always be required in
certain situations. In today's world, you're now looking at computer screen similar to the screen that a
kid looks at when he's playing an electronic game.”
Conditions of abandoned mine sites in this part of the state provide an advantage to productivity, Irey
explains. In south central Pennsylvania, for example, miners were more likely to pile dirt from their
excavations near the high walls, necessitating downhill grading. For downhill grading, a GNSS
provides more of a benefit in terms of grading accuracy. “These jobs are all uphill pushes, so as long
as we have pretty consistent grades throughout the site, we're OK. The issue with downhill grading is
that it goes much faster, so if you overfill an area you overfill it fast, and it may take you three to four
times as long to level it out.”
The use of GNSS minimizes the need for Berner Construction to use conventional methods of site
preparation involving the use of grade stakes. “We would just put stakes up the hill and run a level on
it, which is very hard to do to get control on the hill,” Irey notes. “What [the GNSS] does is allow me
not to be here. We pride ourselves on the fact that once the site is set up, short of moving the base
station around, it's good to go for the entire job.”
Acknowledgment: The author would like to thank Topcon Positioning Systems Inc., of Livermore, CA,
for its assistance on this article. Contact: 925-245-8300 or www.topconpositioning.com
GPS Assists Major Mine Cleanup - WaterWorld http://www.waterworld.com/articles/iww/print/volume-9/issue-2/column...
4 of 5 6/18/17, 8:17 PM

5. About the Author: Don Talend of Write Results, of West Dundee, IL, is a communications and publicity
consultant specializing in the trade media.
GPS Assists Major Mine Cleanup - WaterWorld http://www.waterworld.com/articles/iww/print/volume-9/issue-2/column...
5 of 5 6/18/17, 8:17 PM