United States
 Environmental Protection
Industrial Environmental Research
Cincinnati OH 45268
 Research and Development
 EPA-600/PS7-80-128  Oct. 1980
 Project Summary
Water  Infiltration  Control  to
Achieve  Mine Water  Pollution
Control—The  Dents  Run
Watershed  Demonstration
Jonathan G. Herrmann
  One of the most severe mine drainge
problems  encountered  in  the
Appalachian  coal  fields  is  the
discharge of highly acidic and iron-
bearing drainage from abandoned
underground mines. This problem is
aggravated  by surface water
frequently draining into both active
and abandoned mines and  exposed
auger holes. This water then reacts
with pyritic material in the roof and
floor of underground mines and forms
acid mine drainage, a diluted form of
sulfuric acid and ferrous sulfate. Since
many abandoned underground mines
were either  sloped  so that water
would gravity-drain from the  mine
workings or  have since intercepted
workings at higher elevations, the
contaminated mine water eventually
finds  its way to a surface discharge
  In  1971, the Environmental
Protection  Agency, Office of
Research and Development, awarded
a  grant for  a  mine  drainage
demonstration project on the Dents
Run  Watershed.  The grant  was
awarded to the State of West Virginia,
Department of Natural Resources.
The state, in turn, contracted with the
Cyrus Wm. Rice  Division  of  IMUS
Corporation in that year to conduct
the project  feasibility study  and
subsequent  reclamation design and
monitoring  program.   Actual
reclamation  of  the Watershed
occurred in 1973 and the project was
completed following post-construc-
tion water quality monitoring in 1976.
  The  objective  of the Dents Run
Watershed  Demonstration  Project
was to demonstrate the effectiveness
of surface  mined land reclamation
measures  in  establishing  surface
water infiltration control to prevent or
reduce  pollution  from acid  mine
drainage. The Dents Run Watershed,
located in  Monongalia County, West
Virginia, was replete with unreclaimed
surface mines, drift  mines, auger
mines, refuse dumps, spoil banks, and
borehole discharges; all of which were
determined  to be  significant
generators of acid mine drainage.
  The  project  was initiated with  a
comprehensive field investigation of
the Watershed  to  locate and
characterize  each  mine site and
underground mine opening. Based on
this information and detailed analyses
of regional geologic conditions and
past mining history,  areas of
suspected   high   infiltration were
identified.  Site-specific  reclamation
plans and  specifications were then
prepared; these plans were designed
primarily to increase surface water
runoff   and reduce infiltration of
surface drainage into  underground
mine workings through unreclaimed
surface mines.
  Over 40  hectares of surface mines
were reclaimed during this project and

nearly 100 percent of the pollutional
drainage in the Dents Run Watershed
was   eliminated   through  the
cooperative  efforts  of  government
and industry. Virtually all of the mine
drainage from the active workings of
the cooperating industry. Consolida-
tion  Coal Company, was treated to
acceptable water quality standards at
the Sears and Loar Treatment Plants
before discharge. The project report
defines the  approach  taken in  the
reclamation  effort,   describes each
mine  site and associated reclamation
activities,   outlines   monitoring
strategies,  and  analyzes the overall
effectiveness of the  project.
  This publication is a summary of the
complete project report, which can be
purchased  from   the  National
Technical Information  Service (see
box on last page).
  According to  1978 estimates, West
Virginia  is the  second  largest  coal
producing state,  following Kentucky,
with atotal productionof 82 milliontons
of coal. Historically, West Virginia has
been one of the leading coal producing
states in the nation As a result of this
extensive  mining  activity, acid  mine
drainage has been a significant problem
in the northern portion  of the  state
where the interaction of local  geologic
and  hydrologic  conditions generally
produces  severely  polluted  drainage
from  both  surface and  underground
mining operations.
  The  Dents   Run   Watershed
Demonstration Project was designed to
address this problem The project was
conducted under  the auspices of the
Environmental  Protection Agency  as
specified  in the provisions of the Water
Quality Improvement Act of 1970, PL
91-224. The Act included a subsection
entitled "Area  Acid  and Other  Mine
Water  Pollution  Control  Demonstra-
tions." This subsection became Section
14 of the  Federal  Water  Pollution
Control Act, as amended Section  14
provides   for  the  demonstration  of
techniques for mine drainage pollution
control   and  directs  that   the
Environmental Protection Agency shall
require such   feasibility  studies  as
necessary in selecting  watersheds for
the purpose of demonstration  projects.
Such  feasibility studies are to aid the
Environmental  Protection Agency in
selecting  not only the  mine drainage
pollution control method(s), but also the
watershed  or drainage area for such
application  The Act requires that the
Environmental Protection Agency give
preference to areas which will have the
greatest public value and  uses.
  The Dents Run Watershed is  located
in Monongalia County, West Virginia,
and is  part of the Monongahela River
Basin. As a minimum, reclamation work
in the Watershed was  to be performed
in accordance with applicable State and
Federal regulations  In addition to this
general requirement, however,  special
or  innovative  reclamation and
abatement  techniques  were   to  be
employed  in areas of suspected high
infiltration in order to  reduce drainage
into   both   abandoned  and   active
underground  mine  workings.  It was
believed  that  this  approach . could
reduce water infiltration by as much as
50 percent.
  The terrain of the eastern part of the
Watershed  can generally  be described
as rugged and the western portion, as
rolling.  The elevation of the highest
peak in the Watershed is approximately
488 meters, while the valley floor in the
vicinity of Laurel Point is  291  meters
high with a base of 253 meters at the
mouth  of  Dents Run. Located  in the
Allegheny  Mountains  section,  the
Watershed  is  part of the Appalachia
Plateau's physiographic province. The
mountain tops are forested, while the
valley  sides  and  bottom  are open
grassland  and  farmland   Dents Run
flows from west to east and enters the
Monongahela  River   at  the city  of
Granville, which is due west of the city
of Morgantown
  The most prominent and commercial-
ly developed coals in the Watershed are
the Pittsburgh, Redstone,  Sewickley,
and  Waynesburg  seams.  These coal
seams  outcrop along the valley sides
beginning at the mouth of Dents Run
near Granville The lowest of these is
the  Pittsburgh  seam.  The  Redstone
seam  is approximately  107 to 114
meters above the Pittsburgh seam The
Pittsburgh seam and all others above it
dip  to  the west. The  elevation  of the
Pittsburgh seam is 107 meters below
the valley floor at this point. A typical
cross-section  of  the  Watershed  is
depicted in Figure 1
  Surface  mining  of  the  Pittsburgh,
Redstone, and Sewickley  seams was
confined largely to the eastern  end of
the Dents  Run Watershed, and was
substantially completed prior to 1952.
Additional  surface  mining  of  these
seams took place between  1960 ar
1966. Surface mining of the Wayne
burg outcrop has been practiced ne
the hilltops throughout the Watersh(
since 1 966. The only drift mining not<
in the Waynesburg seam occurs c
isolated tracts in the extreme westei
portions of the Watershed, although tr
Pittsburgh,  Redstone,   and  th
Sewickley seams have been drift mint
extensively in the eastern end of th
Watershed for many years.
  Most  of the  unreclaimed  surfat
disturbance   occurs  in  the  eastei
portion of the Watershed Water th,
entered the subsurface water system £
a result of numerous drift mine mte
ceptions  located  in  the unreclaime
areas  eventually  drained  into  tr
Pittsburgh seam  The original premis
of the project was that surface reclam;
tion  techniques could be employed i
backfill the surface mine pits, cover th
exposed  seam, and  seal the expose
drift  mine entries or interceptions  i
order to reduce the surface water enti
into the subsurface water system. Th
intercepted  runoff  would  then  b
channeled  to  the  normal  surfac
drainage  courses in the Watershed

Technical Approach
  At  the  onset of  this project, th
Consolidation Coal Company operate
six boreholes which discharged water t
the Dents Run Watershed (see Figur
2) Five of the six boreholes discharge
water Irom  active or inactive under
ground  mine  workings  within  th
Pittsburgh  coal  seam. These  pump
were located  within the mines, two c
these, the Valotto and the Laurel Poim
were  constant discharge pumps  Th
Hess, Six-Right, and Loar pumps wer
float-controlled.  Surface  wate
intercepted by abandoned unreclaime
mining operations in the eastern portio
of the Watershed drained to the Hes
discharge point and then  continued 01
to Laurel  Point  The  Laurel  Pom
pumping   facilities  handled a smal
port ion of this drainage while the exces;
continued on to either the Loar or Six
Right discharge  points.  The  Snide
borehole  discharged water  from thi
Sewickley coal seam and the pump wa:
  As previously stated, the objective o
this  comprehensive  mine  drainag*
abatement program was to demonstraK
the effective reduction of pollution frort
acid  mine  drainage through  surfact
water infiltration control This was to b|

        Tributary to
        Dents Run
         , Snider Borehole
                        Waynesburg Coal
           Dents Run Near
           Monitor Station
                               - Vertical Exaggeration = 15
                               -Coal Dips 2% to the West
Tributary to Dents Run Near
Mess Borehold Discharge
                       Tributary to Dents Run Near
         Sewickley   /Monitor Station No 2
                              Redstone Coal
                                Pittsburgh Coal
                                                         Section I
                   Dents Run near,
                   Monitor Station
                   Number 1
                                                                                                      _ River   I
Figure 1.     Typical cross section Dents Run Watershed
 2000    0  2000 4000 6000

         Scale in Feet

 'igure  2.    Borehole locations.

accomplished by selectively employing
specialized reclamation  techniques  at
those   abandoned  surface   mines
identified  as contributing significantly
to infiltration
  The first and  most important step in
such an effort was determining where
interconnections existed  between
underground workings and the surface.
This investigative analysis was initiated
early  in  the   study  and  continued
throughout the fall and winter of 1 971.
Each surfce mine area,  underground
mine opening,  and refuse  bank was
located and evaluated as to its pollution
potential or its potential to contribute to
the underground mine water volume. A
priority listing was then developed for
the work to be performed Priority I sites
referred  to  those   areas  which
contributed  significant  amounts   of
drainage  to  the underground  mine
workings,  while Priority II  sites were
those which contributed  directly  to
stream pollution as a  result of surface
water runoff Priority III sites were those
areas which  contributed to aesthetic
pollution; this includes all of the areas
within the Watershed which were not
included in the first or second priority
    Reclamation work performed as a
result of this study was primarily of the
contour  and   pasture-type  backfills
(Figures 3A and 3B) depending upon the
condition of the highwall at each site
The pasture-type  backfill was used  in
areas where the highwall was relatively
sound and the contour backfill was used
where  the  highwall  was  highly
fractured  In  each case, the backfills
were compacted  in order  to prevent
excessive  infiltration  into  the inter-
cepted  deep mine workings and auger
  Several  of  the  surface  mines
contained  water  impoundments   in
portions of the  unreclaimed pit. When
the reclamation work required draining
these   impoundments,  portable
treatment  facilities were employed  to
provide  adequate treatment  of the
impounded water prior to discharge to a
receiving stream.
  Conventional    heavy  construction
equipment was  used.in the regrading of
the surface mines;  conventional farm
equipment was used  in the  surface
preparation; and seeding,  mulch, and
fertilizer were applied by hydroseeder
Compaction of the backfill in the area of
auger mined highwalls was  done using
a  conventional  55-ton  roller used  in
highway construction AmmimumoflO
passes were made with the roller. The
reclamation specifications calledforthe
placement  of  impervious  material  in
maximum 61 -m3 lifts in the area from
the base of the highwall, a  minimum of
6 meters vertically, and at leasts meters
above   any  auger  holes  or   mine
openings. Where impervious material
was not available, the contractor used
the best material available.
  An important part of a demonstration
project of this nature is documentation
of  the  effectiveness  of  the  control
measures  being  employed  In  this
project,  the  quality and  quantity  of
natural  stream  flows and  borehole
discharges in  the  Watershed  were
monitored. It was felt that this approach
would show both the reduction of acid
mine drainage as evidenced by Consoli-
dation  Coal's reduced  pumping rates,
and the increase in  stream quality due
to the increase in natural surface water
  To this  end,  a   network  of  seven
stream-monitoring   stations was
installed to record transient qualitative
and quantitative effects. These monitor-
ing stations were designed to continu-
ously record pH, conductivity, andflow
Initially, grab samples were collected on
a  weekly  basis at each monitoring
station.  These samples were analyzed
for  pH, total iron, sulfate, turbidity, total
         Original Ground Slope
acidity,  alkalinity,  and  conductivit
Samples were also collected at month
intervals at both the stream momtorin
stations   and  borehole  discharge
These   samples  were  analyzed  fc
alkalinity,  total acidity, conductivity, pi-
turbidity, calcium, magnesium, sulfati
total iron, ferrous iron, total  solid;
suspended  solids,  dissolved  solid;
settleable  solids, aluminum,  an
manganese.  Due  to  the   relativ
inaccessibility and sporadic operation <
the borehole discharge pumps, accural
pumping data was only available for th
Snider   and  Six-Right  borehol
  In  conjunction  with the aforemer
tioned   comprehensive   reclamatio
effort,   Consolidation  Coal  Compar
constructed two  mine  dramge  trea
ment plants to treat discharges from th
boreholes These facilities are describe
 The Loar Treatment Plant
  The  Loar  discharge  and the Laur
 Point discharge were combined unde
 ground and  an  acid  mine  drainac
 treatment plant was constructed at th
 Loar site. This  plant  consisted  of
 conventional hydrated  lime neutralizj
 tion—aeration system and impoum
 ment  for settling and  sludge  storag
                                      Backfilled Ground Slope
Figure 3A.     Typical contour backfill

 Figure 3B.     Typical pasture backfill

The plant was designed for a flow of 637
liters/second,  contains  a  dam  24 m
high and 259 m long, and impounds an
area of approximately 5 3  ha with a
capacity  of  25 x 108  liters  It was
designed for a 25-year life. This plant,
activated in October 1 973, hasoperated
satisfactorily  since startup with  no
major problems Recent water quality
data reported as part  of federal water
quality monitoring program  has shown
compliance with  all  applicable water
quality standards Table 1 showstypical
water  quality data before and  after
treatment, as analyzed and reported by
Consolidation Coal Company

Table 1.    Water  Quality at  Loar
            Treatment Plant.

   Before    Component    After
3170 mg/l
860 mg/l
< 2 mg/l
> Acidity
The Sears Treatment Plant
   The Hess,  Six-Right  and Valotto
discharges were  pumped underground
to the Sewickley seam where they were
combined with the water  discharging
from the Snider  borehole  and treated
near the Snider site The Sears facility
consisted of a conventional hydrated
lime  neutralization—aeration system
and an impoundment  for settling and
sludge storage The plant was designed
for a flow of 252 liters/second, contains
an earthen  dam 34 m  high and 329 m
long,   and   impounds  an  area  of
approximately 15 ha with a capacity of
1 89 x 109 liters It was designed with a
25-year life. This plant  was activated in
September  1974. The discharge from
this  plant  is also  reported  to  be  m
compliance with all applicable water
quality standards Table 2 showstypical
water  quality  data before and after
treatment as analyzed  and reported  by
Consolidation Coal  Company

Table 2.    Water Quality at Sears
            Treatment Plant.

  Before    Component    After
250 mg/l
217 mg/l
< 2 mg/l
> Acidity
  As a result of this cooperative effort of
government and  industry  (Consolida-
tion  Coal Company), nearly all of the
mine drainage pollution  which  was
discharging  to  the  Dents  Run
Watershed  at the outset of the project
was  controlled. As evidenced in Tables
1 and 2, a 99-percent reduction in the
level of  acidity and iron concentrations
contributed to Dents Run was realized
This  was  accomplished through the
previously  described  reclamation
activities as well as  the  design  and
construction  of  two  mine  drainage
treatment  facilities by  Consolidation
Coal  Company
  Surface  reclamation techniques
employed during the project appeared to
have reduced the volume of  drainage,
although flow monitoring data was not
sufficiently  detailed to substantiate this
suspicion Weirs constructed to accom-
modate continuous  stream   flow
measurements were extremely costly
and a constant source of problems due
tosiltation andfloodmg Parshallflumes
are much more suitable to this type of
application  because sediment is  less
likely to  be trapped in the control section
of the flume and cause flooding and
inaccurate stream flow measurements
  Since stream  flow  measurements
through  the  wetrs  could   not  be
accurately  made,  the  pumping
rates from  the Snider and Loar bore-
holes were  used  in  assessing  the
effectiveness of the project in reducing
surface  water infiltration At the onset
of the study, the  Hess, Loar, Six-Right,
and Laurel  Point boreholes discharged
water from the Pittsburgh coal seam
and  the Snider  borehole  discharged
water from the Sewickley seam  This
system was later changed so that Hess,
Six-Right, and Valotto,  discharges  were
pumped  underground  into   the
Sewickley   seam,  which  was   then
dewatered through the Snider borehole
The Loar and Laurel Point waters were
combined and discharged through the
Loar  borehole  The overall Watershed
pumping rates would  reflect the  total
volume  of water infiltrating the Dents
Run Watershed provided that no water
was  transferred  from  this   area  to
another  drainage basin. Assuming this
to be correct, the decrease in the volume
of water discharged from the Sewickley
seam in 1972 and 1974 was

Borehole       1972        1974

Snider     4.54x106  m3 3.31x106 m3
  The  years  1972 and  1974 were
chosen for study since the rainfall for
those two years is approximately the
same (see Figure 4) and reclamation of
the Watershed occurred between those
two years This resulted m a discharge
reduction of 4 54x1 O6 m3 - 3 31x106 m3
= 1 23x106 m3
  The percent reduction for this period
was  1 23x106 m3 -  4 54x106 m3 x 1 00 =
27 percent
When the pumping rates recorded at
Loar borehole were considered,  the
following discharges were calculated
Borehole     1972
Snider    4 54 x 106 m3 3 31 x 106 m3
Borehole     1972        1974

Snider   4 54 x 106 m3 3 31 x 1 O6 m3

Loar       38 x 106 m3   12 x 106 m3

TOTAL   4 92 x 106 m3 3 43 x 1 O6 m3

This resulted m a discharge of 4 92 x
1 O6 m3 - 3 43 x 106 mj = 1  49 x 106 m3
  The percent reduction for this period
was 1 49 x 106 m3 - 4 92 x 1 O6  m3 x 1 00
= 30 percent
  Although this percentage figure is
short of  the  potential  50  percent
reduction believed possible at the onset



"6 n

~ —






l~1 Pumpage
M Precipi-
L-^ tation



                                                                                     1971  1972  1973  1974
                                                                               Figure 4.

            Borehole pumpage vs

of this project, it nevertheless  repre-
sents a very significant total volume of
water  -  4,100  mVday - from  the
combined discharges of the Snider and
Loar boreholes.
  Over 40 hectares of orphaned surface
mined land were regraded and revege-
tated during this project. Unfortunately,
inadequate post-reclamation mainten-
ance has resulted in sparse vegetative
cover  and  development  of  erosion
  Reclamation projects of this nature
should  incorporate  a  routine
maintenance  program  to  assure the
continued success of vegetative cover
and minimize degradation of the site by
erosion  and/or  sedimentation   Also,
access to reclamation sites should be
controlled to prevent degradation of the
site by dumping of trash  and debris,
grazing of livestock, and/or disruption
of water drainage systems by rutting
from vehicular traffic
  State  and Federal  reclamation
agencies should develop inventories of
the  mine   sites  where  selective
reclamation techniques (such as those
demonstrated  in  this study) can be
employed  to  reduce  infiltration  into
underground  mine workings.  By so
doing,  the  responsible  government
regulatory  agency  could  work  with
cooperating mine operators to modify
reclamation practices in order to obtain
maximum   benefit  on  ongoing
reclamation efforts
                                           This Project Summary was authored by Jonathan G. Herrmann, who was also
                                            the EPA Project Officer (see below)
                                           The complete report, entitled "Water Infiltration Control to Achieve Mine Water
                                            Pollution Control—The Dents Run Watershed Demonstration Project" was
                                            authoredbyJ. D. Robinsof Robins andAssociates for Hittman Associates, Inc.,
                                            Lexington, KY 40511
                                           The complete report (Order No. PB 80 217748, Cost: $ 12.00, subject to. change)
                                            will be available from:
                                                  National Technical Information Service
                                                  5285 Port Royal Road
                                                  Springfield, VA 22161
                                                  Telephone- 703-487-4650
                                           The EPA Project Officer can be contacted at:
                                                  Industrial Environmental Research Laboratory
                                                  U.S.  Environmental Protection Agency
                                                  Cincinnati, OH 45268
                                                                           > US GOVERNMENT PRINTING OFFICE 1981 -757-064/02E9

United States
Environmental Protection

Center for Environmental Research
Cincinnati OH 45268

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