by Tom FitzGerald, Director, National Citizens Coal Law Project, Kentucky Resources Council Inc.
This information is derived from a review of the files of the state Department for Surface Mining Reclamation and Enforcement, and is therefore an incomplete record of the history surrounding the structure. This will be revised as other information requested of the US Office of Surface Mining, US Army Corps of Engineers, MSHA and the state Division of Water become available.1
History of the Big Branch Impoundment
As early as 1972, there had been disposal of slurry in an impoundment in Big Branch. According to a report submitted by Kimball and Associates in conjunction with the initial permanent program application to DSMRE, the refuse area was described as a valley fill type embankment located on the Big Branch tributary of Wolf Creek.
The existing facilities in the Big Branch area consist of a
slurry impoundment and a small sedimentation pond at
the toe of the slurry impoundment. The slurry impoundment
was formed by constructing both upstream and downstream
embankments. A 48 inch diameter corrugated metal pipe
conveys up[-]valley stream flow beneath the impoundment.
* * *
Slurry was pumped into the Big Branch impoundment until
1975. At that time, MESA, currently the Mine Safety
and Health Administration, issued an order which deactivated
the Big Branch impoundment until remedial modifications
could be made to the existing structure.
* * *
Slurry was being pumped into abandoned mines and slurry
ponds located northwest of the Big Branch area. Presently
Martin County Coal Corporation is implementing a megamat
filter press that will compress slurry fines into 1 1/4 thick
blocks. Approximately 75.6 tons per hour of cake can be
produced using the filter press. Coal refuse will be hauled
to the Big Branch site using trucks. Future planning may
utilize conveyor belts. Refuse will then be spread and
compacted using bulldozers.
The application for Amendment No. 1 to the permit noted that the refuse disposal area would be constructed as had been proposed by the Kimball and Associates report, i.e. that refuse would be a combination of coarse refuse and material compressed and shredded from the megamat filter press installed at the coal site, and would be placed in shallow layers of less than 24 inches and compacted to attain 90 percent dry density.
In 1984, the permit was proposed for revision in order to convert the dry coal refuse disposal facility to an impoundment. The application included a three-volume report by the Esmer engineering firm, which proposed to replace the dry coal refuse disposal facility with a slurry impoundment. The existing small impoundment, with a elevation at the crest of 890 feet, was to be eliminated during Phase I of the new impoundment, and replaced with an impoundment with a 48.1 year design life based on production rates of approximately 1.7 million tons per year of coarse coal refuse and 392,000 TPY of (dry) fine coal refuse. The foundation was to be constructed of coal refuse in five proposed phases, and at Phase III was designed to attain a dam crest at 1100 feet. The ultimate design height was proposed to be 1200 feet.
In the engineering report section describing the general geologic site conditions, the Esmer report noted that the location of the proposed impoundment had previously been utilized as a refuse disposal area, with a small embankment made of an earthen core with coarse refuse shell, to a height of 800 feet at its crest, behind which fine coal refuse had been pumped to an elevation of 790 feet, and that coarse coal refuse had been placed over the fine coal refuse to convert the area to a dry refuse disposal facility.
The report discussed previous and proposed mining at the site. The entire discussion is reprinted below:
There are underground mines in two (2) coal seams around
the perimeter of the impoundment site. Mine No. 1-S
beneath the eastern edge of the site in the Stockton seam
was abandoned on November 30, 1972. The Stockton seam
outcrop is at elevation 1075 on the western perimeter of
the site. Mine 1-C extends arond (sic) the entire perimeter
of the site in the Coalburg seam and is still in operation.
The Coalburg seam outcrops between elevation 960 and
elevation 1000. The locations of the mining areas are shown
on Drawing No. 83014-1 in Appendix B. It is not
anticipated that subsidence will be a problem, since
the underground mines are situated only beneath the
perimeter of the impoundment site and do not extend
for any appreciable distance directly below the proposed
Esmer, Volume 1, p. 38-9. (Emphasis added).
Other than this paragraph, there is no supporting analysis in the permit application or Esmer report of the possible effects of subsidence on the impoundment, on the extent to which subsidence impacts were possible because of the relationship of the angle of draw from prior mining under the proposed impoundment pool, or any other geotechnical analysis of investigation into the relationship of the prior mining and the proposed impoundment pool. Likewise, there is no analysis provided in the permit application to the possibility of failure of the impoundment pool into outcrop barriers along previously mined seams such as the Coalburg or Stockton seam. The report noted that the Coalburg seam mining was still active, that the coal seam outcropped at between 960 and 1000, and that the impoundment at Phase III would attain an elevation approaching 1100 feet.
Yet no further analysis was supplied other than the conclusion that a problem with subsidence was not anticipated because the prior mining extended only beneath the perimeter of the impoundment site and did not extend for any appreciable distance beneath the proposed impoundment.
The permit was approved by DSMRE, and apparently by MSHA through Phase III.
As to whether the state agency was aware of the extent of underground workings beneath the proposed impoundment, the Esmer Report included in Appendix B a map showing the location of those works. The map provided in the Esmer report outlined the general location of the mine workings and does not correlate to the detailed maps provided in 1994 in conjunction with the plan to repair the impoundment leak. A blasting approval form required by MSHA and the surface mining laws and contained in the state permitting files, included 1985 maps showing in more detail and with more accuracy both active and abandoned mine works in the Broas (Stockton) and Peach Orchard (Coalburg) seams underlying the left and right sides of the impoundment.
The 1993 Special Study On Coal Waste Handling
In response to concerns identified by OSM and DSMRE, a joint study of coal mine waste handling was completed in 1993 and released in 1994. Among the observations of the study was this:
3. Coal mine waste structures are often built on
foundations where underground mining has occurred.
Existing regulations should be highlighted to assure
that subsidence analysis is required for long-term
Among the factors which prompted the joint study, according to the report, were these:
MSHA conducts an intensive plan review and inspection
program of all coal mine waste structures. Their program
and regulations are separate from the laws and
regulations of the DSMRE. MSHA law is primarily for
miners safety and not for environmental protection and
public safety as are the laws of DSMRE and OSM. A
clearer understanding of MSHA responsibilities and
their interaction with DSMRE and OSM requirements is
* * * *
There may be a need to evaluate requirements for changes
to existing DSMRE rules and regulations with regard to
coal mine waste handling.
The study selected 16 sites and visited 14. Of the 14,
eight (8) of the 14 sites have mine maps which show
abandoned mine works within the shadow area or
within the draw-angle influence area of the structures.2
No subsidence analysis was provided for any of these
sites. Upon field investigation, evidence of recent
subsidence was found at one (1) site. The site experienced
damaging subsidence-caused cracking in the impoundment.
The company was forced to abandon the site with 5 years
of storage left remaining. The total impact upon the
environment is not known.
The report continued:
Concern: One of the requirements for a safe impoundment
structure is that deformations be minimized so that cracking
of the structure is eliminated and an adequate freeboard is
maintained. Another requirement is that seepage through
a structure and its foundation be minimized and controlled.
Mine subsidence can jeopardize these structure safety
requirements as a result of zones of tension which are
created at the surface. Cracks can occur in soils and mine
waste materials because such materials have low resistance
to tensile stress. Conduits that pass through a structure
can be pulled apart or otherwise damaged by differential
movements. Differential movements resulting from
subsidence can cause other problems by affecting the
function of internal design features such as filters and drains.
These problems can result in higher pore pressure than the
structure was designed for, and can cause slope failure.
Also sudden subsidence in the foundation could cause
The primary focus of the report thus appears to have been subsidence impacts on the embankment structure itself rather than subsidence effects on the impounded slurry.
Among the proposed actions was this:
It is the applicant s responsibility to determine if there
are any underground mines in the proposed disposal
area. It would help if the permit application specif-
ically asks, Are there any underground mines in
the proposed disposal area? ; the applicant must go
on record stating that either there are or there are
not any there. For high hazard structures, we might
consider having DSMRE personnel check the Mines and
Minerals files to be sure we have all the information.3
There may also be situations where it would be
appropriate to require the applicant to drill the
embankment foundation area.
For the above mentioned concerns, a site that has been
undermined may not be suitable for the construction of
a coal mine waste structure. If there are no alternatives,
and a coal mine waste structure is proposed on a site
that is already undermined, then the permit reviewers should
ask for a more comprehensive foundation investigation,
and remedial measures should be proposed if needed.
Subsidence control analysis should become a part of the
applicant s geotechnical investigations.
DSMRE regulations (405 KAR 16:140 and 405 KAR
` 16:160) do not address protection of coal mine waste
structures (existing or under-construction) from subsidence
induced by underground mines. These regulations should
reference 405 KAR 18:210. It is envisioned that
foundation exploration and a subsidence analysis would
be necessary to determine possible subsidence damage
to coal mine waste structures. Subsidence potential
could dictate locating new underground mines to obviate
the possibility of damage to coal mine waste structures.
There is some indication that additional training was provided to state permit reviewers by MSHA after this study. In 1997, a Memorandum of Understanding was executed between MSHA and the state DSMRE clarifying the permitting coordination between the two agencies. It is unclear to what extent the recommended permit processing changes have been implemented, although there appears to have been no subsidence analysis required for the Big Branch Impoundment even after the 1994 failure.
On May 11, 1994, the state DSMRE inspector conducted an inspection of the waste impoundment, and no problems were noted. Visual inspections are plainly insufficient to determine subsidence or outcrop barrier failure potential.
On May 23 and 24, 1994, a large volume of water (too great to measure) in excess of the allowable water quality standards (suspended solids) [was] discharged from pond #2 into Wolf Creek. The water originated in the refuse impoundment and entered pond #2 via old mine works located around the perimeter of the rufuse (sic) impoundment. Notice of Non-Compliance 41-0200. A Notice of Non-Compliance was issued requiring that the company stop the flow of water entering Wolf Creek by whatever means that are necessary.
Ogden Environmental and Energy Services later estimated the amount of water discharged into the underground mine in the coalburg seam at 342 acre-feet of water.
To remedy the problem, the company submitted Revision #5 on August 18, 1994, which proposed to construct a seepage barrier based on an Impoundment Sealing Plan developed by Ogden Environmental and Energy Services Co., Inc.4 According to the application, the Broas (stockton) seam would be stripmined and the spoil from the mining operation would be used to construct a seepage barrier The impoundment sealing plan was approved by MSHA on October 20, 1994.
The permit application for Revision #5 indicated that when the breakthrough occurred, discharges were observed from three locations - from the South Main Portals, which drain into Andy Branch on the west of the impoundment, from the Mills Branch Portals, which drain into Mills Branch to the southeast, and the Highwall Outlet, which drains to Big Branch to the east.
Revision #5 noted that there would be blasting associated with the stripping of the Stockton seam, and that the surface blasting would overlap the abandoned coalburg seam workings at a vertical distance of 125 feet above the abandoned works.
Revision #5 relied on the Impoundment Sealing Plan developed by Ogden Environmental and Energy Services (August 8, 1994), which made these observations:
On May 22 and 23, 1994, a leak or breakthrough occurred
within the Big Branch impoundment area. This breakthrough
was a result of subsidence of an area where shallow cover existed over the abandoned mine workings in the Coalburg coal seam. As a result, water in the impoundment entered an abandoned and previously sealed portion of the mine. The water drained through the mine and resulted in discharges from
the mine at several locations. As a result of this event, an
Impoundment Sealing Plan was developed on May 23, 1994.
The plan required that both short term and long term actions
be taken. One of the action items required was to perform an
analysis of the relationship of the mine workings to the
impoundment to determine if additional remedial work is
needed. We have completed this analysis and presented
herewith is a summary of the results and our recommendations.
The Ogden report continued, recommending that two primary actions be taken to address the issues:
These actions are: (1) construct a seepage barrier
within the impoundment area and (2) construct a hydraulic
mine seal (bulkhead) in the 1st Left section of the #2
North Mains. We believe these actions will allow for the
safe operation of both the Big Branch Slurry Impoundment and
the operation of the beltline through the #1 and #2 North
We believe the seepage barrier , along with controlling the
water levels within the impoundment, should meet the objective
of limiting the quantity of seepage passing from the impound- ment into the underground mine workings in the Coalburg seam. Also, the seepage barrier should limit the rapid release of impounded water and fine coal refuse from the impoundment should a breakthrough occur.
Although we believe the seepage barrier should adequately
perform the function of reducing the potential of a breakthrough and limit the rapid release of impounded
water in the mine, additional precaution should be taken to
protect the miners that work along the beltline in the #1
and #2 North Mains. Therefore, we are recommending that
a hydraulic mine seal be constructed in the 1st Left section
off the #2 North Mains. To further reduce the flood hazard
potential in the mine and possible inundation of the action #1 and #2 North mains beltline, as discussed in our June
29, 1994 letter, the mine should be allowed to release water from all entries so that no appreciable amount of water is stored in the mine. In our opinion, storage of a significant amount of water in the mine would only create a hazardous condition.
The recommended actions from the Ogden Report included construction of a seepage barrier intended to reduce seepage and to provide bulk that would collapse into the subsided area in the event of another breakthrough and should for a plug , limiting the amount of fine coal refuse and water entering the mine.
According to the Ogden Report:
The limits of the seepage barrier, as shown on Sheet
2 of the drawings, were established over the areas where the
possibility of future subsidence is greatest.
In establishing the limits, consideration was given to the
characteristics of the mining in the vicinity of the impoundment. The lower horizontal limits of the seepage
barrier was established considering potential subsidence.
Therefore, the lower horizontal limits have been estimated
using an estimated draw angle of forty-five degrees
(45o from vertical) from the extreme mining limits. This
should be adequate based on the results of the events of
May 22 and 23, 1994. The breakthrough resulted in a
funnel shape. Although the majority of the water drained
from the impoundment only a small amount of fine refuse
appeared to have discharged through the breakthrough
and there appeared to be a slope of less than forty-five
degrees (45o from vertical) up through the partially
consolidated fine refuse deposit.
The upper limit of the seepage barrier, according to the report, was where there was one hundred feet of cover material over the mine workings. The thickness of the barrier was set at least 12 to 25 feet, based on assumed mine workings of 5 to 12 feet in height with an average of 8 feet. The barrier was to be constructed of shot rock and soil from the surface mining of the Stockton seam, which was located approximately one hundred feet above the Coalburg coal seam and which just happens to coincide with the minimum one hundred feet cover established for the upper limit of the seepage barrier.
Thus, the Stockton seam was to be mined and the spoil material to be used to create a barrier from the Stockton seam to below the outcrop elevation of the coalburg seam. Ogden further suggested that fine refuse be directed along the barrier after construction in order to encourage settlement and consolidation of the fine refuse to reduce the permeability of the barrier further, and that the pool level in the impoundment should be maintained as low as possible, thereby reducing the quantity of clear water in the impoundment and the hydraulic head.
The Ogden report further recommended that a mine seal be constructed to protect miners working in the 1-C mine, based on the conclusion that if there were a breakthrough, there would not be sufficient capacity for storing the water in the mine because
* portions of the mine have been previously abandoned,
sealed and filled by injecting fine refuse slurry;
* the majority of any water that enters the mine will
drain to and discharge through the abandoned portions of
the mine and out of the South Mains or the Mill Branch
portals. However, the discharges from the Mill Branch
portals is limited due to the seals that are constructed
at the portals; and
* In order for water to discharge out of the highwall opening
in the Big Branch hollow, the 1st Left section off the #2
North Mains, and the upper portion of the South Mains
off the #3 North Mains, the flow into the mine would have
to exceed the discharge capacity of the mine by a large
amount resulting in the mine filling and backing up into the mine (i.e., portal elevations are lower than the higher
floor elevations in the mine).
Ogden noted that there are entries where if the mined filled, water could potentially discharge into the #2 North Mains where the active beltline existed, but did not proposed any remedial actions be taken in this area because
[w]e believe the potential for the mine to fill to this level
is limited due to the minimum floor elevation between the
impoundment and the #3 North mains is approximately 981 feet. Also, this portion of the mine has been sealed and filled with fine refuse slurry and no discharge was noted as a result of the events of May 22 and 23, 1994. Based on the measurements made in an abandoned injection well (see Sheets 1 and 2) and the estimates of water levels behind the ventilation seals in the 1st Left off the #2 North Mains,
water levels in the mine were less than about elevation
971 feet. Because the mine did not fill during the past event
and because we believe the seepage barrier when constructed
will reduce the potential for future breakthroughs or at least
the possibility of a rapid release of water into the mine, we
believe it is unlikely that a future breakthrough would occur
that results in filling of the mine and a discharge into the
#3 North Mains.
With regards to the proposed mine seal, the configuration and
location of the seal was selected so that the possibility of a blowout occurring through pillars or the coal seam will be
reduced. Based on our analyses, for a hydraulic head of 18 feet
at the base of the seal, the outflow at the controlled discharge
points would be much greater than the maximum inflow rate
from the impoundment. Therefore, the design hydraulic head of
18 feet is a conservative estimate.
On October 24, 1994, the state Division of Permits sent the first technical deficiency letter to Martin County Coal Corporation regarding Revision 5, asking the company to:
Specify how the slurry impoundment and underground
mine will be protected from adverse impacts of blasting.
Discuss the possibility of subsidence and any adverse
effects from subsidence.
By letter dated November 9, 1994, Summit Engineering, Inc. responded in this manner:
The possibility of subsidence and any adverse effects
was addressed in the Esmer Report submitted with
Amendment No. 1. Any adverse effects of blasting on
the slurry impoundment and the UG mine has been
discussed in Item 24.
As will be recalled, the totality of the consideration of possibility of subsidence and any adverse effects contained in the Esmer Report constituted one paragraph of conclusions, with no supplied or referenced supporting analysis or evidence.
The state also asked, apparently for the first time, that the company:
Show the extent of the abandoned underground mine
on the MRP map. Address the preventative measures
for intercepting and releasing water (blowouts) from
the abandoned ug mine.
The engineering firm responded:
The extent of underground mines have been shown on
other maps. It would not benefit anyone to clutter
the Mining and Reclamation Plan Map with more infor-
mation. The preventative measures to be implemented
for intercepting the water is the Impoundment Sealing
Plan as proposed by Ogden. The release of the water
is through the wet seals as proposed by Ogden.
In the October 24, 1994 deficiency letter, the state permit reviewer also requested information regarding the probable hydrologic consequences of the new proposed surface mining:
7. Item PHC: Address potential adverse effects of the
hydrology with respect to underground works. Identify
short and long-term adverse effects on surface and
groundwater as a result of the breakthrough. Discuss
the potential of future breakthroughs and the effects on
hydrology. Discuss each discharge portal and specify
the receiving sediment pond. Discuss water quality
from the discharging portals.
In response, the engineering firm noted that [t]he PHC has been revised. The PHC, which is the probable hydrologic consequences determination, did not discuss the potential for future breakthroughs and the effects on hydrology, as had been demanded by the permit reviewer, but instead discussed only the effects of installation of the seepage barrier, the acid-producing potential of the Stockton seam (for which reclamation was to be deferred for 20 years).
The October 24, 1994 deficiency letter further expressed concern regarding impoundment stability, and requested additional information:
9. Regarding the seepage barrier and underground
* * *
(b) . . . It appears that the current level of slurry should
be the maximum level since fractures and subsidence cracks could allow further slurry to enter the ground water regime.
The November 9, 1994 response to this concern came from Ogden:
With regard to fractures and subsidence cracks in the Stockton
(Broad) seam due to previous mining of the Coalburg seam
approximately 100 feet below, no surface cracks due to subsi-
dence have been observed around the impoundment. In the
unlikely event that any subsidence fractures connect the
impoundment area to the mine, particularly above the seepage
barrier, we feel that the chance of fine refuse migrating
100+ feet to the Coalburg mine and flowing out of a mine
entry is unlikely. Fine refuse deposited in the impoundment
area will consolidate, resulting in 1) an increase in strength,
2) a reduction in permeability, and 3) a reduction in the
potential of the material to flow, particularly at the lower
depths of the deposit. Therefore, it is unlikely that a
significant amount of material could migrate to the underground
mine workings. Also, fine refuse tends to be self-healing,
and if any refuse were to enter subsidence fractures, we
believe that the fracture would become sealed merely by
the nature of the material. Therefore, we do not believe
it is necessary to limit the fines elevation to the current
elevation. As presented in detail in our report and sub-
sequent responses to MSHA, we believe that if the
proposed plan is implemented, the objective of limiting
the quantity of seepage passing from the impoundment
into the underground mine workings in the Coalburg
seam and the rapid release of impounded water and fine coal
refuse from the impoundment will be met.
The state identified other deficiencies, which were responded to in this manner:
* when asked to [p]rovide a history for slurry injection into UG works. Specify what application, permit, and dates of approval regarding slurry injection, Summit Engineering responded that
[t]his revision does not address slurry injection. 5
* 10. Regarding the impoundment sealing plan view, when
asked by the state to provide information regarding the
past slurry injection, Summit again refused to provide the infor-
mation. The reviewer noted that Slurry is shown in places other than the breakthrough area with no path shown from the breakthrough area and requested that Martin County Coal Cor- poration [p]rovide the history and permitting status of such areas. The MRP map does not reflect a previously approved
The company, through its engineering firm, responded that
[t]he slurry injection is not part of this permit revision. The
revision addresses the construction of the seepage barrier
and a request for a contemporaneous reclamation waiver.
When the permit reviewer noted that [a]n abandoned injection well is shown. Provide the history and permitting status of this well. Include a discussion of all injection points into the UG works. Show and label all such points to include any pipes, wells, auger holes if any, etc. And further noted that (c) An area appears injected without any noticeable entry. Show and label the injection well, pipe, etc. , the response again was
to refuse to supply the requested information on the basis that
[t]he slurry injection is not part of the plan.
* The permit reviewer further noted that: (h) The permit boundary shown on sheet 2 or 3 does not match the MRP map. The areas of slurry injection to include the upper left portion of slurry injection and the area of the injection well are overlain by the permit area per the MRP map. Clarify.
In response, Ogden noted that the maps would be revised.
The revised Sheet 1 of 3 indicates two areas of previous
mining which have been used for injection of coal fines,
overlain in part by the impoundment at maximum design elevation.
When asked by the permit reviewer whether future breakthroughs were possible, Ogden noted:
Future breakthroughs under existing conditions are possible.
However, as indicated in our report, we believe the construction
of the seepage barrier will reduce the potential as further
discussed in the following item.
In the following item, Ogden responded to the state reviewers request to [f]urther explain how the seepage barrier would reduce the possibility of a breakthrough. It has been stated that the breakthrough is a result of subsidence on page 1.:
As presented in our August 8, 1994 report and our
subsequent October 3, 1994 letter, we proposed that the
intent of the seepage barrier is to limit or reduce the
consequences of a sudden breakthrough independent
of the possibility of a breakthrough. However, the bulk
material put in place to plug a breakthrough is buttressed
by consolidating fine refuse. The reduced permeability
of consolidated fine refuse serves to reduce the quantity of
infiltration. These two components serve to reduce the potential for piping-induced breakthroughs. Ultimately
the successful operation of the components of the
Impoundment Sealing Plan, functioning during a break-
through, will provide the necessary safety against inunda-
tion of the belt maintenance activities at the 1st Left
section off the #2 North Mains.
* The permit reviewer asked also that the company [c]larify whether the Stockton coal seam has been undermined, and whether subsidence has occurred. Further explain why a breakthrough is reduced when the impoundment has
increased above the stockton seam. It appears that the
potential is increased if the level is above the Stockton seam
if subsidence has occurred.
The company responded, through Ogden:
Previous mining of the underlying Coalburg seam has
occurred. However, surface cracks or depressions in-
dicating subsidence of the material above the Coalburg
seam have not been observed around the impoundment.
After the impoundment level has increased to a level
above the Stockton (Broas) mine bench, wee believe
the potential for a breakthrough in the future is
reduced. After the impoundment has reached a level
above the Stockton (Broas) seam, there will be at least
100 feet of material between the pool level and the Coal-
burg seam. This material will consist of overburden material
and consolidated fine refuse. As indicated on page 5 of
our August 8, 1994, report, based on the extraction in the
Coalburg underground mines (i.e. no secondary mining),
the information presented in the Bureau of Mines Information
Circular 8741, Results of Research to Develop Guidelines
for Mining Near Surface and Underground Bodies of Water,
and characteristics of the overburden material (i.e. sandstone
with some shale) as the thickness of overburden increases, the
possibility of breakthrough subsidence decreases. Similarly,
with regard to the sallow cover areas, after the seepage
barrier has been constructed and fine refuse has consolidated
to a depth of greater than 100 feet, it is expected that subsidence, if it has not already occurred, would be less
likely to occur.
The permit reviewer noted that [t]he impoundment appears to overlie the abandoned injected well in its final configuration. No sealing of the well has been identified nor proposed. The well should be filled with grout prior to the slurry level reaching the well surface elevation. The company, through its engineering consultant, agreed that the well was inside the current permit boundary and committed to seal it.
The responses provided on November 9, 1994 appear to have satisfied the state Division of Permits, since a subsequent November 17, 1994 deficiency letter did not request further information regarding any of these issues, and the permit was ultimately issued as minor revision #5.
On October 7, 1999, Gharib Ibrahim, a civil engineer with MSHA s mine waste and geotechnical engineering division, expressed concern with allowing construction of Phase 4 (Stage 4) of the Big Branch Slurry Impoundment:
Currently, Phase III of the Big Branch Slurry Impoundment
is under construction. Phase III will raise the crest to
elevation 1,095 feet.
The submitted report proposes to . . . raise the crest elevation
of the embankment 45 feet to elevation 1,140 feet . . . .
In order to complete the review, the following items need to
1. The dynamic stability (earthquake) analyses for the
submitted Stage 4 modification used the pseudo-static
method. Because of the size and the high hazard
classification of this site, the pseudo-static hazard
analysis should not be utilized.
* * *
3. The construction of stage 4 will put an additional load
on the pillars in the Stockton and Coalburg seams. There
is a concern that this load could cause further convergence
of the pillars and consequently may cause subsidence.
A. Provisions to monitor potential subsidence should be
B. The company should address the effect of the transfer
stress (sic) from the embankment overburden to the pillars
in the upper mine and then to the pillars in the lower mine.
4. Problems that may occur in the workings within the coal
seams that could affect the impoundment include floor
heave, pillar crushing, and roof failure. These need to be
It is unclear whether MSHA conducted a geotechnical analysis that included the possible effects of subsidence on Phase III of the impoundment, or whether similar concerns had been voiced by MSHA regarding the relationship of the Phase III impounded slurry elevations and the proximity to underground mine workings. A Freedom of Information Act request is being sent to obtain complete files from MSHA on this impoundment.
On December 11, 1997, a Memorandum of Understanding was executed between MSHA s three District Offices in Kentucky, and the Kentucky DSMRE, to provide for coordination of review of coal refuse piles and impoundments by the two agencies. Under the procedures, MSHA approval occurs prior to DSMRE review, and once MSHA approval is obtained, the applicant submits to DSMRE the approved plan and undertakes its obligations under the surface mining laws.
According to the construction certification supplied for the impoundment, on July 10, 2000 the pool elevation was at 1,059 feet, impounding 7,300 acre-feet of slurry. At capacity, Phase III crest elevation was at 1,095 feet and the impoundment would have impounded 11,110 acre-feet.
On October 11, 2000, Martin County Coal Corporation was issued an Imminent Danger Cessation Order and Notice of Non-Compliance 41-1752, and was ordered to
(1) Cease all substandard discharge into waters of the
(2) Cease placement of slurry material into the refuse
impoundment until approval of a plan to repair the
impoundment has been obtained from the Cabinet.
(3) Reestablish access to all slurry blocked driveways,
and any county or state roads.
Despite the confident predictions of the permit application in 1984 and again in 1994, a second breakthrough did occur into the previously mined workings of the coalburg seam, with devastating effect. It is apparent that the assumptions concerning the failure mechanisms associated with prior underground mining were not accurate, and the remedy proposed in the wake of the 1994 failure which allowed continued elevation of the slurry and the water pool of this impoundment to approximately 100 feet above the elevation of the previously-mined Coalburg seam, was unwise and unsound.
The exact failure mechanisms of the impoundment are yet to be assessed, and there will be many lessons learned from a tragedy of this proportion. However, in light of the 1996 waste dam failures and the 1981 Ages tragedy, some basic and obvious reforms should have been implemented.
Based on the record reviewed and after discussions with many agency officials involved in the review of the waste impoundment failure, these interim recommendations are proposed:
1. Impose a moratorium on further issuance of permit approvals or revisions authorizing new or increased size of coal waste impoundments, and implement process and technical review changes after a comprehensive assessment of the failure mechanisms associated with coal waste impoundment structures.
Among those changes that need to be implemented:
a. Clarify permit forms to assure that coal waste disposal permits ask clearly and specifically the identity and location of all known underground workings. At least twice in the history of the permitting of this impoundment, the applications indicated that no underground mine workings existed beneath the permit area.
b. Where there is any question as to the accuracy of such information, or where the information is unavailable as to whether prior underground mining has occurred, and there are recoverable seams of coal located adjacent to the impoundment pool or beneath the pool or foundation, DSMRE should require core drilling to be advanced to below the depth of any merchantable seams to assure that the extent of prior underground workings is identified in the foundation and pool area and adjacent areas.
c. An alternatives analysis should be required prior to approval
of coal waste impoundments, and impoundments should not be
approved over or within the angle of draw of underground mine
works, and should be limited to locations where the impoundment is classified at the lowest hazard classification for both embankment breach and other failure mechanisms (such as subsidence and earth-
d. For all other situations, require that technology be employed to manage and dispose of the coal fines in compacted dry coal refuse banks, and prohibit new construction or expansion or coal slurry impoundments of moderate or high hazard classification.
e. Underground injection of coal slurry should be explored as an option for coal waste disposal only where appropriate and after coordination with USEPA Region IV and MSHA to assure that there are no adverse effects to public or miner safety and that underground sources of drinking water.
f. Any coal waste impoundment should be required to be bonded at the full cost of reclamation, based on the worst-case analysis of catastrophic failure of the impoundment. Assessing the true impact of the failure of the impoundment, and requiring bonding at that level, creates accountability for the potential environmental and public consequences and better reflects the full cost of the disposal method.
2. The roles of the various agencies in reviewing and approving placement of coal refuse material should be clarified and both coordination and technical review should be strengthened in order to assure protection of the public, miners on the minesite, and the environment.
It appears that, despite the waste dam failures at Ages, Kentucky in 1981, and in Virginia in the 1990 s, that adequate coordination in technical review and alternatives analysis is not being undertaken.
The state permitting files contain no subsidence analysis of the risks of failure of the impoundment into the underground workings of the Coalburg seam, nor of the risks of failure of the impoundment through the outcrops barriers along that seam. Instead, what is contained in the files are conclusory statements indicating that such failures are unlikely .
Likewise, the probable hydrologic consequences determination failed to provide information and analysis of the impacts of impoundment failure, even though such a failure had occurred on a small scale in 1994 and the permit reviewer had specifically asked that the applicant address the risks and effects of another breakthrough.
The lack of coordination in information-sharing among the agencies is also of concern. The existence of the MSHA study of coal refuse impoundments, which ranked the impoundments by hazard classification associated with underground mining, appears to have been unknown to the state surface mining agency until after the news articles appeared
3. Existing impoundments should be reviewed and remedial measures, including dewatering or lowering of impoundment levels, capping and closure of impoundments, and other remedial measures as appropriate, should be mandated where there is any potential for catastrophic failure due to subsidence or earthquake.
4. For all existing impoundments, the probable hydrologic consequences determination and hazards assessment should be reviewed to assure proper consideration of the worst-case failure scenario, and to require reduction of hazards, alternative management approaches, and revised bonding sufficient to fully fund reclamation and repair of all damages under the worst-case failure scenario.
5. Further investigation is warranted into the dates during which underground injection of coal slurry occurred.
The failure of the impoundment occurred into mine workings that were identified on an 8/8/94 mine map as having been previously mined and sealed, and into which fine coal refuse was injected.
It is apparent that at least one of the seals from the section failed, since the water from the impoundment exited that sealed section of the mine en route to discharge at the South Main portals and to the North.
The previous breakthrough failure of the impoundment in 1994, was identified as having occurred due to subsidence in the coalburg seam. The same 1994 mine map identified the location of the 1994 failure as being located at the edge of another area which was previously undermined and sealed, and into which fine coal refuse had been injected.
The dates during which the injection of coal slurry fines occurred cannot be established based on the state permitting files. It is known, based on the information contained in the Kimball report, that
slurry was being pumped into abandoned mines . . . located northwest of the Big Branch area as of 1975. But neither of these areas are northwest of Big Branch; they are instead located in Big Branch itself.
In the application for the permanent program Permit 680-8002, the company indicated that they were presently processing an application with MSHA to do underground injection in some of their abandoned workings. When approvals are acquired this permit will be revised to include this proposed plan.
There is no indication that the state permit was ever revised to authorize slurry injection into underground workings.
On June 25, 1984, any underground injection of coal fines would have been required to obtain a permit from the U.S. Environmental Protection Agency, under the Safe Drinking Water Act Underground Injection Control program.
U.S. EPA Region IV and the Kentucky Department for Surface Mining Reclamation and Enforcement (DSMRE) should jointly investigate the circumstances surrounding any coal slurry injection. The information requested in 1994 by the DSMRE but which the company refused to provide, should be demanded and subpoenaed, if necessary, in order to determine the dates, locations, and extent of underground slurry injection.
6. Enforcement Action Should Be Taken To Recover Penalties For Natural Resource Damage.
The enforcement action taken by the Department for Surface Mining to date does not address the off-site impact on land and water resources. Enforcement action should be taken under the Clean Water Act and mining laws, with penalties sufficient to meet deterrent, punitive and remedial purposes, for all violations of those laws.
7. The role of the U.S. Army Corps of Engineers should
be clarified, and permitting of coal waste disposal sites made
consistent with the Clean Water Act.
Under Section 404 of the Clean Water Act, the placement of
dredged or fill material in waters of the United States, including
intermittently flowing streams, must be preceded by a permit
issued by the U.S. Army Corps of Engineers. While the Section 404
(b)(1) guidelines issued jointly by the Corps and US Environmental
Protection Agency require that an applicant seeking a 404 permit
must engage in a sequential process of avoidance, minimization
and mitigation, which begins with an analysis of alternatives to
the proposed filling that would not impact waters of the United
States, the Corps in practice has granted nationwide permit
coverage to valley fills and coal waste dams without requiring
either the public interest review that it provides for individual
permits, or any alternatives analysis, based on the Corps assumption
that the issuance of a Title V permit under the surface mining
programs adequately address these issues. Unfortunately, as
has been seen, those agencies do not engage in any analysis of
the need for the impoundment or the unavailability of less-damaging
or less-hazardous alternatives such as backstowing or dry refuse
There is a more basic question that the Corps of Engineers and
EPA must first address, however, which is why those agencies have
authorized the construction of these large coal slurry impoundments in waters of the United States. The current Corps of Engineers regulations defining the scope of their 404 permitting program define fill material as any material used for the primary purpose of replacing an aquatic area with dry land or of changing the bottom elevation of a waterbody. The Corps regulation specifically excludes the discharge of any pollutant into water primarily to dispose of waste.
There is little room to argue that the dumping of slurried coal wastes behind impoundments constructed of coarse refuse material is for the purpose of waste disposal, and hence, is not an authorized Section 404 activity for which the Corps can lawfully issue authorization. Lacking such authorization, the placement of coal refuse material in a watershed containing a water of the United States would constitute an unpermitted discharge of a pollutant in violation of the National Pollutant Discharge Elimination System.
The failure of the Corps of Engineers to acknowledge that the placement of this material from coal processing plants is not authorized under its program, has led to construction of substantial impoundments such as the one which failed in this case. The pending joint EPA-Corps rulemaking, which is aimed at undoing the decision of Judge Haden in West Virginia concerning valley fills for disposal of spoil from contour and mountaintop mining operations, would eliminate the primary purpose test and would allow coal wastes impoundments to be lawfully placed in intermittent and perennial streams.
The effect of this rulemaking change would be to legitimize the laissez faire approach of the Corps of Engineers towards the permitting of these coal waste impoundments.
1On October 20, 2000, this open records act request and letter of inquiry was sent by the Council to state and federal officials:
To: Commissioner Carl Campbell, DSMRE William Kovacic, OSMRE Tom Welborn/Eric Somerville, EPA John Dovak, Division of Water Michael Gheen, COE Huntington District From: Tom FitzGerald, Director Kentucky Resources Council, Inc. Re: Coal Waste Structure Collapse, Martin County Coal Co. Gentlemen: I am writing to you concerning the recent catastrophic failure of the coal waste impounding structure, to request information contained in your files regarding this structure under state and federal freedom of information laws, and to further request your response to the questions outlined below. The information I am requesting is as follows: 1. A copy of any permit approval documents, permit applications, inspection and enforcement documents contained in your files regarding the coal waste structure; 2. A copy of any guidelines, policies, or other documents regarding the permitting of such structures in areas with previous underground mine works; and 3. Any inventory, listing or other report analyzing the safety of other coal waste impoundments relative to the risk of failure from subsidence. Regarding the questions that I would like to have answered, the press has focused almost exclusively on the role of the Mine Safety and Health Administration in the approval of this impoundment, but appears not to be aware of the statutory responsibility of each of your agencies regarding the placement of coal waste materials in above-ground impoundments. While MSHA's responsibility by law is primarily protection of the miner on the minesite, the Surface Mining Control and Reclamation Act of 1977 and the Clean Water Act, as well as state dam safety laws, place the responsibility for assuring public health, safety and environmental protection in the siting and design of these impoundments squarely within your jurisdiction. My questions are these: 1. For the Department of Surface Mining Reclamation and Enforcement: a. The regulations require a geotechnical investigation of the subsurface and the foundation for any impoundment. Was the permitting of this structure the result of the failure of the company to identify the existence and proximity of underground mine workings, or were the workings identified and the impoundment approved notwithstanding the existence of such information? b. Does the Cabinet routinely request core drilling and other geotechnical investigation of such impoundments and waste structures to determine the existence of former mine workings? If so, how many similarly-situated structures exist? c. Please explain what actions will be taken to investigate foundation and subsurface conditions at other such structures, and what precautionary steps will be taken in the future to prevent recurrence? d. The surface mining laws and regulations clearly require that water supplies for any beneficial use which have been diminished or impaired by mining be replaced without cost on a temporary and permanent basis. Has the coal company been informed of this obligation and is the company providing such temporary and permanent supplies? e. The permitting and reclamation requirements of the mining laws require that areas affected by mining, including the placement of waste material, be permitted, bonded and reclaimed. Please identify the actions that will be taken to require that all affected areas, including disposal areas for any dredged material, will be properly permitted, bonded and reclaimed. Additionally, has the company been notified of the need to immediately post increased performance bond amounts to cover all anticipated costs of reclamation and remediation? f. Press reports have indicated that there are other waste impoundments that may be similarly situated, of which MSHA is aware. Please explain the level of coordination between your two agencies. Specifically, did MSHA notify your agency of the enforcement action previously taken regarding the failed structure? Were you aware of and did you participate in the 1996-7 MSHA survey? 2. For The federal Office of Surface Mining: a. What steps are being taken to investigate where in the state permitting process the failures occurred which resulted in approval of a structure in an area where failure of the structure could occur into former mine workings? b. When is the last time that, as part of the oversight process, your office reviewed the waste dam permitting process of the state to assure that proper geotechnical investigations were being required and conducted for coal waste dams relative to stability risks posed by previously mine workings? 3. For the state Division of Water: a. Was this structure reviewed by the state Division of Water under the state dam safety program? If so, what were the results of that review. b. Does the state Division of Water review proposed coal waste impoundment structures for geotechnical adequacy and stability relative to subsidence risks from prior underground mining operations. c. In assigning a hazard classification to impounding structures, do the classifications consider risk of failure from subsidence, or are the regulations geared only to risks posed by catastrophic breach relative to impoundment design and construction? 4. For the EPA and Corps of Engineers Huntington District: a. Please explain the legal basis for approval or allowance of coal waste impoundments in "waters of the United States" in light of the Corps of Engineers' regulation prohibiting Section 404 approval of the placement of dredged or fill material in waters of the United States where the placement is for the purpose of waste disposal. b. Was this structure approved under the Section 404 program, and if so, was it approved under an individual or nationwide permit? Please provide a copy of that approval. c. Was the company required to provide any stability analysis relative to the presence of mine workings and the risks to stability posed by subsidence? d. Was the company required to conduct any alternative analysis which might have reduced the impacts to waters of the United States, including backstowing coal processing waste in underground workings, alternative locations or alternative impoundment designs? e. What level of coordination occurs between your agencies, MSHA and DSMRE to assure that the stability and location of these structures is adequate. Thank you in advance for your prompt response to these questions.
To date, the state Department for Surface Mining Reclamation and Enforcement has responded by allowing access to files, but declining to answer any questions.
2 The shadow area is the land surface directly overlying underground mine workings. The draw angle of influence is the maximum angle at the earth s surface where the effects of subsidence would be manifested, and is a wider area than the shadow area.
3 Checking those files alone will not assure that all information regarding previous underground mining will be obtained, since many mine maps have been destroyed.
4 When asked whether the proposed permit area was within 500 feet of known abandoned or active underground mines, the application indicated that it was not. This may have been because the application was not adding to the overall permit area but instead was modifying the method of operation to defer reclamation of the Stockton seam for up to 20 years in order to use the spoil for a seepage barrier to plug the area of the breakthrough instead of the earlier proposal to use the excess stripped spoil to cover the refuse impoundment at closure.
5 The state permitting files contained no information relating to the injection of coal fines underground, even though this activity is plainly regulated under the surface mining regulatory program and should have been reviewed and permitted by the state. In 1985, Martin County Coal Corporation noted that it was presently processing an application with MSHA to do underground injection in some of its abandoned underground workings, and indicated that [w]hen approvals are acquired this permit will be revised to include this proposed plan. The permitting files contained no such revision, so that if the injection of slurry occurred after 1984, it should have occurred only under a permit issued by DSMRE, and only if approved by EPA under the Underground Injection Control program.