FILED

United States Court of Appeals

Tenth Circuit

March 17, 2008

Elisabeth A. Shumaker

Clerk of Court

PUBLISH

UNITED STATES COURT OF APPEALS

TENTH CIRCUIT

PLATEAU MINING

CORPORATION,

Petitioner,

v. No. 06-9582

FEDERAL MINE SAFETY AND

HEALTH REVIEW COMMISSION;

THE SECRETARY OF LABOR,

MINE SAFETY & HEALTH

ADMINISTRATION,

Respondents.

APPEAL FROM THE FEDERAL MINE SAFETY AND

HEALTH REVIEW COMMISSION

(NO. MSHR-1; WEST 2002-207)

Ralph Henry Moore II, Jackson Kelly PLLC, Pittsburgh, Pennsylvania, (Karen L.

Johnston, Jackson Kelly PLLC, Denver, Colorado, with him on the brief), for

Petitioner.

Jerald S. Feingold, Attorney (Jonathan L. Snare, Acting Solicitor of Labor,

Edward P. Clair, Associate Solicitor, W. Christian Schumann, Counsel, Appellate

Litigation, Robin A. Rosenbluth, Attorney, with him on the brief), United States

Department of Labor, Arlington, Virginia, for Respondents.

Before HARTZ, O’BRIEN, and HOLMES, Circuit Judges.

HARTZ, Circuit Judge.
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This appeal arises out of a citation issued to Plateau Mining Corporation

after a fatal methane explosion at its Willow Creek Mine on July 31, 2000. The

citation, issued by the Mine Safety and Health Administration (MSHA), alleged

that the accident was the result of a deficient mine-ventilation system. An

administrative law judge (ALJ) affirmed the citation, though not on the primary

theory of liability advanced by MSHA. On review, the commissioners of the

Federal Mine Safety and Health Review Commission (the Commission) split

evenly, with the effect of allowing the citation to stand. Exercising jurisdiction

under 30 U.S.C. § 816(a)(1), we reverse the decision of the ALJ because

substantial evidence does not support a finding that Plateau was on notice that its

ventilation system was performing inadequately.

I. INTRODUCTION

Plateau operated the Willow Creek Mine, an underground coal mine in

Carbon County, Utah. The coal was extracted using a method known as longwall

mining, which permits a mine operator to remove a seam of coal without leaving

behind pillars of coal for support. 

Before longwall mining begins, a set of tunnels—called entries—is

constructed around a large, rectangular block of coal, called a panel. (See

schematic drawing below.) The two entries running along one long side of the

block of coal are known as the headgate entries. A conveyer belt is installed in
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one of these entries. The entries on the other long side are known as the tailgate

entries. A machine called a shearer is placed at one end of the block of coal,

known as the face. The shearer takes “passes” across the longwall face, severing

approximately a 30-inch slice of coal from the seam with each pass. The severed

coal falls onto a chain conveyer that runs along the face, which feeds the coal

onto the conveyer belt on the headgate side for transport out of the mine. 

Temporary roof supports called shields advance behind the shearer as the panel of

coal retreats. The shields support the roof above the miners and the equipment.

Behind the shields, the roof is allowed to collapse. This mined area behind the

shields is known as the “rubble zone.” An “area where mining has been

completed” is known as a “worked-out area.” 30 C.F.R. § 75.301. The mined

area and the entries immediately adjacent to it are referred to as the “gob.” 
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-5-

Some mines, such as Willow Creek, are considered “gassy” mines because

their operation liberates a significant amount of methane. Methane is trapped

within the pores of a coal bed and is released when the coal is broken up during

mining. Gassy mines present a challenge because methane-air mixtures are

explosive at concentrations of 5 to 15% methane. Mine operators use a

ventilation system, called a “bleeder system,” to dilute methane in worked-out

areas. The methane is released from the coal at a concentration of 100%; the

purpose of the bleeder system is to dilute the methane so that only small

quantities are in the explosive range and concentrations are well below 5% near

likely ignition sources, such as areas where miners are present and work is being

done. At the longwall panel involved in this case (the D-3 panel), a fan blew

fresh outside air into one of the headgate entries. The air was forced across the

longwall face, which was 815 feet wide, and also through the rubble zone. 

Streams of fresh air—air from the headgate side that had not ventilated the gob

and air from the tailgate side brought in to maintain appropriate ventilation

pressure—joined the air coming off the rubble zone, diluting the methane further. 

From there the air entered tunnels on the tailgate side, known as bleeder entries,

and eventually traveled out of the mine. After mining on the D-3 panel had

progressed approximately 350 feet, the bleeder system would be supplemented

with gob vent boreholes, which are holes from the earth's surface down to the

ceiling of the gob. The holes had been drilled, and once the coal under them had
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been removed, they would ventilate methane directly upward to the surface of the

mine at high concentrations. At the time of the accident, Plateau believed that it

would reach the first gob vent borehole within a few days. 

II. REGULATORY BACKGROUND

Section 101(a) of the Federal Mine Safety and Health Act of 1977,

30 U.S.C. § 811(a), directs the Secretary of Labor to establish mandatory health

and safety standards for mines. Under this authority the Secretary has

promulgated a set of regulations governing underground-coal-mine ventilation. 

See 30 C.F.R. §§ 75.300–75.389. These regulations set forth various

requirements for a ventilation system, including for the operation of mine fans;

for air quality, quantity, and velocity; and for monitoring and evaluating the

effectiveness of the system. Aside from following these generally applicable

standards, each mine operator is also required to develop and follow a

mine-specific ventilation plan, which must be approved by an MSHA district

manager. See 30 C.F.R. § 75.370(a). After approval any major change to the

plan must be approved by MSHA, see 30 C.F.R. 75.370(a)(2); Wyoming Fuel Co.,

16 FMSHRC 1618, 1624 (Aug. 1994).

The citation that Plateau challenges on appeal is for a violation of one of

the generally applicable standards, 30 C.F.R. § 75.334(b)(1), whose relevant

language states:
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[A] bleeder system shall be used to control the air passing through

the [worked-out] area and to continuously dilute and move

methane-air mixtures and other gases, dusts, and fumes from the

worked-out area away from active workings and into a return air

course or to the surface of the mine.

The Commission has interpreted this provision to mean that the bleeder system

must function “effectively,” see RAG Cumberland Res. LP, 26 FMSHRC 639,

647, aff’d sub nom. Cumberland Coal Res., LP v. FMSHRC, 171 F. App’x 852

(D.C. Cir. 2005) (unpublished), although a mine operator can be sanctioned only

if it knew or a reasonably prudent person would have known that the system was

not functioning effectively. Cf. Ideal Cement Co., 12 FMSHRC 2409, 2416 (Nov.

1990) (“[T]he appropriate test is whether . . . a reasonably prudent person familiar

with the mining industry and the protective purposes of the standard would have

recognized the specific prohibition or requirement of the standard.”) 

III. FACTUAL BACKGROUND

A. The Ventilation Plan

Before beginning mining at the D-3 panel, Plateau obtained MSHA’s

approval for the panel’s bleeder system, as required by 30 C.F.R. § 75.370. 

Because of difficult mining conditions at Willow Creek and a previous fire at the

mine, MSHA had given the plan heightened attention, subjecting it to review not

only at the district level but also at national headquarters. MSHA rejected an

early ventilation plan submitted by Plateau, prompting two meetings to resolve

issues in the plan. To obtain plan approval, Plateau agreed to use a more
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extensive monitoring system than what was in use at most mines. By regulation,

a person certified by the state or by MSHA must take air-quality measurements at

least once a week, see 30 C.F.R. § 75.364, but Plateau also had a sophisticated

system of sensors that continuously and instantaneously reported on the

conditions in the mine.

The MSHA-approved ventilation plan authorized Plateau’s use of what is

known as a “two-entry system.” MSHA requires that a longwall mine use three

entries along each side of the longwall panel, but when a mine faces roof-control

challenges, a mine operator may petition MSHA for permission to use a two-entry

system. To be granted the modification, a mine operator must show that the

two-entry system is at least as safe as the three-entry system. See 30 C.F.R.

§ 44.4. Plateau petitioned for and was granted permission to use a two-entry

system at Willow Creek.

B. Mining on the D-3 Panel

1. Methane Liberation and Concentrations

Mining on the D-3 panel, the third longwall panel to be mined at Willow

Creek, commenced on July 17, 2000. As mining progressed, the levels of

methane being liberated in the mine increased. Increased methane liberation is to

be expected in the early stages of longwall mining, for two reasons. First, there is

a “ramping-up period” in longwall mining: at the start of mining, the shearer

takes fewer passes across the face each shift than it does once the full coal-
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production level is reached. Because methane is released as the coal at the face

fractures, an increase in the number of passes increases the liberation of methane.

Second, the gob, from which methane seeps, grows larger as mining progresses. 

On July 18 and 19, 2.5 million cubic feet of methane were carried by the bleeder

system each day. By July 31, the day of the accident, the level had risen to over 7

million cubic feet, although that level was lower than the predicted level for that

stage of mining and lower than the mine’s estimated capacity. The predicted

levels and estimated capacity had been submitted to MSHA during the

ventilation-plan approval process.

With an increase in the amount of methane liberated, readings of the

automated atmospheric monitoring systems (AMS) at certain measuring point

locations (MPLs) showed rising methane concentrations. On July 19, two days

after mining began, readings at MPLs 7 and 8, located where air exiting the gob

entered the bleeder entries, ranged between 0.5% and 1.25%. Then, as Plateau

increased its production level around the 29th of July, methane concentrations

rose sharply. On July 31 they averaged between 2.5 and 3.0%; the highest point

reached was a concentration of approximately 3.5% at MPL 8 early in the

morning of July 31, approximately 20 hours before the accident. Such rising

concentrations are expected in the beginning stages of longwall mining, although

the rise is not linear, because sudden releases of methane cause spikes in the

level, which drop as the methane clears.
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Plateau had a protocol that dictated its response when methane

concentrations at the measuring point locations reached specified levels. The

“action level” established by Plateau for MPLs 7 and 8 was 4.0%. At that level

Plateau would cease production until methane levels dropped to 3.7%. If an

MSHA inspector notes a level of approximately 4.5% at one of those locations,

the inspector issues an “imminent danger” order, requiring the evacuation of most

mine personnel until the hazard is corrected. Plateau had set the action level

lower than MSHA’s unofficial threshold so that it could stop production before

dangerous levels were reached. The staff at Willow Creek had noticed a rise in

methane levels at MPLs 7 and 8 but did not believe that the levels warranted a

response because (1) the rise was expected, (2) the levels had not reached the

action level, (3) the staff had the option of ceasing production if methane became

excessive, and (4) the ventilation system at the time was exceeding the airquantity requirements of the plan. In addition, the mine was experiencing fewer

methane stoppages on the D-3 panel than it had on the previous longwall panel. 

Among other locations at which Plateau took methane-concentration

readings was the MPL B1 point, which was also known as the § 75.323(e)

measuring point. That section specifies that the measuring point be placed

“immediately before the air [in the bleeder system] joins another split of air.” 

30 C.F.R. § 75.323(e). In the Willow Creek mine that location was at the end of

the D-1 panel’s tailgate, approximately 8,000 feet from the D-3 gob. Section
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75.323(e) prohibits methane concentrations above 2.0% at that measuring point. 

It is the only limit specifically set by regulation with respect to methane

concentrations within the bleeder system.

Under Plateau’s protocol, production would cease if methane levels at MPL

B1 exceeded 1.95% and would resume only when methane levels had dropped to

1.75%. At 2.5%, Plateau would evacuate the mine and notify MSHA. In the

early morning of July 31—approximately 20 hours before the accident—methane

levels twice exceeded 1.95%; on one of those occasions, the level rose slightly

above 2.0%. These exceedances of the action level occurred when production

was idle, likely because it took some time for the air to travel the distance from

the gob to MPL B1. Plateau waited for the levels to drop before resuming

production. MSHA did not issue Plateau a citation for the exceedance at the

§ 75.323(e) measuring point.

An MSHA ventilation expert testified at the hearing before the ALJ that the

readings at the § 75.323(e) measuring point would have been higher if not for an

atypically large amount of fresh air leaking into the return entries that carried air

away from the gob. The fresh air leaked into those return entries from an intake

bleeder entry that ran parallel to them. Some of this fresher intake air leaked

through electrical installations, which the mine operator was required to ventilate,

and some leaked through stoppings, which seal off the connections between the

different entries. MSHA’s expert testified that air entering the return bleeder
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entries likely had methane concentrations around 2.3 to 2.6% but that leakage

between that point and the § 75.323(e) measuring point diluted the methane to

below 2.0%. 

2. Airflow

As mining progressed on the D-3 panel, airflow in the ventilation system

decreased. This was to be expected as the roof of the gob caved in, increasing

resistance to airflow within the gob. Plateau’s ability to bring more air into the

mine was limited because the mine fan was running at or near its maximum speed 

and the sliding doors of the ventilation control devices (called regulators) were

open as far as possible. Plateau’s former general mine manager testified at the

hearing that there were changes that Plateau could have made to bring in more air,

but that those changes had not been thought necessary because air quantities at

the face were still substantially higher than required in the ventilation plan.

3. The Accident

By July 31 the longwall panel had retreated a short distance, approximately

250 feet out of a projected 4200 feet. Plateau and the Secretary dispute the

precise chain of events involved in the accident, but the cause of the accident is

not an issue on appeal. According to the Secretary, on the night of July 31 a

section of the roof collapsed in the gob, igniting a small pocket of methane. The

Secretary believes that the flame from the initial ignition then came into contact

with a small accumulation of methane in the explosive range. This explosion
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disrupted the ventilation system, which allowed more methane to accumulate,

causing two subsequent explosions that resulted in the deaths of two miners and

injuries to eight others.

Both sides agree that neither the presence of some methane in the gob nor

an explosion of methane in the gob is conclusive evidence of an ineffective

ventilation system, because methane is liberated from coal at concentrations at or

near 100% yet is explosive only at concentrations between 5 and 15% percent. 

As the methane is diluted to concentrations in the low single digits, there will

necessarily be a period when methane is present in the explosive range, and an

event such as a rockfall can ignite that methane. 

After the accident the mine was sealed. MSHA conducted an investigation,

which led to the issuance of the citation that Plateau challenges on appeal.

4. The Citation

The citation alleges that Plateau violated § 75.334(b)(1). The first

paragraph mostly paraphrases the regulation but adds “and distribute” to the

regulatory language: 

During pillar recovery of the D-3 longwall panel, the bleeder system

being used did not control and distribute air passing through the

worked-out area in a manner which continuously diluted and moved

methane-air mixtures and other gases, dusts, and fumes from the

worked-out area away from active workings and into a return air

course or to the surface of the mine. 
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Plateau Mining Corp., 25 FMSHRC 738, 743 (Dec. 2003) (emphasis added). The

next paragraph provides a bit more detail but is still rather vague:

The following factors impaired the bleeder system’s effectiveness at

controlling and diluting the air passing through the worked-out area:

a limited mine ventilating potential; the configuration and

distribution of airflow in the bleeder system and worked-out area;

and temporary controls installed within the worked-out area which

restricted airflow through the pillared area. As production increased

and pillared area expanded, methane liberation increased and airflow

paths changed within the worked-out area. These changing conditions

resulted in reduced airflow and elevated methane concentrations

within the worked-out area at locations containing potential ignition

sources and within close proximity to the active longwall face. 

Id. The citation further alleges that the accident occurred upon ignition of an

explosive mixture that had accumulated in the worked-out area.

IV. THE HEARING BEFORE THE ALJ

At the hearing before the ALJ, MSHA’s primary theory was that Plateau’s

bleeder system had failed to distribute air properly throughout the gob, allowing

explosive pockets of methane to accumulate. During opening argument, counsel

for the Secretary informed the ALJ that the focus of the Secretary’s case would be

the alleged distribution failure. “[T]he difficulty with the design of the Willow

Creek ventilation system,” asserted counsel, was that “it made it difficult, but not

impossible, for [Plateau] to adequately monitor the airflow distribution in the

headgate side of the gob.” R. Vol. 2 at 12. One MSHA witness testified that to

control the air, as required by § 75.334(b)(1), “means to properly distribute” the

air. Id. at 96. Over the course of the hearing, MSHA introduced extensive
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testimony in an attempt to establish that airflow was restricted on the headgate

side of the gob, allowing a small pocket of methane to accumulate there. MSHA

also introduced evidence intended to show that three installations in different

locations within the worked-out area inhibited the proper flow of air. Even a

slight change in airflow distribution, MSHA asserted, could have reduced the

accumulation of methane and prevented the explosion. In response, Plateau’s

witnesses contended that it is impossible to direct airflow to any particular area

within the gob and that § 75.334(b)(1) did not require it to do so. Plateau also

presented evidence that the installations either were not present at the time of the

accident or did not cause distribution problems.

Although MSHA’s witnesses repeatedly asserted that faulty airflow

distribution was the major flaw of the ventilation system, the Secretary also

advanced the theory, not mentioned by the Secretary’s counsel in her opening

statement, that the mine had “limited . . . ventilating potential.” Id. at 60. We

have found no use of the term “mine ventilating potential” in any administrative

or judicial opinion, nor in U.S. Bureau of Mines, Dictionary of Mining, Mineral,

and Related Terms (2d ed. 1996), a standard mining dictionary, but apparently it

is a measure of the ability to bring sufficient air into the mine to dilute the

liberated methane. Thus, as we understand the record, the Secretary argued that

Plateau’s ventilation system was overwhelmed by the amount of methane being

liberated. 
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In support of this theory, MSHA’s witnesses testified that because the mine

fan was running at capacity and the regulator doors were open as far as possible,

Plateau could not bring more air into the mine or increase the air pressure. An

MSHA supervisory special investigator, Gary Wirth, also cited Plateau’s use of

the two-entry system approved by MSHA as a factor creating the limited mine

ventilating potential. He further testified that the measurements of reduced

airflow should have indicated to Plateau that additional evaluation of the

ventilation system was necessary. He did not explain, however, why the decrease

in flow should have put Plateau on notice of a problem, given that reduced

airflow was expected. Moreover, the chief of MSHA’s ventilation division, John

Urosek, testified later that airflow in the mine was sufficient. 

The most important testimony on the issue of mine ventilating potential

came from Mr. Urosek. Although his testimony appears somewhat inconsistent,

he repeatedly stated that the volume of airflow in the mine was adequate and,

more importantly, he never explained why a reasonable mine operator would have

known before the explosions that the volume was inadequate. Initially,

Mr. Urosek testified that when the 2% limit at the § 75.323(e) point is exceeded,

the ventilation system is “maxed out” and is “approaching a point where it is no

longer effective.” R. Vol. 3 at 547. At that point, he said, the operator should

realize that additional measures need to be taken, either to limit the amount of

methane being produced or to increase the amount of airflow. His understanding
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was that Plateau’s response had been to stop production so that they could “keep

the system at the levels [at which] they could still function.” Id. at 548. They

were “just maintaining the acceptable levels by limiting production” because the

system was “pretty much at its maximum.” Id. Vol. 4 at 607.

On the issue of fresh-air leakage, Mr. Urosek explained that the methane in

the air was diluted as it passed through the bleeders running from MPLs 7 and 8

to MPL B1. After the air entered the bleeders just after MPLs 7 and 8, it likely

had methane concentrations of 2.3 to 2.6%. Mr. Urosek asserted that the purpose

of § 75.323(e) is “to control the methane that is actually coming from the gob

area to two percent,” but that “unfortunately, the way the regulation is written,” it

does not require the measuring point to be placed near the gob. Id. at 601–02. 

Because the true concentrations (the levels that would have been present absent

the significant leakage) exceeded the 2% limit at MPL B1, the system was over

capacity. He did not say whether this leakage would have been apparent while

mining was occurring.

When asked by counsel for the Secretary how MSHA had determined that

the Willow Creek mine was in violation of § 75.334(b)(1) at the time of the

explosion, Mr. Urosek focused on the distribution of fresh air through the gob. 

He first explained that there will be areas of explosive methane in the gob and

that the purpose of the ventilation system is to minimize the explosive zone and

keep it away from likely ignition sources. The regulation’s requirement that the
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mine operator “control” the air “really refer[s] to air flow distribution within the

system,” he said. Id. at 616. Mr. Urosek further explained that MSHA believed

that a rooffall had ignited a pocket of methane, which slowly propagated until it

reached an accumulation of methane, resulting in an explosion. “So the

accumulation is what was important to the 334 [violation]. It wasn’t being

diluted as effectively as it should have been,” he said. Id. at 618. Counsel for the

Secretary asked: “And that should have been handled through the distribution or

control of the air?” Id. “Yes,” he replied. Id.

Later, when asked again by counsel for the Secretary what had convinced

MSHA that there was a § 75.334(b)(1) violation, Mr. Urosek began by mentioning

that the investigators had noticed the exceedance of the 2% limit at MPL B1,

which caused them to investigate further, leading to the discovery of the leakage,

another cause of concern. He then proceeded to discuss indications that the

distribution of airflow within the system was flawed. He concluded: “So those

are some of the things that we use to evaluate the distribution. This was a system

where distribution was a real problem.” Id. at 642–43. Upon further questioning

by counsel for the Secretary, he twice confirmed that the problem was primarily

with distribution:

Q: It is my understanding you are saying on 7-31 we mainly had a

problem with distribution; is that correct?

A: Yes.

Q: If they had continued mining past 7-31, would we also expect

problems with quantity, as well? 
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A: It is difficult to say. We expected that the system itself, as it

mined more gob, that the air flow path would become more

resistant. Our concern early on in working with district in the

plan was at what point would they still get enough air to

ventilate the face, ventilate the longwall, and make sure the

system is effective to move the methane. 

That is the reason early on we decided once the longwall

was squared up, we would do a ventilation survey to see how

well the system was working. If we found problems, then to

work with the operator to do whatever improvements, and

enforcement actions would be up to the district, depending on

what we found.

Q: Your problem on 7-31 was mostly with distribution?

A: Yes.

Id. at 644–45 (emphasis added). Mr. Wirth, MSHA’s accident investigator, had

previously made a similar statement: “Due to the configuration of the system and

the distribution as it was occurring, it likely was more of a distribution problem

than it was a quantity problem.” Id. Vol. 2 at 61. 

On cross examination Mr. Urosek stated that the ventilation system had not

been designed to handle the amount of methane encountered. He did not explain

this assessment, however, which appears inconsistent with the evidence in the

record that the amount of methane actually encountered was less than the amount

that Plateau had projected in its submissions to MSHA. He conceded that

§ 75.323(e) does not require a mine operator to change its ventilation system after

an exceedance, but he asserted that Plateau should have done something beyond

what the plan required by having an employee verify that the MPLs were

“actively reflecting what [was] going on with the system.” Id. Vol. 4 at 654–55.
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He failed to explain why Plateau should have doubted the accuracy of the

monitors, nor did he offer any ground for believing that the monitoring had been

faulty. Mr. Urosek also conceded that the regulations set no requirements for

methane levels in the air at MPLs 7 and 8 and that the 2.3 to 2.6% level (which he

calculated to be present just past those locations) did not violate any standard or

Plateau’s own guidelines. Nevertheless, he said that the levels would cause an

operator to “look at that system.” Id. at 661. To do that, he said, employees

would have to go into the “internal paths” to investigate the system. Id. Upon

questioning by Plateau’s counsel, however, he acknowledged that the internal

paths were either unsafe for travel or were closed to miners. He named no

internal path that was open and safe. In addition, Mr. Urosek agreed that

relatively sudden methane-liberation events are anticipated in mining and that

these may require cessation of production until the methane clears. 

At the end of the hearing, MSHA called Mr. Urosek as a rebuttal witness. 

On direct examination by the Secretary, he reiterated that the pressure differential

at Willow Creek was sufficient. Airflow at the mine, he said, was also sufficient. 

He then stated that the § 75.323(e) measuring point is important because it reveals

whether there is sufficient airflow in the system. If the methane concentrations

exceed 2% at that point, the system needs more airflow or less methane. He

added that the only way to reduce the methane concentration is to bring additional

airflow into the system. He did not reconcile this statement with his immediately
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prior statement that reducing methane liberation would also lower the

concentration. Nor did he address whether stopping production to slow methane

emissions, as dictated by Plateau’s protocol, would have been an appropriate

method to reduce methane liberation.

During this testimony Mr. Urosek again asserted his belief that § 75.323(e)

meant to establish a 2% limit for methane concentrations in air in the bleeder

system. Because the regulation did not require the measuring point to be placed

where air enters the bleeder system, he called it a “loop hole regulation.” Id.

Vol. 10 at 1373. He believed that the system was overextended because the air

shortly after entering the bleeder system likely had methane concentrations above

2%, which fell to below 2% only after dilution with fresh air. On crossexamination, Mr. Urosek conceded that exceeding the § 75.323(e) limit once or

twice did not necessarily mean that the mine operator needed to change its

ventilation plan; but experiencing consistent readings over 2%, he stated, would

indicate a problem with the system. 

V. THE AGENCY PROCEEDINGS

A. Decision of the ALJ

The ALJ rejected the Secretary’s principal theory—namely, that there was a

problem with the distribution of airflow in the mine. He decided that the

Secretary had failed to prove a distribution problem, 25 FMSHRC at 750–51, or

that the presence of temporary ventilation controls had contributed to a violation
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of § 75.334(b)(1). Id. at 751–53. Instead, the ALJ upheld the citation on the

ground that the bleeder system was “over-extended” and therefore “could not, on

July 31, 2000, control the air passing through the area so as to continuously dilute

and move methane-air mixtures and other gases from the gob into the bleeders.” 

Id. at 746.

The ALJ found that “[t]he key element in diluting and moving methane-air

mixtures from the gob is to ensure that there is a sufficient quantity of air

sweeping the gob.” Id. at 747. He said that even though methane liberation had

increased “quite significant[ly],” id., the quantity of air sweeping the gob had

decreased, id. at 747–48, the mine fan was running “at or near full capacity,” id.

at 747, and the regulator doors were wide open, id., Plateau did not make any

changes to its system, id. at 747, 748. (He failed to state, however, what changes

could have been made.)

The ALJ further found that the methane-concentration readings at MPL B1

would have revealed a deficiency in the bleeder system had it not been for

leakage of fresh air into the bleeder entries lowering the readings. Id. at 748. 

Two MPL B1 readings at the action level, he said, meant that the system had been

“max’ed out.” Id. at 748 (internal quotation marks omitted). Plateau had “failed

to recognize the effect of the leakage when it established its action level for MPL

B1.” Id. at 749. Although the ALJ acknowledged that § 75.323(e) does not

require the 2.0% regulatory limit to be met as the air exits the gob, he said that “if
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the mixing occurs thousands of feet [away] as a result of air leaking into the

bleeders from an intake air course, a mine operator has no means of determining

whether it is properly ‘controlling’ the air passing through the gob . . . .” Id. 

In addition, the ALJ stated that “the increasing difference” between the

methane concentrations at MPLs 7 and 8 and those at MPL B1 indicated that

airflow from the gob “was becoming a smaller percentage of the total airflow at

MPL B1.” Id. at 750. “Quite simply,” he concluded, “methane was accumulating

in the gob more rapidly than the ventilation system was able to dilute and move it

into the bleeders.” Id.

Finally, the ALJ found that the Secretary had established that an explosion

of accumulated methane had triggered the subsequent explosions during the

accident. This evidence, he found, helped to establish a violation of

§ 75.334(b)(1). 

The ALJ addressed the question of notice as follows:

A mine operator may violate section 75.334(b)(1) even though it is

fully complying with the approved ventilation plan. First, the mine

operator has better knowledge of the conditions that will be

encountered when mining commences. More importantly, because an

underground coal mine is a dynamic environment, a mine operator

must be constantly vigilant when monitoring the conditions

underground and it must make changes to its ventilation system as

conditions warrant. I agree with the Secretary that Plateau should

have been on notice that its bleeder system was not functioning

properly on July 31, 2000.
-24-

Id. at 746. The ALJ did not again explicitly address the issue of notice, although

in the summary of his findings and conclusions he stated that “the evidence

presented was not based on speculative post-ignition investigative assumptions,

theories, and conclusions.” Id. at 756 (internal quotation marks omitted). “In

order to comply with the standard,” he continued, “Plateau should have reacted to

the increased methane levels and [the] reduced ventilation through the gob by

making changes to its ventilation system before the first gob vent borehole was

reached.” Id. at 757. He did not state what changes should have been made, but

he asserted that Plateau possibly could have “achieved compliance by decreasing

the rate of production.” Id.

B. Decision of the Commission

The ALJ’s decision was appealed to the Commission. The Commission

summarized Plateau’s arguments before it as follows: 

Plateau argues that its bleeder system complied with the requirements

of section 75.334(b)(1) and that the judge erred in finding a

violation. It maintains that the judge erred in interpreting the

standard to prohibit methane accumulations in a gob, and that the

judge’s conclusion that its ventilation system was overextended is

not supported by substantial evidence. Plateau asserts that the judge

also erred by relying upon a misinterpretation of section 75.323(e)

and in concluding that a violation of section 75.334(b)(1) could exist

even if the operator complied with its ventilation plan. Finally,

Plateau submits that section 75.334(b)(1) does not provide criteria

for determining the effectiveness of a bleeder system, and that the

judge’s finding that Plateau knew or should have known that its

system was not functioning effectively was not supported by

substantial evidence.
-25-

Plateau Mining Corp., 28 FMSHRC 501, 508–09 (Aug. 2006) (internal citations

omitted).

Four commissioners heard the appeal. They split evenly on whether

substantial evidence supported the ALJ’s finding of a § 75.334(b)(1) violation,

thereby allowing the ALJ’s decision to stand. For convenience, we refer to the

commissioners in favor of affirming as the affirming commissioners and to the

commissioners in favor of vacating and remanding as the dissenting

commissioners. In several respects, however, the Commission’s decision was

unanimous. All commissioners reaffirmed the Commission’s holding in an earlier

case that implicit in § 75.334(b)(1) is a requirement that “‘a bleeder system must

effectively ventilate the area within the bleeder system and protect active

workings from the hazards of methane accumulations.’” Id. at 509, quoting RAG

Cumberland Res. LP, 26 FMSHRC at 647. The Commission explained that the

regulation expresses the effectiveness requirement in general terms “to be broadly

adaptable to myriad circumstances.” Id. at 510 (internal quotation marks

omitted). But because of this generality, a mine operator cannot be punished for a

violation unless it has proper notice that it is violating the regulation. The

Commission explained:

[S]uch broad statements must afford reasonable notice of what is

required or proscribed. When faced with a challenge that a safety

standard fails to provide adequate notice of prohibited or required

conduct, the Commission has applied an objective standard, the

“reasonably prudent person test.” The appropriate test is not whether
-26-

the operator had explicit prior notice of a specific prohibition or

requirement, but whether a reasonably prudent person familiar with

the mining industry and the protective purposes of the standard

would have recognized the specific prohibition or requirement of the

standard. The Commission has recognized that various factors that

bear upon what a reasonably prudent person would do include

accepted safety standards in the field, considerations unique to the

mining industry, and the circumstances at the operator’s mine.

Id. (citations, footnotes, and internal quotation marks omitted)

All the commissioners also agreed that compliance with the mine-specific

ventilation plan does not preclude a violation of § 75.334(b)(1). See id. at 511;

id. at 520 (opinion of affirming commissioners); id. at 531 (opinion of dissenting

commissioners). An affirming commissioner explained the relationship between

the regulation requirement and ventilation plans: 

Ventilation regulations and ventilation plan provisions were designed

to recognize that mine ventilation is a dynamic process. The

provisions of 75.334 set forth a level of safety required at all mines,

while ventilation plan provisions specify precautions and practices

applicable to the particular conditions at a mine. . . . [A]n operator is

required to comply with ventilation plan provisions, which

encompass conditions specific to a mine, in addition to the more

general requirements of section 75.334, which establish a general

baseline which all mines must meet. Conditions in a mine may

change unexpectedly so that compliance with specific ventilation

plan provisions may not necessarily assure that the general

protections imposed by ventilation regulations are being met. Thus,

an operator is required to address its bleeder system if the bleeder

system is not effectively controlling air through the worked-out area

as required by section 75.334, even if the operator is complying with

the terms of its ventilation plan. 

Id. at 511. 
-27-

Two commissioners, Duffy and Suboleski, voted to vacate the ALJ’s

decision and remand the case. In their view the ALJ had tried to rescue the

Secretary from her unsupported theory of liability by concocting another theory

contradicted by the Secretary’s own witnesses. The overview section of their

opinion states: 

This is a case in which MSHA had little evidence that the

ventilation system was malfunctioning, yet the mine experienced an

explosion and fire. Prior to the first explosion, air volumes were

above design levels and all measuring points were within expected

ranges. The explosion itself was caused by a very small amount of

methane (50 cubic feet), a volume that would not be unexpected at

the fringe of the rubble zone. However, MSHA found what it

believed to be the causes of a distribution problem, near the headgate

at the inby corner of the gob, where the explosion was believed to

have originated. This problem, which was allegedly caused by a

combination of a largely intact undercast, an un-removed check

curtain, and a series of check curtains in the set up rooms, combined

to restrict air flow in this corner, and resulted in a violation of

section 75.334(b)(1). However, trial testimony showed that these

obstructions were not present and MSHA’s primary case fell apart. 

In the course of presenting that case, MSHA witnesses pointed

out that the mine fan was at capacity; that, as production increased

from start-up at the longwall, methane levels were rising; that the

tailgate-side bleeder regulators were open as wide as possible to

maximize air flow across the face and gob; that it took a great deal of

air to dilute the methane level from the face and gob to the 2%

concentration limit specified at the point where the bleeder air enters

another air stream; and that once, two shifts before the explosion, the

system’s ability to dilute to the 2% level, i.e., the bleeder-system

capacity, had briefly been reached. Finally, MSHA testified that

Plateau’s only recourse when it reached system capacity was to

temporarily halt production.

The judge, rather than dismissing the case, used these

circumstantial facts to construct an entirely new theory of the case
-28-

since MSHA had failed to prove that the ventilation system had

significant distribution problems. Moreover, he added a crucial

element that directly contradicted the testimony of the MSHA

witnessess—that the volume of air in the gob was inadequate. 

Id. at 523.

The dissenters took issue with the ALJ’s reliance on the evidence regarding

the mine fan and the regulator doors. They argued as follows: That the fan was

operating at full capacity did not mean that the full capacity was insufficient. 

Likewise, evidence of a decrease in the air volume sweeping the gob did not

establish that there was insufficient air, because “[d]ecreased flow is not the same

as insufficient flow.” Id. at 527. Moreover, the ALJ’s finding of insufficient air

was contrary to uncontradicted testimony from two of the Secretary’s witnesses,

Mr. Urosek and Mr. Wirth. Also, the ALJ’s conclusion that gob airflow was

becoming a smaller percentage of total airflow was based on a mathematical

error. In light of these mistakes, the ALJ’s finding that methane was

accumulating too rapidly in the gob was unwarranted. 

In addition, the dissenting commissioners rejected the ALJ’s criticism of

Plateau for its response to the elevated readings at MPL B1. They did not believe

that the evidence showed that Plateau should have taken any additional action. 

Plateau had reacted as its protocol required, by temporarily ceasing production. It

could not have made other changes to its ventilation system because major

changes to an MSHA-approved ventilation plan require approval. According to
1

This statement is apparently based on the dissenting commissioners’

perception that faulty distribution was the only theory that the Secretary presented

at the hearing. The dissenters are correct that the Secretary’s primary theory

related to distribution, but certain lines of questioning at the hearing indicate that

the Secretary also may have been pursuing the theory that the mine had a limited

ventilating potential.

-29-

the dissenters, Plateau could not have investigated the cause of the exceedance at

MPL B1 because the methane levels there dropped when production ceased. They

thus “fail[ed] to see what Plateau would have investigated.” Id. at 528–29 n.9. 

The dissenting commissioners further contended that the evidence was

insufficient to support a finding that Plateau had notice that its system was in

violation of § 75.334(b)(1). The case, they said, “turns on whether the Secretary

can establish that a reasonable operator familiar with the conditions in the mine

. . . would have made adjustments to the bleeder system,” but “if the Secretary

and the [ALJ] cannot agree on the basis for determining whether the bleeder

system was operating effectively, it is unclear how Plateau could have

responsively addressed any performance problems in the system under

75.334(b)(1).”1

 Id. at 524. The dissenters believed that the methane readings at

MPLs 7 and 8 were better indicators of conditions in the gob than MPL B1

because the air at MPLs 7 and 8 was closer to the gob and had been mixed with

fewer sources of other air; and they noted that those readings did not reveal any

problem with the system. They concluded that “it is difficult to ascertain how a
-30-

reasonably prudent operator would have known that there was a violation of the

regulation.” Id. at 532. 

Commissioner Young, joined by Commissioner Jordan, said that substantial

evidence supported the ALJ’s conclusions. Like the ALJ, Commissioner Young

found it significant that the mine fan was running at capacity and the regulator

doors were wide open. He agreed with the ALJ that the leakage of fresh air into

the bleeder entries meant that the readings at the § 75.323(e) measuring point

(MPL B1) were “artificially low,” id. at 511, and “were a critical indicator that

the bleeder system was ineffective,” id. at 516. He disputed the dissenters’

assertion that the ALJ should have placed primary importance on the readings at

MPLs 7 and 8, stating that the MPL B1 location had “inherent significance”

because its limit was established by regulation. Id. at 516 n.5. He did not

address the mathematical error that the dissenting commissioners described.

Commissioner Young also agreed with the ALJ that a reasonably prudent

mine operator would have known that the mine was operating at its maximum

ventilation capacity and would have recognized a disruption in the system’s

effectiveness because of the elevated § 75.3232(e) readings. In support of this

conclusion, he pointed to the testimony of two of Plateau’s witnesses, mine

manager Kerry Hales and mining engineer Steven Jones. Commissioner Young

described their testimony:
-31-

Jones and Hale[s] testified that they were aware of an increasing

trend in methane in late July. Hales acknowledged that methane

readings “were a little high” and that they had been “struggling with

it for a few days, trying to reach the next gob vent borehole,” and

that reaching the borehole would have alleviated the “methane

problem.” Hales testified that the increasing trend in methane was of

particular concern because the fan was at full capacity. Hales and

Jones testified that the operator’s only option was to slow down or

cease production to let the methane bleed off. Nonetheless, even

with this information, the operator increased production and did not

take the corrective action required.

Id. at 517–18 (citations omitted). Considering this evidence, Commissioner

Young concluded, Plateau’s notice argument must be rejected.

VI. ANALYSIS

Because the Commission split two-to-two on the issue, there is no opinion

of the Commission on the existence of a § 75.334(b)(1) violation, and the ALJ’s

affirmance of the § 75.334(b)(1) citation was allowed to stand. We therefore

review the ALJ’s findings of fact to determine whether they are supported by

“substantial evidence.” 30 U.S.C. § 816(a)(1). We review de novo the ALJ’s

legal conclusions. See Olson v. FMSHRC, 381 F.3d 1007, 1011 (10th Cir. 2004).

A. Effectiveness Requirement of 30 C.F.R. § 75.334(b)(1) and

Relationship Between § 75.334(b)(1) and Ventilation Plans

Plateau argues on appeal, as it did before the ALJ and the Commission, that

§ 75.334(b)(1) does not address the adequacy of a bleeder system. Plateau also

renews its argument that it could not be in violation of § 75.334(b)(1) because it

was in compliance with its approved ventilation plan. The two arguments are
-32-

closely related: under Plateau’s interpretation, § 75.334(b)(1) sets no standards

for the bleeder system because all the specific requirements are contained in the

mine’s ventilation plan. According to Plateau, § 75.334(b)(1) merely establishes

“the general requirement that a bleeder system is to be used” and describes “how

it is to function.” Pet’r Br. at 48. A mine that used a bleeder system that to any

degree controls air in the worked-out area and dilutes and moves methane-air

mixtures away from active workings and into a return air course would be in

compliance with § 75.334(b)(1). The standards for a bleeder system’s

effectiveness, Plateau argues, come from the mine-ventilation plan required under

§ 75.370 and the specific methane limits set in § 75.323. Because the

requirements of § 75.334(b)(1) are so minimal under Plateau’s interpretation, any

mine operating a bleeder system according to its ventilation plan would already

have satisfied that paragraph.

Plateau’s interpretation, though not an implausible reading of

§ 75.334(b)(1), is at odds with the interpretation of the Secretary and the

Commission. The Commission reaffirmed in this case its previous holding in

RAG Cumberland Res. LP, 26 FMSHRC at 647, that “[a]lthough section

75.334(b)(1) does not literally set forth a requirement that a bleeder system shall

function effectively, such a requirement is implicit in the standard’s language and

underlying purpose.” 
-33-

The Commission below further explained that a mine operator can be out of

compliance with § 75.334(b)(1) even though it fulfills all the conditions of its

mine ventilation plan because “mine ventilation is a dynamic process,”

28 FMSHRC at 511, and the provisions of the ventilation plan may not be able to

address every contingency. For an operator to violate the regulation, however, it

must be on notice of the problem—that is, it must be shown that a “reasonably

prudent person familiar with the mining industry and the protective purposes of

the standard” would realize the “specific prohibition or requirement of the

standard.” Id. at 510 (quoting Ideal Cement Co., 12 FMSHRC at 2416). In the

circumstances of this case, the affirming commissioners expressed the test as

whether a reasonably prudent person “would have recognized that Plateau’s

bleeder system failed to control and continuously dilute and move methane-air

mixtures from the worked-out area away from active workings as required by the

standard.” Id. at 517. And the dissenting commissioners adopted essentially the

same test: “whether Plateau had notice that, under the Secretary’s regulation, its

bleeder system was in violation because it was not moving and diluting methane

in the gob area.” Id. at 523. 

An agency’s interpretation of its own regulation is ordinarily controlling

unless “plainly erroneous or inconsistent with the regulation.” See Auer v.

Robbins, 519 U.S. 452, 461 (1997) (internal quotation marks omitted). One

exception to the general rule was recognized by the Supreme Court in Gonzales v.
-34-

Oregon, 546 U.S. 243, 257 (2006), which held that Auer deference is not

applicable when an agency has promulgated a regulation that merely parrots or

paraphrases the statutory language. The Court stated: “An agency does not

acquire special authority to interpret its own words when, instead of using its

expertise and experience to formulate a regulation, it has elected merely to

paraphrase the statutory language.” Id. In such a case, the question becomes

whether the agency’s position is a permissible interpretation of the statute. See

id. at 258.

To determine whether the Gonzales exception applies here, we examine the

history of § 75.334(b)(1). The Federal Coal Mine Health and Safety Act of 1969

established for underground coal mines certain interim mandatory safety

standards that were to remain in effect until the Secretary of the Interior

promulgated standards that would supersede them. See Pub. L. No. 91-173,

§ 301, 83 Stat. 765 (codified as amended at 30 U.S.C. § 861). (The Federal Mine

Safety and Health Amendments Act of 1977 transferred this authority to the

Secretary of Labor, see Pub. L. 95-164, § 301, 91 Stat. 1290). One such interim

provision was 30 U.S.C. § 863(z), which established standards for ventilation by

bleeder systems. It provided that worked-out areas: 

shall be ventilated by bleeder entries or by bleeder systems or

equivalent means, or be sealed . . . . When ventilation of such areas

is required, such ventilation shall be maintained so as continuously to

dilute, render harmless, and carry away methane and other explosive
-35-

gases within such areas and to protect the active workings of the

mine from the hazards of such methane and other explosive gases.

30 U.S.C. § 863(z)(2) (emphasis added). The initial regulation promulgated to

supersede the statutory standard (codified at the time at 30 C.F.R. § 75.329)

copied the statutory language verbatim. See Mandatory Safety Standards,

Underground Coal Mines, 35 Fed. Reg. 17890, 17906 (Nov. 20, 1970). That

regulation was amended and recodified at § 75.334(b)(1) in 1992. See Safety

Standards for Underground Coal Mine Ventilation, 57 Fed. Reg. 20868,

20919–20920 (May 15, 1992). The current regulation’s language is similar to that

of the statute: 

During pillar recovery a bleeder system shall be used to control the

air passing through the area and to continuously dilute and move

methane-air mixtures and other gases, dusts, and fumes from the

worked-out area away from active workings and into a return air

course or to the surface of the mine.

30 C.F.R. § 75.334(b)(1). The relevant differences are that the phrase “render

harmless” is omitted from the regulation, and the regulation elaborates that the

methane-air mixtures be directed into a return air course or to the surface of the

mine. 

Although the wording of the statute and the regulation that has superseded

it are quite close, the differences, which are central to the issue before us, suggest

the “expertise and experience” of the agency, making Auer deference appropriate. 

Indeed the commentary accompanying the promulgation of the 1992 regulations,
-36-

see 57 Fed. Reg. 17890 ff, clearly evidence the application of experience and

expertise. The omission from the regulation of the “render harmless” language

appears to be in recognition of the impossibility of rendering methane-air

mixtures completely harmless. The regulation therefore tempers the rigid and

impractical statutory language. At the same time, however, the interpretation of

the regulation by both the Secretary and the Commission clarifies that the

regulation does not totally negate the command of the original statute—in fact, no

new mandatory safety standard may reduce the protection afforded miners by an

existing standard, see 30 U.S.C. § 811(a)(9)—but merely limits it to requiring

what a reasonably prudent person would know to be possible and necessary for

safety.

In short, the concern underlying the Gonzales exception to Auer deference

does not apply here. Turning, then, to whether the interpretation by the Secretary

and Commission satisfies Auer, we do not hesitate in concluding that it does. It is

neither “plainly erroneous [n]or inconsistent with the regulation.” Auer, 519 U.S.

at 461 (internal quotation marks omitted). Unlike Plateau, we do not see why

§ 75.334(b)(1) must be read as nothing more than an introductory placeholder,

with all substantive content deferred to the subsequent provisions; it is quite

reasonable to read it as establishing a baseline of safety that a mine operator must

meet at all times in case unanticipated conditions render the subsequent

provisions inadequate to ensure the effectiveness of the system. The Third
-37-

Circuit recently reached the same conclusion. See Cumberland Coal Res., LP v.

Fed. Mine Safety & Health Review Comm’n, 515 P.3d 247 (3rd Cir. 2008)

(compliance with an approved ventilation plan is not a defense to a violation of

§ 75.334(b)(1)). 

B. Evidence of § 75.334(b)(1) Violation

The ALJ’s factual findings regarding the occurrence of a § 75.334(b)(1)

violation are conclusive if they are supported by substantial evidence. See

30 U.S.C. § 816(a)(1) (“The findings of the Commission with respect to questions

of fact, if supported by substantial evidence on the record considered as a whole,

shall be conclusive.”). 

Substantial evidence is such evidence that a reasonable mind might

accept as adequate to support the conclusion reached by the

decisionmaker. Substantial evidence requires more than a scintilla

but less than a preponderance. The possibility of drawing two

inconsistent conclusions from the evidence does not prevent an

administrative agency’s findings from being supported by substantial

evidence. Thus, we may not displace the agency’s choice between

two fairly conflicting views, even though the court would justifiably

have made a different choice had the matter been before it de novo.

Zoltanski v. FAA, 372 F.3d 1195, 1200 (10th Cir. 2004) (citation, brackets, and

internal quotation marks omitted). Still, a reviewing court must “take into

account whatever in the record fairly detracts from [the] weight” of the evidence

that supports the finding. Universal Camera Corp. v. NLRB, 340 U.S. 474, 488

(1951).
-38-

To establish a violation of § 75.334(b)(1), the Secretary must prove two

elements: first, that the bleeder system was not functioning effectively, and

second, that the mine operator had notice. We need not address the first element,

because we hold that there was insufficient evidence of the second.

To establish notice, the Secretary must prove that a reasonable operator

would have known that the bleeder system was not functioning effectively and

that additional actions were necessary for safety. The ALJ did not discuss the

issue of notice, making only the conclusory statement: “I agree with the

Secretary that Plateau should have been on notice that its bleeder system was not

functioning properly on July 31, 2000.” 25 FMSHRC at 746. We therefore must

assume that the facts that the ALJ found to support a violation of the safety

standard are the same facts that would have put Plateau on notice of a problem. 

First, the ALJ found that because the mine fan was running at full speed

and the regulator doors were wide open, the ventilation system was apparently

stretched beyond its capacity. But these facts do not support the conclusion that

Plateau should have been on notice of an inadequate ventilation system. As the

dissenting commissioners put it, “because the fan could not do more does not

indicate it was not doing enough.” 28 FMSHRC at 526 n.5. Plateau’s witnesses

explained that the burden on the ventilation system was expected to reach its peak

at that time (because the borehole had not yet been reached) and that Plateau had

chosen to run at the maximum so as to maintain airflow levels above
-39-

requirements. Running the fan at capacity and keeping the doors wide open was

therefore no indication that anything unexpected was occurring.

Relatedly, the ALJ emphasized the importance of ensuring that enough air

sweeps the gob. He found that the amount of air sweeping the gob “actually

decreased” as methane levels increased. 25 FMSHRC at 747–48. But, again, as

the dissenting commissioners noted, “[d]ecreased flow is not the same as

insufficient flow.” 28 FMSHRC at 527. It is undisputed that airflow was

expected to decrease during the early stages of mining. There is no explanation

why Plateau should have believed that the decrease was too steep: the quantity

and velocity of air were exceeding the requirements of the ventilation plan—a

plan thoroughly reviewed and ultimately approved by MSHA personnel, including

John Urosek, the ventilation-division chief at MSHA’s national headquarters. 

Indeed, Mr. Urosek himself testified that airflow had been sufficient. 

Also on the subject of airflow, the ALJ found that the increasing difference

between the methane concentrations at MPLs 7 and 8 and those at MPL B1

indicated that airflow from the gob was becoming a smaller percentage of the

airflow at MPL B1. According to his analysis, this revealed that methane was

accumulating in the gob faster than the system could remove it. 25 FMSHRC at

750. But his analysis was wrong. To be sure, he was correct that as methane

concentrations at MPLs 7 and 8 rose between July 29 and July 31, the difference

between the concentrations measured at MPLs 7 and 8 and those at MPL B1 also
-40-

grew. But as the calculations by the dissenting commissioners demonstrated, the

difference between the readings at MPLs 7 and 8 and those at MPL B1 would

grow as readings at MPLs 7 and 8 rose regardless of whether the percentage of air

at MPL B1 that had passed through MPLs 7 and 8 “decreased, remained constant,

or even modestly increased.” 28 FMSHRC at 530 & n.11. Because the air

passing through MPLs 7 and 8 mixed with streams of fresher air before arriving at

MPL B1 (as the ALJ fully recognized), any rise in levels at MPLs 7 and 8 would

be reflected as a lesser increase at MPL B1. Obviously, and contrary to the ALJ’s

reasoning, these data did not provide notice to Plateau that something was amiss. 

In addition, the ALJ found the increase in the amount of methane liberated

at the face and in the gob to be significant—and problematic. This increase in

methane liberation was to be expected, however; in fact, the levels of liberated

methane were lower than the predictions Plateau had submitted to MSHA for that

stage of mining. Also, concentrations of methane at MPLs 7 and 8 were well

below Plateau’s action levels, and MSHA never asserted that the concentrations at

those locations were too high. Indeed, the concentrations of methane had not

even reached as high as the post-action safety level—the level at which

production could resume after production had halted because an action level had

been reached. Without more, the rising methane levels did not constitute notice

to Plateau of an ineffective bleeder system.
-41-

The ALJ found that the methane readings at MPL B1 in particular indicated

a problem with the system. But when the methane levels at MPL B1 exceeded

Plateau’s action level—as happened twice, approximately 20 hours before the

accident—Plateau acted in conformity with its protocol by waiting for the

methane concentrations to return to acceptable levels before restarting production. 

The protocol already accounted for the occasional exceedance of the action

level—the very point of establishing an action level is to trigger a response before

higher levels are reached—and nothing happened that called into question the

adequacy of that response. Moreover, as MSHA’s own ventilation expert

testified, one or two exceedances of the 2.0% regulatory limit itself—and Plateau

had only one—do not necessarily mean that changes to the system are required. 

Unavoidable sudden releases of methane may cause spikes in the methane

concentrations, and although these should not trigger regular exceedances, an

isolated occurrence does not prove that the system is ineffective. 

Further, the ALJ relied upon the evidence of leakage of fresh air into the

bleeder system between MPLs 7 and 8 and MPL B1 to conclude that the readings

at MPL B1 should have indicated a problem to Plateau. According to the ALJ,

without the leakage the readings at MPL B1 “would have revealed” a problem

with the bleeder system. 25 FMSHRC at 748. The Secretary’s witnesses never

addressed, however, whether Plateau should have known about the leakage of

fresh air before or during mining on the D-3 panel or whether the leakage was
-42-

merely understood after the accident as evidence of a flawed system. 

Revealingly, Mr. Urosek testified that the leakage “tells us” that the system was

overextended, R. Vol. 4 at 602 (emphasis added); he did not state that it would

have put Plateau on notice at the time. The ALJ did not explain how a reasonable

operator would have known of the leakage and understood its significance when

MSHA apparently failed to appreciate the point when reviewing the plan.

And even if Plateau had known that the readings at MPL B1 would have

been higher without the fresh-air leakage, the ALJ failed to explain why, in light

of the normal readings at MPLs 7 and 8, these readings would have caused

concern to a reasonable operator. Considering that all the air exiting the gob

passed through MPLs 7 and 8—before traveling more than 8,000 feet and being

mixed with air from other sources on its way to MPL B1—the ALJ gave no

reason to treat the readings at MPL B1 as a better measurement of gob conditions

than the readings at MPLs 7 and 8. Commissioner Young contended that the

readings at MPLs 7 and 8 did not necessarily provide a “materially more accurate

picture of methane in the gob” given that the air exiting the gob was diluted by

another stream of air before passing through MPLs 7 and 8, see 28 FMSHRC at

516 n.5; but the fact remains that the air leaving MPLs 7 and 8 was even further

diluted—and delayed—on its way to MPL B1.

Nor did the affirming commissioners provide a reasonable explanation of

how Plateau was on notice. Commissioner Young placed great weight on the
-43-

statements by Plateau’s witnesses Mr. Hales and Mr. Jones. But those statements

do not support a finding of notice. Although Hales and Jones acknowledged that

the system was running at full capacity, they never testified that the ventilation

system had been pushed beyond its capacity or that the system was not performing

as required or expected. Jones, a staff mining engineer, testified that he had been

watching the rise in methane levels after July 26 and that through July 31 the

mine had not reached a stage that warranted a change in the system. The increase

in methane was not alarming, he said, because the size of the gob was also

increasing. He did not feel that any action was necessary because they were still

“way above [the] requirements on the face.” R. Vol. 4 at 802. He did not

specifically remember whether he had been aware of the two exceedances of the

action level at MPL B1, and he testified that had he been aware of them, he would

have been concerned that the levels were “close to what we could handle in the

ventilation system.” Id. at 803. But he maintained that they “had not exceeded”

that level. Id. Hales, the mine manager, likewise testified that on the day of the

accident, methane levels were “a little high” but “in requirements,” and that he

“didn’t see any warning.” Id. at 752. Both testified that Plateau’s only option,

given that maximum capacity had been reached, would have been to cease or slow
2

Commissioner Young faulted Plateau for continuing to increase its

production rate on July 31, 28 FMSHRC at 518, and the ALJ also suggested that

Plateau could have “achieved compliance by decreasing the rate of production,”

25 FMSHRC at 757. Neither explains why slowing the rate of production is

preferable to stopping production when an action level is reached, particularly

given the unusual feature of continuous monitoring, which allowed the mine

operator to respond promptly to changes.

-44-

production.2 This is not evidence that the ventilation system’s capacity had been

exceeded or that Plateau should have known that it had been.

To be clear, the fact that Plateau was operating its bleeder system in

compliance with its ventilation plan does not itself preclude a finding of a

§ 75.334(b)(1) violation. Conditions not anticipated by the plan may arise that

would alert the reasonably prudent mine operator that an out-of-plan response is

necessary. But the absence of any occurrence not anticipated by the MSHAapproved plan indicates that there was nothing that should have put Plateau on

notice that additional action was necessary.

VII. CONCLUSION

Because substantial evidence does not support the ALJ’s finding that the

regulation’s notice requirement was satisfied, we reverse the decision of the ALJ.