January 28, 2022
In the matter of Petition for Modification
Morton Salt, Inc.
Weeks Island Mine
I.D. No. 16-00970 Docket No. M-2020-001-M
PROPOSED DECISION AND ORDER
On June 23, 2020, Morton Salt Inc., filed a petition seeking a modification of the application of 30 C.F.R. § 57.22603(c) and (d) concerning re-entry procedures following blasting at its Weeks Island Mine, located in Iberia County, Louisiana.
The relevant standard, 30 C.F.R. § 57.22603 Blasting from the surface (II-A mines), in its entirety provides that:
(a) All development, production, and bench rounds shall be initiated from the surface after all persons are out of the mine. Persons shall not enter the mine until the mine has been ventilated for at least 15 minutes and the ventilating air has passed over the blast area and through at least one atmospheric monitoring sensor.
(b) If the monitoring system indicates that methane in the mine is less than 0.5 percent, competent persons may enter the mine to test for methane in all blast areas.
(c) If the monitoring system indicates that methane in the mine is 0.5 percent or more, the mine shall be ventilated and persons shall not enter the mine until the monitoring system indicates that methane in the mine is less than 0.5 percent.
(d) If the monitoring system is inoperable or malfunctions, the mine shall be ventilated for at least 45 minutes and the mine power shall be deenergized before persons enter the mine. Only competent persons necessary to test for methane may enter the mine until the methane in the mine is less than 0.5 percent.
(e) Vehicles used for transportation when examining the mine shall be approved by MSHA under the applicable requirements of 30 CFR parts 18 through 36. Vehicles shall not be used to examine the mine if the monitoring system is inoperable or has malfunctioned.
These standards prohibit reentry to all underground areas of a Category II-A mine when methane is 0.5 percent or more in any area, unless the monitoring system is inoperable or malfunctions. In that case, competent persons may enter to test for methane. The petition proposes a modification of 30 C.F.R. § 57.22603(c) to permit miners to reenter “unaffected” areas of the mine (areas showing methane levels below 0.5 percent), pursuant to specific procedures, to resume normal work. It also proposes a modification of 30 C.F.R. § 57.22603(c) and (d) to allow miners to reenter the mine post blast to determine whether a monitor is faulty, isolate the affected area, and make ventilation changes that reduce the level of methane within the mine.
The proposed additional safety procedures include: whether or not the monitoring system is operable, (1) ventilating the mine for at least 45 minutes during which the mine power shall remain deenergized; and (2) after this time, if methane levels remain at or above 0.5 percent, allowing competent persons to enter the mine to (a) test for methane and (b) make ventilation changes to reduce the level of methane. These competent persons would be required to take certain safety measures, such as: (1) entering the mine via the fresh air intake shaft; (2) checking to ensure no damage has occurred to ventilation controls on the fresh air side; (3) ensuring that all instruments are calibrated before going underground; (4) repairing ventilation controls only in fresh air; and (5) being trained on these procedures.
If methane levels remain at or above 0.5 percent, competent persons would again (1) enter the mine via the fresh air intake and proceed to the active landing; (2) use a permissible ride to advance from the active landing toward the affected area(s); (3) check methane levels with handheld monitors and a monitor on a pole against the back (ceiling); and (4) barricade/deenergize /restrict entry to areas with methane levels at or above 0.5 percent until these levels recede below 0.5 percent. The affected area will be posted/barricaded a minimum of 200’ away from methane entry point. However, the power underground would be reenergized outside the affected area(s) to allow auxiliary fans to assist in reducing methane levels and allow normal operations to commence outside the affected areas.
The petition alleges that the alternative method will at all times guarantee not less than the same measure of protection as the existing standards.
MSHA personnel conducted an investigation and filed a report of their findings with the Administrator for Mine Safety and Health Enforcement. After a careful review of the entire record, including the petition for modification and the investigative report, this Proposed Decision and Order is issued.
Background
Weeks Island Mine is an underground Category II-A1 gassy salt mine located south of New Iberia in Louisiana. Salt is drilled, undercut, and blasted underground utilizing a room and pillar mining method. Broken salt is transported by belt conveyor to a vertical shaft where it is crushed and then hoisted to the surface.
Crushed salt is sold for a variety of commercial uses.
Weeks Island Mine is one of several domal salt mines in Iberia County, Louisiana. These domal salt mines have experienced incidents with methane liberation and outbursts related to blasting. The most notable outburst event in this region occurred at the Belle Isle Mine, on June 8, 1979.
The Belle Isle Mine Report of Mine Explosion Disaster2 issued April 30, 1980 summarized the event as follows;
On Friday, June 8, 1979, an outburst of flammable gases and salt occurred following a face blast in 8 Main Entry East at about 2300 hours, and a gas explosion occurred in the mine approximately 10 minutes later. At the time of the explosion, 22 persons were in the mine. Ten persons were on the upper level and twelve persons were on the lower level. Seventeen persons were rescued and five persons died as a result of the explosion.
The report explains the ‘outburst’ phenomenon that can occur in domal salt mines, initiated by blasting, that violently expels fractured salt and methane. The Belle Isle Disaster resulted in over 15,000 tons of broken salt and 6 million cubic feet of methane liberated over the ensuing week.
In response to the tragedy at the neighboring Belle Isle Mine, MSHA promulgated new safety standards for methane in metal and nonmetal mines, establishing a new gassy mine category system. The category system considers both the actual liberation of methane and the potential to liberate methane, the type of gas occurrences, the degree of hazards, the combustibility of the material being mined, and the diversity of the mining methods. It also considers the history of the mine and the history of the geological area in which the mine is located. The preamble to the final rule clarifies, “the Agency has developed standards which are unique to each category of mines. Consequently, with respect to methane-related hazards, 1 See 30 C.F.R. § 57.22003(a)(2)(i), “Subcategory II-A applies to domal salt mines where an outburst reportable under §57.22004(c)(1) has occurred” and 30 C.F.R. § 57.2, “Outburst means the sudden, violent release of solids and high-pressure occluded gases, including methane in a domal salt mine.” 2 Final Report of Mine Explosion Disaster, Belle Isle Mine, Cargill, Inc. Franklin, St. Mary Parish, Louisiana, MSHA, 1979.
mines are required to comply only with standards that apply to a particular category or subcategory.”3 Furthermore, a 1988 investigation of methane occurrence and outbursts in the Cote Blanche domal salt mine4, in Iberia County, Louisiana provided an in-depth study into methane at domal salt mines. The study determined outbursts, especially related to blasting, as the primary mode of methane emission into the mine. At the Cote Blanche mine more than 80 outbursts, ranging in size from 1 to 50 feet in diameter were documented.
At the Weeks Island Mine methane liberation incidents, resulting from blasting, have included eight face fires and five outbursts on the following dates:
Outbursts Face Fires
March 24, 2020 April 18, 2011
April 16, 2018 June 10, 2010
March 7, 2007 May 18, 2010
April 8, 2002 August 31, 2007
January 25, 2002 March 13, 2006
February 18, 2005
October 30, 2004
September 25, 2001
Face fires involving flames at several shot holes and/or points where methane is burning on the muck pile have most commonly been extinguished by the crew upon locating the fires. The reported outburst events have presented much greater potential hazards to miners. Of the reported outbursts at the mine, methane was allowed to bleed off for periods ranging from a couple hours to five days or more before the mine resumed operation.
A well-documented outburst at the Weeks Island Mine occurred on April 16, 2018. MSHA Technical Support Ventilation Division personnel assisted the District and mine operator personnel for two days during this event. Observations from this outburst event highlighted several relevant issues. First, the mine has large entries which reduce air velocities. This means it takes longer for hazardous gasses, like methane, to exit the mine after an outburst. Second, the mine has a single-split ventilation system, which means that there is only one intake air course that provides
3 52 Fed. Reg.24924-5, Safety Standards for Methane in Metal and Nonmetal Mines; Final Rule (July 1, 1987).
4 Molinda, Greg M., Investigation of Methane Occurrence and Outbursts in the Cote Blanche Domal Salt Mine, Louisiana, Bureau of Mines RI 9186 (1988).
fresh air to the mine. Therefore, any highly concentrated pocket of methane would have to travel this air course as it works its way out of the mine, affecting all work areas and escapeways downwind. Additionally, ventilation curtain leakage and air recirculation caused by auxiliary fans further compromise air flow in the mine.
Lastly, MSHA noted the presence of non-permissible equipment.
And yet again, on March 24, 2020, a methane inundation event occurred as a result of blasting. MSHA became aware of this incident some 48 hours later via an anonymous hazard condition complaint. On April 2, 2020, MSHA issued a Section 104(d)(1) citation (Citation No. 9457566) for a violation of 30 C.F.R. § 57.22603(c). The citation reads as follows:
On 3/24/2020, at approximately 11:00 pm, the Mine Production General Foreman and one production miner entered the mine from the surface to check the ventilation system and close an air door on the 1400’ level with multiple Atmospheric Monitors (AMS) indicating methane readings above 0.5%. At approximately 12:00 am on 3/25/2020, with AMS monitors indicating methane readings above 0.5%, the Mine Production General Foreman and five miners entered the mine and performed handheld monitoring next to the AMS monitor at 26E and identified a reading of 1.5% methane. The Mine Production General Foreman, directed the crew to begin isolating the 1500’ and reestablishing ventilation and electrical power in the rest of the mine, this also required blocking (deactivating) the AMS sensor on the 1500’ level.
On September 10, 2020, MSHA conducted a site investigation, discussing the allegations in the petition, with particular focus on the proposed mine re-entry procedures post blast, as the mine’s alternative method of complying with the petitioned standard. The investigation included a number of interviews with both hourly and management personnel. Notably, the results of 21 interviews revealed that 1 miner and 2 managers were in favor of the petition. The remainder of those interviewed (18) were not in favor of what the petition proposed.
Findings of Fact and Conclusions of Law
Assuming the AMS system is operable and functioning, sending miners, including methane testers, underground when any area of the mine contains methane of 0.5 percent or more is less safe than waiting for the methane to be less than 0.5 percent.
Methane emission in salt mines is different than in coal mines. Instead of the continuous bleed of gas from the face, roof, and rib as in coal mines, methane in domal salt is emitted mainly as an instantaneous release of gas from salt broken during the blasting of production faces.5 This phenomenon explains in part why the Weeks Island mine has had five outbursts and eight face fires over the last 20 years after blasting. It also explains the violent 1979 explosion at the nearby Belle Isle mine that killed five miners. It is why MSHA promulgated 30 C.F.R. § 57.22603, Blasting from the surface (II-A mines) – to protect miners from the unique hazards that exist after blasting in domal salt mines with a history of outbursts.
Methane mixed with air is explosive in the range of from 5 to 15 percent methane, provided that 12 percent or more oxygen is present. The presence of dust containing volatile matter in a gassy atmosphere may further enhance the explosion potential of methane in a mine.6 Effective AMS monitoring can alert mine operators of the occurrence of outbursts following blasting, but may provide only limited information of the actual magnitude and impact of the event; all high-methane locations in the mine may not be known. Variables affecting the potential for unknown areas of high methane include the number and location of methane sensors in the mine, size of mine openings, velocity of airflow in the vicinity of the outburst, quantity of explosives, and number and locations of faces blasted. Given all these different variables, allowing personnel to enter the mine only when AMS for the entire mine indicates less than 0.5 percent methane protects personnel from potential hazards.
The petition does not include a ceiling on the amount of methane in the mine under which miners would be allowed to work. Rather, it would allow miners to work underground when potentially explosive atmospheres exist. Even when electrical power in the mine is deenergized, ignition sources would exist in the mine, such as battery terminals connected to diesel-powered equipment. Waiting 45 minutes before sending a competent miner into these known conditions, which may be hazardous, to repair the ventilation systems, isolate areas with methane over 0.5 percent, and then otherwise allowing for normal operations, even with the additional proposed safety measures, is not as safe as waiting until the operator knows methane in the mine is less than 0.5 percent, as required by 30 C.F.R. § 57.22603(c). This is especially true at the Weeks Island mine because MSHA has: (1) documented that removing large quantities of hazardous gases is adversely affected by large entries resulting in low air velocity, the “Single split” mine ventilation system, and
5 Id.
6 50 Fed. Reg. 23,628, Safety Standards for Gassy Metal and Nonmetal Mines; Proposed Rule (June 4, 1985).
ventilation curtain leakage; and (2) observed that it takes from a couple of hours to up to five days for methane to clear after reported outbursts.
Additionally, the proposed alternative method of barricading some areas of the mine after blasting and commencing work in other areas is insufficient. As mentioned above, the mine’s single-split ventilation means that when areas of high methane concentration exist they must move through all downwind areas of the mine before exiting the mine, including work areas and escapeways. While barricades can keep miners out of an area, they cannot keep methane in the barricaded area. In sum, allowing normal operations 200 feet away from areas with known, elevated methane levels, is not as safe as waiting until the operator knows methane in the mine is less than 0.5 percent, as required by the standard.
When the AMS system is broken, sending miners underground, into potentially explosive methane, to work is less safe than waiting for the methane level to be compliant.
Title 30 C.F.R. § 57.22603(d) provides a narrow exception to the prohibition of miners entering the mine after blasting; i.e., when the monitoring system is inoperable or malfunctions, the standard allows only those competent persons necessary to test for methane to enter the mine until the methane in the mine is less than 0.5 percent.
These persons, however, cannot enter the mine until it has been ventilated for at least 45 minutes and the mine power has been deenergized.
The proposed alternative method would expand, beyond only testing, the work miners are allowed to perform when the monitoring system is broken -- allowing miners to reenter the mine after blasting to determine whether a monitor is faulty, isolate the affected area, and make ventilation changes.
It is important to the safety of all the miners to determine methane levels underground following blasting. The need for that specific information is why the standard contains a limited exception for competent methane testers only when the AMS system is malfunctioning. But this exception also involves a risk for the methane tester, as the methane levels are unknown. Allowing this person to perform any tasks other than testing and exiting the mine as quickly as possible if the methane level is above 0.5 percent increases that risk. Upon testing for methane, if the methane in the mine is less than 0.5 percent, the proposed alternative method would be moot because the standard would no longer prevent miners from entering the mine. However, if the testing reveals methane to be 0.5 percent or higher, then allowing non-testing work in these known conditions, as opposed to waiting for methane levels to reduce to below 0.5 percent as required, is less safe than the standard for the reasons stated above.
Blasting from the surface (II-A mines), 30 C.F.R. § 57.22603, is the only relevant standard after blasting.
Morton argues that because its alternative method provides protection equal to other non-petitioned standards, it should be granted a modification of § 57.22603. Under Mine Act § 101(c), 30 U.S.C. § 811(c), MSHA has no authority to grant a petition based on an alternative method if the method does not provide protection equal to the petitioned standard. In any event, the other standards Morton cites do not apply in the post-blasting context; § 57.22603 is the only relevant standard. As previously discussed, methane in domal salt is emitted mainly as an instantaneous release of gas from salt broken during blasting of production faces. This phenomenon explains in part why Weeks Island mine has had five outbursts and eight face fires over the last 20 years after blasting. It also explains the violent 1979 explosion at the nearby Belle Isle mine that killed five miners. It is why MSHA promulgated 30 C.F.R. § 57.22603 -- to protect miners from the specific hazards that exist after blasting in domal salt mines with a history of outbursts.
To that end, the preamble to the final rule, Safety Standards for Methane in Metal and Nonmetal Mines clarifies, “the Agency has developed standards which are unique to each category of mines. Consequently, with respect to methane-related hazards, mines are required to comply only with standards that apply to a particular category or subcategory.”7 It also included the following explanation of expectations prior to reentering a Category II-A mine following blasting, which further clarifies and explains the agency’s rationale for promulgating separate blasting standards for each category of mines: “This final rule is a new standard and requires that blasting be done from the surface after everyone is out of the mine. It prohibits reentry until the mine has been examined by persons or the atmospheric monitoring system indicates that the mine contains less than specified minimum methane levels. . . methane [in domal salt mines] could be ignited by blasting and would affect the entire underground mining environment.”8
The petitioner, however, claims that two other MSHA standards for Category II-A mines, §§ 57.22232 and 57.22235, would compel them, to make ventilation changes with workers underground so § 57.22603 cannot be read literally. These other standards apply generally to Category II-A mine operations. The public was free to comment during rulemaking on § 57.22603 whether it makes sense to require more protective standards for miners post-blast than for general mine operations. MSHA made the decision to promulgate standards specific to post-blast conditions to complement the general standards. A petition for modification is not the venue to revisit that decision; the Administrator for Mine Safety and Health Enforcement is not
7 52 Fed. Reg, 24,924-5 (1987).
8 Id. at 24,938.
free to nullify the content of § 57.22603 in deciding whether to grant a modification of it.
Section 57.22232 requires that, if methane reaches 0.5 percent in the mine atmosphere, ventilation changes shall be made to reduce the level of methane. Until methane is reduced to less than 0.5 percent, electrical power shall be deenergized in affected areas, except power to monitoring equipment determined by MSHA to be intrinsically safe under 30 CFR part 18. Diesel equipment shall be shut off or immediately removed from the area and no other work shall be permitted in affected areas.
Section 57.22235 requires that: (a) if methane reaches 1.0 percent in the mine atmosphere, all persons other than competent persons necessary to make ventilation changes shall be withdrawn from affected areas until methane is reduced to less than
0.5 percent; and (b) if methane reaches 1.0 percent at a work place and there has been a failure of the main ventilation system, all persons shall be withdrawn from the mine.
Sections 57.22232 and 57.22235 do not address the specific hazards of instantaneous methane release from salt broken during the blasting of production faces. These blasting hazards are addressed under § 57.22603, which requires that no miners enter the mine until the monitoring system and testing indicates that methane in the mine is less than 0.5 percent (except for testing under paragraph (d)).
Section 57.22603 allows normal mining operations to resume once methane is below
0.5 percent after blasting. This is because the post-blasting hazards would have subsided; i.e., any methane outburst after blasting would have cleared. At this point, however, once miners resume working, they may encounter other methane-related hazards; § 57.22232 prescribes protective measures when methane is 0.5 percent or more, and § 57.22235 prescribes protective measures when methane reaches 1.0 percent. These standards, therefore, are complementary, not contradictory.
The petition also claims that requirements under 30 C.F.R. §§ 57.22602 (I-C Mines), 57.22604 (II-B Mines), and 57.22605 (V-A mines) support the conclusion that, once underground, Morton’s miners are permitted to work in unaffected areas. Petitioner asserts that §§ 57.22602(b), 57.22604, and 57.22605 each require examination of the “blast site,” “blast areas,” and “places blasted,” respectively, (rather than the entire mine). This comparison is incorrect.
Unlike § 57.22603, §§ 57.22602(b), 57.22604, and 57.22605 do not apply to Category II-A mines. These three standards do not address how methane in domal salt mines is emitted mainly as an instantaneous release of gas from salt broken during the blasting of production faces. The separate requirements are consistent with how MSHA designed its safety standards for methane in metal and nonmetal mines: standards are made to be unique to each category of mines, and mines are required to comply only with standards that apply to a particular category or subcategory. Again, MSHA made these policy decisions during its rulemaking process and the public was free to comment then on whether it makes sense to have different safety rules depending on methane levels and history in metal and nonmetal mines. A petition for modification is not the venue to revisit those choices and the Administrator has no authority to nullify § 57.22603’s requirements for Category II-A mines.
Section 57.22602(b) applies to Category I-C mines and § 57.22604 applies to Category II-B; these categories do not include mines that have documented methane emissions, such as the Weeks Island mine that has had five outbursts and eight face fires over the last 20 years after blasting. Lastly, Section 57.22605 applies to Category V-A mines, petroleum mines that operate entirely or partially within an oil reservoir, and all other petroleum mines in which (A) a concentration of 0.25 percent or more methane has been detected in the mine atmosphere and confirmed by laboratory analysis; or (B) an ignition of methane has occurred. Notably, each of these mine categories present different hazards than domal salt mines, such as the sudden release of gas or liquid due to reservoir pressure after blasting. Even here, though, MSHA’s approach to post-blasting hazards is consistent: only examiners are allowed to enter the mine until the mine has been examined by a competent person and the methane level is below a prescribed hazard level.9
After a careful review of the entire record, including the petition and MSHA's investigative report, MSHA finds that the alternate method proposed by the petitioner does not provide an alternative method of compliance that will at all times guarantee no less than the same level of protection afforded to the miners.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Mine Safety and Health Enforcement, and pursuant to § 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 811(c), it is ordered that Morton Salt Inc.’s Petition for Modification of the application of 30 C.F.R. § 57.22603(c) and (d) in the Weeks Island Mine is hereby:
DENIED.
9 See 30 C.F.R. § 57.22605(c), which states: “If the monitoring system indicates the presence of 1.0 percent or more methane, persons other than examiners shall not enter the mine until the mine has been examined by a competent person and the methane level is less than 1.0 percent.
Any party to this action desiring a hearing on this matter must file in accordance with 30 C.F.R. § 44.14, within 30 days. The request for hearing must be filed with the Administrator for Mine Safety and Health Enforcement, 201 12th Street South, Suite 401 Arlington, Virginia 22202.
If a hearing is requested, the request shall contain a concise summary of position on the issues of fact or law desired to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than Petitioner who has requested a hearing shall also comment upon all issues of fact or law presented in the petition, and any party to this action requesting a hearing may indicate a desired hearing site. If no request for a hearing is filed within 30 days after service thereof, the Decision and Order will become final.
Timothy R. Watkins
Deputy Administrator for
Mine Safety and Health Enforcement
Certificate of Service
I hereby certify that a copy of this proposed decision was served personally or mailed, postage prepaid, or provided by other electronic means this 28th day of January, 2022, to:
Donna Vetrano Pryor, Esq.
Donna.Pryor@huschblackwell.com
HUSCH BLACKWELL LLP
1801 Wewatta St., Suite 1000
Denver, CO 80202
Nathan Boles
nboles@mortonsalt.com
General Manager
Morton Salt, Inc.
P.O. Box 1496
Weeks Island, LA 70560
Robert Freeman
Miners’ Representative
Morton Salt, Inc.
P.O. Box 1496
Weeks Island, LA 70560
Don Vickers
Mine Safety and Health Specialist