April 17, 2024
In the matter of PETITION FOR MODIFICATION
Nevada Gold Mines LLC
Goldrush Mine
Mine I.D. No. 26-02822 Docket No. M-2022-011-M
PROPOSED DECISION AND ORDER
On April 6, 2022, Nevada Gold Mines LLC (NGM), Mine I.D. No. 26-02822, filed a petition seeking modification of the application of 30 CFR § 57.11052(d) at its Goldrush Underground Mine in Eureka County, Nevada. The petitioner alleges that the alternative method in the petition will at all times guarantee no less than the same measure of protection afforded to the miners by the standard.
The petitioned standard, 30 Code of Federal Regulations (30 C.F.R.) § 57.11052(d) –states, in relevant part,
Refuge areas shall be –
(d) provided with compressed air lines, waterlines, suitable handtools, and stopping materials.
Petitioner is requesting a modification of the standard to permit the use of sealed, purified drinking water in lieu of providing potable water through waterlines. The petitioner states that:
1. The Goldrush Mine is an underground portal gold mine that began operating in 2017 and expects to continue mining for another 35 to 40 years. The mine is located at Crescent Valley, in Eureka County, Nevada, and the mailing address is 1655 Mountain City Highway, Elko, Nevada 89801.
2. The Goldrush Mine currently has three refuge chambers located throughout the underground portion off the mine. In these refuge areas, drinkable water is currently supplied via commercially purchased water in sealed pouches.
3. At the present time, each refuge chamber is provided with a waterline. However, due to the configuration and condition of the waterlines and the quality of the water source, the water flowing through these lines is not potable. Installing waterlines that provide potable drinking water to each refuge chamber is not feasible due to the
lack of essential infrastructure. Further, the waterlines may be susceptible to damage during certain mine emergencies, thus the water supply could be cut off completely. Given the suspect source of the water and the potential for waterline damage, there is no guarantee that potable drinking water can be provided via the waterlines, as required by § 57.11052(d). Application of the standard could adversely impact the safety of miners using the refuge area if they were to rely on the waterlines that run from the portal to the refuge chambers. The alternative method of storing sealed, purified water inside each refuge chamber provides certainty that miners will have sanitary drinking water available to them, regardless of the current condition of the water supply or the nature of any emergency that might occur in the future.
4. All three of the underground refuge chambers at the Goldrush Mine are portable. By allowing the use of refuge chambers that are not connected to waterlines, the mine will have greater flexibility in the locating the refuge chambers. This will allow the refuge chambers to be located near where miners are working, and to be relocated more quickly to working areas where needed.
5. The mine seeks an alternative method of compliance with 30 C.F.R. § 57.11052(d) and proposes the following:
a) The three portable refuge chambers in use at the Goldrush Mine are MineARC refuge chambers and are made of steel. Each of these portable refuge chambers is equipped for a maximum capacity of 16 miners. The combined capacity exceeds the normal maximum work crew of approximately 40 miners underground on any given day during any shift.
b) Drinking water will be supplied via commercially purchased water in sealed individual portion-sized pouches in each refuge chamber. The water will be supplied by the case and packaged into 4.227 fluid ounce/125 milliliter portions with 50 individual portions per case.
c) While MSHA's standard at 30 C.F.R. § 57.11052(d) is silent on the amount of water required, MSHA's underground coal standard at 30 C.F.R. § 75.1507(d)(l) requires a minimum of 2.25 quarts of potable water per person per day for at least 96 hours (4 days). At present, the refuge chambers at the Goldrush Mine are equipped for a maximum of 16 miners each, for a maximum of 36 hours. This includes a 36-hour supply of water in the amount of 2.25 quarts per day per person. The mine proposes providing 9 cases of water in each refuge chamber, enough for only 36 hours instead of 96 hours.
d) The water will have a maximum shelf life of 5 years. The operator will replace the existing water supply with fresh water before the expiration date of the water. The condition and quantity of water will be confirmed by inspection, on no less than a monthly basis.
e) Written instructions for conservation of water shall be provided with the refuge chamber supplies.
f) All miners affected will receive training in the operation of the refuge chambers and will receive refresher training annually.
g) The refuge chambers will be inspected monthly, and the inspections will be documented by the Mine Manager or his designee.
Nevada Gold requests this Petition for Modification apply to the existing refuge chambers and to future refuge chambers and locations. NGM asserts that the proposed alternative method will guarantee at all times no less than the same measure of protection as that afforded by the existing standard. The information provided is proposed by the petitioner and does not necessarily reflect what will be granted by MSHA.
There are presently no miners’ representatives at the Goldrush Mine. NGM posted a copy of the Petition on the mine’s bulletin board. It shall remain posted until the Petition becomes final. After the Petition was filed, NGM provided a copy of the petition to 8 miners. All read the Petition and indicated by their signature that they had no comments or concerns.
Findings of Fact and Conclusions of Law
MSHA conducted an investigation of the Goldrush Underground Mine on June 14, 2022. Yasser Akbarzadeh, MSHA Staff Assistant, met with Kurt Parker, NGM’s Safety & Health Training Manager, and Nathan Dillon, NGM’s Safety & Health Superintendent, and reviewed the Petition. Both then accompanied MSHA during the investigation and inspection of the mine’s 3 refuge chambers. MSHA followed up via emails and telephone calls with members of NGM’s safety and health staff. During the mine visit and in follow-up contacts, information provided by the mine operator was verified and additional pertinent details were gathered. MSHA reviewed the mine’s inspection history and the operator’s reports of accidents.
The mining method at the Goldrush Mine is mechanized cut and fill stope mining. The mine began operating in 2017 and expects to continue mining for another 35 to 40 years. Currently, NGM employs a total of 141 persons at the Goldrush mine, and all employees work underground. The mine works two 12-hour shifts, 7 days a week. Shift changes occur on the surface of the mine; the maximum number of miners underground at any one time is 40 persons on dayshift Monday through Thursday. There are fewer miners working the nightshift and Friday through Sunday because some of the salaried and support staff are scheduled off.
The Goldrush Mine has three 16 person MineArc refuge chambers. Table 1 shows the refuge chamber models, types and capacities. See next page:
| Model | Refuge Chamber Number | Capacity in Persons |
|---|---|---|
| NPN | GRUG MAA-334-R | 16 |
| MS-ND3-16-ELV-36 | GRUG MAA-651 | 16 |
| MS-ND3-16-ELV-36 | GRUG MAA-652 | 16 |
Each of the refuge chambers is provided with a waterline, however, the water has a light brown color and is not potable. Due to the condition of the water within the waterline, the mine operator currently supplies all refuge areas with commercially available potable water, packaged in 4.227-fluid ounce/125-milliliter portions, with 50 individually sized portions per case. In accordance with 30 CFR § 57.20002 – Portable water, the petitioner intends to continue providing the water in small individual portions so that additional or extra drinking cups are not required. In accordance with the same standard, the mine will also provide a receptacle for empty water packages.
The mine intends to preserve the existing waterlines, not for drinking water purposes, but for firefighting purposes. To protect miners from drinking unhealthy water, it is important to conspicuously mark the existing waterlines as “non-potable”. MSHA conducted a risk analysis to determine the adequate amount of water. MSHA’s experience with refuge chambers in underground mines includes discovery of previously unknown, unreported, or unrepaired damage to waterlines and includes discovery of previously unknown, unreported, or unrepaired damage to waterlines and air lines. MSHA is also aware that persons sometimes enter refuge chambers during non-emergency periods an consume supplies of water, food, etc., and therefore compromise the effectiveness of refuge areas. MSHA reviewed the mine’s refuge chamber monitoring equipment and the procedures used to verify chamber readiness. NGM’s mines have a variety of ways that chamber readiness can be monitored.
Refuge chambers located in areas where miners are working are available for a daily, visual observation of the exterior by the miners who are working in the area, and who would be relying on the refuge chamber in the event of an emergency. They can also be inspected by miners who are passing nearby on their way to another work location. Observing the chamber nearby or seeing from a distance that the refuge chamber’s light is green would assure miners that the chamber is ready should it be needed. Refuge chambers located in remote areas where no miners are currently scheduled to work and are not expected to be needed for use, can be visually observed less frequently, such as several times each week.
It is important to examine the exterior of each refuge chamber on a regular basis to verify the condition of the waterline, compressed air lines and their connections, back (roof) and rib conditions, and for the presence of the refuge chambers’ tamper-evident seals. If a tamper-evident seal is found to have been removed or broken, an examination of the interior of the chamber should be promptly conducted to assure the required amount of potable water and other supplies are present. After the entire examination is completed, a new tamper-evident seal should be installed. These exterior inspections should be performed daily and included in the secondary escapeway examinations that are conducted at least weekly. Daily exterior observations are believed to provide an adequate level of protection for miners working underground.
All three refuge chambers are portable, or sometimes referred to moveable or temporary. All portable refuge chambers are equipped with gas monitoring instrumentation to monitor atmospheric conditions, packaged potable water, compressed air supplied via air lines, medical grade oxygen in cylinders, oxygen candles (in chambers sized for 12 persons or greater), toilet, radio, phone, air conditioning, blankets, first aid supplies and food rations.
The mine has agreed to provide potable water in sufficient quantity to supply the rated maximum number of refuge chamber occupants (12 to 16 persons in each refuge chamber) for 96 hours. Potable water is water which meets the quality standards prescribed in the U.S. Public Health Service Drinking Water Standards, published in 42 CFR Part 721, or water which is approved for drinking purposes in the State or local authority having jurisdiction.
By ending its reliance on water supplied by a waterline and changing to a packaged water supply, the mine will be transitioning from an unlimited supply of water to a limited supply of water. Therefore, it is critical that the amount of water provided is sufficient for the safety and health of miners who would be trapped in the underground mine during an emergency. Further, it is important that the mine operator verify that the water stored in the refuge chamber is in place and ready for use when miners are working near the refuge area and expecting to use it in case of an emergency. It is also important to ensure that miners are properly instructed and trained on the importance of rationing water and using the water conservatively to effectively sustain miners’ lives.
The petitioner stated potential hazards to waterlines include damage, interruption, and survivability of the mine’s water lines should an underground event occur. The petitioner reports on page 2, section 3:
“Further, the waterlines may be susceptible to damage during certain mine emergencies, thus the water supply could be cut off completely. Given the suspect source of water and the potential for waterline damage, there is no guarantee that potable drinking water can be provided via the waterlines, as required by §57.11052(d). Application of the standard could adversely impact the safety of miners using the refuge area if they were to rely on the waterlines that run from the portal to the refuge chambers. The alternative method of storing sealed, purified water inside each refuge chamber provides certainty that miners will have sanitary drinking water available to them, regardless of the current condition of the water supply or the nature of any emergency that might occur in the future.”
The petitioner’s statement related to the mine’s waterlines prompted MSHA to also investigate the potential susceptibility of the air lines. The air lines now in use are a combination of steel and plastic. In general, 6-inch inside diameter (ID) steel pipe manifolds are provided, and are reduced downstream to 2-inch ID. To reduce weight and allow for easier handling, 1-inch ID, high density polyethylene (HDPE) solid-wall pipes are run to the refuge chambers from the smaller diameter steel air lines. The water and air supply lines are typically installed in close proximity to each other near the tunnel back (roof) or at the spring line (the meeting of the roof arch and the sides of a tunnel). The spring line is typically approximately 14-15 feet above the floor, and the back is typically approximately 17 feet above the floor.) When a refuge is relocated, the mine installs additional HDPE air pipe to the new location, with the last portion of the line being a short flexible hose.
According to information published by the manufacturer Mine Safe, the MineARC refuge chambers are equipped with an electrical scrubbing system and pre-packaged MARCISORB chemical absorber cartridges to remove the buildup of harmful carbon dioxide (CO2) and carbon monoxide (CO) from the air inside the refuge chamber. The fixed position refuge chamber is also equipped with chemical absorbers to remove the buildup of harmful carbon dioxide (CO2) and carbon monoxide (CO) from the air inside the refuge chamber for 96 hours.
Concern about the condition of the mine’s water lines prompted MSHA to verify that the compressed air lines are in good condition, not susceptible to damage during mine emergencies, nor in danger of the air supply being cut off completely. The airlines now in use are hard-piped, one-inch inside diameter. If a portable refuge is relocated, the mine plans to install additional hard air pipe to the new location, with the last portion of the line being a flexible hose.
The quality of compressed air was investigated. Compressed air is produced by oil-lubricated compressors that have their air intake on the surface. The supplied air is breathable. Air passes through a MineARC CAMS (Compressed Air Management System), which consists of 4 filters: a water separator, a pre-filter, a coalescing filter, and an absorption filter. All filters are equipped with an auto-drain feature. The system also includes an air toxicity monitor. The compressed air system is inspected weekly, monthly, and every 120 days. During the 120-day inspection, the pre-filter, coalescing filter, and absorption filter are replaced, the water separator is examined and is replaced if needed. All brass check valves are replaced during the 120-day inspection. The filter system inspection and maintenance schedule is per Mine ARC’s instruction, which has been tested to ISO 12500-1 (Filters for compressed air – Test methods – Part 1: Oil aerosols) and is designed to meet AS/NZS 1716:2003 (the Australian/New Zealand Standard for Respiratory protection devices).
MSHA verified that the scrubbers provided for the refuge chambers are properly equipped. The 16-person refuge chambers are equipped with 26 CO2 scrubbers and one CO scrubber. The scrubbers are stocked to MineARC specifications. Every refuge chamber is equipped with a gas detection unit.
MSHA investigated ambient temperatures in the mine to determine if the mine’s depth might cause temperatures in the refuge chambers to be overly warm, and if so, require more than the proposed supply of 2.25 quarts of water per person per day. Refuge chambers are located between elevations 6,105 and 6,370 feet above mean sea level. The mine stated that mine temperatures vary throughout the year depending on the surface temperature, with the hottest temperature recorded in 2021 being 102°F at the bottom of the North vent raise. The mine temperature does not drop below 32°F. The mine’s ventilation fans are equipped with burners that heat the air to prevent temperatures from dropping below freezing. The refuge chambers are equipped with temperature sensors that warn at 50°F and 32°F, and at 95°F and 104°F. The refuge chambers are equipped with air conditioning units that maintain the chamber’s internal temperatures at 86°F when at full capacity and running on battery power.
The petitioned standard, 30 CFR § 57.11052(d), is a subsection of 30 CFR § 57.11052 – Refuge areas. The investigation reviewed the details of compliance with all subsections. The petitioner intends to meet the minimum requirements of 30 CFR § 57.11052. Because the mine must remain compliant with the entire standard, the investigation reviewed the details of compliance with all subsections. The mine is compliant with, or will be compliant with all subsections, as follows:
a) “Of fire-resistant construction, preferably in untimbered areas of the mine;”
According to the manufacturer’s published descriptions and specifications, the MineARC portable refuge chambers are fire resistant. The exterior housing is constructed using 5mm thick steel plate, the interior is equipped with stainless steel hardware throughout, and the refuge chambers have a 5-psi blast rating.
b) “Large enough to accommodate readily the normal number of persons in the particular area of the mine;”
MSHA’s investigation determined that the portable refuge chambers are positioned where necessary to accommodate all miners working in active areas of the mine.
c) “Constructed so they can be made gastight;”
MSHA also determined that the MineARC portable refugee chambers are manufactured using similar materials and methods as those used to construct Part 7-approved refuges for the coal industry. MineARC constructs the refuge chambers with outward opening doors, double-locking handles and vacuum tested seals.
d) “Provided with compressed air lines, waterlines, suitable handtools, and stopping materials.”
The waterlines are specifically being petitioned. The petitioner raised concerns about the survivability of the waterlines should there be an underground event, which could also impact the compressed air lines. Therefore, the waterlines, compressed air lines (and the associated provision of breathable air) were included in MSHA’s petition investigation.
As required in subsection “c” above, the petitioner provides sealing materials inside the fixed position refuge chambers and suitable tools to maintain the seal around the door when necessary. The petitioner has standardized the equipment, use and training for all refuge areas, therefore all suitable tools should be provided in a consistent manner for all refuge areas. MineARC’s standard refuge chamber equipment includes a fire extinguisher. The petitioner intends to maintain a fire extinguisher suitable to fight a fire within or near a refuge area.
The alternate methods proposed in NGM’s Petition for Modification, and MSHA’s investigation, review and recommendations were used to develop the Proposed Decision and Order provide the factual basis for the Terms and Conditions.
The granting of this petition would affect all underground miners at this mine.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Mine Safety and Health Enforcement and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 811(c), it is ordered that Nevada Gold Mines LLC’s Petition for Modification for relief of the application of 30 C.F.R. § 57.11052(d) in the Goldrush Mine is hereby:
GRANTED, for the operator to provide life sustaining potable water and life sustaining breathable air to all refuge areas including each existing refuge chamber, and all future newly constructed or repositioned refuge chambers. Potable water will be provided via commercially available packaged water, sealed and sized in individually consumable portions. Life sustaining breathable air will be provided using air via compressed air supply lines, with backup oxygen provided in accordance with the specifications of a refuge chamber manufacturer that produces Part 7-approved refuge alternatives, subject to the conditions of this Order:
TERMS AND CONDITIONS
Nevada Gold and MSHA agree to modify the standard 30 C.F.R. § 57.11052(d) at Nevada Gold’s Goldrush Mine in Eureka County, Nevada as follows:
1. This Order shall apply to the existing refuge chambers, to relocated refuge chambers and to future refuge chambers.
2. Refuge chambers shall accommodate the maximum number of persons that can be expected to be working in the mine at any time.
3. Each refuge chamber shall be supplied with water sufficient for the number of miners for which the refuge is designed, for up to 4 days.
4. Potable Water Supply:
a. Drinking water shall be provided via commercially purchased purified water in individual portioned packaged pouches.
b. Sufficient water shall be provided in each refuge area to provide 2.25 quarts of water for each person per day, for at least 4 days.
c. Water shall be stored in a manner that makes the expiration dates readily visible for inspection.
d. Water shall be exchanged with a fresh supply prior to the water manufacturer’s specified expiration dates, or at intervals not to exceed five years, whichever occurs first. If the expiration dates are not legible, or if they become illegible, the water shall be replaced by the end of the next working shift.
e. The condition and quantity of stored water shall be confirmed by inspection on at least a monthly basis, and the inspections shall be documented.
f. A weekly examination of the exterior of the refuge chamber shall be conducted to verify the condition of the compressed air line and its connection, roof and rib conditions, and for the presence of the tamper-evidence seals. If the refuge area is in an active work area, the exterior of the refuge chamber shall be inspected in the same manner as part of the regular workplace examination. If the tamper-evident seals are found to have been removed or broken, an examination of the interior of the chamber shall be conducted to assure the required amount of potable water is present. After the examination, a tamper-evident seal shall be replaced.
g. Written instructions for conservation of water shall be provided in the refuge chamber.
5. The mine shall leave existing waterlines in close proximity to refuge areas intact. The waterlines will be conspicuously labeled as “non-potable” and shall be maintained legible to miners.
6. Refuge chamber environmental systems shall be maintained in functional operating condition and inspected and maintained per the manufacturer’s specifications and instructions. These systems include but are not limited to; electrically powered scrubbing system MARCISORB chemical absorber cartridges, air conditioning units to maintain temperatures at 86°F when at full capacity and running on battery power.
7. Refuge chambers shall contain gas detection equipment capable of monitoring concentrations of oxygen, carbon dioxide, carbon monoxide, and other harmful gases specific to the mine. The detection equipment must be functional for up to 96 hours.
8. Training on refuge chambers and their environmental systems and instructions for use shall be provided for affected personnel at least semi-annually. Training shall include:
a. The hazards associated with insufficient and excessive concentrations of oxygen, carbon dioxide, carbon monoxide and other harmful gases specific to the mine,
b. The use of gas detector(s) to monitor concentrations of oxygen and potentially harmful concentrations of gases, and
c. The operation and chemical recharging of the refuge chamber’s interior atmosphere scrubbing and other environmental systems.
9. Applicable revisions or appropriate changes to the mine’s 30 C.F.R. Part 48 training plan regarding the conditions in this Order shall be submitted to the MSHA District Manager for revision and approval prior to implementation of the training plan by the Petitioner. Nevada Gold Mines LLC shall include the above terms and conditions in the initial and annual refresher training to ensure that miners are aware of the stipulations contained in this Order.
10. The mine shall comply with all other requirements of 30 C.F.R. § 57.11052 – Refuge areas.
Unless specifically mentioned herein, nothing in this Order changes or supersedes the requirements otherwise imposed by the Mine Act, other mandatory standards or regulations, or approved plans.
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, 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 the Petitioner who has requested a hearing may 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 and must be posted by the operator on the bulletin board at the mine.
__________________________________________
Brian Goepfert,
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 paid, or provided by other electronic means this ___17th______day of ____April___________,
2024, to:
Laura E. Beverage
Karen L. Johnston
Jackson Kelly PLLC
1099 18th Street, Suite 2150
Denver, CO 80202
lbeverage@jacksonkelly.com
kjohnston@jacksonkelly.com
Kurt Parker, Safety & Health Mgr.
Nevada Gold Mines LLC
1655 Mountain City Hwy
Elko, NV 89801
klparker@nevadagoldmines.com
___________________________
Michele Gussie
Secretary for Mine Safety and Health Enforcement