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Final Rule on
Sealing of Abandoned Areas
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MSHA Mine Seal Requirements

The final regulation addresses sealing abandoned areas in underground coal mines. It includes requirements for seal strength, design, construction, maintenance and repair of seals and monitoring and control of atmospheres behind seals in order to reduce the risk of explosions in abandoned areas of underground mines. It also addresses the level of overpressure for new seals.

  • The regulation for underground mine seals includes a requirement for seals designed to 50 psi if the atmosphere behind the seal is inert and requires seals designed to at least 120 psi if the atmosphere is not inert.

  • Sealed areas shall be monitored, whether ingassing or outgassing, for methane and oxygen concentrations and the direction of leakage. Atmospheres with seals of 120 psi or greater shall be sampled until the design strength is reached. Atmospheres with seals less than 120 psi shall be monitored and maintained inert.

    • MSHA Guidelines for Completing the Seal Design Application - 30 CFR § 75.335(b)

    Section 75.335(b) of the seal final rule requires that seal-design applications from seal manufacturers or mine operators be in accordance with paragraphs (b)(1) or (b)(2). The list of information provided below will assist design engineers who are submitting a seal design to MSHA for approval under the requirements of Section 75.335(b)(1) on or after October 20, 2008. Depending on the type of seal (wall, plug, etc.), and construction details, some of the listed information may not be necessary.

        - Guidelines for the Seal Design Application

    Compliance Guide Questions and Answers

    This document is presented in a question and answer format with the questions asked from the perspective of the mine operator regarding the final rule on Sealing Abandoned Areas in Underground Coal Mines

        - See Guide

    Information on 20 PSI Seals including Concrete Block and Alternative Seals

  • Guide for Solid Concrete Block Seals
  • Guide For Existing Alternative Seals

    • Stakeholders Meeting Presentation - April 18, 2008

  • Powerpoint ® Version
  • PDF Version
    • Approved Seals under the Final Rule
  • Seals Designed to Withstand an Overpressure of 50 psi
  • 50M-01.1 - Strata Mine Services Plug Seal- For Entry Dimensions Up To 16 ft. High & 40 ft. Wide
  • 50M-02.3 – Minova Main Line Tekseal® - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 50G-03.1 – Minova Gob Isolation Tekseal® - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 50G-04.0 - MICON Gob Seal - For Entry Dimensions Up To 20 ft. High & 28 ft. Wide
  • 50M-05.0 - MICON Main Line Seal - For Entry Dimensions Up To 20 ft. High & 28 ft. Wide
  • 50G-06.1 - JennChem Gob Isolation J-Seal - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 50M-07.0 - JennChem Mainline J-Seal - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 50M-08.0 – Micon Hybrid II Main Line Seal with or without Door - For Entry Dimensions Up To 20 ft. High & 28 ft. Wide

  • Seals Designed to Withstand an Overpressure of 120 psi
  • 120M-01.3 - Strata Mine Services Plug Seal - For Entry Dimensions Up To 16 ft. High & 100 ft. Wide
  • 120M-02.3 – Minova Main Line Tekseal® - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 120M-03.0 - BHP Billiton Concrete Main Line Plug Seal- For Entry Dimensions Up To 20 ft. High & 26 ft. Wide
  • 120M-04.1 - Precision Mine Repair (PMR) 8x40 Concrete Seal- For Entry Dimensions Up To 8 ft. High & 40 ft. Wide
  • 120G-05.2 – Minova Gob Isolation Tekseal® - For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 120M-06.1 - MICON Mainline Hybrid Seal- For Entry Dimensions Up To 20 ft. High & 28 ft. Wide
  • 120M-07.1 - Precision Mine Repair (PMR) Concrete Seal- For Entry Dimensions Up To 6 ft. High & 40 ft. Wide
  • 120M-08.1 - Precision Mine Repair (PMR) Concrete Seal- For Entry Dimensions Up To 10 ft. High & 40 ft. Wide
  • 120M-09.1 - Precision Mine Repair (PMR) Concrete Seal- For Entry Dimensions Up To 12 ft. High & 40 ft. Wide
  • 120M-10.1 – Minova Main Line Tekseal® - For Entry Dimensions Up To 30 ft. High & From 30 ft. to 40 ft. Wide
  • 120M-11.4 - MICON Mainline Hybrid II Seal - For Entry Dimensions Up To 32.5 ft. High & 28 ft. Wide
  • 120G-12.0 - MICON Gob Isolation Hybrid II Seal - For Entry Dimensions Up To 20 ft. High & 28 ft. Wide
  • 120M-13.0 - MICON Mainline Hybrid III Seal - For Entry Dimensions Up To 20 ft. High & 28 ft. Wide
  • 120M-14.0 - Strata Mine Services Reinforced StrataCrete Seal - For Entry Dimensions Up To 12 ft. High & 40 ft. Wide
  • 120M-15.2 – JennChem Mainline J-Seal - For Entry Dimensions Up To 30 ft. High & 33 ft. Wide
  • 120G-16.0 - JennChem Gob Isolation J-Seal- For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 120M-17.0 - JennChem Mainline 1-Day J-Seal- For Entry Dimensions Up To 30 ft. High & 30 ft. Wide
  • 120M-18.0 - Strata Mine Services Reinforced StrataCrete Seal - For Entry Dimensions Up To 8 ft. High & 40 ft. Wide

  • Seals Designed to Withstand an Overpressure > 120 psi

    Currently, no seals have been approved under this category.

    • Mine Inerting Information

    The following is a listing of sources for inerting gases and generators that MSHA is aware of. The list may not be exhaustive.

        - See List

    Regulatory History of the Seals Rule

  • FedReg Doc. E8-10662 - 30 CFR Part 75 - Sealing of Abandoned Areas; Correcting amendments.

  • FedReg Doc. 08-1152 - 30 CFR Part 75 - Sealing of Abandoned Areas; Final Rule
  • Regulatory Economic Analysis - Sealing of Abandoned Areas; Final Rule

  • FedReg Doc. 07-6128 - Part 75 - Sealing of Abandoned Areas; Final rule; limited reopening of comment period; availability; notice of public hearing; close of comment period.

  • FedReg Doc. 07-3977 - 30 CFR Part 75 - Sealing of Abandoned Areas; Extension of comment period.

  • Procedure Instruction Letter I11-V-9 - Procedures for Inspection of Seals

  • FedReg Doc. E7-12242 - 30 CFR Part 75 - Sealing of Abandoned Areas; Extension of comment period.

  • FedReg Doc. 07-2535 - 30 CFR Part 75 - Sealing of Abandoned Areas; final rule (ETS)
  • Regulatory Economic Analysis - Sealing Of Abandoned Areas - Emergency Temporary Standard
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