---
kind: "section"
citation: "30 C.F.R. § 75.334"
title: "30"
number: "75.334"
heading: "Worked-out areas and areas where pillars are being recovered."
url: "https://uscodex.org/cfr/30/75.334"
---

# §75.334. Worked-out areas and areas where pillars are being recovered.

- (a) Worked-out areas where no pillars have been recovered shall be—
  - (1) Ventilated so that methane-air mixtures and other gases, dusts, and fumes from throughout the worked-out areas are continuously diluted and routed into a return air course or to the surface of the mine; or
  - (2) **Sealed.**
- (b)
  - (1) 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.
  - (2) After pillar recovery a bleeder system shall be maintained to provide ventilation to the worked-out area, or the area shall be sealed.
- (c) The approved ventilation plan shall specify the following:
  - (1) The design and use of bleeder systems;
  - (2) The means to determine the effectiveness of bleeder systems;
  - (3) The means for adequately maintaining bleeder entries free of obstructions such as roof falls and standing water; and
  - (4) The location of ventilating devices such as regulators, stoppings and bleeder connectors used to control air movement through the worked-out area.
- (d) If the bleeder system used does not continuously dilute and move methane-air mixtures and other gases, dusts, and fumes away from worked-out areas into a return air course or to the surface of the mine, or it cannot be determined by examinations or evaluations under [§ 75.364](/cfr/30/75.364.md) that the bleeder system is working effectively, the worked-out area shall be sealed.
- (e) Each mining system shall be designed so that each worked-out area can be sealed. The approved ventilation plan shall specify the location and the sequence of construction of proposed seals.
- (f) In place of the requirements of paragraphs [(a)](#a) and [(b)](#b) of this section, for mines with a demonstrated history of spontaneous combustion, or that are located in a coal seam determined to be susceptible to spontaneous combustion, the approved ventilation plan shall specify the following:
  - (1) Measures to detect methane, carbon monoxide, and oxygen concentrations during and after pillar recovery, and in worked-out areas where no pillars have been recovered, to determine if the areas must be ventilated or sealed.
  - (2) Actions that will be taken to protect miners from the hazards of spontaneous combustion.
  - (3) If a bleeder system will not be used, the methods that will be used to control spontaneous combustion, accumulations of methane-air mixtures, and other gases, dusts, and fumes in the worked-out area.

## Notes

### Authority

Authority: 30 U.S.C. 811, 863.

### Source

Source: 61 FR 9829, Mar. 11, 1996, unless otherwise noted.

### Authority

Authority: 30 U.S.C. 811, 813(h), 957.

### Source

Source: 35 FR 17890, Nov. 20, 1970, unless otherwise noted.