When an open ditch or trench is used to connect between mud tanks, or between shale shaker and mud tanks; or open, active mud pits located outdoors with unrestricted ventilation, the area shall be classified as shown for mud tanks in Fig. I-3.
The area surrounding a mud pump shall be unclassified unless it is located in an area that is classified because of some other facility.
The area surrounding a degasser which is a closed system, is unclassified except for the vent from the degasser, which shall be classified as shown in Fig. I-7.
The area surrounding an open sump which contains volatile, flammable liquid shall be classified the same as for a mud tank as shown in Fig. I-3.
The area around the diverter line shall be classified as shown in Fig. I-7 for gas vent.
Areas adjacent to producing oil and gas wells shall be classified as follows:
Where there is danger of machinery being started or electrical circuits being energized while repairs or maintenance work is being done, the electrical circuits shall be locked open and/or tagged. Where there is danger of machinery being started or of steam or air creating a hazard to workers while repairs or maintenance work is being done, the employees shall disconnect the lines or lock and tag the main valve closed or blank the line on all steam driven machinery, air driven machinery, pressurized lines or lines connected to such equipment if they would create a hazard to workers.
Utah Admin. Code R614-2-9