HSE : IQA : Excavation

www.safetygoodwe.com

The Safety Interview Question & Answer

Topic: Excavation

1. What is the excavation? And types of excavation? 
• Any man-made cavity, cut, trench, or depression on an earth surface formed by earth removal. 
• Types of Excavation:
• A. Manual Excavation: The excavation without using any powered equipment.
• B. Mechanical Excavation: The excavation work using any electrical or mechanical equipment. 
2. Explain about Excavation Notification? 
• Excavation notification is a document to notify concerned authorities, who have responsibility and jurisdiction for the safety and integrity of the aboveground and underground services existing at the proposed site of excavation.
• Excavation notification must be supported by a work permit.
• Excavation notification is valid for 90 days from the date of issue.
• Excavation notification is required for all excavations regardless of depth. 
3. Why is an excavation notification required for excavation? 
• Excavation notification gives detailed information about the underground facilities, and it is to be signed by all concerned KOC departments to confirm that the proposed excavation location has been identified and all safety measures have been taken for the existing underground facilities. 
4. What is EXCAVATION HAZARDS?
• Cave in or collapse of soil
• Risk due to the presence of underground installations, pipelines, and cables.
• Drowning due to water seepage into the trench.
• Soil vibration due to machinery/heavy vehicle operations in the vicinity.
• Lack of oxygen or asphyxiation, etc.
• Underground obstruction or damage to buried pipelines & services
• Accidental fall of personnel or equipment inside a trench
• Struck / hit by excavating machinery
• Dropped / falling objects
• Flammable & / or toxic gas release
• Exposed to airborne contaminants
• Fire & explosion
• Electrical shock due to contact with energized electrical/telecom cable.
• Possible presence of explosive devices 
• Damage to shallow underground services due to the weight of heavy equipment such as mechanical excavators.
• Encountering wet soil (mixed with water) or reaching the water table.
• Encountering contaminated soil 
5. Enlist precautions to be taken prior to and during excavation work? Or what are the safety precautions required for a safe excavation?
• No excavation work in the KOC area without clearance of Explosive Ordinance Disposal (EOD).
• No mechanical excavation closer than 5 meters to any hydrocarbon-carrying pipeline.
• No mechanical excavation closer than 3 meters to a non-hydrocarbon carrying pipeline, cables, and services.
• For any excavation deeper than 1 m, the ladder must be positioned projecting a minimum of 1 meter above the edge of the excavation.
• Ladders shall be provided every 7.5 meters (25 feet) of lateral travel in the trench.
• Ladders shall be securely supported at the bottom as well as at the top.
• Excavated material shall be placed 1 m from the edge of the excavation for depths up to 1.2 meters.
• (Accordingly, placement of excavated material shall be increased in proportion to the depth of excavation.)
• Heavy equipment and machinery shall be kept at least 3 meters away from the edge.
• Any walkway across the trench shall have a scaffold-type platform with handrails.
• All trenches shall have barriers (such as fixed guardrails) and reflective warning notices clearly displayed. Flashing lights are mandatory during poor visibility.
• The access to plant, equipment, and emergency services must not be obstructed by the trenches.
• No mechanical excavation is allowed inside the existing KOC facilities (Gathering Center, Booster Station, water injection and handling facilities, etc.).