Emergency Plan - Grand Strand Water and Sewer Authority

EVENT SPECIFIC GUIDELINES 16(ESG-16)
TRENCH / EXCAVATION COLLAPSE
3.4. Trench / Excavation Collapse
3.4.1. SITUATION
GSWSA employees routinely need to enter and work in trenches and excavations in
order to maintain the water lines, wastewater lines, valves, fire hydrants, water
meters, etc., throughout the water and wastewater systems.
Trenches and excavations present certain inherent hazards, and the potential exists
for various emergencies to occur while employees are in them, up to and including
cave-in, or collapse, of the excavation walls.
3.4.2. THREAT or HAZARD INFORMATION
Trenching and excavation work sites can present numerous hazards. These may
include, but are not limited to:
• collapse or cave-in
• toxic gases
• flammable gases
• low oxygen content
• contact with electrical utilities or wiring
• flooding / drowning / engulfment
• passing traffic
• vehicles / equipment / heavy loads falling in
3.4.3. CONCEPT of OPERATIONS
Refer to the GSWSA Safety Manual for detailed procedures and requirements for
trenching and excavation in accordance with OSHA 29 CFR 1926.650, 651 and
652.
Excavations four (4) feet or deeper require a ladder or some other means for
employees to enter and exit the hole.
Excavations five (5) feet or deeper require either sloping the walls to a safe angle,
or, installing shoring or shielding to prevent wall collapse.
Spoil piles, and all other heavy loads, must be kept at least two (2) feet away from
the edge of the hole.
Excavations in locations subject to atmospheric hazards, such as near underground
fuel storage tanks, in marshy / swampy areas, etc., require testing of the air in the
hole before employees enter to work.
A “Competent Person” (trained and qualified employee) must evaluate the
excavation and determine it is safe before anyone enters, and as needed during the
work.
Grand Strand Water & Sewer Authority 135 CONFIDENTIAL MATERIALS
Emergency Management Plan
SECURITY SENSITIVE
June 7, 2013
NOT FOR PUBLIC
DISCLOSURE