Employee Safety Series

Excavating is recognized as one of the most hazardous construction operations.

Source: OSHA revised Subpart P, Excavations, of 29 CFR 1926.650, 29 CFR 1926.651, and 29 CFR 1926.652

An excavation is…any man-made cut, cavity, trench, or depression in an earth surface formed by earth removal.

Cave-ins… pose the greatest risk and are much more likely than other excavation-related accidents to result in

worker fatalities.

• Two workers are killed every month. • U.S. Bureau of Labor Statistics (BLS) data show that 271

workers died in trenching or excavation cave-ins from 2000 through 2006.

• Per NIOSH-488 deaths, 1992 and 2000. Averaging 54 fatalities each year.

• More than half of those killed are coworkers, fire dept. personnel & bystanders attempting to rescue.

[29 CFR 1926.32(f)]

OSHA Trenching and Excavation 29 CFR 1926.651

• Trenches 5 feet (1.5 meters) deep or greater require a protective system.

• Exception is solid, stable rock. • Less than 5 feet deep, a “competent person”

will decide if a protective system is needed. • Who is a “Competent Person” ?

Per OSHA, a "competent person" is defined as "one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them”.

The standard does not specify particular training requirements for the competent person. It is a critical roll, because they evaluate & determine the safety of the excavation or trench others will enter.

Excavation Safety ChecklistContractor________________ Competent Person_________________ Dimensions____________Rescue Equipment__________ Date______________ Location____________ Intersecting__________ Miss Utility__________ COMPETENT PERSON CHECKLIST •This inspection: Start of day____________, During shift_________________ Hazard increasing occurrence________________________

•Inspection: Excavation: _____________________, Adjacent Area____________ Protective systems________________, Surface Encumbrances____________ Underground Utilities______________, Spoil Pile________________ Equipment_______________________, Other___________________ Access & Egress__________________, Vibrations________________

•Vehicular Traffic: Vest_______________, Warning Lights___________________ Mobile Warning Equipment___________________________ •Hazardous Atmospheres: Explosive_____, Flammable_____, Corrosive_____, Oxygen Deficient_____, Poisonous_____, Toxic_____, Irritating_____, Oxidizing_____, Other_____

•Water Accumulation: Removal__________, Prevent surface run off__________, Method__________, Forecast__________ •Soil Classification: Soil classification used____________, Soil type__________, Visual test__________, Manual test____________ Tabulated data on site______________, Copy of standard_________

•Protective Systems: Sloping__________, Benching__________, Shoring__________, Trench Box__________, Aluminum Hydraulic__________, Other_______________, Manufacturers Data _____________ Timber______________

Maryland Fire and Rescue Institute Susan Harwood Grant SH-16582-07

Source: https://www.osha.gov/dte/grant_materials/fy07/sh-16582-07/competent_person_checklist2.pdf

Employee Safety Series

Ingress and Egress• In trenching and excavation operations, ingress and

egress means a way for employees to enter or exit an excavation or trench, such as a ladder or ramp.

• Trenches deeper than 4 feet MUST be provided with a fixed means of egress, such as secured ladder.

• Spacing between ladders must be 25 feet or less to the nearest means of egress.

• Ladders must be secured and extend a minimum of… 3 feet above the landing.

Secure ladders to prevent displacement. At the top, nail the ladder or lash it with wire or rope to a secure object. At the bottom, secure it against movement by blocking, tying or another

suitable method. (National Safety Council Data Sheet I-568 Rev. June 2006”)

Protective Systems-3 Types• Sloping (or benching) involves cutting back the

trench wall at an angle inclined away from the excavation.

• Shoring requires installing aluminum hydraulic or other types of supports to prevent soil movement and cave-ins.

• Shielding protects workers by using trench boxes or other types of supports to prevent soil cave-ins.

The protective system type shall be determined by a “Competent Person” who will test the soil both

manually and visually.

Sloping & Benching

Sloping inclines away from the excavation.

Benching is dug in stair like levels.

Shoring

Install aluminum, hydraulic supports…

…or other types of supports such as timber.

Shielding

Protects workers by using trench boxes.

Photo: Courtesy of Virginia Department of Labor & Industry-2011 Trenching and Excavation - PSAhttp://www.doli.virginia.gov/agency/youtube_psa_gallery.html

The Dirty Facts• OSHA Classifies Soil Types as A, B, C…or solid rock. • 1 cubic foot of soil can weigh from 100-125 lb.• The weight of 1 cubic yard of soil can weigh 2700-

3000lbs. Water adds weight. • A typical trench collapse involves three to five cubic

yards of soil, or about 6,000 to 20,000 pounds! • An excavation wall shearing off, can happen as fast as

45 mph.

Would you risk being hit by a car going 45mph? A cubic yard of soil shearing off onto a worker,

has the same impact.

• You play a critical role in keeping the jobsite safe. • Each excavation is different and can change at any

moment causing cave ins to happen without warning.

• All related injuries and fatalities can be prevented. • Most cave ins were a result of poor or no pre-

planning.• Too many are caused by not strictly adhering to the

OSHA standard, job site safety rules and company procedures. One cave in is too many.

EQUIPMENT

LADDER

STONE

WATER

BULGING

SPOIL

?

Basic Excavation Rules

• Know where underground utilities are located before digging.

• Keep excavated soil (spoil) and other materials at least 2 feet from trench edges. • Test for atmospheric hazards such as low

oxygen, hazardous fumes & toxic gases > 4’ • Remove or minimize all surface obstacles at the worksite that may create a hazard• Identify other sources that might affect an excavations stability.Traffic Vibration… Disturbed soil… Multiple contractors

• Inspect excavations before you start each day/shift.• Inspect again after rain or any occurrence that could

have changed conditions & excavation integrity.• Never work under suspended or raised loads. • Wear high visibility/reflective clothing when exposed to traffic. • Install proper warning signs & barricades. • Keep heavy equipment away from trench edges.

More Basic Excavation Rules

Gas Related Hazards

• Accidental PE line punctures or ruptures• Leaking Gas• Confined Space• Asphyxiation• Pigging or purging hazards• Static Electricity• Fire/Explosion

Excavation Emergencies• Hazardous effects include compression and

asphyxiation. (Crushing effects=organ failure)

• Typical extrication can take one to seven hours.

• 60% of fatalities are would-be rescuer as well as the person originally in danger.

Source: Virginia Tech-http://www.ehss.vt.edu/programs/EXC_emergencies.php

Rescue Workers Training

• Excavation and Trenching Safety• Natural Gas Awareness• Gas Fire Fighting Techniques• Joint Emergency Action Plans• Contractor Town Hall Meetings• General Public Services Messages

Pre-planning Saves Lives !

The Investigation

OSHA, District Attorney, Company Rep & Media

Without Warning

2015-Too Late for Two

Preparation saves lives: 12 critical questions

• 1. Have all underground utilities and their estimated locations been accounted for (sewer, telephone, fuel, electric, water lines)? [29 CFR 1926.651(b)]

• 2. Is there proper access and egress? [29 CFR 1926.651(c)]• 3. Will there be vehicular traffic exposure near the excavation? [29 CFR 1926.651(d)]• 4. Is there proper protection from exposure to falling loads? [29 CFR 1926.651(e)]• 5. Is there a warning system for mobile equipment? [29 CFR 1926.651(f)]• 6. Is there a potential for exposure to hazardous atmospheres?[29 CFR 1926.651(g)]• 8. Will the excavation be near existing structures? If so, what is the stability of the

adjacent structures? [29 CFR 1926.651(i)]• 9. What types of soil will be found? • 10. Is there adequate protection from loose rock or soil? [29 CFR 1926.651(j)]• 11. If a protective system is needed, what type of system is adequate? [29 CFR

1926.652(a)]• 12. If employee exposure to any hazard is anticipated, is there a plan in place to

perform daily inspections of excavations, adjacent areas and protective systems?[29 CFR 1926.651(k)]

Safety BeginsWith YOU !

We Need You

And So Do They

Employee Safety Series