Write a pre-task plan for excavation and trenching work

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# What are the soil classification categories? (cont.) ## What safety factors should be considered when bidding on a job? (cont.) ■Contact and notify the utility companies or owners involved to inform them of the proposed work within established or customary local response times. ■ Ask the utility companies or owners to establish the location of underground installations prior to the start of excavation work. If they cannot respond within 24 hours (unless the period required by state or local law is longer) or cannot establish the exact location of the utility installations, employers may proceed with caution, which includes using detection equipment or other acceptable means to locate utility installations. ■Determine the exact location of underground installations by safe and acceptable means when excavation operations approach the approximate location of the installations. - Ensure that while the excavation is open, underground installations are protected, supported or removed as necessary to safeguard workers. ## Protective Systems ## How can employers prevent cave-ins? OSHA generally requires that employers protect workers from cave-ins by: ■Sloping and benching the sides of the excavation; ■ Supporting the sides of the excavation; or ■Placing a shield between the side of the excavation and the work area. ## What types of protective systems can employers use to protect workers from cave-ins? In many cases the type of protective system needed is well known and simple to use. At other times employers will undertake the more complex process of designing a protective system. Designing a protective system requires consideration of many factors, including: soil classification, depth of cut, water content of soil, weather and climate, and other operations Trenching and Excavation Safety 5

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# Tennessee OSHA's Special Emphasis Program on Trenching & Excavation Because trenching and excavation collapse is deadly and often involves multiple victims, Tennessee OSHA has established a special emphasis program to focus attention and resources on these hazards. It is impossible to predict when an excavation or trench will collapse. The sudden collapse of the walls makes escape almost impossible. The only way to prevent collapse is to slope or shore the walls or install a trench shield and follow the TOSHA trenching and excavation standards contained in 29 CFR 1926 Subpart P. Under this special emphasis program, all TOSHA compliance and consultative services personnel will be on the lookout for trenching or excavation work sites. Personal observation, reports of imminent danger, fatality/catastrophe reports, safety and health agency referrals, employee complaints, and media reports are also used to locate trenching and excavation work. Each occurrence is handled with an appropriate intervention by TOSHA. ## Hazards on the Excavation Site Excavation workers are exposed to many hazards, but the chief hazard is cave-in. TOSHA requires that all employees exposed to potential cave-ins be protected by sloping or benching the sides of the excavation, shoring the sides of the excavation, or placing a shield between the sides and the work area. In addition to cave-in hazards, workers must also be protected from adjacent utility lines, exposure to vehicular traffic, falling loads, hazardous atmospheres, and fall hazards. Utility lines such as gas, electrical, sewer, and water must be located and supported prior to placing employees in an excavation. Employees working in, or near, roadways must wear high visibility vests. Workers are not to work beneath suspended loads, and walkways crossing excavations must be equipped with guardrails. Precautions, including atmospheric testing and emergency rescue procedures and equipment, must be taken when workers enter excavat…

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Trenching Safety Preventing Cave-ins Trenching work is risky; cave-ins occur suddenly and bring lasting, tragic consequences. Safety preplanning, oversight, and training are key to ensuring work is set up and performed safely in trenches. ## Protective Systems Protective systems prevent cave-ins and protect workers from falling materials. There are three types: ■ Sloping and benching removes soil to eliminate the chance of cave-ins (benching isn't an option for sand, gravel, and other Type C soils). a ■Shoring uses supports to brace the walls of trench (e.g., aluminum hydraulic supports). ■ Shielding protects workers inside of the shielded area (e.g., trench boxes). Protective systems are required for all trenches four feet or deeper; and for those less than four feet deep if a potential for cave-in exists. Systems for trenches over 20 feet deep must be designed by a registered professional engineer (or designed according to tables, charts, and other tabulated data approved by them). ## Competent Person A competent person is someone who: ■ Conducts daily safety inspections of excavation areas, including protective systems, to identify existing and potential hazards. ■ Has the knowledge and authority to take immediate corrective measures to eliminate hazards and conditions; and has the authority to remove workers promptly if hazardous conditions are found. ## Getting In and Out Safely Workers must be able to easily and safely enter and exit trenches four feet or deeper. A way in or out must be available every 25 feet. The most common method for access is a straight ladder or an extension ladder. If a ladder is used, it must extend at least three feet above the landing. Other means could be a stairway or ramp designed by a registered professional engineer. ## General Safety Tips ■Don't let workers enter or work inside an unprotected trench four feet or more in depth. ■Never work inside a trench if the spoils pile is less than two feet away from the e…

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# MIOSHA Fact Sheet # Trenching and Excavation Protective Systems MIOSHA Michigan Occupational Safety and Health Administration Cave-ins are perhaps the most feared trenching hazard. However, other potentially fatal hazards exist in trenching and excavation operations, including asphyxiation due to lack of oxygen, inhalation of toxic fumes, drowning, etc. Electrocution or explosions can occur when workers contact underground utilities. MIOSHA has investigated five fatal excavation accidents in the period of 2018 through 2022. MIOSHA requires that workers in trenches and excavations be protected, and that safety and health programs address the variety of hazards they face. Construction Standard Part 1, General Rules, Rule 114 requires an Accident Prevention Program at every construction work site. ## How to Avoid Hazards Pre-job planning is vital to accident-free trenching; safety cannot be improvised as work progresses. The following concerns must be addressed by a competent and/or qualified person: • Preplan: contact utilities (e.g., gas, electric) to locate underground lines, plan for traffic control when necessary, and determine proximity to structures that could affect choice of protective systems. • Evaluate soil conditions and select or construct appropriate protective systems in accordance with Construction Standard Part 9, Excavation, Trenching, and Shoring. Appropriate protective systems to prevent a cave-in may include trench boxes, shields, benching, and/or appropriate sloping of trench sides. • Test for low oxygen and hazardous gases and vapors, especially when gasoline engine equipment is running nearby, or the soil has been contaminated by leaking lines or storage tanks. Fossil fuel powered equipment produces carbon monoxide in exhaust and must not be used without adequate ventilation. • Provide appropriate respiratory protection when necessary. • Provide safe access into and out of the excavation. • Provide appropriate protections if wate…

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OSHA DEPARTMENT OF LABOR AND INDUSTRY # Fact sheet # Trenching and excavation safety From 2014 through 2019, four Minnesota workers died in a trench, excavation or ground collapse. Cave-ins pose the greatest risk and are much more likely than other excavation-related accidents to result in worker fatalities. Minnesota law requires employers to provide a workplace free of recognized hazards that may cause serious injury or death. This includes the trenching and excavation requirements of 29 CFR 1926.651 and 1926.652. An excavation is any man-made cut, cavity, trench or depression in an earth surface, formed by earth removal. A trench - or a trench excavation - is a narrow excavation (in relation to its length) made below the surface of the ground; in general, the depth is greater than the width, but the width of a trench (measured at the bottom) is not greater than 15 feet. ## Dangers of trenching and excavation In addition to cave-ins, other potential hazards include falls, falling loads, hazardous atmospheres and incidents involving mobile equipment. Two cubic yards of soil can weigh about 6,000 pounds or as much as a small car. An unprotected trench is an early grave. Do not enter an unprotected trench. ## Trench safety measures Trenches five feet deep or greater require a protective system unless the excavation is made entirely in stable rock. If the trench is fewer than five feet deep, a competent person may determine a protective system is not required. Trenches 20 feet deep or greater require that the protective system be designed by a registered professional engineer or be based on tabulated data prepared and/or approved by a registered professional engineer in accordance with 1926.652(b) and (c). ## Competent person OSHA standards require employers ensure trenches - before worker entry - are inspected by a competent person daily and as conditions change, to ensure elimination of excavation hazards. A competent person is an individual: who is capab…

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# Trenching and Excavation (cont.) ## What are the hazards associated with trenching and excavation? (cont.) - Contact with buried service lines such as electrical, natural gas, water, sewage, telecommunications, etc. - Contact with overhead electrical lines. - Slips, trips and falls as workers climb on and off equipment, or from inappropriate access and egress methods. - Being struck by moving machinery, or by falling or flying objects. - Hazards related to materials handling (e.g., lifting, struck by, crushed between, etc.). ## What is meant by soil types? Definitions of soil types vary by jurisdiction in Canada. In addition, some jurisdictions have not defined soil types, but do require preventative measures when an excavation reaches a certain depth or proportion. When a soil type is defined, the purpose is to try to identify or predict the potential for the soil to move and cause a collapse while the work is being done. Soil types typically use a scale of 1 to 4 where 1 is hard and dense to 4 which is loose, soft, wet or muddy soil, or a scale of A to C where A is hard and solid, and C is soft, sandy, filled or loose. The soil type is determined by the characteristics of the soil's consistency, ease of removal, appearance, ability to excavate with hand tools vs. machine, water seepage, whether the soil has been excavated before, etc. ## What should occur before beginning an excavation? The employer or supervisor is responsible for the work, and must take the necessary steps to identify all the hazards and risks before beginning any work. These steps include to: - Identify the soil type(s) related to the excavation or trench you are going to dig. Soil properties often vary widely within a single trench (e.g., the soil type changes from top to bottom and along the length of a trench). - Look for the legislative requirements that apply in your jurisdiction and the type of protective measures to be taken. - Locate all buried services. Contact t…

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# Competent Person Evaluation Excavation and Trenching (cont.) IV. Soils Classification Did the CP do the following: Yes No 1. A visual test? [ ] Yes [ ] No 2. A manual test [ ] Yes [ ] No a. If yes, which manual test(s) were performed?:<empty> b. Name of person who classified the soil if someone other than your designated CP?:<empty> What qualifies them to perform the soils classification?: <empty> <empty> <empty> <empty> 3. What types of soils were identified?:<empty> 4. Have the soil conditions changed since the classification was made? [ ] Yes [ ] No 5. Based on the soil classification, and the depth and the width of the excavation, has the proper cave-in protective system been selected? [ ] Yes [ ] No 6. Does the cave-in protection meet the criteria outlined in Part N, Chapter 296-155, WAC Rules by chapter [ ] Yes [ ] No What is the soils classification for this site?:<empty> <table><tr><th>V.</th><th>Access/Egress</th><th>Yes</th><th>No</th></tr><tr><td>1.</td><td>If ramps are involved, are they constructed according to Part N, Chapter 296-155, WAC Rules by chapter</td><td></td><td></td></tr><tr><td>2.</td><td>Is safe access/egress being provided into and out of the protective system?</td><td></td><td></td></tr><tr><td>3.</td><td>When using a ladder, does it remain within the protection of the system at all times?</td><td></td><td></td></tr></table> VII. Comments Do you consider the individual to be competent within the requirements of Part N, Chapter 296-155, WAC Rules by chapter: [ ] Yes [ ] No If Not, Why?:<empty> Employer Signature Date F417-104-000 Competent Person Evaluation - Excavating 11-14

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# EXCAVATIONS AND TRENCHES WAC [redacted identifier] defines an excavation as "Any person-made cut, cavity, trench, or depression in the earth's surface, formed by earth removal." A trench is "A narrow excavation in relation to its length made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench (measured at the bottom) is not greater than 15 feet. If forms or other structures are installed or constructed in an excavation so as to reduce the dimension measured from the forms or structure to the side of the excavation to 15 feet (4.6 m) or less (measured at the bottom of the excavation), the excavation is also considered to be a trench." One cubic yard of soil can weigh up to 3000 pounds - approximately the weight of a small car. The fatality rate for excavation work is 112% higher than the rate for general construction, according to data from the Occupational Safety and Health Administration (OSHA). The agency lists "employee injury from collapse" as the primary hazard of excavation work and includes "no protective system" among the leading causes of worker injuries. ## EXCAVATION AND TRENCHING HAZARDS Trenching and excavation work presents serious hazards to all workers involved. Cave-ins pose the most significant risk and are more likely than other excavation- related incidents to result in worker fatalities. One cubic yard of soil can weigh as much as a car. • Collapse of soils and materials (cave-in) due to lack of, inadequate, or weak protective systems • The striking or damaging of underground utility services • Persons falling into excavations due to a lack of barriers or inadequate fencing • Asphyxiation from toxic gases which have collected in the excavation/trench • Spoil (soil from excavation/trench) or materials/equipment being placed too close to the sides of the excavation/trench, which then become overloaded and collapse • Failure to check and maintain shoring, particularly after incle…

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# Trenching and Excavation (cont.) ## Housekeeping (cont.) - Excavated material, pipes etc. are placed 1 metre away from the edge of the excavation or trench wall? - Are pumps available to remove water? - Is the base and foot of the ladder secure, and free of garbage or water? - Are materials placed on the site obstructing the worker's or vehicle's ability to move freely? - Are established traffic controls used, where required, including adequate signage, personnel, and lighting? - Has the excavation been marked to make the workers and others aware of the excavation (e.g., fence, flags, or other safeguards)? - Are sanitary facilities available at the site, as appropriate? ## General - Are proper barriers or guardrails in place to protect anyone or equipment falling into the excavation or trench? - Has the air in the excavation been tested for low oxygen, and hazardous gasses and vapours? - Is a safe means of entry and exit provided such as a sufficiently long and secured ladder placed at appropriate distances (within 25 feet of all workers)? - Are cracks visible in the ground around the trench or excavation that may indicate soil movement? - Are there any signs of water seeping into the trench or excavation? - Are workers wearing appropriate PPE (e.g., hard hats, respirators, , safety boots, hearing protection)? - Are high visibility vests or clothing provided and worn by all exposed to vehicular traffic? - Is first aid equipment available at the site? - Are operators qualified to operate the heavy machinery or equipment? - Does a competent person regularly inspect the excavation (at the start of each shift before work begins or after any event likely to have affected the strength or stability of the excavation)? - Is there a competent person stationed at the surface of the trench to warn workers in the trench of danger and to provide emergency help? - Is the trench a confined space, and are the requirements of the confined space program met?…

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TENSIN MASSACHUSETTS DEPARTMENT OF LABOR STANDARDS # Trench Hazard Alert MASSsafety Works! Workplace Safety is No Accident Every year, workers are killed or seriously injured conducting work in trenches, including utility repair, utility inspections, and construction. Trenches are recognized by OSHA as one of the most hazardous construction work conditions, with a fatality rate more than double that for construction work overall. ## Requirements for Trench Work • Protect workers from soil cave-ins in all trenches 5' or deeper, and in shallower trenches where a cave-in hazard exists. Do this by supporting the walls with shoring, shielding workers with trench boxes, or sloping the walls back wide enough, in accordance with the OSHA Excavation Standard. • Provide ladders to workers in trenches 4' or deeper. • Underground utilities must be identified and supported. Call Dig Safe at 1-(888) 344-7233. • Ensure that workers wear high visibility clothing when exposed to vehicle traffic, and use appropriate work zone signage and traffic channeling set-ups. . Spoils must be kept back a minimum of 2' from the trench edge. Keep equipment and heavy material as far back from the trench edge as possible. • Stabilize undermined adjacent structures. • Protect employees from water accumulation by pumping out ground or utility water, and preventing drainage or other water from entering the trench. • Do not allow employees to work under suspended or raised loads or materials. • Conduct pre-job planning and inspections of trench worksites. A competent person must inspect each trench worksite, including the soil protective system, prior to the start of work, and again if there is a hazard-increasing change in conditions such as a rainstorm. Unsafe trenches are dangerous! Trenches more than 20 feet in depth must be designed by a registered professional engineer. ## Workers in trenches face other significant hazards in addition to cave-in of the soil walls, including: . …

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# Trenching and excavation safety (cont.) ## General trenching and excavation rules (cont.) • Test for atmospheric hazards, such as low oxygen, hazardous fumes and toxic gases when greater than four feet deep. • Inspect trenches at the start of each shift and following a rainstorm or other water intrusion. • Do not work underneath suspended or raised loads and materials. • Inspect trenches after any occurrence that could have changed conditions in the trench. • Ensure personnel wear high-visibility or other suitable clothing when exposed to vehicular traffic or mobile earth-moving equipment. ## Protective systems There are different types of protective systems – sloping, shoring and shielding. <table><tr><th>Type of protective system</th><th></th><th>Illustration of system</th></tr><tr><td>Sloping involves cutting back the trench wall at an angle inclined away from the excavation.</td><td>20 MAX</td><td></td></tr><tr><td>Shoring requires installing aluminum hydraulic or other types of supports to prevent soil movement and cave-ins.</td><td></td><td></td></tr><tr><td>Shielding protects workers by using trench boxes or other types of supports to prevent soil cave-ins. Designing a protective system can be complex because many factors must be considered: soil classification; depth of cut; water content of soil; changes caused by weather or climate; surcharge loads (spoil, other materials to be used in the trench); and other operations in the vicinity.</td><td></td><td></td></tr></table> ## More information To learn more about excavation safety, view the standards at osha.gov. Revised March 2025

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# What are the soil classification categories? (cont.) ## Why is preplanning important to excavation work? (cont.) work starts to correct mistakes in shoring or sloping slows down the operation, adds to the cost of the project, and makes a cave-in or other excavation failure more likely. ## What safety factors should be considered when bidding on a job? Before preparing a bid, employers should know as much as possible about the jobsite and the materials they will need to have on hand to perform the work safely and in compliance with OSHA standards. A safety checklist may prove helpful when employers are considering new projects. Factors to consider may include: ■Traffic ■ Proximity and physical condition of nearby structures ■Soil classification ■Surface and ground water ■Location of the water table ■ Overhead and underground utilities ■Weather ■Quantity of shoring or protective systems that may be required ■Fall protection needs ■Number of ladders that may be needed ■ Other equipment needs. Employers can gather the information they need through jobsite studies, observations, test borings for soil type or conditions, and consultations with local officials and utility companies. This information will help employers determine the amount, kind, and cost of safety equipment they will need to perform the work safely. How can employers avoid hitting underground utility lines and pipes during excavation work? Before starting work, the Excavation standards require employers to do the following: ■Determine the approximate location(s) of utility installations— including sewer, telephone, fuel, electric, and water lines. One common industry practice is to call 811, the "Call Before You Dig" number, to establish the location of any underground utility installations in the work area. Occupational Safety and Health Administration 4

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# Trenching and Excavation (cont.) ## What should occur before beginning an excavation? (cont.) - Check areas near the site for potential hazards and sources that can impact the stability of the soil. Be aware that nearby vehicles and equipment can cause the soil to vibrate and then collapse. - Determine if nearby buildings or structures and their foundations may put pressure on the soil and affect the walls of the trench. - Test for hazardous gas, vapours, and dust before entering. Test for oxygen levels in the space before entering, and during the work as required. - Plan appropriate organization of the work site, and good housekeeping practices including moving debris and excavated soil far enough away from the excavation site. - Remove water from the excavation. - Protect workers from falling into the excavation. - Identify appropriate personal protective equipment including high visibility apparel for vehicular traffic and make sure every worker wears them as required. - Have a worker above ground when a worker is working in the trench to warn those in the trench of danger and to provide emergency help. - Determine if the trench is considered a confined space If so, do not allow workers to enter the trench until the requirements of the organization's confined space program are met, including entry permits and training. - Prepare work permits for work in confined spaces, as appropriate. - Have a means of exit provided from the inside of the trench, usually no more than 8m (25 ft) away from any worker in the trench. - Plan for adverse weather conditions (e.g. hot or cold environments, storms, etc.). - Prepare an emergency plan and rescue procedures. - Keep first aid equipment at the site. - Educate and train workers about all existing and potential hazards and risks and appropriate safety measures. ## What factors determine what is the appropriate protective system to use? In general, trenches that are 1.2 metres (4 feet) deep or great…

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# Trench and Excavation Safety Trench collapses, or cave-ins, are the leading hazard in excavation work. Safe trenching helps prevent falls, falling loads, hazardous atmospheres, and incidents involving mobile equipment. ## Trench Safety Measures Trenches 5 feet or deeper require a protective system unless dug in stable rock. For trenches less than 5 feet, a competent person must decide if protection is needed. Trenches 20 feet or deeper must have a protective system designed or approved by a registered professional engineer, as required by OSHA 1926.652(b) and (c). ## Competent Person Before workers enter a trench, a competent person must inspect it daily and after any condition changes to ensure safety. This person is trained to identify hazards, determine soil types, select protective systems, and has the authority to correct issues immediately. ## Access and Egress • Keep heavy equipment and spoils at least 2 feet from trench edges - Locate underground utilities before digging • Test for atmospheric hazards in trenches over 4 feet deep • Inspect trenches daily, at the start of each shift, after storms, and after conditions change • Never work under suspended loads - Wear high visibility clothing when near traffic # Protective Systems • Benching: a method of protecting workers from cave-ins by cutting the sides of an excavation into horizontal steps. Benching is not allowed in Type C soil. • Sloping: involves cutting back the trench wall at an angle inclined away from 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 supports to prevent cave-ins. Designing these systems can be complex, as factors like soil type, trench depth, moisture, weather, nearby loads, and site activity must all be considered. OSHA standards require that employers provide workplaces free of recognized hazards. The employer must compl…

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# Trenching and Excavation (cont.) ## Temporary protective structure (cont.) - Trench Boxes are commonly used in open areas that are away from utilities, roadways, and foundations. Trench boxes can be used to protect workers in cases of cave-ins, but not to shore up or support trench walls. They can support trench walls if the space between the box and the trench wall is backfilled with soil and compacted properly. Otherwise, a cave-in or collapse may cause the trench box to tilt or turn over. Workers should not be present in the box when it has to be moved. - Other: In some cases, the trench or excavation walls are made of rock but are not entirely stable. Support the walls by using rock bolts, wire mesh, or a method that provides equivalent support. ## What should NOT be done during an excavation? - Do not enter an unprotected trench deeper than 1.2 metres (4 feet), or as specified in the legislation. - Do not start digging before locating and de-energizing the buried services. - Do not enter a trench before testing the air for hazardous gasses and vapours, or the lack of oxygen. - Do not place the sections of pipes, piles of spoil, unused tools, and timber, and other materials within 1 metre from the trench's edge. - Do not rely on natural freezing to act as a method of soil stabilization. - Do not work under suspended or raised loads and materials. - Do not stand behind a backing vehicle. ## What can be included in a trenching and excavation inspection checklist? The following are some points to consider. Each circumstance will be different, so be sure to adapt the questions to suit your situation. ## Underground or Utility Services - Know the contact numbers? - Located, identified and informed respective parties? - Grounded, isolated, de-energized, or protected from unplanned release? ## Housekeeping Trenching and Excavation CCOHS

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# What do employers need to do to maintain materials and equipment used for protective systems? (cont.) ## What other excavation hazards do employers need to address? (cont.) support or shield systems to prevent cave-ins, water removal to control the water level, or the use of a safety harness and lifeline. If an employer uses water removal equipment to control or prevent water accumulation, the equipment and operations must be monitored by a competent person to ensure proper use. If excavation work interrupts the natural drainage of surface water, the OSHA standards also require the use of diversion ditches, dikes, or other suitable means to prevent surface water from entering the excavation and to provide adequate drainage of the adjacent area. In addition, a competent person must inspect excavations subject to runoffs from heavy rains, and excavations subject to such runoffs are subject to the requirements described previously in this paragraph. ## How can employers protect workers from hazardous atmospheres inside excavations? Atmospheric testing is required before workers enter an excavation greater than 4 feet (1.22 meters) in depth where an oxygen deficiency or a hazardous atmosphere is present or could reasonably be expected, such as in excavations in landfill areas or excavations in areas where hazardous substances are stored nearby. If there are any hazardous conditions present, the employer must ensure that adequate precautions are taken to prevent employee exposure to those conditions. Such precautions include providing workers with proper respiratory protection or ventilation. In addition, when controls are used to reduce the level of atmospheric contaminants to acceptable levels, testing must be conducted as often as necessary to ensure that the atmosphere remains safe. If hazardous atmospheric conditions exist or may reasonably be expected to develop in an excavation, the employer must ensure the ready availability of emergency rescue equipment, …

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WASHINGTON State FACE Program Fatality Assessment & Control Evaluation # CONSTRUCTION FATALITY NARRATIVE FACE INCIDENT FACTS ## Contractor and Laborer Buried in Trench Collapse REPORT #: 71-240-2023 ## SUMMARY A 66-year-old contractor and a 32-year-old laborer died when the trench they were working in collapsed, burying them. The contractor and three employees had been working at a residence for a week to replace a sewer line. The contractor was the competent person on the site. To replace the sewer line they used an excavator to dig a trench that was 26-feet long and 24-feet deep. It was 24-feet wide at the top and 8-feet wide at the bottom. The sides of the trench were steep and nearly vertical. They dug the trench in unstable Type C soil and did not use protective systems such as shoring, shields, trench boxes or sloping and benching of the sides. The day before the incident, the trench collapsed after a rainstorm. REPORT DATE: May 29, 2023 INCIDENT DATE: July 4, 2022 WORKERS: 66 and 32 years old ## INDUSTRY: New Single-Family Housing Construction ## OCCUPATIONS: Contractor and laborer This narrative was developed to alert employers and workers of a tragic incident and is based on preliminary data ONLY and does not represent final determinations regarding the nature of the incident or the cause of the injury. Developed by WA State Fatality Assessment and Control Evaluation (WA FACE) Program and the Division of Occupational Safety and Health (DOSH), WA State Dept. of Labor & Industries. The WA FACE Program is supported in part by a grant from the National Institute for Occupational Safety and Health (NIOSH grant# 5U600H008487). For more information visit www.lni.wa.gov/safety-health/safety-research/ongoing-projects/work-related-fatalities-face. SCENE: Residence ## EVENT TYPE: Following the incident, investigators found: Trench collapse • Trench protection (shoring, shielding, benching, and sloping) was not used. • There was some shoring equi…

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# Table of Contents Introduction ... 1 What is the difference between an excavation and a trench? ... 1 What are the dangers of trenching and excavation operations?..... 1 What do the OSHA Excavation standards cover, and how do they protect workers? 1 - What are the soil classification categories?. 2 What is a competent person? .3 Preplanning.... .3 - Why is preplanning important to excavation work?..... What safety factors should be considered when bidding on a job?..... - 4 How can employers avoid hitting underground utility lines and pipes during excavation work? 4 Protective Systems... .5 How can employers prevent cave-ins?. .5 - What types of protective systems can employers use to protect workers from cave-ins?.. .5 What other precautions do employers need to take to protect workers from cave-ins? - 7 What are the requirements for safely installing and removing protective systems?.. .8 What do employers need to do to maintain materials and equipment used for protective systems? .9 ## Additional Hazards and Protections ... 9 What other excavation hazards do employers need to address? .... .9 What is the effect of water accumulation on excavation safety and what do employers need to do to protect workers from water-related excavation hazards? ... 10 How can employers protect workers from hazardous atmospheres inside excavations?.. 11