When working in underground construction, contractors are faced with manydifferent hazardous situations, from laying pipe in a trench to entering aconfined space, but most of these hazardous conditions can be avoided ifcontractors follow the proper safety procedures.
In 2004, theOccupational Safety and Health Administration (OSHA) formed an industry workgroup to find ways to reduce the number of trench and excavation fatalities.According to OSHA, 75 percent (36 of 53) of construction workers who were killedin trench-related accidents died in trenches that were not equipped withprotective systems. That means all these deaths werepreventable.
Confined space entry also poses major health risks. Althoughconstruction workers have been using the Permit Required Confined Space EntryStandard for the General Industry (1910.146), as well as state regulations toguide them during a confined space entry, OSHA presented a draft of aconstruction industry confined space entry standard to the Advisory Committeefor Construction Safety and Health (ACCSH) in October 2004. When the finalstandard is complete in about two years, it will be similar to the generalindustry standard with only a few minor changes.
“Safety is everyone’sresponsibility,” said George Kennedy, vice president of safety at the NationalUtility Contractors Association (NUCA). “However, at the construction jobsite,the front line manager is responsible for ensuring that the company’s safetyprogram is implemented. Unless jobsite managers take an active interest insafety, the possibility of workers being injured or killed on the jobsite risesdramatically.”
Job-related injuries andfatalities occur every day in the workplace, often because employees are nottrained in proper job procedures. The first step in establishing safer and moreefficient work methods is to conduct a Job Hazard Analysis (JHA) — a techniquethat focuses on the relationship between the worker, the task, the tools and thework environment in order to identify hazardous actions/conditions before anaccident occurs.
In brief, the JHA involves: 1) selecting jobs foranalysis; 2) breaking a job down into individual steps or operations; 3)identifying existing or potential hazards, unsafe conditions and unsafe workpractices associated with each step/operation; and 4) identifying the correctand safe way to perform each step/operation. Ideally, after the hazards havebeen identified, steps will be taken to implement the recommendedprocedures.
Because workers perform many different jobs as part of theirjob classifications, it is important to analyze each different job or task, suchas assembling a trench shield, installing shoring, entering a confined space,handling pipe or changing a directional drill rod. Each of these jobs presentsdifferent hazards that should be evaluated. By creating a step-by-step jobprocedure for each task, managers can significantly improve safety on thejobsite, as well as provide consistent and effective job training to employees.And, should an accident occur, a completed JHA could serve as a benchmark forthe accident investigation.
As noted above, JHA involves listing jobsteps, identifying the hazards associated with each step and developingsolutions for controlling each hazard. A JHA form, like the one shown in thediagram, can be used to record this information.
Phase 1: List the job steps
Every jobmust be broken down into distinct steps in the order of occurrence. Recordenough information to describe each job action, but do not make the breakdowntoo detailed. Review the steps with the workers to ensure they are complete anddescriptive.
Phase 2: Identify thehazards
Your goal is to discover the following:
• What can gowrong?
• What are the consequences?
• How could it arise?
• What areother contributing factors?
• How likely is it that the hazards willoccur?
Each step should be examined to discover any existing or potentialhazards. Each step will have a list of hazards. Questions similar to the oneslisted below should be asked to determine the potential hazards.
• Is theworker using the appropriate personal protective equipment (PPE)?
• Are workpositions, machinery, pits or holes and hazardous operations properlyguarded?
• Is the worker wearing loose clothing or jewelry that could getcaught in machinery?
• Are lockout procedures in place to ensure that theequipment or power source has been deactivated?
• Are materials properlystored?
• Can the worker be caught in, under, or between machine parts,moving equipment, or moving or suspended loads?
• Is the ventilationadequate?
• Is the worker in an off-balance position at any time?
• Canthe worker fall from one level to another?
• Can the worker be injured fromlifting or pulling objects or carrying heavy objects?
• Does the workerrequire assistance with the task?
• Is the worker exposed to dust, chemicals,welding rays, heat or excessive noise?
When the hazards have been identified, they should be reviewed withemployees. This is a good time to enlist the workers’ help in determining if andhow the hazards could be controlled or eliminated.
Phase 3: Determine theprecautions
Hazards must be reviewed and recommendations should bemade to eliminate or control them. Hazards can be minimized by changing thesequence of steps; modifying or changing the tools, machines, equipment, ormaterials; implementing engineering controls; installing guards; changingmethods; providing personal protective equipment; etc. Upon completion, reviewthe JHA document with the workers that perform the job. Remember that changesfrom past procedures will require employee training.
“The most underratedsecret to a safe workplace is good housekeeping,” said NUCA Safety Committeechairman L.D. Alexander, of RMCI Inc. in Albuquerque, N.M.
Excavation and Trenches
Trench-relatedaccidents and fatalities are industry-wide problems that are everyone’sresponsibility — from OSHA down to the individual contractors. So what is beingdone?
Informed underground utility contractors know that the way toprevent fatalities in trenches and excavations is to use protective systems —sloping, shoring or shields. They also know that no one system can provideprotection for workers in all situations, so it is important to choose themethod that best suits the job.
While sloping and benching the sidewallsof a trench is an easy solution to the problem, it is not always the mostpractical because of limited right-of-way and the amount of soil that must beremoved to create a 1:1 (Type B soil, i.e. angular gravel, silt, silt loam, dryunstable rock) or 1½:1 slope (Type C soil, i.e. granular soils, sand, loamysand, submerged).
Aluminum hydraulic shoring is easy to use andrelatively inexpensive to purchase or rent, but some contractors have not eventried to use it because they are uninformed about the availability of it and theuses for it. Shoring is also flexible in that it can be used in different soilconditions and around underground utilities to protect areas that wouldotherwise be exposed when shields are used. Like timber shoring, it alsosupports the trench walls and prevents damage to parallel utilities bypreventing cave-ins that could tear utilities out of trench walls.
Trenchshields are the most commonly used form of a protective system because they canbe purchased or rented in a wide range of sizes. There are other types ofprotective systems available that are a bit more costly and often require aprofessional engineer to design and lay out. For example, soldier beams,lagging, steel sheeting and slide rail systems are available and used regularlyto shore large excavations, underground tank work and other complex jobs.
“Always, always use the proper type of trench shoring,” Alexandersaid.
In short, there is always a job-appropriate method of protectingworkers from excavation or trench cave-ins. Every trench fatality is preventableif excavators follow the OSHA and state regulations and ensure that every trenchor excavation is equipped with a protective system.
“As responsibleunderground contractors we need to do our part to eliminate the needless deathsand serious injuries that plague our industry,” said Kennedy. “So, please helpNUCA spread the word to dig safely.”
Confined Space Entry
The first thing todo on a jobsite is to determine if confined spaces are present in the workplace.Because every confined space is unique, each must be carefully evaluated andhazards must be eliminated or controlled before workers enter the space. Allconfined spaces must be tested with an appropriate, properly calibratedair-monitoring device as part of the evaluation. Some physical hazards will haveto be locked/tagged out to control potential worker exposure.
Uponcompleting the evaluation, the confined space must be classified and thecontractor must meet the requirements applicable to that classification. Theconfined space will have to be reassessed if the conditions within the spacechange. All Permit-Required Confined Spaces (PRCS) will have to be posted withdanger signs that require a permit to enter and prohibit unauthorizedentrants.
Employers need to provide training for entry supervisors,attendants, entrants, and the employer must ensure that the employees candemonstrate proficiency in the duties required by the standard. All trainingwill be completed before entry into the confined space is permitted. Employersmust keep training records for each employee.
Contractors must alsoestablish a rescue plan. Workers expected to be assigned rescue duties will alsohave to be trained to perform the rescue and practice rescue in spaces similarto those they might encounter during a rescue operation.
Employers mustalso instruct workers who are not trained that they are not to enter intoconfined spaces, and train employees about the dangers of attempting suchrescues.
Employers that expect workers to enter into confined spaces willbe required to maintain a copy of the standard at the worksite or a writtenconfined space entry program that incorporates the requirements of the standard.For work areas where workers will enter into PRCS, the entry supervisor will berequired to evaluate the space, establish the necessary precautions to eliminateor control hazards that are identified and complete and sign the entrypermit.
The confined space entry permit is similar to permits used by thegeneral industry. The purpose of the permit is to assure that the space isevaluated by the supervisor and to assure safe entry into the space.
If OSHA visits a jobsite,it will ask the pertinent questions about soil type, hazards, etc., so fieldsupervisors who are expected to oversee specialized operations that involve anexcavation, trench or confined space must have training that is specific to thattype of work.
Construction owners and managers, including foremen andsupervisors, have a duty and obligation to prevent accidents and provide workerswith a safe and healthy place to work. Safety rules are not enough, because theytend to address only the obvious hazards. Many hazards are hidden and notobvious; therefore if managers and employees are trained to identify what causeshazards, they will have the knowledge they need to avoid hazardous situations.
“Contrary to what some people believe, safety, production and qualityall depend on each other,” Kennedy said. “Efficient production and qualityworkmanship depend on safety because if an accident occurs, injuries and deathscan happen, production is halted and equipment can be destroyed or damaged. Infact, studies have demonstrated that companies that operate safely are moreefficient and more profitable than companies with lackadaisical safetyprograms.”