When thinking of weather-related hazards, we tend to focus on tornadoes, hurricanes, or lightning strikes. But most people don’t realize that flooding kills more people in the U.S. in an average year than any of those three — nearly twice as many deaths as each of the others.
When a worksite becomes flooded, supervisors will stop work. It’s nearly impossible — and definitely unsafe — to work on a site covered with a large volume of water and mud. A comprehensive safety plan will spell out evacuation plans and guidelines for determining when it’s safe to return.
If workers return before flooding ends, they should stay out of floodwaters. Besides the danger of drowning, floodwaters may hide debris and other hazards and contain dangerous levels of bacteria. However, those dangers don’t end when the water starts to recede. A worksite that has suffered a flood poses a wide variety of hazards. We’ll examine the most common hazards, along with precautions that can be taken.
Erosion and stability
As floodwaters scour a construction site, they can dig channels that create trip hazards, and can undermine structures. Ground that appears to be solid could be anything but. Before workers (and heavy equipment) return to the site, it should be inspected to ensure the ground is strong and stable. Driveways or other areas that have been damaged should be repaired before work resumes.
Floodwaters pick up (and create) debris, so it’s possible that the receding waters will leave a mess on your worksite. Some debris could be sharp or otherwise dangerous, and much of it will pose a trip hazard.
Be especially careful around debris that has collected around power poles, transformers, and other high-voltage electric equipment. A utility worker or an electrician should inspect and test electrical equipment to ensure that it hasn’t been damaged.
Debris presents additional hazards for workers who have to move it. Lifting heavy objects creates a risk of injuries to the back, knees, and shoulders, especially because items may be odd-shaped, with unusual centers of gravity. Remind workers of the benefits of working in teams and using correct techniques for lifting.
Exposed electrical equipment
Electrical boxes, panels, or other equipment that have been exposed to water should not be touched or used before inspection by an electrician. The best place to turn off power is the main breaker or service panel, and if that wasn’t done before flooding began, do so before any workers return to the area.
Remember that downed power lines may still carry current, and the ground within several feet can become energized. Never touch or attempt to move a downed wire, even if you’re convinced that it isn’t live. Call in the power company or an electrician to verify that the wire is dead and to make any needed repairs. Flooded areas can also expose workers to electrocution if any live circuits are in contact with the water. Even a slightly damp surface such as a concrete floor can conduct electricity.
Flooding can also disable emergency equipment such as fire protection systems. Alarms, sprinklers, and other protection devices should be inspected carefully before work resumes.
Floodwaters can disrupt or destroy the habitats of many creatures, forcing them to find shelter elsewhere. Venomous snakes and rodents could be hiding on your worksite, frightened and ready to bite a worker who reaches into their temporary homes.
If your site is in area where venomous snakes and animals such as rats are common, remind workers to wear gloves and proceed with caution when reaching into potential hiding places. Rodents can spread many diseases, so proper hygiene is important after coming in contact with them.
Insects may also be a problem. Besides large swarms of flies and mosquitoes, floodwaters may dislodge colonies of fire ants, wasps, and other biting or stinging insects.
Many other biohazards
Floodwaters often lead to discharges of raw sewage that’s full of dangerous bacteria and other biohazards. Rotting animals and other organic wastes may also turn water into a toxic cocktail.
That’s why wearing proper personal protective equipment (PPE) and avoiding skin contact with floodwaters is important. Personal hygiene, such as showering immediately after work, can reduce the potential exposure and limit the possibility that a worker may infect family members.
Other types of biohazards include chemical storage tanks that may have been compromised, along with different types of containers. Valves on tanks may have been damaged and should be inspected before handling.
Carbon monoxide gas
Equipment used to clean up after flooding, such as generators and pressure washers, may emit carbon monoxide gas. While workers are rushing to clean things up, it’s easy to forget about that familiar hazard. Remind everyone that gas- and diesel-powered devices of all types must not be used in confined spaces or indoors.
Mold: a post-flooding menace
One of the most dangerous biohazards after flooding is the formation of mold. There are many types of mold, and their effects on humans vary greatly depending upon the type, the degree of exposure, and the strength of the individual’s immune system.
Many mold spores are small enough to be inhaled and can cause serious respiratory problems. Workers who will be cleaning in areas where mold has formed should use proper face masks with the right kinds of filter cartridges. Surfaces upon which mold has appeared should be cleaned thoroughly, and then disinfected with bleach water to prevent future mold growth.
Workers experiencing stress
The damage and disruption caused by floodwaters may lead workers to spend extra hours repairing damage and making up for lost time. Workers may become exhausted, impacting their awareness of proper safety procedures. They may also be at greater risk for heat exhaustion or hypothermia.
Supervisors should monitor workers closely to spot any signs of any of these issues, and take immediate action if problems crop up. Use toolbox talks or reminders at the beginning of shifts to remind workers to pace themselves, stay hydrated, and wear proper clothing and PPE.