For CH2M HILL, concern about the heat takes on new dimensions as employees perform their work on the Department of Energy's Hanford site in the hot and dry Columbia Basin of Eastern Washington. Workers often find themselves involved in challenging projects wearing multiple layers of protective clothing as well as respiratory protection, including self-contained breathing apparatus (SCBA).
While physical conditioning, proper planning and preparation go a long way toward warding off problems caused by the heat, often extra measures to keep workers safe and productive are required.
The Hanford site is home to the nation's largest volume of radioactive and chemical waste, a byproduct of producing nuclear materials for the nation's defense. While the defense mission at Hanford ended more than two decades ago, the site is now one of the largest environmental restoration projects in the world. Teams of workers are aggressively cleaning up and disposing of the radioactive and chemical waste.
Daily tasks might range from routine surveillance activities to heavy industrial work that includes operation and setup of cranes and rigging, erection of scaffolding and equipment maintenance. These tasks can be physically demanding under the best conditions, but add in the conditions found at the Hanford site, and worker protection becomes even more important.
CH2M HILL's responsibility is to safely manage more than 53 million gallons of highly radioactive and chemical waste stored in 177 underground tanks, grouped in 18 "farms." Each farm usually includes 12 to 15 tanks buried under 10 feet of soil and connected to the surface by pipes. These pipes, or risers, allow for the insertion of various monitoring instruments, pumps and leak detection equipment.
Unlike the wet, rainy climate of the coastal areas of western Washington, the eastern half of the state is an arid land of sagebrush and irrigated farms, receiving an average annual rainfall of less than 7 inches and plenty of clear, blue sky.
Spring comes early to the Columbia Basin. An early spring is good for local farmers but always gives way to a hot summer, which brings with it unrelenting heat that seems to last for months. For much of June, July, August and September, temperatures can range from the high 80s to low 90s under clear skies. In late July through early August, daytime temperatures typically exceed 100 F. Add in low humidity, which rapidly strips away moisture, and the ever-present wind caused by being down-slope of the Cascade Mountains, and working outside can swiftly change from being uncomfortable to being hazardous to a worker's health.
"Most of our work managing Hanford's radioactive and chemical waste is performed outdoors," says Fran Ito, CH2M HILL vice president for safety, health and quality assurance. "Some can be done in shirt sleeves, but other work requires the use of personal protective equipment that can include heavy coveralls, hoods, rubber gloves and supplied air respirators, all of which take a toll on a worker's stamina, especially when the summer sun is beating down."
To beat the heat, CH2M HILL sometimes changes schedules to conduct work on swing or graveyard shifts to take advantage of the cooler nighttime temperatures, says Ito, adding, "but workers don't like it as well as working in the daylight."
The company always has stressed hydration while working, and provides drinking water both during and after all outdoor projects. Large quantities of bottled water are delivered to worksites on a regular basis to make sure workers have access to all they need. But the company didn't stop there.
Input from Employees
Ito put together a team of workers and managers and gave them the freedom to brainstorm ideas that could help workers beat the heat.
"We looked at three types of solutions, recognizing that every option has positive and negative aspects," Ito remembers.
The first solution is to avoid the heat. Second is to change the work environments. Third, look at good practices, knowing different tasks are going to require a choice of several different solutions.
"Our first priority is to ensure that the heat stress program requirements for engineering controls, personal hydration, good communication, work/ rest regimens and self-monitoring are clearly understood and followed by all," says Bill Smoot, CH2M HILL's Heat Stress Program manager.
One of the team's first recommendations was to install a cool-down tent just inside the fence of a tank farm if work was going to take place for an extended period. Since workers have the potential to come in contact with radioactive contamination, the cool-down tents give them a place to take a break, drink water and get out of the sun without having to remove all of their protective clothing for the duration of their break.
"We also installed misters in some of the cool-down tents to help cool the workers, and installed air conditioners to provide a constant flow of cool air," Smoot says.
In addition to the cool-down tents, this year's efforts also are aggressively addressing the actual work environment. To control the potential spread of radioactivity in certain projects, large, temporary structures are routinely erected from scaffolding and plastic. Workers refer to them as greenhouses, and as their name implies, they turn into hot, confined work areas. To mitigate the heat, recirculation air conditioning units with HEPA filters are being installed inside containment tents where the work is actually being performed.
"Lessons learned from Hanford as well as other sites have also underscored the value of installing netting over the containment tents to break the sun, resulting in lowering the ambient temperature of the worksite," Ito says.
The team also recommended special cooling vests be provided to workers. The vests use a type of hydrated gel that is designed to hold any temperature it is exposed to for extended periods. It weighs a mere 2 pounds and by freezing the vests, they can provide cooling for up to 2 hours. This is a far cry from the old-style vests that used up to 30 pounds of ice and restricted movement due to their bulk.
"There is another type of vest available to workers that use ice water. It lasts about 3 hours, and can be recharged in less than 1 minute," says Smoot.
Another recommendation made by the group has brought about a change in the type of coveralls being used. Some protective clothing is heavy and not well-suited to hot, dry climates. Other types work well in dry climates but quickly become uncomfortable under misters in the cool-down tents.
"We did some research and found coveralls that are lightweight and perform well under a variety of conditions. Workers like them and they get the job done," Ito says.
Ito says CH2M HILL is developing a toolbox of options for its heat stress program, so managers and field work supervisors are able to select the right options for the existing conditions. Through the use of new engineering controls, revised administrative procedures and updated personal protective clothing, CH2M HILL is making summer work in the desert environment much safer.
Mike Berriochoa is a communications specialist at CH2M HILL at the Hanford site in Richland, Wash., and has been writing about Hanford cleanup progress and challenges since 1989.
Sidebar: Protecting Yourself from Heat Stress
When the body is unable to cool itself by sweating, heat-induced illnesses such as heat stress or heat exhaustion and the more severe heat stroke can occur, and can by deadly.
Factors leading to heat stress include high temperature and humidity, direct sun or heat, limited air movement, physical exertion, poor physical condition, some medicines and inadequate tolerance for hot workplaces.
Symptoms of heat exhaustion include:
- Headaches, dizziness, lightheadedness or fainting.
- Weakness and moist skin.
- Mood changes such as irritability or confusion.
- Upset stomach or vomiting.
- Symptoms of heat stroke include:
- Dry, hot skin with no sweating.
- Mental confusion or losing consciousness.
- Seizures or convulsions.
The best way to "treat" heat stress is to prevent it. Know the signs and symptoms of heat-related illnesses and monitor yourself and co-workers. Block out direct sun or other heat sources, and use cooling fans and air conditioners. Remember to rest regularly and drink lots of water about 1 cup every 15 minutes and avoid alcohol, caffeinated drinks and heavy meals. Wear lightweight, light colored, loose-fitting clothes.
If a co-worker appears to be suffering from heat-related illness, call 9-1-1 (or local emergency number) at once. While waiting for help to arrive:
- Move the worker to a cool, shaded area.
- Loosen or remove heavy clothing.
- Provide cool drinking water.
- Fan and mist the person with water.