Hurricane Matthew: the Science of Cleanup

Hurricane Matthew's floodwaters are receding, but it's the mess, left behind, that could be dangerous. NC Science Now's Frank Graff explains the hazards of cleaning up.

FAYETTEVILLE — If you want to understand the power of water, simply drive along the road that borders the campus of Fayetteville State University.

There’s a branch of Cross Creek on the right side of the road. The campus is off to the left. Not far down the road, there’s a huge stone mound across the creek. The pile is roughly three stories high. The man-made stone mountain is banked, so it hugs each side of the valley created by the creek. Two giant, corrugated pipes pierce the bottom of the mountain, allowing Cross Creek to run through the pipes and continue on its way.

The mountain forms the train bed for a CSX railroad line to reach Fort Bragg. The line was destroyed by the flood waters from Hurricane Matthew, racing down the creek. Atop the mountain, construction crews are laying new track, dump trucks bring in more stone and bulldozers spread out the stone along the track bed.

The entire story of what happened at the railroad bridge is a testament to the power of nature as well as to the ingenuity, strength and resilience of human engineering.

But the real focus of this story is downstream. Because it’s no surprise that after knocking out that railroad bridge the water continued its rampage through a neighborhood on Washington drive. The entire area is covered in mud, a lot of it from that railroad bridge. The water would eventually reach to the top of the porch railing on the first house on the street. That’s about four to five feet high.

“It came up to the top step of our back door and once it did that I told the kids to grab some bags and throw your best clothes inside; grab your trombone, your favorite toy and go,” says Tabitha Miller, whose rental house was flooded by the storm. I met her as she and her family drove by to look at the overall damage that was done to the house.

The house is now caked with a couple inches of mud. So is everything else that the family could not salvage as the floodwaters quickly rose. Miller says the water was about knee high as she and her family escaped the house and fled to a nearby gas station. It was up to her waist when she returned a short while later to grab a few more items and rescue the dog.

“The couches were floating around, there was a tree inside my bedroom and the basketball goal that was on one side of the house was floating around on the other side,” remembers Miller.

Farther up Washington Drive we found Joshua Haire. He’s a landlord with seven properties flooded by Matthew. His tenant is trying to salvage anything she can. Haire is doing what he can to help, and is working around all of the items set out to dry. But despite all of the windows and doors being open, the clothes in the house are already starting to be covered by mildew.

“She won’t leave the house, she stays here to cover all of her things,” Haire says. He tries to separate the clothes that are hanging on a rack in the middle of a bedroom. Haire says he keeps moving them so there will be a little more air to help them dry.

“She’s torn up emotionally which I can totally get,” adds Haire. “This flood did a lot more damage than just physical, it messed these folk up and that’s for real. And since she has nowhere to go except a shelter, small landlords like me are trying to work extra hard to get these places back to where they were, but you can only do so much until everything dries.”

If the pressure to get things back to normal isn't enough, the cleanup after Hurricane Matthew is a race against mold and bacteria. Both can grow quickly in a damp environment.

Mold is especially dangerous because it can cause breathing problems. People with asthma or allergies are especially sensitive; however, high levels of mold can also cause problems for people who are relatively healthy.

Bacteria poses a risk in this situation because floodwaters are often contaminated, carrying sewage and animal waste. Bacteria can cause dangerous gastrointestinal and skin infections.

Haire is well aware of the dangers. He’s had properties flooded out by other storms.

“So once it dries out, we’re going to continue the repairs and I’m already figuring that because of the swelling and buckling of the floors, we’ll have to cover these floors,” continues Haire, as he scans the living room in front of him. He then turns his gaze to the hallway and into the bedroom. It’s a small, one story house with five rooms, but there is so much work to be done.

“Once it dries, we’ll cover it with plywood and then put carpet on top of that,” he says. Putting his hand on a wall, he adds, “I can’t do anything with the walls because they are still damp.”

Rachel Noble, Ph.D., believes Haire is smart in how he is planning his cleanup, because mold and bacteria are not to be taken lightly in these situations. Noble is a distinguished professor at the University of North Carolina Institute of Marine Sciences.

“We want to know more about those types of bacteria that are making people sick,” says Noble.

Noble is developing a diagnostic test to rapidly detect viral and bacteria contamination. The validated, user-friendly diagnostic kits would provide nearly real-time determination of dangerous bacteria and viruses in marine water and seafood. They would help public health officials and medical professionals better prevent and stop outbreaks of disease.

“The organisms we test for are the same; the same entero-caucus, E. coli, or fecal coliform, that has been tested by the EPA for decades. It’s just the technology is different,” Noble adds.

Noble’s work could one day be used in situations like hurricane cleanup. Currently, the test for water contamination requires incubation, or growing cells on a plate in a lab. But that can take 12 - 24 hours or even longer. So, Dr. Noble offers these tips to stay safe while cleaning up after contaminated water.

  • Throw away items that can’t be washed and disinfected.
  • Clean all hard surfaces with a weak bleach solution. 
  • Wash all clothes contaminated with floodwater.
  • Wear protective gear, including gloves, boots and goggles while cleaning.
  • Use fans and dehumidifiers to help the drying out process.
  • Avoid putting your hands near your face or mouth when working and remember to wash your hands every time you finish working. 

They are all tips Joshua Haire follows. He’s learned to be patient because various areas of a building dry out at different rates. He’s also learned that in these situations, bleach is your best friend.

“It’s going to take us about five gallons of bleach beneath the house to ensure that the mold doesn’t come up,” explains Haire. “You’ve got to bleach the foundation wall, as well as the bottom of the house itself. Once we do that we come inside and do the same thing all around the perimeter. The good thing with bleach is that dries quickly, just like alcohol, but it also kills. ”

The damage of Hurricane Matthew is being ammended cautiously, and smartly, by people like Joshua Haire who know the science behind flooding damage. People across eastern North Carolina are continuing to work to get their towns and homes back to normal.

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