Floodwaters leave behind hidden dangers

Friday, September 22, 2017
Floodwaters leave behind bacteria, dangers
ABC13 tested Harvey's lingering floodwaters for chemicals and other bacteria.

HOUSTON, Texas (KTRK) -- When the rain finally stopped, floodwater sat on Houston's streets for more than a week in some neighborhoods.

We hit the road, testing water across the Houston area to see what was left behind. From Memorial to the Energy Corridor to the northeast, down to Superfund sites, ending on the bay. We all had concerns about how gross the water is.

We collected water and took it the lab and when we got the results, there was some good news and some bad news.

Houston city council member Greg Travis brought floodwater from his flooded Memorial district to City Hall two weeks ago.

Water bottles filled with floodwater sit in front of Houston council member Greg Travis during a city council meeting.

"If you want to smell it, I'll let you," Travis said. "In fact, what you are seeing here is probably one of your neighbor's burritos from yesterday."

He was right.

Our water sample from the flooded corner of Gessner and Woodstone showed substantial levels of E. Coli and fecal coliform, both concrete pieces of evidence of fecal germs flooding into the neighborhood - sewage and wildlife the most likely sources.

We found concerning levels at the sample near Katy, too. Levels were lower in floodwater just north of Interstate 10 in the Energy Corridor.

"It's not like lake water," said Houston's medical and public health authority director Dr. David Persse. "It's completely different water. It's much dirtier than lake water."

By the time that water flowed downstream to Galveston Bay, levels of sewage contaminants were below reportable levels at both Trinity Bay and the Texas City dike. Levels were just barely above reportable levels at two sites along the San Jacinto River.

When it comes to chemical testing, the list of potentially hazardous chemicals we looked for was long - pages long.

A rainbow-like sheen is seen on floodwaters from Tropical Storm Harvey on Friday, Sept. 1, 2017.
AP Photo/LM Otero

We could smell chemicals in the area of some of our tests, but when we sent the standing water on your streets and flowing into your homes to the lab, their tests found no reportable levels of hydrocarbons, volatile organic compound or petroleum by-products.

"When you have so much precipitation, a very large amount of flood water mixed with the chemicals, so there is a fair amount of dilution as well," said Rice University chemist Dr. Qilin Li.

Dr. Li added many lightweight petroleum products - like gasoline - evaporate quickly.

So what do you do about anything that may have been left behind? Even if there aren't petrochemicals in the water, sewage can make you unpleasantly sick.

"I don't use the word clean, I use the word sanitize," Dr. Persse said when asked what flooded residents should be doing.

That means mopping or scrubbing hard surfaces with a bleach solution and letting it dry thoroughly before rebuilding. Soft surfaces, like furniture, mattresses, dry wall, carpets, clothes and even well-loved stuffed animals may have to be thrown out.

Teddy bears damaged by floodwaters lie in a pile a debris outside a home that was flooded in the aftermath of Hurricane Harvey Monday, Sept. 4, 2017.
AP Photo/David J. Phillip

"Could it be cleaned? Probably, technically, it could, but it's going to be really hard and when are you going to know when that stuffed rabbit got clean enough that it is safe for your kid?" Persse said.

Do you have a story tip, idea or question for Ted Oberg Investigates? Let us know, at abc13.com/tedstips