Harvey likely caused millions of gallons of sewage overflows in Houston

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12 overflows already reported to state environmental agency

Environment Texas

AUSTIN, AUGUST 31 — At least 12 sewage overflows in the Houston area have been reported since Hurricane Harvey hit, according to Environment Texas, a statewide nonprofit advocacy group. Volume amounts have yet to reported. But given that up to 2 million gallons of sewage have been released in previous storms with only 10 inches of rain or less, Hurricane Harvey’s much higher rainfall amounts should be expected to cause millions of gallons in sewage overflows.

“Houston didn’t just flood—it flooded with contaminated water,” said Brian Zabcik, Clean Water Advocate at Environment Texas. “Anyone who was forced to swim or wade through high waters should be alert for any possible signs of illness, especially stomach or gut problems.”

In addition to the sewage overflows, 36 industrial facilities have reported toxic chemical spills to the National Response Center as of Thursday morning. In 13 of these instances, the spills entered into adjacent bayous and waterways. For example, mineral oil, possibly including toxic polychlorinated biphenyls (PCBs), spilled from two pole-mounted transformers in Fort Bend County into Dry Creek, a tributary of the Brazos River.

Sewage overflow data is collected by the Texas Commission on Environmental Quality (TCEQ). Since Harvey hit Houston, the agency has logged reports of sanitary sewer overflows (SSOs) from municipal wastewater systems for Memorial Villages, West University Place, Friendswood, and Crosby. TCEQ has also received SSO reports from industrial facilities operated by Albemarle, Dow Chemical, GB Biosciences, Noltex, Sasol, Shell, and Valero. 

The overwhelming majority of sewage systems in the Houston area have yet to file overflow reports. Although TCEQ rules state that overflows must be reported within 24 hours of occurrence, even the commission’s own regional office in Houston remains closed. According to a TCEQ statement, the U.S. Environmental Protection Agency will begin field sampling floodwater for contamination “as soon as conditions allow.”

A total of 833 wastewater facilities are located in the 25 Texas counties most affected by Harvey, according to a Sierra Club analysis of EPA data. A total of 449 industrial facilities in the affected area are monitored by the EPA for potential release of toxic chemicals.

According to the TCEQ, contaminated floodwater can contains many hazards, including infectious organisms, intestinal bacteria, and other disease agents. Contact exposure with this pollution can cause a range of waterborne illnesses, including stomach flu, skin rashes, pinkeye, ear, nose and throat problems, dysentery, hepatitis, respiratory ailments, neurological disorders, and other serious health problems. For senior citizens, small children and people with weak immune systems, the results can be fatal.

Health risks are even greater for people with open wounds. According to a study by the U.S. Centers for Disease Control and Prevention, 5 people with infected wounds died after Hurricane Katrina hit New Orleans in 2005, and health officials believe that contact with polluted floodwater contributed to their deaths.

Previous storms in Houston have lead to substantial overflows from the city’s wastewater systems. After 10 inches of rain fell on the city in October 2015, more than 2 million gallons of untreated sewage were released. And more than 1 million gallons were released after 4-6 inches fell during a storm this past January. Rainfall totals from Hurricane Harvey exceeded 50 inches in some Houston-area locations.

After the October 2015 sewage overflows, Alvin Wright, a spokesperson for the city’s Department of Public Works & Engineering, told KTRK-TV, “When you’ve got 10 inches of rain in a 24 hour period, all systems are going to be compromised.” Wright explained that floodwater inundates the wastewater system through manhole covers, which then forces untreated sewage to be forced out of other manholes.

The scope of Harvey’s destruction has been compared to other devastating storms such as Hurricane Sandy, which hit northeastern states in 2012. Climate Central, an independent think-tank, found that heavy rainfall caused 776 million gallons of sewage spills in the states affected by Sandy.

“While any city would have flooded with 50 inches of rain, Houston’s development patterns have undoubtedly made the city’s flooding problems worse,” said Environment Texas’s Zabcik. “We’ve already been working in Houston to promote green infrastructure in new construction, which can reduce runoff and water pollution. Harvey’s devastation shows that smart and responsible development is crucial to Houston’s continued growth.” More information about green infrastructure is available in Environment Texas’s recent report, “Catching The Rain.”

Environment Texas advocates for clean air, clean water, and preservation of Texas’ natural areas on behalf of 35,000 members and activists statewide.