How to keep your drinking water free of cancer-causing chemical

HOUSTON – There is a cancer-causing chemical found in Houston's drinking water. The levels we found on average are more than 30 percent higher than the state of California recommends.


"It has the potential to cause increased risk of cancer," said Dr. Qilin Li, associate professor of civil and environmental engineering at Rice University.

Chromium-6 is a cancer-causing chemical that can be naturally occurring or come from industrial pollution.

The Environmental Working Group (EWG) reviewed test results across the Houston area. Channel 2 discovered ZIP code 77099 had levels 300 times more than California's health goal. 

The movie "Erin Brockovich" documented the deaths of California residents exposed to high levels of chromium-6.

So what can you do to keep your drinking water safe?

"There are multiple technologies that can take out chromium-6 from drinking water," Dr. Li said.

Li said a fairly proven method to remove chromium-6 is to use reverse osmosis filtration systems. Some can be installed under your sink. They'll cost you anywhere from $100 to $1,000.

"This becomes a really good personal choice because EPA has not made a conclusion on what is a safe level of chromium-6 in drinking water yet, but there is toxicologists studies that indicate you may get increased cancer risk at this very low concentration so it becomes a personal choice whether you wanted to install home water treatment devices," Li said. "If I lived in this area, if I find high concentrations I probably would."

Carbon filters like the Brita brand, Li said, will not completely eliminate chromium-6 and would require frequent maintenance if you were specifically using it to filter heavier metals.

"There is ion exchange material in the Brita filter that could take out some chromium-6. Although, the capacity would be fairly low so that's why you will probably need to replace the filters much more frequently than what they are designed for," Li said.

She says it is wrong to assume bottled water is any better because it has even fewer regulations.

Rice University is working with three other institutions to develop a large-scale filtering system for entire communities. Although it is not ready for market yet, the Nanotechnology Enabled Water Treatment (NEWT) claims, "it will be easy to deploy, capable of tapping unconventional water sources and will enable access to clean water and wastewater reuse almost anywhere in the world."

The NEWT system is being built to specifically treat industrial wastewater, which may contain chromium-6. 

Knowing where your water comes from, you can figure out the amount of chromium-6 in your water. We have maps of the Houston area and surrounding counties here.

Congressman calls for investigation after KPRC 2 story

After the Channel 2 Investigation into Chromium-6 in drinking water aired, Congressman Al Green sent a letter to the EPA to investigate drinking water in his congressional district of Houston.

He wrote in part, "I have attached herewith a copy of a news story recently run by KPRC Channel 2, a local news channel in Houston, that outlines drinking water concerns in Houston. I share these concerns and firmly believe that we should take prompt corrective actions when a credible threat is identified."


File: Rep. Green's letter to EPA regarding Chromium-6

In a statement, Green said, "The health and safety of All Americans is a priority, especially as it relates to our drinking water. Evidence of harmful chromium-6 levels must be investigated. To this end, I am sending a letter requesting the EPA to investigate the circumstance presented by KPRC Channel 2. I am also asking EPA to accelerate its integrated risk information system (IRIS) assessment of hexavalent chromium. 

"I have supported and will continue to support legislation in Congress to strengthen the Safe Water Drinking Act, such as H.R. 4470, The Safe Drinking Water Act Improved Compliance Awareness Act, which was passed in response to the Flint, Michigan water crisis."

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