I-Team: Radiation in Houston’s tap water, long history of contamination


by Mark Greenblatt/Chief Investigative Reporter

Part three of an ongoing series.

Posted on November 15, 2010 at 11:02 PM

Updated Wednesday, Oct 30 at 9:24 AM

HOUSTON-- The City of Houston is one of the only major cities in Texas with radioactive elements, like uranium and radium, present in its drinking water, according to data provided by the Texas Commission on Environmental Quality and internal City of Houston e-mails.  

The elements, which emit something known as alpha radiation, are not present in detectable amounts in Dallas, Arlington, Austin, Beaumont, San Antonio, or many other major cities in Texas.

Small amounts of radioactive elements have contaminated Houston’s water supply going back for as many years as the city keeps records on hand, which is presently for tests performed as far back as 1996.  The problem appears to be isolated to the city’s groundwater wells, which provide more than 70 million gallons a day of drinking water for Houston.  Some neighborhoods in Houston depend entirely on groundwater wells, while the majority of the city depends on water that is a mixture of surface water and groundwater.

Surface water sources, which include rivers and lakes, have not been found to contain radiation.  City officials say the “mix,” the majority of Houston depends on, delivers about 81 percent surface water and 19 percent groundwater on average.

The Department of Public Works says it has records of 78 water samples, collected by state officials since 2004, for regulatory purposes. The four samples that came from surface water sources were “non-detect” for radiation.  However, the vast majority of ground wells contained at least some alpha radiation.   Six of the 78 samples contained so much they were “above the 15 (picocuries per liter)” legal limit set by the EPA for alpha radiation in water.   

KHOU has learned the United States Geological Survey, a federal agency that does not regulate contaminants in drinking water (but assists in determining potential geological conditions that lead to contamination), has been conducting its own study of radiation in Houston’s water.  The results of that study have not yet been made public, but internal e-mails written between public works employees suggest the federal study may have detected a much larger share of Houston wells testing above the federal legal limits for radiation, compared to what state regulators found.  One e-mail, written on Oct. 12th 2010 from one public works employee to top staff members of the water-quality division, says that the USGS study found “10 out of 68 wells contain alpha particles higher than or equal to (the federal legal limit).”

Dr. Joshua Hamilton, a toxicologist who has a specialty in drinking water, says there is no safe amount of alpha radiation, even if the radiation is below that federal legal limit.  

“This particle is highly energized, and it's coming in at high velocity. If DNA is in its path it will basically attack the DNA,” he said.

Hamilton is the Chief Academic and Scientific Officer at the Marine Biological Laboratory in Massachusetts and he received his PhD from Cornell University in New York.  He previously taught as a professor with tenure at Dartmouth Medical College, and has been a visiting scientist at Harvard.  He was also the director of the Center for Environmental Health Sciences at Dartmouth.  

Hamilton says attacks on your DNA by any amount of alpha radiation can lead to mutations, which can produce “wild cells.”  The EPA has stated in its 2000 rule for regulating radiation in water that, “a single 'wild' cell can give rise to a cancer. For alpha particles, it has been shown experimentally that a single alpha passing through a cell is sufficient to induce a mutational event.”

Hamilton says that is why the federally-recognized public health goal (called a Maximum Contaminant Limit Goal) is zero for alpha radiation. That number is set by the Environmental Protection Agency and is listed in the federal register of the United States government.  The reason for the goal is because alpha radiation is a known “class A” carcinogen.

The legal limit for radiation (called a Maximum Contaminant Limit), however, is set above zero and at various limits depending on what radioactive element is present in the water. Hamilton says your risks still increase for cancer when any amount is present, even if the amount is below the legal limit or if your water utility tells you they still meet all legal standards.

“One alpha particle, if it hits DNA in the right place, can cause a change which leads to a mutation,” he said. “Every increase in hits increases the likelihood that one of those will cause a mutation that leads to cancer.”

However, there is some good news to report about Houston's water:  It has never been cited for a federal violation of the legal limits for radiation.  In order to get a violation, the city is judged on the “running annual average” reading it receives for tests of its wells, not on individual tests performed at individual water well locations.

City spokesperson Alvin Wright released a written statement to KHOU claiming that “we have not detected … any reason for concern based on the levels detected.”

A read through internal city e-mails and documents, released to KHOU after we filed a request using the Texas Public Information Act, reveals a different story.

One internal e-mail dated Oct. 13, 2010, from a city analyst to public works water division employees Kira Smith and Bruce Kao states, "Jersey Village, Spring Branch, and Southwest are areas that have alpha particle and uranium concern."

Another e-mail written from the same analyst follows up on the same day to name a number of groundwater wells along Bellaire Boulevard inside the city limits of Houston as "one more area we need to watch out."

Updated Note: Wells along Bellaire Boulevard  in Houston that are referenced in Houston's internal emails do NOT provide water to  the City of Bellaire, according to Bellaire officials. 

"The water we receive from the City of Houston is stored in tanks along with our own groundwater and distributed to our residents and businesses," Bellaire City Manager Bernie Satterwhite said. As for any water the city of Bellaire does purchase from Houston, Satterwhite says, "Our water comes from surface water treatment facilities, which, as I understand, are not sources of Houston (groundwater)."


The documents obtained from the city of Houston also reveal how, after KHOU began asking questions about radiation in water, the city began running various models and scientific studies on radiation in its water. 



For one neighborhood near the southwest side of Houston, called Chasewood, city staff ran one scientific model they called a “worst-case scenario,” which studied the amount of radiation residents there were exposed to during high-demand periods.

Internal city documents show that Chasewood water tested at or above the legal limit for alpha radiation all three times it was tested, dating back to 2004. Chasewood, according to those documents, has three different groundwater pumps. One e-mail written on Oct. 20, 2010, to public works supervisor Bruce Kao notes that the “Model showed that Chasewood water reaches out a fairly large area even when one pump is on.”   

Early models the city ran in October predicted only a limited amount of hours each day that groundwater with high radiation readings would flow to the area, predicting surface water that contained zero radiation would quickly flow to the neighborhood.  An e-mail sent on Oct. 21, 2010, from Public Works employee Yu Cang to Mr. Kao noted: “After our phone conversation, I went back and reviewed the model … after the plant is shut off; it takes about 5 hours for the affected area to shrink half and 10 hours for the affected area … to be gone. The surface water does not come into the area as soon as I (was) expected after the plant is shut off.”

Soon after that e-mail, top city leaders made the decision to shut off the Chasewood well altogether.

What are the risks?

The TCEQ has identified Harris County as one of “several areas of Texas (with) elevated radionuclide levels.”  Houston itself, however, is not in violation of legal limits for radionuclides.

KHOU asked Boston University professor and drinking water specialist David Ozonoff to help us understand the risks of drinking from Houston tap water where radionuclides are present in measurable amounts. Ozonoff is the Chair Emeritus of Boston University’s School of Public Health.  He is also on the Massachusetts Cancer Advisory Committee.

KHOU:  "Some people may say the risks won't lead to cancer all that often. What would you tell them?"

OZONOFF:   "You're involuntarily buying a lottery ticket of which winning is the wrong thing."

KHOU:  "If you keep playing, the odds go up?"

OZONOFF: "If you keep playing, your odds go up and the more tickets you buy the more your odds go up."

Ozonoff said, just like the real lottery, having low odds does not mean someone does not win.

OZONOFF:  "If it's one in 10,000, if there are 1 million people in the water supply or 2 million people in the water supply, then somewhere around 100 or 200 people are winning that lottery."

Ozonoff said city officials should strive to join other major Texas cities, which have no detectable amounts of alpha radiation in their water.  He also encouraged them to limit alpha radiation where the city can determine a lot of it is coming from, whether or not the sources exceed federal legal limits.

How does Houston compare to other cities?  

The Environmental Working Group, a national science-based, public-interest organization, recently studied the water quality of 100 major U.S. cities.   It ranked Houston near the very bottom, 95th out of 100, which meant Houston was named one of the “Lowest Rated Utilities” in America by EWG.

We asked them why Houston received such a low ranking, and the organization mentioned radioactive alpha particles as a primary reason.

The City of Houston has said the EWG report is unfair, saying large cities test more for radiation and will therefore find more.   

A KHOU analysis of internal city documents reveals the city is aware the following cities had no known amounts of alpha radiation in 2009: New York, San Diego, Dallas, San Jose, Detroit, San Francisco, Jacksonville, Indianapolis, Austin, Columbus, Fort Worth, Memphis, Boston, Seattle, Nashville, Milwaukee, Portland, New Orleans and Corpus Christi.

Internal documents in the city’s possession cite the following cities as having some amounts of alpha radiation in 2009 above the limits of detection the EPA recognizes:  Los Angeles, Chicago, Phoenix, Charlotte, Denver, El Paso, Las Vegas and Riverside, Calif.

Those same documents record Houston as having the single highest individual test for alpha radiation in 2009 for any large city in the United States.  That recording was taken in the Chasewood neighborhood.

KHOU intended to ask Mayor Annise Parker about Chasewood during a 10-minute interview to which the mayor agreed. We also informed the mayor’s staff we had planned to ask about what solutions she might implement for other neighborhoods mentioned in the city’s internal e-mails. However, her staff canceled that interview after KHOU’s first report in this series aired.

The mayor sent a written statement instead, which is posted in its entirety here in conjunction with this story.

What the city could do

The City of Houston is not required to do anything about radiation readings at any location in its water system, even though its own employees have identified some neighborhood wells as areas of “concern," because Houston’s overall system is not in violation of federal legal limits. Violations, as noted previously, are not given out for individual test results (or even for averages of results at specific locations) but rather are based on the average radiation scores the entire system receives.

In addition, city officials say attempting to install filtration systems that could remove the vast majority of radiation would be expensive.
The reason? Houston’s main water system has radioactive groundwater wells scattered all across the city.  The city also has some smaller, stand-alone systems which rely solely on groundwater. The water from these stand-alone systems is not purified in a central location.

However, after reviewing the city’s internal e-mails, Dr. Hamilton and Dr. David Ozonoff both said the city should still take more action to limit radiation in the hot spots it has already identified internally.   Hamilton and Ozonoff cite health risks that still exist even when the city is not in violation of legal limits. And they are not the only scientists who believe risks still exist.

“Any contamination above (zero) will produce an increase in cancer risk, even if the level is below the (federal legal limit),” Dr. Arjun Makhijani said. Makhijani is a recognized expert on energy and radiation science and leads the Institute for Energy and Environmental Research just outside Washington D.C.  Makhijani did not review Houston-specific information in detail and made his comments on the basis of general scientific principles.
“There is no safe level of radiation dose, according to the best available science.  This is the basis of all radiation protection regulation, including that of the EPA,” he said.  

KHOU has learned that members of the mayor’s staff contacted Dr. Joshua Hamilton, who recommended the city take further action than just at Chasewood.  He says any area identified as pumping a significant amount of radioactive water (either in overall volume or overall radiation readings) should either be shut down or have some kind of filtration system installed at those individual locations.  
Implementing the suggestion at individual locations would not be without precedent in Houston, which has not always implemented the same water treatment upgrades at all of its facilities.

Hamilton says that he offered a number of engineering solutions the city could implement.  He and Ozonoff agree that by taking care of those high radiation locations named in city e-mails such as Bellaire, Spring Branch, Southwest, etc. it might help substantially reduce the overall number of “lottery tickets” pumped into Houston’s water. When those “tickets” get pumped into the water, they are mixed with and pollute otherwise radiation-free surface water.

In addition, the city’s own staff told KHOU that certain engineering measures could be implemented to clean out the radiation, which does not respond to normal chlorination. City officials confirm that none of the following possibilities are currently in place at any locations throughout Houston:

Treatment Technologies for Removing Radionuclides from Drinking Water (as provided by the City of Houston to KHOU)

Below is a summary of the more common treatment technologies for the removal of various radionuclides from water.  Most of these are on EPA’s list of Best Available Technologies for compliance with the Radionuclides Rule.

•    Ion exchange (for removal of uranium, radium, and polonium)

•    Reverse osmosis (for removal of uranium, thorium, radium, and polonium)

•    Lime softening (for removal of hardness, radium, and uranium)

•    Green sand filtration (for removal of radium)

•    Co-precipitation with barium sulfate (for removal of radium)

•    Air stripping (for removal of radon)

•    Granular activated carbon (for removal of radon, uranium, radium, lead, and polonium)

•    Electrodialysis/electrodialysis reversal

•    Pre-formed hydrous manganese oxide filtration (for iron, manganese, and radium)

•    Activated alumina

•    Enhanced coagulation/filtration (for iron, uranium, and polonium)

•    Nanofiltration (for removal of uranium, radium, lead, and polonium)