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Chattanooga: Science flows ahead of cure

By: Lauren Gregory
(Contact)

Included in this article

Marion Kainer

The lights never go off in the slightly stinky laboratory at the Moccasin Bend Wastewater Treatment Plant.

Twenty-four hours a day, seven days a week, 365 days a year, a team of lab technicians braves the sight and smell of millions of gallons of human waste to make sure nothing is getting back into the Tennessee River that shouldn’t.

“All the time, we’re looking to see if there are any violations,” said Paul Patterson, manager of laboratory services at the plant, which runs three shifts so as not to let any excess ammonia, nitrogen, phosphorus or E. coli bacteria slip by.

But the team doesn’t test for any pharmaceuticals. They don’t need to, according to Jerry Stewart, director of Chattanooga’s waste resources division. Neither the Tennessee Department of Environment and Conservation nor the U.S. Environmental Protection Agency requires any screening for drugs in the water, Mr. Stewart said, because neither agency has determined the levels safe for humans or wildlife.

And on top of that, he added, there’s no point — because the current wastewater treatment system in Chattanooga couldn’t filter those things out anyway.

New technology has made it possible for scientists to determine that people are excreting unused portions of the medications they’re taking back into the nation’s water supply. University of Tennessee at Chattanooga professors Sean Richards and Steven Symes have detected traces of 13 common drugs in the Tennessee River, including caffeine and various antibiotics and antidepressants.

But the water treatment industry hasn’t quite caught up to the science, Mr. Stewart said.

“The city has been proactive about getting ahead of the enforcement curve. We’re doing all we have to be doing,” he said.

Chattanooga is in line with all required environmental regulations on water treatment, “but our sewer system dates back to 1890,” he said.

Staff Photo by Dan Henry
Paul Smith , a City of Chattanooga waste resources lab technician, performs a daily test on total solids from samples taken within the Moccasin Bend Wastewater Treatment Facility Wednesday morning. The facility treats an average of 55-million gallons of water daily discharging it into the Tennessee River near Moccasin Bend.

Though the system was updated in 2001, he said, much more work is required. It would take millions of dollars the city doesn’t have to implement any kind of filtering technology sensitive enough to remove trace amounts of pharmaceuticals, according to Mr. Stewart.

Many public water systems use activated carbon to improve taste, odor and color of their water, said TDEC spokeswoman Meg Lockhart. That, she said, is “some of the best technology available to reduce pharmaceuticals in the water supply.”

But carbon is expensive, Mr. Patterson said, and the city would have to figure out where to dispose of it once it was used. So although the city’s water supply meets all safety standards, it is still the color of iced tea when it is deposited back into the Tennessee River, even after chlorination treatments.

An “emerging issue”

Chattanooga is not alone in its need for infrastructure improvements, said Christian Daughton, a research scientist with the EPA’s Office of Research and Development. The detection of drugs in the water supply over the past few years has led to nationwide questions about how to remove such substances, he said.

“Sewage treatment plants were designed to handle pathogens and aesthetic things,” Dr. Daughton said. “They were designed many decades ago, before anybody began to think about this.”

Drinking water treatment systems are equally unprepared, according to Tennessee-American Water Co. President John Watson. The science of detecting drugs in water is so new that there aren’t yet reliable procedures to monitor their levels regularly, let alone filter them out, Mr. Watson said.

“This is what we would refer to as an emerging issue,” he said. “The EPA has no protocol, no monitoring requirements, nor does it have a set of treatment standards to address pharmaceuticals in water. There aren’t even any quality control procedures available to do the testing.”

The company supports further federal testing just to make sure, Mr. Watson continued. In the meantime, unlike the wastewater treatment system, the water company does use carbon to clear out as many extra additives as possible.

Dr. Symes recently tested carbon filtration systems and has determined that they are effective in removing pharmaceuticals. Though he has yet to test actual samples of drinking water here, he used a controlled laboratory solution on home filtration systems and found that the filters absorbed known quantities of drugs.

“All three of the brands we tested (Brita, Pur and DuPont) were remarkably effective at removing those drugs,” he said.

Preliminary results show each filter brand was 98 percent to 99 percent effective, he explained.

Even so, Mr. Watson said, drugs are sure to make it into our systems in other ways.

“Soybeans, vegetables and coffee already have pharmaceutical-type items in them, and we consume them every day at levels much higher than those reported in the water,” he said.

Further study is essential, because the problem isn’t going away anytime soon, concluded Robert Bringolf, an assistant professor at the University of Georgia’s Warnell School of Forestry and Natural Resources who studies drug impact on mussels and other aquatic wildlife.

People can’t just stop taking drugs, he said in an e-mail, because “the benefits of pharmaceuticals and personal care products in our society is undeniable.”

But also undeniable is the fact that the parts of those drugs that go unused are going to have to be deposited somewhere, Mr. Patterson pointed out.

“There are only three places you can put it: the water, the soil or the air,” he said. “That’s where risk assessment comes in. It’s just like a landfill. We don’t want it in our backyard.”

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