By DMITRI BARVINOK
Capital News Service
LANSING — The emerging threat of pharmaceuticals, everyday chemicals and personal care products in drinking water may be the most difficult that water treatment plants have faced, experts say.
Lake Michigan takes 99 years to “turn over,” meaning chemicals that entered the lake a century ago may only just be exiting, according to the Alliance for the Great Lakes, which has offices in Grand Haven and Plymouth.
Its new report says that surface water in Lake Michigan contains six of 20 “priority” chemicals, or emerging contaminants identified by environmental engineers from Michigan State University. They include flame retardants and a cholesterol-lowering drug.
After treatment, only a fire retardant remained in ready-to-drink water.
Experts say that membrane bioreactors may remove some pharmaceuticals while treating wastewater, but they cannot catch all the diverse medicines.
There are 35 treatment plants in the Great Lakes region that use such membrane technology: 14 on Lake Michigan, 13 on Lake Huron, five on Lake Superior, two on Lake Erie and one on Lake Ontario, according to Siemens Water Technologies, a company that constructs the membranes.
One in Traverse City, was the largest in the nation when it opened in 2004. It serves 45,000 people in the city and surrounding area.
It took more than two and half years and about $31 million to upgrade an old plant deemed too small for the growing local population.
A forum for public comment identified two goals: use the existing plant in some way and exceed federal water requirements, said Scott Blair, the manager of the Traverse City wastewater treatment plant.
A membrane bioreactor plant was chosen as the ideal upgrade. This kind of plant uses a membrane that passes through treated water to remove debris, contaminants, bacteria and potentially some pharmaceuticals.
However, the membrane itself cannot filter all pharmaceuticals because there are so many kinds, said Blair.
Large molecules, including bacteria, cannot pass through the membrane, but medicines have different-sized molecules. That means some pass through.
The water is run through “activated sludge” that forms clumps of bacteria called “floc.” Some pharmaceuticals also degrade and attach themselves to the sticky blobs. They are then filtered out by the membrane.
Pharmaceuticals in water have recently come under attention from scientists and government agencies like the Department of Environmental Quality (DEQ).
It’s an emerging area of concern just beginning to be recognized, with many research projects going on at the federal level, said Richard Benzie of the community drinking water program at DEQ’s Office of Drinking Water and Municipal Assistance.
“Are we going to wait until it gets into the drinking water sources to deal with it, or start removing it in the waste streams?” he said.
Included in the pharmaceuticals group are personal care products, like cosmetics and suntan lotion, which also find their way into water sources, Benzie said.
“I admit, I’m probably contributing to the concentration of Lipitor in the environment,” he said.
However, the concentration of this cholesterol medication is low.
For a person to consume the equivalent of one dose of Lipitor, he or she would have to drink two liters – 4.2 pints – of contaminated water daily for 1,721 days, according to the Alliance for the Great Lakes report.
DEQ reports that pharmaceuticals have been detected in ground water, lakes and streams. They can harm aquatic life, and scientists say damage to human health may become apparent in the future, or will become more likely as concentrations of medicine in the water increase, said the department’s deputy director, Jim Sygo.
Pharmaceuticals from human and animal waste end up in the water. And they get there when people flush unused medicines down the drain, something the Environmental protection Agency encouraged until the 1970s, according to Sygo.
Pharmaceuticals have already damaged wildlife in New York, where birth control pills were linked to male fish developing female characteristics and becoming sterile, according to the U.S. Geological Service.
Standard water treatment plants are not equipped to remove pharmaceuticals from water.
In fact, some drugs may become more dangerous during conventional treatment, according to a recent study led by Stuart Khan from University of New South Wales in Australia.
Preliminary findings suggest that the pharmaceuticals change due to an enzyme reaction or interaction with bacteria.
DEQ’s Benzie said that if the pharmaceuticals have an organic carbon base, then disinfection by chlorine could potentially create dangerous byproducts, but there is no definite evidence yet.
Even if small levels of dangerous compounds are created, it’s still up to the EPA to determine whether that danger outweighs changing the disinfecting process, which protects people from outbreaks of diseases like typhoid, Benzie said.
Every five years the EPA identifies up to 30 compounds that have no drinking water standards. Then, the agency requires a statistically significant number of public water systems to track the identified compounds, over five years. When the results are in, the EPA begins the task of determining if there’s a health risk.
Some studies say membrane bioreactors do a better job of removing medicines from water, Blair said.
A plant can’t determine which pharmaceuticals it removes. That kind of research fits better in academia, Blair said.
By DMITRI BARVINOK