drugs in water

Old water tests, new pollutants worry scientists

11/19/00
KATHERINE BOUMA
and PATRICK HICKERSON
News staff writers

Birmingham water managers brag that they have some of the cleanest drinking water in the nation because they hold themselves to standards even tougher than the law.

Water Works treatment manager Joel Rhaly likes to tell a story about the chief of Alabama's drinking water division making his last stop in the Shades Mountain Filter plant - at a drinking fountain.

But many of the nation's leaders in drinking water technology say it's time for even the best water plants to get tougher.

"We're still using the same kinds of tests we've used since the '60s," said Jay Grimes, a University of Southern Mississippi professor who sits on a panel of microbiologists working to recommend new tests to the U.S. Environmental Protection Agency. "They're not specific. They're not rapid. They take at least 48 hours. By then, you've either drunk the water or you haven't."

And there's not a city in the nation testing or treating for what some scientists consider the latest emerging pollutants - prescription and over-the-counter drugs including nicotine, antibiotics, pain relievers and hormones.

No tests have been performed in Alabama, but in a recent EPA report, researchers write that they have no doubt the drugs will be found everywhere drugs are used.

100-year-old methods

The U.S. Safe Drinking Water Act requires 79 tests for contamination before any utility can pipe water into customers' homes. Many of those tests are taken rarely, but a few must be conducted daily. Such large utilities as the Birmingham Water Works conduct some tests, including those for chlorine levels and clarity, every hour.

Birmingham's drinking water has had no violations from the Alabama Department of Environmental Management in the past 10 years. In fact, Birmingham was cited 12 years ago by Omni magazine for having some of the best drinking water in the country.

But in Birmingham and virtually every other city in the nation, the coliform bacteria test is the only way to detect disease carried by human or animal waste. That test has changed little in a century.

If coliform bacteria are present, the logic goes, human or animal waste probably is present. Technicians treat the water accordingly, usually with chlorine - another technique dating back a century.

Coliform is associated with fecal material, but the association is loose. Some pathogens can be present even when coliform is not. And coliform doesn't always indicate fecal waste.

"It's just an indicator," said Grimes. "We have the technology to actually look for the culprits, the pathogens that would actually cause hepatitis, enteroviruses, polio."

Some disease-causing microbes, even some killers, don't respond to the chlorine most often used for disinfection.

In Milwaukee in 1993, more than 100 people died and 403,000 were sickened when cryptosporidium entered the city water supply. City officials say their water met every legal disinfection standard when the outbreak occurred.

The intestinal parasite is not killed by chlorine or other conventional disinfection methods. It must be filtered out of the water. EPA is developing requirements to prevent cryptosporidium contamination.

The source of the deadly microbe in Milwaukee never was proved. Some pointed the finger at a food processor that disposed of animal waste. One government report suggested the fault lay with human waste in Lake Michigan.

"The practice of putting rou tinely treated wastewater into our water supply is a risk," Grimes said. "The risk can be acute."

In Birmingham, like Milwaukee, treated sewage is poured into the drinking water supply. Above the Cahaba River intake, 12 sewage treatment plants send their wastewater into the river. At Mulberry Fork, three sewage treatment plants discharge into the water. Two more plants pour sewage into Smith Lake.

Rhaly said he became fascinated with a cryptosporidium test long ago and brought it back to Birmingham years before Milwaukee, years before most water managers had heard of the microbe. He believes his treatment methods are effective in pulling out everything that could pose a hazard.

Treating the water

For most over-the-mountain communities, water treatment starts outside the 110-year-old Cahaba Pumping Station. Water is drawn from a pool on the Cahaba River. When needed, water is released from Lake Purdy to fill the pool.

Just outside the station's intake, water passes through wire mesh and under a concrete wall and is peppered with activated carbon to improve taste.

The need for carbon increases during dry periods because more algae grows, and algae can make the water taste and smell odd. During this year's drought, the utility used the expensive activated carbon almost nonstop to draw the unpleasant taste and odor out of water from the Cahaba and Mulberry Fork, said Randy Chafin, assistant general manager of the Water Works.

At the Cahaba plant, pumps then push the water out of the valley for a 30-minute trip to the Shades Mountain Filter Plant, where it falls into the receiving basin n ear Rocky Ridge Road.

The water, slightly darker because of the carbon, cascades on a flume while lime, alum and chlorine are dripped in.

Lime helps adjust the water so it's neither too acidic nor too basic. Alum gathers mud, dirt and silt together, forming larger particles called floc. Chlorine's job is to kill bacteria and viruses.

But it can form something else, too. When chlorine meets organic materials, it creates minute amounts of cancer-causing trihalomethanes.

As dirt, leaves and other natural materials, such as nutrients, increase in the water, so do the carcinogenic byproducts.

EPA is drafting tighter rules on how much of the carcinogens can be in drinking water.

The Water Works hasn't begun testing its water for trihalomethane chemicals, but it may have to build onto its treatment plants to meet the proposed standards, consultants said.

Before making expensive changes, the utility might ask the state to allow it to use something other than chlorine to disinfect the water, reducing the amount of toxins produced during treatment.

Rhaly said the Water Works has asked Alabama Power's parent company for grant money to study new treatment technologies such as ozone and ultraviolet light.

After lime, alum and chlorine are dripped into the water at the plant, they are mixed together, then distributed to four flocculator units.

Like cabana boys fanning tourists in a dated movie, flocculators slowly waft paddles through the water, encouraging particles to cling together, get heavy and settle at the bottom - but not too quickly. That would cloud the water, increasing turbidity.

Turbidity is the measure of particles suspended in the water - it's cloudiness. A low turbidity number is the benchmark for any water treatment system.

Like a sales manager, Rhaly has posted a goal for Birmingham's water: 0.1 turbidity. The state standard is 0.3.

Rhaly has a lower standard because studies show that with every increase in microscopic dirt, hospitalization rates for water-borne illness rise, he said. Even after treatment, pathogens cling to microscopic dirt specks. People drink them and get sick.

From the flocculators, the water moves to the receiving basin, where the floc settles. The resulting, clearer water enters its first building, the filter plant.

Water shuttles to 15-foot-high filter tanks and steeps through layers of anthracite coal and sand to filter out chlorine-resistant microorganisms.

After filtration, the water is sent to a holding tank, then routed to one of about 30 tanks in the Shades Mountain system.

Drugged waters

But as efficient as Birmingham's plant is, scientists agree there's not a sewage or water treatment plant in the nation equipped to remove the drugs and medicines being found in American waters.

Scientists in Europe for many years have reported drugs in open waters. They've found dozens of compounds, including chemotherapy drugs, ibuprofen and antibiotics.

More than 50 drugs in various waters lead scientists to believe that every commonly prescribed drug or over-the-counter medication could be found in U.S. waters, too.

Scientists have known for decades that wastewater was high in caffeine, a drug excreted by every coffee drinker, and nicotine, from tobacco users.

In fact, caffeine and nicotine have been used as markers of wastewater's presence in open water, said Christian Daughton, an environmental toxicologist with the U.S. Environmental Protection Agency in Las Vegas.

"No one very seriously sat down and thought, 'Well, if those two are here, what else is here?'" Daughton said.

In part, that is because EPA and other agencies were focusing on traditional pollution discharged by industries and engines. Drugs have not been considered pollutants. In many states, including Alabama, health agencies flush or rinse drugs directly into the sewage system full strength - at the state's mandate.

But now, U.S. officials are starting to widely test the waters for drugs. The U.S. Geological Survey is looking at hundreds of water bodies, focusing on agricultural areas in the Midwest, in particular, because of questions about antibiotics given to animals.

Officials aren't releasing their findings in the midst of the study for fear of tainting the results. Their first report is expected out late this year.

Scientists emphasize the levels of drugs present in rivers and streams are extraordinarily low - in parts per trillion. Most drinking water standards look for traditional pollutants in parts per million or, less commonly, parts per billion.

"That's like finding $10 in the federal budget," said Ed Furlong, a research chemist with the Geological Survey. "It's such an inconceivably small amount."

For example, the levels of caf feine contamination found are so low that a person would need to drink 100,000 liters of water to get the caffeine hit of one cup of coffee.

Many unknowns

There's no way to know what is in Birmingham's drinking water, since no tests have been conducted. The Water Works' Rhaly said it's too early to know whether water utilities should be treating for such chemicals.

"I think our ability to quantify and identify exceeds our ability to understand the implications of what we're looking at," he said.

Most scientists believe the primary risk of contamination is to aquatic organisms. The most likely problems would come from hormones, which act at levels far lower than drugs.

But the risk could move up to humans. It's not known, for instance, whether bacteria exposed to low levels of antibiotics in the water could develop resistance to the drugs.

Nor does anyone pretend to know what the long-term results could be of exposure to so many different drugs or antibiotics.

Glen Boyd, a Tulane University professor who specializes in drinking water, recently found drugs in water flowing from the faucet in his laboratory. But his test, the first known test of treated tap water in the United States, is so preliminary that he is requiring six months more work before submitting it for scientific peer review.

"There are so many unknowns," said Boyd. "What's the cumulative effect of all these low levels? We need to figure out what's out there, and is this something we should be concerned about? I think we need to find out."