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What’s In the Water We Drink?

By John Pekkanen, July 18, 2012

Washington’s tap water meets or exceeds federal water-quality standards. But new, emerging pollutants are not removed by current water-purification technology. Could these be linked to alarming increases in obesity, diabetes, autism, and more?

Washington’s tap water, most of which comes from the Potomac River, meets or exceeds federal water-quality standards. But new pollutants have emerged that are not removed by current water-purification technology. Evidence suggests that the same contaminants that caused massive fish kills and deformities in recent years are linked to increases in obesity, diabetes, autism, cancer, and other disorders—and that medications and products we use every day might contribute to the problem.

Of all the natural resources in the Washington area, none is more important than the potomac river. Besides the beauty and recreation it provides, the area pulls nearly 400 million gallons of water a day out of it—about 90 percent of our drinking water.

In some ways, the Potomac is cleaner today than it was 40 or 50 years ago. Back then, people were warned not to swim in the river or eat fish from it; a tetanus vaccination was recommended for anyone who did swim there. On many days, you could smell the Potomac before you saw it.

Improvements in wastewater treatment and conservation upgraded the water quality of the river, which wends its way nearly 500 miles from its origin in the Appalachian Plateau to Point Lookout, Maryland, where it empties into the Chesapeake Bay. These efforts helped reduce major pollutants—such as nitrogen and phosphorous from fertilizers, pesticides, and soaps—that fed algae, rootless plant-like organisms that grow in sunlit water. Algae blooms—rapid accumulations of microscopic algae in water that can stretch for miles—deplete the water of oxygen and release harmful toxins. They can virtually destroy a river if left to grow unchecked.

Despite this progress, the river is not "clean." In 2011, the Potomac Conservancy, an organization that monitors the river, gave the Potomac a grade of D, a drop from the D-plus the organization assigned it in 2007. The conservancy noted that more than a third of the estimated 10,000 stream miles in the Potomac watershed are threatened or impaired.

Even so, the drinking water in the Washington area is closely monitored and meets or exceeds every Environmental Protection Agency water-quality standard. But as some of the old pollutants have been removed from the river, new ones have emerged that are not removed by current technology and may be harmful to human health, especially for the very young.

This emerging class of contaminants, called endocrine-disrupting compounds (EDCs), a variety of natural and manmade chemicals from many sources, first came to light in a dramatic way in the summer and fall of 2002 with massive fish kills along the south branch of the Potomac River in West Virginia, about 200 miles upstream from DC. Some of the contaminants are new, and others have been discovered recently because new measuring techniques permit scientists to identify EDCs in minute quantities.

Says Luke Iwanowicz, a scientist with the US Geological Survey: "Many of these emerging contaminants have been off our radar until now, mostly because we did not have the ability to detect them."

Jeff Kelble ran a fishing-guide business on the Shenandoah River, long considered one of the nation's great fishing rivers, especially for smallmouth bass. The Shenandoah empties into the Potomac at Harpers Ferry, West Virginia. Kelble remembers when fish were so plentiful that they fought over his lures—it wasn't uncommon for the sport fishermen he guided to catch 50 to 60 fish in a day, all of which Kelble released back into the river.

That changed in the last week of March 2004, when Kelble learned that fish kills had struck the north fork of the Shenandoah. From his boat, when the murky spring water was clear enough, Kelble could see redbreast sunfish and smallmouth bass lying motionless on the riverbed.

Kelble didn't know what to make of the scene. Had a poison been dumped into the river? Was this fish kill related to the kills that had struck the south branch of the Potomac in 2002 and 2003? Had a large quantity of milk somehow found its way into the water from dairy farms along the riverbank? Milk has a voracious appetite for oxygen and might have robbed the river of enough to kill the fish, but when the river's oxygen levels were measured, they were normal.

Kelble tried catching fish but had little luck. Finally, he hooked a smallmouth bass.

"We were excited at first," Kelble says, "but when we lifted the fish out of the water, we saw it was covered with red sores that looked like cigar burns, and it had lost many of its scales. I'd never seen anything like it. I have an engineering degree—I'm not a biologist—and I had no idea what was wrong. We caught a few other fish, and almost all had similar sores on them." Kelble caught more fish. "Between 50 and 60 percent of the fish had lesions," he says.

Kelble, now a conservationist with Potomac Riverkeeper—a nonprofit that monitors river quality throughout the four-state Potomac watershed—estimates that in 2004 and 2005, 80 percent of the adult smallmouth-bass population was wiped out in the Shenandoah River. The bass are back, Kelble says, but he still sees sick fish.

Vicki Blazer, a fish pathologist with the US Geological Survey (USGS), had the job of finding the cause of the fish kills. Working out of Kearneysville, West Virginia, Blazer led a team onto the rivers to collect dead and dying fish. Electroshocks in the water stunned the fish and brought them to the surface, where Blazer's group netted them and put them into water buckets to which an anesthetic was added.

As Blazer dissected scores of smallmouth bass, she was surprised to find that many of the males had characteristics of both sexes. Some 80 percent of the male fish had oocytes—precursors of egg cells produced by females—in their testes, a condition known as intersex.

Intersex among some species of fish is not unheard of but, Blazer says, "you just don't see this intersex phenomenon with bass."

Ed Merrifield, president of Potomac Riverkeeper, calls the river fish kills "the canary in the coal mine."

Our region is not alone. Fish die-offs have been reported in waterways throughout the United States. Last September, thousands of white bass died in the Arkansas River with no clear explanation. Beginning in 2008, fish kills and fish with lesions were seen in the upper James River, and lesions were seen on the Jackson and Cowpasture rivers in Virginia as well. Intersex fish also have turned up in the Great Lakes and the Mississippi River.

Back at the lab, Blazer and her colleagues examined fish tissue microscopically and discovered that some bass had bacterial infections while others had fungal infections and still others were afflicted with parasites. This finding led her to conclude that the plague killing the fish wasn't a toxin, a bacterium, or any single agent but resulted from immune suppression that permitted opportunistic infections to flourish and kill the fish.

"I think the fish kills were caused by the same chemicals in the river water that are inducing intersex," Blazer says. "Besides leading to intersex, exposure to these chemicals, particularly estrogenic hormones, depresses the immune system. The intersex occurs when the fish are exposed to these estrogenic compounds at a young age."

The study found that even bass with no signs of intersex contained detectable levels of at least one endocrine-disrupting compound.

Based on a USGS study published in Fish & Shellfish Immunology in 2009, it appears that estrogenic compounds can lower levels of hepcidin, an iron-regulation hormone found in mammals (including humans), amphibians, and fish. Researchers believe hepcidin acts as a first line of defense against certain disease-causing bacteria, viruses, and fungi, which could explain why intersex fish and the fish kills occurred at the same time.

Blazer and her colleagues published their findings in 2007 in the Journal of Aquatic Animal Health. The report concluded that intersex fish were "an important indicator of potential endocrine disruption."

What About Bottled Water?

Blazer has found intersex fish on both the lower and upper branches of the Potomac and on both forks of the Shenandoah. She says the fish kills and intersex are most prevalent along the most agricultural areas of the rivers—where dairy, cattle, and poultry businesses reside—but that those are probably not the only sources of the chemical soup that kills fish.

Kelble says he saw the highest mortality in the upper reaches of the Shenandoah, which are close to the highest-intensity animal-feeding operations. The nine-county Shenandoah Valley has more than 900 poultry farms, with more than 87 million chickens in Rockingham County alone. On several occasions, Kelble and others have seen cattle herds wading in tributaries of the Shenandoah. The residue of human and animal excrement, which holds both natural and manmade chemicals, is considered a significant source of EDCs. The USGS reported that a higher incidence of intersex fish occurred in streams that drain areas with intensive agricultural production and high human population when compared with non-agricultural and undeveloped areas.

Blazer also has found intersex fish in the Conococheague Creek and the Monocacy River in Maryland. She believes the intersex fish are the result of a "toxic soup" of endocrine-disrupting compounds that are finding their way into the Shenandoah and Potomac rivers. This mixture comes from homes, farms, and industry and has been added to the water for years. When it reached critical mass, tens of thousands of fish died.

So what do dead fish 200 miles upstream from Washington have to do with the quality of water we drink?

EDCs are a broad class of molecules that the EPA defines as natural or synthetic agents that interfere with "natural blood-borne hormones that are present in the body and are responsible for homeostasis, reproduction, and developmental process."

Natural hormones are secreted by endocrine glands into the bloodstream and bind with specific cell receptors. Once bound, the receptor carries out the hormone's instructions, either modifying existing proteins or directing the cell's DNA to produce specific proteins. Because EDCs mimic natural hormones and interfere with the endocrine system, they can adversely affect normal growth, cognitive function, metabolism, and reproduction in animals and humans.

Measuring their risk to human health has been hard because they interact in complex ways at minute concentrations, both alone and in combination with one another.

How they act in combination remains unclear. EDCs have been in the environment in one form or another for more than 50 years and are present in hundreds of millions of people worldwide. At last count, more than 80,000 synthetic chemicals, mostly derived from petroleum and vegetable sources, are in use today. The process of making these synthetics involves toxic catalysts and reagents. Few of these 80,000 chemicals have been tested to determine what effect they have on humans.

Individuals respond to EDCs in different ways, but one thing is clear: Never before have humans had so many diverse synthetic chemicals assaulting their bodies, a phenomenon some observers have called "the largest uncontrolled science experiment in history."

EDCs are present in many household items, such as preservatives, plastics, cosmetics, and antibacterial soaps that contain triclocarban, an endocrine disrupter that is flushed into wastewater and ultimately into the river. Scented soaps and shampoos, hair-coloring agents, skin creams, and sunscreen lotions contain them, as do some spermicides, toilet papers, and facial tissues.

They're also found in birth-control pills, hormone-replacement therapies, and androgen-blocking or androgen-enhancing agents. Chemotherapy and thyroid medications, antibiotics, and other prescription drugs, some of which contain EDCs, enter the environment when they're excreted into wastewater and flushed down the toilet. Pharmaceuticals can enter the water supply directly when unused pills are thrown away.

In 2008, the Associated Press published a series of stories entitled "Pharmaceuticals Found in Drinking Water." The AP conducted a survey of water quality and found that pharmaceuticals were present in the water systems of two dozen major metropolitan areas. Washington's drinking water contained evidence of six drugs, including carbamazepine (an antiseizure medication), monensin (an antibiotic used in animal feeds), sulfamethoxazole (an antibiotic often given for ear infections), ibuprofen (Motrin and Advil), naproxen (Aleve), and caffeine. Philadelphia's drinking water contained evidence of 56 drugs and byproducts. The AP estimated that the health-care industry flushes 250 million pounds of drug waste down drains each year.

In tests conducted by the USGS between 2003 and 2005, trace amounts of 26 chemical compounds were detected in Potomac River water, including the herbicide 2,4-D, a component of Agent Orange, and insecticides including DEET. Atrazine, a chemical commonly used in weed killers, has been associated with intersex in amphibians and has been found in many rivers, including the Potomac. Studies revealed that male frogs exposed to atrazine produce eggs in their testes, the same phenomenon seen with intersex fish.

EDCs also enter the Potomac watershed from antibiotics and synthetic hormones given to cattle and poultry to prevent disease and stimulate growth. Once excreted by the animals, the chemicals find their way to the river, usually via rain runoff. In Shenandoah and Potomac tributaries upriver, cattle are allowed to walk into the water, a form of "direct deposit," Blazer says.

"We don't have smoking guns that tell us what specific chemicals may be causing problems in the river," says Potomac Riverkeeper's Ed Merrifield, "and it could take years to find out what chemical or chemicals cause intersex fish."

Even if we could identify potentially dangerous EDCs, current municipal water-filtration methods in our area cannot remove them, nor does the EPA require them to. A recent USGS study of several rivers nationwide, including the Potomac, reported the same concentrations of some compounds in the river water before and after it went through the filtration process.

Many of the EDCs that flow into the Potomac River and other bodies of water are thought to be estrogenic, meaning they mimic estrogen hormones in the body.

"Estrogenic compounds are important, but they are just part of the picture," says the USGS's Luke Iwanowicz. "We have also found androgenic compounds in the river that we suspect come from livestock feeding, and we'd like to find out what else is in the river. A lot of people throw away anti-inflammatory medications, and I also want to see if there are thyroid hormones in the river. I'd be shocked if there weren't."

"The exposure to EDCs that we get just from drinking water is probably a very low level," Blazer says, "but we know EDCs get past the placental barrier and enter the embryo, when the organism is most sensitive, and this is when we really need to worry because very low levels at those times will have a harmful impact. The changes initiated by EDCs may not show up until the person goes through sexual maturity or later. There are all sorts of things we don't understand right now."

In time, the impact of EDCs on humans will be better understood. The technology for measuring human exposure to synthetic chemicals has advanced in recent years. Centers for Disease Control and Prevention (CDC) labs now can monitor human blood and urine for more than 200 so-called halogenated and non-halogenated chemicals and their metabolites. These include pesticides and chemicals used in cosmetics, perfumes, detergents, toys, plastics, and fire retardants. But the ways in which different EDCs might combine in the human body will likely remain uncertain for some time.

The Washington Aqueduct, headquartered on MacArthur Boulevard in Northwest DC, is the major supplier of drinking water for the District and parts of Northern Virginia, including Arlington and Falls Church. The aqueduct distributes some 160 million gallons of drinking water a day, and on hot days up to 180 million gallons.

The Washington Suburban Sanitary Commission, in Maryland, distributes water from the Potomac to homes and businesses in Montgomery and Prince George's counties and has two reservoirs on the Patuxent River that distribute water to parts of Prince George's.

Fairfax Water serves Fairfax County and Alexandria; 55 percent of its water is drawn from the Potomac and the remaining 45 percent from the Occoquan Reservoir. These are the area's three major suppliers of tap water.

Tom Jacobus, general manager of the Washington Aqueduct, says current water-filtering technology doesn't neutralize EDCs that enter the system from the river's intake pipes, but he notes that those levels are very low.

"The problem right now is we don't know the effect of very low levels of EDCs on human health," Jacobus says. "So we are trying to decide what kinds of water treatments we may need to go after some of these endocrine-disrupting compounds. Right now I can say without qualification that our drinking water meets all federal standards and therefore is safe to drink. But that is not a good enough answer, because safe enough for whom? So we are looking into the possibility of installing ozone UV [a technology that has the capacity to remove many EDCs from water] to further ensure that we can neutralize the anthropomorphic activity of EDCs in the water, but there are significant costs to this and other new technologies as well."

The Blue Plains Advanced Wastewater Treatment Plant, in Southwest DC, the world's largest such plant, treats and discharges 370 million gallons of Washington-area wastewater a day—up to a billion gallons during rainstorms. Untreated water is piped in from the District, suburban Maryland, and Fairfax and Loudoun counties and is pumped back into the Potomac River after it undergoes tertiary treatment. Says George Hawkins, general manager of the District of Columbia Water and Sewer Authority: "We put back water into the Potomac that is often cleaner than the water in the Potomac. It is a remarkable technical achievement."

But just as the Washington Aqueduct doesn't filter out EDCs, neither does Blue Plains or upriver wastewater-treatment plants in Rockville and Poolsville, whose treated wastewater goes into the Potomac and finds its way to the Washington area's water-intake pipes, to be recirculated through our freshwater supply.

Hawkins, former director of DC's Department of the Environment, says the water industry is paying a lot of attention to EDCs. A local group formed to investigate the issue decided that not enough science is currently available about EDCs to justify the expense of trying to remove them.

"We need to know which of these new contaminants may pose the greatest health dangers so we can develop a plan," Hawkins says, "because right now our ability to detect these chemicals as low as one part per trillion has outstripped our ability to know what their consequences may be. But does this issue of endocrine disrupters keep us awake at night? You're doggone right it does."

In the best of all worlds, the Clean Water Act of 1972 might have eliminated the EDC problem in the water supply before it began, or at least reduced it, because a goal of the act was to prevent all manmade pollution from entering our waterways. While that law has led to improvements in the quality of many of our nation's waterways, it is also routinely ignored. According to EPA data reported in the New York Times in September 2009, between 2004 and 2009 there were 506,000 violations of the Clean Water Act nationwide.

In 1996, Congress created an EPA office dedicated to EDC research, called the Endocrine Disruptor Research Initiative. It has yet to release significant information about the risk of EDCs to metropolitan drinking water.

Now that we know our drinking water contains EDCs, here is the question: Even at the very low concentrations that EDCs reach Washington's water-intake pipes, is there evidence that they pose human health consequences? If so, what are they?

Two of the most remarkable aspects of the current obesity epidemic are its scope and the rapidity with which it has grown. Between 1980 and 2008, obesity rates have doubled worldwide, according to a study published in the British medical journal the Lancet, and other studies have shown a threefold increase in North America and Europe. The epidemic cuts across socioeconomic, age, and sex lines.

In 2000, no state in the US had an adult obesity rate higher than 30 percent, according to the CDC. By 2010, 12 states had reached that level, and another eight states are close. It's estimated that more than a third of adult Americans are clinically obese and that 68 percent of Americans age 20 and older are overweight or obese.

Obesity is considered a threat to human health by the National Institutes of Health and the World Health Organization. WHO says more people in the world now are obese than are undernourished. A risk factor for Type II diabetes, cardiovascular disease, stroke, and high blood pressure as well as for breast, colon, and renal cancers, obesity is a major force driving up health-care costs.

Why have we gotten so fat so fast? In children, the rapid rise of obesity and Type II diabetes has been linked to everything from too much TV and video games to fast food and the lack of physical education in schools. A recent WHO statement lays the blame on less exercise coupled with increased consumption of "nutrient-poor foods" with high levels of sugars and saturated fats.

All of these factors probably are contributing to the rise in obesity, but until recently no one linked the epidemic to the disruption of hormonal regulation, which can change our bodies and diminish our ability to stabilize weight.

A 2009 statement issued by the Endocrine Society, called "Endocrine-Disrupting Chemicals," found "alarming signals" that EDCs may be triggering obesity and other serious health problems. In many if not most cases, research indicates that prenatal and early childhood are the most vulnerable periods because exposure can affect development. Health problems may not be seen until many years later; this situation has given rise to an area of scientific inquiry called "the developmental origins of adult disease."

The report noted that the increasing incidence of obesity matches the rise in industrial chemicals in the environment, and it cites a number of scientific studies linking certain EDCs (called obesogens) to obesity.

The first-of-its-kind statement went through "incredible scrutiny," says Dr. Andrea C. Gore, one of the coauthors. It's 54 pages long and lists 485 scientific papers to support its claims that EDCs appear to be triggering obesity and other human-health problems, including diabetes and cardiovascular disease.

Says Gore, a professor of pharmacology and toxicology at the University of Texas: "We felt there is a very strong weight of evidence supporting the link between endocrine disrupters and dysfunctions in all the endocrine systems in humans and wildlife. Much of that is based on very good lab research that has been coming out in recent years. So the reason we were able to make such a strong statement is that the data really support it."

The report says: "The literature demonstrates a role of EDCs in the etiology of complex diseases such as obesity, diabetes mellitus, and cardiovascular disease, yet these processes are still poorly understood."

The report goes on to explain that "even infinitesimally low levels of exposure—indeed, any exposure at all—may cause endocrine or reproductive abnormalities, particularly if exposure occurs during a critical developmental window." Surprisingly, the report found that "low doses may even exert more potent effects than higher doses."

Because EDCs are ubiquitous in the environment, it's unclear whether those we get from drinking water play a prominent role in human health, but a reasonable assumption based on the fish kills and other evidence is that they could.

EDCs have also been linked to the rising rates of breast and prostate cancers, both of which are hormone-related. There are undoubtedly many environmental and genetic factors involved in cancers, but one of the strongest pieces of evidence for the role of EDCs in prostate cancer came out of a large epidemiological study conducted by the National Cancer Institute and the National Institute of Environmental Health Sciences. The study evaluated more than 55,000 agricultural pesticide applicators in North Carolina and Iowa and found that exposure to pesticides, some of which may interrupt normal hormonal balance, increased prostate-cancer rates in men with a family history of the disease, leading the authors to speculate that the pesticides interacted with genes in those men.

According to the Endocrine Society paper, several signals suggest that people may be at risk for reproductive compromise because of EDCs. Declining male sperm counts reported in countries around the world, including the United States, may be linked to EDC exposure, the report says. Additionally, young women in the 15-to-24-year-old group currently have the fastest-growing rate of involuntary subfertility. Subfertility doesn't mean that a woman can't bear children but that she may encounter more difficulty and delay in becoming pregnant than would otherwise be expected.

There are some indications that hypospadias, a malformation of the urethra, may develop in a baby boy when a genetic susceptibility is triggered by environmental exposure prior to pregnancy or within the first 16 weeks of fetal development, the time when the urethra develops. Epidemiologic studies suggest that environmental exposures increase the incidence of hypospadias and other birth defects.

According to the CDC, metabolites from one type of phthalate were found to be five times higher in the urine of American women ages 20 to 40 than in any other segment of the population. Phthalates make plastics flexible and are used in perfumes, nail polish, and shampoos. The phthalate from the study, dibutyl phthalate, has been found to be estrogenic in laboratory animals, leading to developmental disorders in male offspring. It also interferes with the thyroid system.

A study in the United Kingdom found that the male children of vegetarian mothers, who consumed more phytoestrogens from agricultural fertilizers than mothers on regular diets, had five times the rate of hypospadias as the sons of nonvegetarian mothers.

Many theories have been advanced to account for the increasing prevalence of autism in children, a disorder the Autism Society of America calls "the fastest-growing development disability" in the world. A CDC report in the June 2011 issue of Pediatrics reported that the percentage of children and teens in the US diagnosed with developmental disabilities such as autism has increased by 17 percent since the late 1990s. This upward trend of neurological impairment was also seen in the increased prevalence of attention deficit hyperactivity disorder as well as stuttering and learning disabilities.

While genes probably play a role, there is growing suspicion that EDCs are also involved in a range of neurological impairments, including autism.

Gore notes that autism is a complicated disorder and has no single cause. But, as with obesity and hormone-related cancers, she says, "the timing of autism's increase in the population also coincides with the rise of EDCs in the environment. We don't want to overinterpret the data, but the ways in which we've changed the environment appear to be changing how our brains develop. Low-dose exposures in early development are very important and very potent, but the problem is it is hard to detect them."

For example, a large body of evidence from the Great Lakes and other areas links maternal polychloride byphenyl (PCB) exposure, largely from fish consumption by mothers during pregnancy, to lower IQs in children. One avenue by which PCBs are believed to do this damage is through thyroid disruption. Normal thyroid function is vital to proper neurological development.

"A loss of four or five IQ points may not seem like such a big deal," Gore says, "but when you consider the whole shift of the population's IQ because people are being exposed to these contaminants, there could potentially be a dumbing-down of the population."

Once used widely by industry for many purposes, including as a lubricant and coolant, PCBs were banned in 1979 because of environmental concerns. Made by combining benzene and chlorine, PCBs—which are classified as endocrine disrupters—sink to the bottoms of rivers and lakes. They enter aquatic plants and, when fish eat them, become part of the human food chain. When people consume them, they get stored in fat.

PCBs also aerosolize—meaning they break down over time and can turn into a fine, powdery substance carried by wind—and as a result are in virtually every body of water in the world, including the Potomac River. The EPA has issued a PCB advisory warning against the consumption of fish from the Potomac, especially of bottom feeders such as carp and catfish.

Scientific studies show that salmon raised in fish farms in the Atlantic Ocean have a heavier burden of PCBs than salmon caught in the wild—in part because farm-raised salmon don't swim as vigorously as those in the wild and as a result have more body fat. Although there are fewer PCBs in the environment than before, because of their long half-life they continue to pose a danger to humans, especially during early development.

The best way to prevent EDCs from entering Washington's drinking water would be to keep them out of the Potomac River in the first place. Tom Jacobus notes that the Potomac River Basin Drinking Water Source Protection Partnership was formed by area water utilities in 2004 to address this issue. Although the body has no enforcement powers, it's working with the Environmental Protection Agency and agricultural extension services in the states to raise awareness of the consequences of such practices as allowing cattle, especially those treated with hormones, to roam freely in tributaries. Efforts are also being made to convince cattle and chicken operations to control runoff into the river. Jacobus says the message is simple: "If you have a cattle-feeding operation that uses a lot of hormones, please don't let the cattle have access to the water, and control your runoff."

Jacobus says the best way to keep EDCs from the river is not to put them there in the first place. "I would also ask people not to throw your pills down the toilet and to look at labels on personal-care products and avoid those that may have EDCs in them." This is an important message but one unlikely to be heeded by most people.

Because there are hundreds if not thousands of chemical compounds, Jacobus says, water officials are trying to get a clearer understanding of the classes of chemicals and to regulate them: "We are looking at new and innovative treatment techniques, and within two years we will have treatment plans for some EDCs. We need to determine as an industry what these treatment levels should be, and we need to look at cost-effectiveness. Some of these EDC-removal technologies could cost $100 million. Ozone treatment, for example, works through electricity, so it's expensive to operate. We're not resisting this, but we don't want to get ahead of the science."

For now, Jacobus says, the Washington Aqueduct will continue to monitor the EDC issue. "We have a lot of confidence in the EPA, but at the same time we want to do better than EPA regulations because our customers want to us remove some of the unknown," he says. "We are also involved in a cooperative research project to understand more about endocrine-disrupting compounds and their role in drinking water.

"From the science we know now, we do not see a threat to drinking water at levels we can detect. But are we looking at it and thinking of future treatments? Yes, we are."

Contributing editor John Pekkanen has written about health and medicine for more than three decades. His September 2011 article, “Coming Back: Battling the Invisible Wounds of War,” about military servicemembers with brain injuries that would have been fatal in earlier tim es, can be found here.

This article appears in the July 2012 issue of The Washingtonian.