Drinking Your Neighbor's Drugs

Trace levels of pharmaceuticals and personal care products (PPCPs) have been discovered in some drinking water supplies. It has not been scientifically determined that PPCPs harm humans, yet the issue is hot and the debate is impassioned. Many people express concern that the U.S. could face future challenges if it doesn't address the issue of unregulated contaminants in the nation's water systems. When detected, pharmaceutical compounds have been typically measured in single-digit parts per trillion (ppt). To put this in context, most drinking water standards respond to issues in the parts per billion (ppb) range, which is 1,000 times higher.

Still, the topic garners interest and alternative opinions from consumers and water professionals alike.

The public receives an increasing amount of news on the subject from the media. Associated Press, for example, conducted a five-month inquiry into the matter and reported that PPCPs—from aspirin to hormones to mood enhancers and sunscreen—have been identified in the drinking water in 24 major metropolitan areas. That report recently spread through the nightly news programs; the online version of one of them sparked 95 blogged responses from the public.

"The [AP] articles were widely distributed and sparked strong interest across a wide sector of the public, and that's a step in the right direction," says Dan McCarthy, president and CEO of Black & Veatch's global water business. "Increased public interest and involvement in the debate on the environment in general and water quality in particular can only be beneficial. Well-informed consumers who understand the complexity of the issues being presented can make better decisions about supporting the increased investment necessary to improve water supplies globally, not just in the United States."

Some believe the reports are embellished and overstated. "While the original Associated Press (AP) story in March suggested otherwise, the presence of PPCPs in drinking water is neither a serious or new issue," says Steve Reiber, Ph.D., the drinking water quality technical lead for HDR's water business group. "The AP account failed to put the story in the proper context." Reiber says that embedded deep in the story are the "obligatory qualifiers and reluctant factual acknowledgements that, if presented earlier in the story, would not have created the reactionary responses and out-of-context discussions."

Still, there is a need for open dialog and communication of solid research and a mandate to serve the public with facts and figures. "Recognizing that consumers need information to make personal choices and water utilities need data to make informed decisions on treatment options, the water sector has not waited for U.S. Environmental Protection Agency or Federal Drug Administration to address pharmaceuticals found in water," comments Diane VanDe Hei, executive director of the Association of Metropolitan Water Agencies (AMWA). "Our attention to this issue is demonstrated by the ongoing work of water research organizations and through proactive monitoring carried out by water utilities. The media has been proactive, too, by reporting on this subject for a decade or more."

The American Water Works Association's upcoming Annual Conference and Exposition (ACE08) in Atlanta will feature multiple sessions on PPCPs, including two public affairs sessions on June 9 and a panel discussion on June 11.

YOU CAN HELP

Most research resources confirm that prescription drugs are the greatest source of PCPPs and that prevention is the best medicine to cure the problem.

Federal guidelines for the proper disposal of prescription drugs are available online (www.whitehousedrugpolicy.gov/). The following precautions allow any person to remediate the intrusion of drugs into potable water sources:

• Remove prescription drugs from their original containers and throw them in the trash.
• Mix prescription dugs with coffee grounds or kitty litter and dispose of them in empty cans or sealed bags.
• Flush prescription drugs only if the label or accompanying patient information specifically recommends it.
• Take advantage of community pharmaceutical take-back programs that allow the public to bring unused drugs to a central location for proper disposal.

Cause & Effect

"Questions remain about the effects of unintended chronic exposure to sub-therapeutic doses of pharmaceuticals by consuming water," McCarthy says. "Further, while the concentrations of individual pharmaceuticals have not been a problem, additional research is needed to determine if the combined effects of various pharmaceuticals could cause problems."

"The fact that a substance is detectable in drinking water does not mean it is harmful to humans," says Greg Kail, director of public affairs for American Water Works Association. "To date, research has not demonstrated an impact on human health at the trace levels these compounds are being found."

Wastewater discharges are the key source of these contaminants. Most water treatments modalities do not remove all drug residues. Currently, treatment facilities aren't required to test for pharmaceuticals or to filter them out. Water treatment reduces the concentration of pharmaceuticals in water, but water suppliers are studying alternatives for removing trace amounts that escape the treatment regimen.

"Basically, all that has changed is our ability to effectively monitor these compounds at the nanogram and picogram levels," says Reiber. "Soon we will be able to measure these compounds at the femtogram level, allowing us to identify several as yet undiscovered compounds."

According to AWWA, research on the health effects on humans has focused on two areas: What are the possible cumulative effects of long-term exposure? And will these compounds react in ways that are different from their intended purpose when they are introduced into the environment?

"The water community is paying close attention to health effects research in this area," Kail says, "and also conducting additional research on which treatment technologies remove these compounds." Because of the wide array of chemical structures and properties associated with PPCPs, no one single treatment can remove them all. Technologies under investigation include membranes and GAC which physically remove compounds and ozone or UV which break them down.

Reiber believes it's too early for utilities to take action to remove or to treat for PPCPs. "It really boils down to this—the cost of removing PPCPs is high, the risks from exposure appear to be microscopic, and no one has as yet conducted or even begun any of the necessary epidemiologic studies on which a cost/benefit analysis can be made."

Regarding specific treatments, Reiber says that activated carbon shows some promise, but its effectiveness will depend on the specific microconstituent, the presence of competing constituents and the type of activated carbon that's used.

He also believes that membrane filtration techniques show promise depending on the pore size of the membrane. "Most of the membrane filtration systems in place weren't designed to remove microconstituents but may be removing some during normal operations," he says. "Oxidation and advanced oxidation processes also have show promising degradation capability for some organic endocrine disruptors."

This is not the first time that the water industry has dealt with safeguarding potable supplies through proper management of conflicting risk factors. Balancing the need for disinfectants to reduce waterborne disease with the need to minimize carcinogenic by-product formation is one recent example.

"The risk of consuming trace quantities of PPCPs must be balanced against the need for drug treatments vital to disease management and the risk of environmental degradation that will arise from treatment applications that create concentrated residual management problems," says Joan Oppenheimer, vice president in the applied research department at MWH. "PPCPs originate from wastewater effluent discharges and other non-point sources. Water agencies should work in partnership with wastewater municipalities and pharmaceutical companies to minimize entry of these compounds into watersheds."

Research & Reaction

"To responsibly address the issue of pharmaceutical compounds in drinking water, scientists must know at what concentration these substances impact human health, not simply whether they can be detected," says Shane Snyder, Ph.D., research and development project manager for Southern Nevada Water Authority.

Snyder has served as principal investigator for many research projects related to the trace-level detection, removal and toxicology of pharmaceuticals in water supplies. In his research, he found the highest concentration of any pharmaceutical compound detected in U.S. drinking waters to be approximately five million times lower than one would take in a medical dose. He described that amount as roughly equivalent to one half of an inch in the distance between the earth and the moon, or in terms of time, approximately one second in approximately 750 years.

"I can tell you with absolute certainty that, if we regulate contaminants based upon detection rather than health effects, we are embarking on a futile journey without end," Snyder adds.

He believes that pharmaceutical compounds should instead be considered within the framework of U.S. EPA's Contaminant Candidate List process. Similarly, EPA's Unregulated Contaminant Monitoring Rule provides a framework for decisions concerning testing and reporting to customers about contaminants that are not currently regulated.

Congressional Testimony

In April, the congressional subcommittee on transportation safety, infrastructure security and water quality held a hearing entitled, Pharmaceuticals in the Nation's Water: Assessing Potential Risks and Actions to Address the Issue. In his opening remarks, U.S. Sen. Frank R. Lautenberg (D-NJ) commented that there are more than 140 chemicals in our drinking water that the EPA does not regulate and that small amounts of drugs are in the tap water that 41 million Americans drink every day.

"We need to act by increasing funding for our crumbling water infrastructure, including our wastewater and drinking water treatment facilities," Lautenberg said. "Those facilities are responsible for cleaning up our water, and they need the resources to do it." He pointed to EPA estimates that there is a $271 billion gap between what wastewater treatment plants need and what they receive. "We need to close that gap," he added.

David Pringle campaign director for the New Jersey Environmental Federation provided testimony on Behalf of New Jersey Environmental Federation and Clean Water Action. He said, "The presence of hundreds of unregulated pharmaceuticals and other man-made chemicals in the nation's surface, ground, waste and drinking water is becoming increasingly well documented due to increased monitoring, better testing techniques and greater use. While the data to date reveals concentrations at relatively low levels, current conventional treatment does not effectively remove them. This is cause for concern, albeit not panic, and cause for timely action. More research and other common sense measures are needed, and some are well beyond the current regulatory framework process and timeframes."

Snyder also testified at the hearing, providing testimony on behalf of the American Water Works Association. He suggested the following recommendation to the subcommittee members:

• Work among EPA, states, utilities and others to develop policies that minimize contamination of source waters by pharmaceutical products and other contaminants.
• Encourage more pharmaceutical take-back programs that reduce flushing of unused medications. Snyder noted that these programs are likely to only address a small part of the concern, however, since pharmaceutical compounds pass through humans and into the wastewater stream.
• Support an increase in EPA's drinking water health effects research budget to levels at least equivalent to the air pollution health effects research budget.

RECOMMENDATIONS OF THE ASSOCIATION OF METROPOLITAN WATER AGENCIES

• AMWA strongly encourages U.S. EPA to make research into treatment technologies a high priority.
• U.S. EPA and FDA must address whether the presence of trace amounts of pharmaceuticals result in short-term or long-term effects on human health and how such chemicals affect the environment.
• Water utilities should take steps to keep their consumers informed of their efforts to monitor and remove pharmaceuticals from water sources. Just as water utilities need data to make informed decisions, we believe that consumers should have the information they need to make personal health decisions.
• Animal feeding and production operations should endeavor to reduce their contributions of antibiotics and steroids into water supplies, and that industry should drop its efforts to seek liability exemptions from federal hazardous waste laws.
• The federal government should take the lead in developing a national program to provide consumers with an easy way to dispose of unused prescriptions. Likewise, the government should revise federal guidelines that currently encourage consumers to flush certain unused prescriptions down the sewer system.

What's Being Done

One way to combat the problem is through treatment. Three recent studies looked at processes to prevent PPCP intrusion into the water supply.

The Water Environment Research Foundation funded an evaluation to demonstrate how compound passage can relate to the solids retention time in the activated sludge process. It also evaluated the impact of wastewater granular media filters and microfiltration/reverse osmosis (MF/RO) and compared the performance of a full-scale activated sludge facility with side-by-side operation of a pilot membrane bioreactor.

The California Dept. of Water Resources tested the integrity of RO membranes during water reclamation applications and studied the passage of compounds through four RO membranes and the effect of RO staging and membrane breaching on compound passage.

A third study, funded by various California water agencies, considered ultraviolet (UV)/peroxide treatment as a barrier against the compounds in RO-treated tertiary wastewater effluent.

In addition, "the water sector will continue to invest in research and work with the public, the public health community and the federal government to ensure that the needed research is conducted," VanDe Hei says. "The sector will also continue to work with citizens and pharmacies to expand disposal programs that can have an immediate impact on source water quality."

The Bottom Line

"To date, no peer-reviewed published research has found ill effects on humans from pharmaceuticals in the environment at the trace levels we have seen in drinking water," Snyder says. "However, drinking water providers would like to see more research on this matter, so that we can either take appropriate action to address an actual health risk if there is one, or reassure the public that there is not one."

McCarthy looks at this with a bit different perspective. "The water industry, political leaders and the media must work together to help the public become better informed and to bring these issues front and center, while being careful not to over-simplify the problems or create undue anxiety among consumers," he says. "Let's add a dose of objectivity to the debate. We know that drinking water today is safer than it was 25 years ago, and 25 years ago it was far safer than 150 years ago ... water utilities and global water service companies are taking appropriate measures to ensure safe, high-quality water for future generations. We all need to do our part and support those efforts."

A Balanced Solution

"The solution to this problem does not end with advancements in water treatment," VanDe Hei says. "We also need to be protecting the environment and our sources of drinking water. A comprehensive solution requires the collective effort of the federal government, animal feeding and production operations, water utilities and consumers."

It also requires balance. As Reiber states, "Although evidence of environmental progress abounds, many environmentalists have not matured to the point of acceptance of miniscule risk in return for meaningful reward."

The truth also remains that purity of water is a relative issue and PPCPs are just one type of problem that influence water quality. "Americans should ensure that they properly understand all of the issues surrounding this topic so they can make informed rather than emotional decisions," Oppenheimer says. "There is no such thing as pure water and what is important is whether the compounds present in our tap water are present at hazardous levels."

Publication date: 6/2/2008
Media Outlet: Engineering News-Record