Pharmaceuticals in drinking water

Source: Crs

As monitoring technologies have become available and testing has increased, traces of more pharmaceuticals and personal care products (PPCPs) have been detected in surface waters and drinking water supplies. Pharmaceuticals include prescription drugs, veterinary drugs, and overthe- counter medicines. Personal care products cover a broad spectrum and include cosmetics, hair products, sun-screens, fragrances, anti-bacterial soaps, and vitamins. These chemicals are released to the environment in various ways, including elimination of human and animal waste, disposal of unused medicines down the toilet, veterinary drug usage, hospital waste disposal, and industrial discharges.

Although significant research is being conducted, much is unknown about the occurrence and movement of PPCPs in the environment, their occurrence in drinking water supplies, or about the potential health risks from exposure to PPCPs at extremely low levels through drinking water. Nonetheless, the detection of pharmaceuticals and related products in public water supplies generates concern, because many of these products are specifically designed to have a biological effect in humans, animals, and/or plants. Pharmaceuticals often contain chemical compounds that can affect the endocrine system by altering, mimicking, or impeding the function of hormones. Such endocrine disrupting chemicals (EDCs) have the potential to affect growth, development, reproduction, and metabolism. Over the past decade, scientists and regulators have become increasingly concerned about the effects that exposures to low levels of PPCPs may be having on aquatic organisms, and also potentially on human health.[1]

The U.S. Geological Survey (USGS) and the U. S. Environmental Protection Agency (EPA) have identified a wide array of research needs and gaps that, if addressed, would help delineate the scope of environmental and human health issues that might result from the presence of PPCPs in the environment. The USGS has conducted research on the occurrence of hormones, pharmaceuticals, and other wastes in residential, industrial, and agricultural wastewater, and has found that a broad range of these chemicals occur commonly downstream from large urban areas and concentrated animal production areas.[2] EPA has been conducting and supporting numerous PPCP research projects in several areas, including the relative importance of different sources of PPCPs in the environment (e.g., veterinary vs. human medicine), how PPCPs move through the environment, human exposure pathways, ecological exposure pathways, monitoring and detection tools, assessment of potential human health effects, and assessment of potential ecological effects. Research is also being conducted to evaluate the ability of drinking water treatment technologies to remove various PPCPs.

Ecological research has received particular attention because exposure risks for aquatic life have been considered to be much greater than those for humans.[3] Nonetheless, a key research issue concerns the possible health risks from exposure to very low doses of the myriad chemicals found in PPCPs. Because PPCPs occur in the environment at low concentrations, their effects may be subtle. Among other research gaps, EPA has identified a need to develop tests that can detect more subtle health effects.

The agency is also conducting a study to determine the amount of PPCPs that are discharged to wastewater treatment plants from various sources. As part of this study, EPA is evaluating how hospitals and other institutions dispose of unused medications.[4] Other research projects address the development of analytical methods to determine the source and fate of PPCPs in the environment.

As noted above, EPA proposed its third list of unregulated contaminants being considered for regulation in February 2008. This Contaminant Candidate List 3 (CCL 3) contains 104 contaminants, none of which are pharmaceuticals. Following recent reports of the detection of pharmaceuticals and commonly used over-the-counter drugs in the drinking water supplies of 24 large community water systems, EPA has asked its Science Advisory Board (SAB) and stakeholders to evaluate and comment on the contaminant candidate screening and selection process to determine whether the process requires revision.[5]

Because of ecological concerns, as well as human health concerns, regulating contaminants in drinking water represents only part of the response to this multi-faceted problem. Recognizing that people and animals will continue to take and use pharmaceutical products, water suppliers and other stakeholders consider changes at wastewater treatment plants to be a key part of the solution.

The Association of Metropolitan Water Agencies (AMWA), which represents the largest publicly owned water systems, has made several recommendations to address this emerging drinking water issue. Among these recommendations, the AMWA strongly encouraged EPA to make research on treatment technologies a high priority, and urged water utilities to inform consumers of efforts to monitor and remove pharmaceuticals from water sources. AMWA also called for EPA and the Food and Drug Administration (FDA) to determine whether the presence of trace amounts of pharmaceuticals results in short-term or long-term effects on health and the environment, recommended that the federal government take the lead in developing a national program for disposing of unused prescriptions, and called for animal feeding operations to reduce their contributions of antibiotics and steroids into water supplies.[6]

Legislation in  the United States Congress

Several bills addressing this issue have been introduced in the United States Congress, including two that have passed the House: H.R. 1145 (H.Rept. 111-76) would call for research on prevention and removal of contaminants of emerging concern, including PPCPs, in water resources; and H.R. 1262 (H.Rept. 111-26) would direct EPA to conduct a study on the presence of PPCPs in the nation’s waters. Additionally, the House Appropriations Committee report for EPA’s FY2010 appropriations (H.R. 2996, H.Rept. 111-180) encourages EPA to develop a plan to synthesize available research on contaminants of emerging concern and to apply a systematic approach to addressing the problem of such contaminants in water supplies. The House report further directs EPA to publish a list of at least 100 chemicals for screening in the Endocrine Disruptor Screening Program that includes drinking water contaminants such as PPCPs. H.R. 276 was introduced in January 2009 to require the EPA Administrator to convene a task force to develop recommendations for the proper disposal of unused pharmaceuticals to protect water sources.


  1. ^For more information on EDCs and potential health risks, see CRS Report R40177, Environmental Exposure to Endocrine Disruptors: What Are the Human Health Risks?, by Linda-Jo Schierow and Eugene H. Buck.
  2. ^See for example, U.S. Geological Survey, Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. Streams, USGS FS-027-02, June 2002.
  3. ^Aquatic organisms face higher risks of exposure than humans for several reasons. For example, these organisms have continuous exposure, and generally are exposed to higher concentrations of PPCPs in untreated water, compared to treated drinking water.
  4. ^For further information on PPCPs and related EPA activities, see
  5. ^Information of the CCL3 is available at,
  6. ^Association of Metropolitan Water Agencies, AMWA Discusses Pharmaceuticals in Water Supplies, March 11, 2008,

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Congressional Research Service. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Congressional Research Service should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

Note: The first version of this article was drawn from RL34201 Safe Drinking Water Act: Selected Regulatory and Legislative Issues by Mary Tiemann, Congressional Research Service on September 2, 2009.



(2009). Pharmaceuticals in drinking water. Retrieved from


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