WATER QUALITY NEWS: RECENT MEDIA FOCUS ON PHARMACEUTICALS IN DRINKING WATER
Recent media attention has focused public attention on pharmaceuticals in driking water. The LADWP and Metropolitan Water District are committed to helping our customers better understand this issue and address any concerns customers may have.
It is important to know that while water experts view this as an emerging issue, all MWD and LADWP water continues to meet state and federal drinking water standards and our water remains well within all public health guidelines. In fact, the LADWP tested our own source water in 6/2001 and 2/2002 at a sensitivity of 10 parts per TRILLION. Both found no pharmaceuticals in our drinking water. Testing was done at all intake points and also included treated effluent at Tillman reclamation facility. In addition, although our treatment facilities were not designed for removal of pharmaceuticals, our major LA Aqueduct Filtration Plant employs ozone, and it is know to be an effective oxidant to destroy many pharmaceutical compounds.
The recent media attention included information obtained from the Metropolitan Water District, including results from a 2006 survey of source and treated water at the district's Joseph Jensen Water Treatment Plant, conducted as part of an American Water Works Association Research Foundation/California Urban Water Agencies study. That survey revealed the presence of trace amounts (in the parts-per-trillion range) of nine different pharmaceuticals, two human steroids, one personal care product and two pesticides in the Jensen plant's influent waters. Metropolitan's supplies, however, continue to meet and exceed all safe drinking water standards.
During the survey, the presence of two pharmaceutical compounds also were identified in samples collected from the plant's treated effluent and at a distribution site downstream. The pharmaceuticals dilantin (an anti-epileptic drug) and meprobamate (an anti-anxiety drug) were found in parts-per-trillion concentrations that are substantially lower than therapeutic levels. For example, an individual would need to consume 300 million liters of water containing the trace levels of meprobamate in the Jensen supplies-equivalent to the water held in about 120 Olympic-sized swimming pools-to achieve the therapeutic adult dose of 1,600 mg/day.
Key Facts Regarding Pharmaceuticals as an Emerging Issue:
- The LADWP and MWD are committed to protecting public health. With water quality a priority, we have identified the presence of PPCPs and endocrine disrupting compounds (EDCs) in source and treated waters as an emerging issue that demands attention.
- Many water sources-rivers, streams and groundwater-are susceptible to PPCPs and EDCs through wastewater input and/or agricultural practices. Some of these compounds can persist through the water treatment process.
- The presence of PPCPs and EDCs in source waters is not a new phenomenon. These chemicals have been present since their initial use by consumers and industry.
- The development of more sensitive analytical techniques has only recently allowed the detection of these compounds at such low environmental levels.
- Wastewater discharge and runoff from agricultural areas are considered significant factors associated with the presence of PPCPs in surface waters.
- A survey of Colorado River Water conducted in 2002 by the U.S. Geological Survey detected eight pharmaceutical compounds and three PPCPs; all detections were in low parts-per-billion to parts-per-trillion ranges.
- In general, most PPCPs cannot be removed by conventional treatment. Ozone, however, is considered one of the most cost-effective treatment technologies capable of removing a wide range of PPCPs and EDCs. Advanced treatment processes such as membrane technology can remove most PPCPs.
- The human health effects, if any, of drinking water with extremely low trace levels of PPCPs and EDCs are not known at this time. This is being studied but considerably more work is required to determine whether there are any impacts.
Additional Background Information on Pharmaceutical Compounds and Personal Care Products
The water community is committed to protecting public health. Water professionals are researching the occurrence of personal care products and pharmaceutical compounds in drinking water supplies and are paying close attention to health effects research in this area.
Water professionals have the technology today to detect more substances - at lower levels - than ever before. As analytical methods improve, pharmaceutical compounds and personal care products are being found at very low levels in many of our nation's lakes, rivers and streams.
The fact that a substance is detectable does not mean the substance is harmful to humans. To date, research throughout the world has not demonstrated an impact on human health from pharmaceuticals and endocrine disrupting compounds in drinking water.
While these compounds may be detected at very low levels in source waters, people regularly consume or expose themselves to products containing these compounds in much higher concentrations through medicines, food and beverage and other sources. The level in which they are found in source waters is very small in comparison.
The U.S. Environmental Protection Agency maintains an active program called the Contaminant Candidate List (CCL) to identify contaminants in public drinking water that warrant detailed study. The CCL does not currently include any personal care products or pharmaceuticals.
While research has not demonstrated human health impacts from these compounds, the ongoing conversation should remind us of how precious our source waters are and the need to protect them from harmful substances. As a society, we should encourage policies that protect source water from contaminants introduced by pesticides, gasoline or industrial products. The best and most cost-effective way to ensure safe water at the tap is to keep our source waters clean.
If any customer would like additional information about pharmaceuticals in drinking water or to discuss this issue further with a LADWP water quality expert, please call 1-800-DIAL-DWP.
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