RESTON, VA — The US Geological Survey (USGS) has published online data from two of its national-scale reconnaissance studies on the environmental occurrence of organic wastewater contaminants, such as pharmaceuticals, personal care products and other emerging contaminants, in groundwater and untreated sources of drinking water in the United States.
According to the USGS, water samples were collected from a network of 47 groundwater sites across 18 states in 2000 for the groundwater study. The sample wells, which typically were not used for drinking water, were analyzed for 65 chemicals.
The most frequently detected chemicals include N,N-diethyltoluamide (insect repellant), bisphenol A (BPA, a plastic- and epoxy-manufacturing ingredient), tri(2-chloroethyl) phosphate (fire retardant), sulfamethoxazole (veterinary and human antibiotic), and 4-octylphenol monoethoxylate (detergent metabolite). The concentrations of chemicals detected were low, the USGS said.
In the 2001 source water study, a network of 25 groundwater and 49 surface water sources of public drinking water supply in 25 states and Puerto Rico were sampled and analyzed for 124 emerging contaminants. This study looked at water sources for populations ranging from one family to more than 8 million people, according to the USGS.
All samples in the source water study were collected at surface-water intakes or wellheads prior to water treatment. At least one emerging contaminant — including some naturally occurring compounds such as plant and animal steroids — was detected in about 96 percent of the samples, the USGS reported. The most frequently detected chemicals in surface water were cotinine (nicotine metabolite) and 1,7-dimethylxanthine (caffeine metabolite); and in groundwater were carbamazepine (pharmaceutical), BPA, 1,7-dimethylxanthine and the fire retardant tri(2-chloroethyl) phosphate.
According to the USGS, the two reconnaissance studies are considered the first to collect baseline information on the environmental occurrence of pharmaceuticals, personal care products, detergents, flame retardants, naturally occurring sterols and other organic contaminants in US groundwater and untreated sources of drinking water. Although The Associated Press(AP) released in March its investigative report on pharmaceuticals in drinking water sources, the USGS’ Michael J. Focazio told WaterTech Online™ on October 28 that the USGS data was not yet available to the public when the AP report was released.
“They were aware of our pending study results and they were also informed that it would be published soon. Unfortunately, they put together a story without our data and therefore missed an important opportunity,” he said, noting that the USGS projects require rigorous quality assurance/quality control (QA/QC).
According to Focazio, who was the lead researcher on the sources of drinking water study and paper, the USGS emerging contaminant project is ongoing, and has many facets and studies associated with it. However, this is the first time data from the sources of drinking water study have been released. Focazio also helped coordinate the USGS Toxic Substances Hydrology Program under which the emerging contaminant project is supported.
“The contaminants we detected represent a wide range of medicines, personal care products, and other compounds excreted or disposed of by typical homeowners in our daily lives,” said Focazio. Although not part of the study, some of these compounds are likely found in food and food ingredients, such as preservatives and chemicals used in food packaging as well as feed additives and medicines given to livestock.
“These results highlight the fact that products used and choices made by homeowners and consumers living in our watersheds are impacting the quality of our own drinking water,” said Focazio.
Although there is an increasing number of stewardship programs designed to handle disposal of unused pharmaceuticals, the programs do not address the “potentially larger source of pharmaceuticals to the environment caused by excretion from our bodies and into our wastewaters,” added Focazio, who noted the connections between consumers and drinking water quality.
According to the USGS Web site, data from these surveys will help scientists, regulators, water-resource managers and health professionals to determine if the concentrations and mixtures of chemicals measured in the sampled waters pose a threat to human or environmental health, and will help with the development of mitigating strategies where needed.
These studies follow a previous baseline survey of US streams for emerging contaminants.
To access the USGS reconnaissance studies, click here.
To view USGS images of its emerging contaminants studies, click here.
For related information, click here. 
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