Tracing Wastewater - Using Unique Compounds to Identify Sources of Contamination

Discharge from a wastewater treatment plant on Fourmile Creek, Iowa. USGS scientists have been studying the fate and transport of emerging contaminants in the creek and their potential use as indicators of wastewater contamination (Click on photo for larger version)

U.S. Geological Survey (USGS) and U.S. Environmental Protection Agency (EPA) scientists have shown that wastewater treatment plants are a significant source of pharmaceuticals and other emerging contaminants to rivers. A recent study analyzed treated wastewater being discharged to rivers from 10 wastewater treatment plants (sewage treatment plants) for 110 emerging contaminants, and found between 28 and 50 of these compounds in the wastewater. Commonly detected compounds included antimicrobial disinfectants (triclosan), antibiotics (sulfamethoxazole), musk fragrances (tonalide), antihistamines (diphenhydramine), and antiepileptic drugs (carbamazepine). After analyzing water-quality samples that were collected upstream and downstream of the treatment plants, the scientists determined that wastewater treatment plants are a significant source of emerging contaminants in the streams that were sampled.

This study and others provide evidence that many emerging contaminant compounds may make ideal tracers and indicators of wastewater in rivers and other water bodies because they are used only by humans. For example:

• Average frequency of detection of emerging contaminants by compound class in 10 wastewater discharges from across the Nation. Numbers in parentheses indicate the number of compounds in each class (Click on photo for larger version)

  Concentrations of rare earth elements in wastewater discharged to Boulder Creek, Colorado, compared with upstream and downstream samples. Concentrations are normalized to the North American Shale Composite**, and shown on a logarithmic scale. Upstream sample is 60 meters upstream and the downstream sample is 0.5 kilometers downstream of the wastewater discharge point (Click on photo for larger version)

  USGS and EPA scientists have identified 35 compounds in wastewater from sewage treatment plants that have the potential for use as indicators of human fecal contamination. Water resource managers need rapid methods to assess whether or not drinking and recreational waters are free from pathogens associated with human fecal matter in many wastewaters. Current methods are very time consuming, and these compounds could potentially be used as an early warning of the likelihood for unhealthy conditions. Many pharmaceuticals, such as carbamazepine and diphenhydramine, are candidates because they are ingested and excreted by humans.
• In another study, USGS scientists have shown that the discharge from wastewater treatment plants can be enriched with gadolinium (Gd), a rare earth element. Gadolinium is used by medical facilities as a contrasting agent for MRIs (magnetic resonance imaging). Organometalic gadolinium complexes make good contrasting agents because of their large magnetic moments and extreme stability in the human body. Their stability and their ease of measurement (when compared to many emerging contaminants that are organic compounds) make them ideal tracers of wastewaters in the environment. Water resource managers could use gadolinium in studies of the effects of wastewaters on streams, wetlands, and other water bodies.

References

• Glassmeyer, S.T., Furlong, E.T., Kolpin, D.W., Cahill, J.D., Zaugg, S.D., Werner, S.L., Meyer, M.T., and Kryak, D.D., 2005, Transport of chemical and microbial compounds from known wastewater discharges – Potential for use as indicators of human fecal contamination: Environmental Science and Technology, v. 39, no. 14, p. 5157-5169, doi: 10.1021/es048120k.
• Verplanck, P.L., Taylor, H.E., Nordstrom, D.K., Barber, L.B., 2005, Aqueous stability of gadolinium in surface waters receiving sewage treatment plant effluent, Boulder Creek, Colorado: Environmental Science and Technology, v. 39, no. 18, p. 6923-6929, doi: 10.1021/es048456u.

More Information

• Emerging Contaminants in the Environment
  • Sources and Source Pathways - Wastewater Treatment Plants
  • Transport and Fate - In-Stream Processes
• Research in Analytical Environmental Trace Element Chemistry and Its Impact on Water Quality
• Chemical Modeling and Thermodynamic Data Evaluation of Major and Trace Elements in Acid Mine Waters and Ground Waters

Related Headlines

• Biosolids, Animal Manure, and Earthworms: Is There a Connection?
• Household Chemicals and Drugs Found in Biosolids from Wastewater Treatment Plants
• Wastewater Indicators Shown to Degrade in Streams
• Endocrine Disruption Found in Fish Exposed to Municipal Wastewater
• Pharmaceuticals Found in Soil Irrigated with Reclaimed Water
• Are Pharmaceuticals in Your Watershed? Understanding the Fate of Pharmaceuticals and Other Contaminants in Watersheds
• Book Chapter on Exposure Modeling and Monitoring of Human Pharmaceuticals in the Environment
• USGS Scientists Contribute to New Book on Pharmaceuticals in the Environment
• USGS Scientists Develop New Method to Measure Pharmaceuticals in Water
• Developing Methods to Measure New Contaminants in Aquatic Environments
• National Reconnaissance of Pharmaceuticals, Hormones and Other Organic Wastewater Contaminants in U.S. Streams is Making an Impact
• "National Reconnaissance of Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in Streams" Named as One of the Top 100 Science Stories of the Year
• What's in Our Wastewaters and Where Does it Go?

USGS Information on Gadolinium

• Rare Earth Elements - Critical Resources for High Technology: USGS Fact Sheet 087-02
• Rare Earths, Statistics and Information

Back to Headlines page