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Constituents of Emerging Concern (CECs)

"Constituents of emerging concern (CECs)" is a term used to include a broad range of unregulated chemical components found at trace levels in many of our water supplies, including surface water, drinking water, wastewater, and recycled water.  Other terms include "emerging constituents," "endocrine disrupting chemicals," or "pharmaceuticals and personal care products."


This web page includes information about current research and efforts regarding CECs in water supplies.



NWRI Research Project Report (Posted May 19, 2010)



MET report CEC cover2010 NWRI Final Project Report on "Source, Fate, and Transport of Endocrine Disruptors, Pharmaceuticals, and Personal Care Products in Drinking Water Sources in California"


This report was prepared by researchers at the Metropolitan Water District of Southern California and Orange County Water District who conducted an-NWRI sponsored research project to better understand the presence and levels of CECs in major Southern California Drinking water sources (State Water Project, Colorado River water, and Santa Ana River water). 


As part of this project, water samples were taken from the three water sources at 32 locations, ranging from upstream of the City of Sacramento to down south in Orange County, CA, as well as locations along the Colorado River in Arizona and Nevada.



Supplemental Documents (Posted May 19, 2010)


2009 Intertox, Inc. Report on “Comparison of Analytical Results for Trace Organics in the Santa Ana River at the Imperial Highway to Health-Based Screening Levels”


OCWD retained Intertox, Inc. to review the water quality data collected during the NWRI research project at the Santa Ana River at Imperial Highway sampling point, which serves as a diversion point to OCWD’s spreading basins (used for groundwater recharge). The purpose of the review was to determine the potential significance of detected concentrations of CECs to human health by comparing concentrations to health risk-based screening levels. Click here to download the Intertox report.



2010 NWRI Independent Advisory Panel Report for the Orange County Water District’s Santa Ana River Monitoring Program on Reviewing Studies of Contaminants

of Emerging Concern


OCWD requested that a scientific and technical “blue ribbon” panel of experts examine and evaluate the proposed findings of the Intertox study as soon as the risk assessment had been completed. The panel “unanimously concluded that none of the detected constituents were present in concentrations that would cause any health concern.” Click here to download the Panel report.




Joint NWRI Report


SCCWRP CEC Workshop Cover 2009 Workshop Report on "Managing Contaminants of Emerging Concerns in California"


This workshop report was prepared by a consortium of nonprofit and university sponsors interested in water quality issues in California for the purpose of highlighting strategies to begin addressing CECs in California’s water resources. 


Included is a list of recommended steps that involve new and evolving approaches for prioritizing compounds to study, identifying monitoring goals and objectives, and assessing thresholds of human and ecological heath concern.


The workshop report was released in September 2009.   Please click here to download the 52-page workshop report.





Other CEC Related Activities


State Water Resources Control Board Science Advisory Panel on Chemicals of Emerging Concern in Recycled Water


The State Water Resources Control Board and California Department of Public Health co-convened a “blue ribbon” expert advisory panel in 2009 to assess how CECs may impact public health or the environment and to guide future actions relating to the monitoring of CECs in recycled water used for landscape irrigation and groundwater recharge.


The panel’s draft recommendations were presented in a report entitled "Monitoring Strategies for Chemicals of Emerging Concern (CECs) in Recycled Water."


The draft report was released for public review on April 15, 2010; a final report will be available in July 2010.

The 180-page draft report can be downloaded online at www.sccwrp.org/view.php?id=574 (look in the table under “April 15”).



Advisory Panel for CECs in Coastal and Marine Ecosystems


The David and Lucile Packard Foundation has partnered with the Southern California Coastal Water Research Project (SCCWRP) to support an expert advisory panel that will provide the State of california with recommendations on how to best limit the impact of CECs on our oceans, estuaries and wetlands.


One question the panel will address is "What approaches should be used to assess biological effects of CECs to sentinel species in coastal aquatic systems?"


This panel was initiated in 2009 with anticipated completion in 2011. More information is available at www.sccwrp.org.



Santa Ana Watershed Project Authority (SAWPA) Emerging Constituents Workgroup’s Proposed Sampling and Analysis Plan for the 2010-11 Emerging Constituents Characterization Study in the Santa Ana Watershed


SAWPA’s Emerging Constituents Workgroup has developed a water quality investigation work plan to characterize 11 target CECs in surface waters and imported waters in the Santa Ana Watershed in Southern California.


The 11 CECs (which include caffeine, DEET, and Ibuprofin, for example) were selected based on detection within previous national studies and on recommendations as surrogates for wastewater indicators.


The work plan provides guidelines for sample collection, quality assurance/quality control procedures, data assessment, and other necessary criteria for sampling and laboratory analysis. A release date for the work plan is pending.


Click here for more information about SAWPA's Emerging Constituents Workgroup.




Additional Resources


- Web page on Pharmaceuticals in Drinking Water


- Web page on Constituents of Emerging Concern


- Web page on Pharmaceuticals and Personal Care Products (PPCPs)

- Web page on PPCPs in Water

- Web page on the Safe Drinking Water Act

- Web page on the Clean Water Act

- Web page on the Unregulated Contaminants Monitoring Program

- Web page on Drinking Water Contaminant Candidate List (CCL3)

- Web page on Endocrine Disruptors (EDC) Research

- Web page on Endocrine Disruptor (EDC) Screening Program

- Web page of Ecosystem Services Research (or Ecosystem Health)

- Web page on Human Health Criteria (Surface/Drinking Water)


- Web page on Pharmaceutical Drugs


- Web page on Fate of Pharmeceuaticals in Watersheds


- Toxicological Relevance of Endocrine Disruptors and Pharmaceuticals in Drinking Water


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