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What are Contaminants of Emerging Concern?

Contaminants of Emerging Concern are broadly described as chemicals or substances that are not yet regulated by the U.S. Environmental Protection Agency but which potentially might pose a threat to human health or the environment.

These potential contaminants include endocrine disrupting compounds, pharmaceutical drugs, personal care products, and persistent organic pollutants, or nanomaterials. As analytical technology advances, these substances are increasingly being detected in surface water, mostly at low levels. Because of the emerging nature of these substances, and because knowledge about the chemicals is still in its infancy, the levels at which they might become a threat are not well understood. Additionally, reliable analytical and treatment technologies are not yet available.

What is WSSC Water Doing?

To ensure that our customers continue to receive safe drinking water, WSSC Water and its partners in industry have studied the issue of contaminants of emerging concern for more than a decade. Here's what we're doing to protect you and your drinking water:

  • WSSC Water works with two regional partners and coordinates with the Metropolitan Washington Council of Governments to collect samples from the Potomac and Patuxent rivers. Tests showed the presence of extremely small amounts of CECs in the area’s water supply. These low level detections do not necessarily indicate a concern to human health. 
  • In line with EPA’s Unregulated Contaminants Monitoring Regulations, as well as related Maryland law, WSSC Water regularly monitors groups of contaminants in water produced by the Potomac and Patuxent water filtration plants. These contaminants are identified by the EPA based on the latest knowledge of nationwide occurrence and human health impacts, and are renewed every five years. 
  • WSSC Water voluntarily monitors some of the CECs based on known or suspected risks at our water system. These contaminants include hexavalent chromium and cyanotoxins from algal blooms.

Read our reports

Historical data on detected containments can be found in Unregulated Contaminants Monitoring Regulations reports. 

Read the Report

Total chromium levels in WSSC Water's water are routinely less than 2 parts per billion, 50 times less than the EPA limit.

Hexavalent Chromium

Chromium occurs naturally, and certain forms are beneficial to human health. But the wrong kind of chromium is toxic. Learn more about how we monitor chromium in the water.

Monitoring for Chromium

Algal Blooms

WSSC Water monitors both treated and untreated water for cyanotoxins during the warmer months to ensure it does not enter our water system.

Learn More about Algal Blooms

Per- and Polyfluoroalkyl Substances

Per- and Polyfluoroalkyl Substances, or PFAS, are in a lot of products you likely use: non-stick cookware, dental floss, cleaning products and cosmetics. While it's not clearly understood if or how PFAS affects humans, find out how WSSC Water is closely monitoring for them.

Learn More About PFAS

Be Saltwise (Road Salt)

When winter weather hits, avoid using too much salt to fight the snow and ice. Because that salt can contaminate drinking water, harm aquatic plants and animals, and damage metal and concrete.

Learn about Road Salt Usage

Last Modified: March 14, 2023, 1:31 pm EDT