Contaminants of Emerging Concern

Potomac River Basin Drinking Water Source Protection Partnership

What are they?

Contaminants of emerging concern are chemicals or materials in water, soil, river sediments, or air — typically present at very low concentrations — and which may be perceived as a potential or real threat to human health or the environment. A contaminant may also be of emerging concern because of the ability for it to be detected by new test methods or by the discovery of a new source or a new pathway to humans.

Many pharmaceuticals and personal care products detected in the environment can be considered contaminants of emerging concern since they lack published health standards. However, the word “emerging” used in the context of contaminants detected at low levels in water should not be confused with the word “emergency” or be taken to mean that such detection is cause for alarm.

Some of the terms used to refer to different classes of emerging contaminants include:

  • Pharmaceuticals and personal care products (PPCPs)
  • Endocrine disrupting chemicals (EDCs)
  • Organic wastewater contaminants (OWCs)
  • Persistent organic pollutants (POPs)
  • Microconstituents
  • Nanomaterials
  • Algal toxins
  • Harmful algal blooms (HABs)

Why are we concerned?

New analytical techniques have been developed that allow scientists to measure very low levels of numerous chemicals in water and other media.

There is mounting evidence that even low levels of some contaminants of emerging concern in the environment may affect wildlife, sometimes causing non-lethal but adverse ecological health effects. Although no direct adverse impact on human health has been established from consuming drinking water treated to current EPA standards, the presence of very low levels of unregulated contaminants in the source waters used for drinking water supply can be a cause for concern.

Find out what the Partnership is doing to address contaminants of emerging concern in the basin.

Learn more

Many DWSPP utility members have provided information on pharmaceuticals detected in their source waters:

Relevant Research:

More information on the US EPA programs for regulating drinking water contaminants, endocrine disrupting chemicals research, and human and ecological health effects:

More information on emerging contaminants from the Environmental Council of the States (ECOS):

More information on related USGS studies: