Contaminants of Emerging Concern

According to EPA, an emerging contaminant is a chemical or material characterized by a perceived, potential, or real threat to human health or the environment or by a lack of published health standards.  A contaminant also may be "emerging" because of the discovery of a new source or a new pathway to humans.

The Remediation Standard Regulations do not contain numeric cleanup standards for emerging contaminants, but do require remediation using the procedures for Additional Polluting Substances (APS).  Regulated parties and their environmental professionals must consider whether emerging contaminants are constituents of concern when evaluating Phase I information and test for those emerging contaminants where warranted. Doing so will help to avoid uncertainty, audits, and further work in the future.  If emerging contaminants are detected, please contact the Department in advance of submitting APS criteria approval to clarify any issues.

General Information on Chemicals of Emerging Concern
Per- and Polyfluoroalkyl Substances (PFAS) page
1,4-Dioxane page
Trichloroethylene (TCE) Developmental Risks page
Perchlorate Information
Pharmaceuticals and Personal Care Products Information
Nanomaterials Information

 Where are they found?
 Analytic Method/Media/Notes
  • Military sites – ammunition and rocket fuel
  • Associated with nitrates and explosives, solvents or metals
  • Pyrotechnics (fireworks), grenades, signals and flares, black powder and airbag initiators
  • EPA Methods 314/331/332 for water
  • EPA SW-846 Methods 6850/6860
  • Sample both surface and deep soil and test adjacent surface and groundwater
  • Used in manufacture of sunscreens, cosmetics, sporting goods, stain resistant clothing, tires and electronics
  • Medical diagnosis, imaging and drug delivery
  • Varied by components
  • Migrates with groundwater and accumulates in soil, surface water and groundwater
(Pharmaceuticals and personal care products)
  • Lotions and creams, fragrances, cosmetics
  • Insect repellants
  • OTC pharmaceuticals and prescription pharmaceuticals
  • Medical care facilities
  • EPA Method 1694
  • Sample multiple mediums and locations due to different chemistries and migration patterns
Disclaimer:  Table is provided for general information purposes only.  New information about emerging contaminants should be expected, as research is ongoing.  You are advised to complete your own research to determine whether emerging contaminants are contaminants of concern at a particular site.

General Information on Chemicals of Emerging Concern

State-Based Resources
Federal/National Resources


Pharmaceuticals and Personal Care Products (PPCPs)

Please note: Surface water bodies to which sewage effluent is discharged are not used for drinking water in the State of Connecticut, limiting certain exposures referenced in some pages listed below.

Content Last Updated June 27, 2023