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Risk Assessment

MIRA: Environmental Indicators

What is an Indicator?

An indicator is a measure of something that we want to know the condition of or that we want to track (e.g., environmental condition). Indicators help us understand where we are, where we are going, and how far we are from the goal.

An indicator is information that represents a piece of the system in which we want to decide on an action or make a decision.

A good indicator has the following characteristics (from Indicators and Information Systems for Sustainable Development (PDF). (95 pp, 418 K, About PDF) Exit

  • Clear in value
  • Clear in content
  • Compelling
  • Policy relevant
  • Feasible
  • Sufficient
  • Timely
  • Appropriate in scale
  • Democratic
  • Supplementary
  • Participatory
  • Hierarchical
  • Physical
  • Leading
  • Tentative

One way to use indicators is to track EPA’s programmatic activities. For this, EPA has organized data and measures into six levels that correspond to the type of activity measured.

Indicator Hierarchy

Illustration showing the hierarchy of indicators.


Level 1 - resources used and activities taken by governmental agencies and environmental groups, such as permits written or grants issued; designed to result in an action by a second party that reduces or prevents pollution or exposure to pollution

Level 2 - steps taken by entities in response to Level 1 actions to reduce pollutants entering air, water, or land


Level 3 - actual amounts of pollutants emitted by sources

Level 4 - levels of pollutants detected in local communities

Level 5 - chemical or biological changes which occur to some pollutants, for example, concentration of a toxin as it moves up the food chain

Level 6 - the true Indicator or condition we seek to attain

EPA has used the Indicator Hierarchy since 1982. It corresponds fairly closely to the categories used in MIRA Logic Models to plan activities.

Additional Information


Bill Jenkins (
Associate Division Director
Office of Environmental Information & Analysis (3EA10)
Environmental Assessment & Innovation Division 
US EPA Region 3
1650 Arch St.
Philadelphia, PA 19103-2029