About the ROE
To accomplish its mission, EPA must pay close attention to trends in the condition of the nation's air, water, and land, and to the associated trends in human exposure and health and ecological condition. The ROE compiles the most reliable indicators currently available to help answer 23 questions that EPA believes are of critical importance to its mission and the nation's environment. The ROE focuses on trends within the United States, even when those trends might be affected by sources and conditions outside U.S. borders. Data on environmental trends:
- Allow EPA and the public to assess whether the Agency is succeeding in its overall mission to protect human health and the environment.
- Provide valuable input to EPA in developing its strategic outlook and priorities.
This version of the ROE presents 80+ indicatorindicatorA measurable feature that singly or in combination provides manageable and scientifically useful evidence of environmental and ecosystem quality or reliable evidence of trends in quality.s, all of which were peer-reviewed to meet high standards for accuracy, representativeness, and reliability. The indicators are supported by data gathered from federal and state agencies and non-governmental organizations. Each indicator comprises:
- One or more graphics showing the trends in indicator data over time, or a national baseline when data are not yet available to show a trend. Note: In the ROE, the word "trend" simply means the direction of change, and does not imply statistical significance.
- Text describing:
- What the indicator covers.
- What the data show.
- Any limitations that generate uncertainty in the trend characterized by the indicator.
- Data sources and references.
- Technical Documentation describing the underlying data and methods used to produce the indicator. Learn more about the Indicator Technical Documentation.
The ROE does not propose actions to reduce data limitations or fill gaps, nor does it analyze the costs and benefits of doing so.
The ROE is a dynamic resource. EPA adds new indicators to better answer the ROE questions as suitable data become available from federal, state, and non-governmental organizations. EPA also updates the ROE indicators on a rolling basis to provide the latest available data.
For each indicator, the update frequency depends on the frequency with which new data become available. Some indicators are updated annually; others may only be updated every few years. For some indicators, data do not become available to the ROE until after the data collection program has processed samples and compiled the results. This can create a time lag between data collection and update publication.
- Access Explore ROE Indicators list to locate the most recently updated indicators.
EPA has identified 23 areas where trend information is critical for the Agency to stay adequately informed about the condition of the environment and human health. In the ROE, these areas are listed as questions. The ROE presents indicators that help EPA address these questions:
- What are the trends in the extent and condition of fresh surface waters and their effects on human health and the environment?
- What are the trends in the extent and condition of ground water and their effects on human health and the environment?
- What are the trends in the extent and condition of wetlands and their effects on human health and the environment?
- What are the trends in the extent and condition of coastal waters and their effects on human health and the environment?
- What are the trends in the quality of drinking water and their effects on human health?
- What are the trends in the condition of recreational waters and their effects on human health and the environment?
- What are the trends in the condition of consumable fish and shellfish and their effects on human health?
- What are the trends in land cover and their effects on human health and the environment?
- What are the trends in land use and their effects on human health and the environment?
- What are the trends in chemicals used on land and their effects on human health and the environment?
- What are the trends in wastes and their effects on human health and the environment?
- What are the trends in contaminated land and their effects on human health and the environment?
- Human Exposure and Health
- Ecological Condition
- What are the trends in the extent and distribution of the nation's ecological systems?
- What are the trends in the diversity and biological balance of the nation's ecological systems?
- What are the trends in the ecological processes that sustain the nation's ecological systems?
- What are the trends in the critical physical and chemical attributes of the nation's ecological systems?
- What are the trends in biomarkers of exposure to common environmental contaminants in plants and animals?
ROE indicators are simple measures that track the state of the environment and human health over time. They are based primarily on measurements of physical or biological conditions within a clearly defined geographic area.
To maintain a high level of scientific integrity and consistency among the indicators used in the ROE, EPA established an explicit definition and six criteria for ROE indicators. The criteria are based in part on EPA's Information Quality Guidelines, which cover important information that EPA provides to the public. All ROE indicators were peer-reviewed against this definition and criteria to ensure that they are useful, objective, transparent, and scientifically reliable.
Indicator Definition and Criteria
Indicator definition: An ROE indicator is a numerical value derived from actual measurements* of a driver, stressor, state or ambient condition, exposure, or human health or ecological condition over a specified geographic domain, whose trends over time represent or draw attention to underlying trends in the condition of the environment.
- The indicator is useful. It answers (or makes an important contribution to answering) a question in the ROE.
- The indicator is objective. It is developed and presented in an accurate, clear, complete, and unbiased manner.
- The indicator is transparent and reproducible. The specific data used and the specific assumptions, analytic methods, and statistical procedures employed are clearly stated.
- The underlying data are characterized by sound collection methodologies, data management systems to protect their integrity, and quality assurance procedures.
- Data are available to describe changes or trends, and the latest available data are timely.
- The data are comparable across time and space, and representative of the target population. Trends depicted in this indicator accurately represent the underlying trends in the target population.
*There is some flexibility in this criterion. For example, the air emissions indicators, solid waste indicator, and sustainability indicators have several components that are based on estimation or partial estimation methodologies applied to the best available data.
The ROE excludes:
- Administrative indicators such as permits issued, regulations promulgated, and enforcement actions undertaken.
- Indicators based on results predicted by environmental fate and transport models or predicted risks to people or ecological systems.
- One-time studies unless they serve as baselines for future trends that can be tracked over time.