Air Monitoring Basics

Diagram of Air Monitoring Schematic

The Connecticut Department of Energy and Environmental Protection (CT DEEP) monitors air quality to protect public health and the environment.  Air monitoring began in Connecticut in the 1950's, when the Health Department started to monitor for total suspended particulates (TSP). In 1971, the CT DEEP was formed and by 1973 had installed it's first computerized monitoring network.

In 1970, the federal Clean Air Act (CAA) was signed into law. The CAA and its amendments provided the framework for CT DEEP to protect air quality. The Environmental Protection Agency (EPA) established the National Ambient Air Quality Standards (NAAQS) and required States to monitor the air quality.  According to the EPA, air monitoring is used to:

  • To judge compliance with and/or progress made towards meeting ambient air quality standards.
  • To activate emergency control procedures that prevent or alleviate air pollution episodes.
  • To observe pollution trends throughout the region, including non-urban areas.
  • To provide a data base for research evaluation of effects: urban, land-use, and transportation planning; development and evaluation of abatement strategies; and development and validation of diffusion models.

On January 1, 1975, in cooperation with the Connecticut Lung Association and the National Weather Service office at Bradley International Airport, the Air Monitoring Unit of CT DEEP began forecasting air quality and disseminating an Air Quality Index every weekday.  Real-time air quality monitoring data has been a crucial part of the daily air quality forecast ever since.  Since the 1970s, monitored pollutant trends of the criteria pollutants have decreased significantly due to various control measures implemented by CT DEEP and the EPA.

For more information:

PM10 and PM2.5 Attainment Fact Sheet 
Ozone Planning Efforts
Air Quality Summaries and Trends
Connecticut Air Monitoring Network
Current National Ambient Air Quality Standards (NAAQS)
The EPA Ambient Air Monitoring Web Site

Content last updated on January 23, 2017