Air Monitoring Section Overview

The Division of Field Services (formerly known as the Division of Air Quality Services) was formed in 1972 when the legislature officially created the Department of Environmental Protection, which included the Bureau of Air Quality Control and three Divisions within the Bureau. The Division was responsible for; 1) ambient air monitoring to meet state and federal requirements, 2) data correlation and evaluation, 3) designing and operating special air quality studies, 4) providing data to the public and to technical users; 5) performing visible emissions evaluations and 6) investigating air pollution complaints. Initially, there was a staff of ten to accomplish the Divisions tasks. The initial monitoring programs consisted of Technicon IV Monitors for continuous measurement of sulfur dioxide, Intertech monitors for continuous measurement of carbon monoxide, MRI Weather Stations for continuous measurement of wind speed and direction, General Metal Works High Volume Sampler for 24-hour averages of suspended particulate concentrations and Tri-Craft Specialty Bubbler Box for 24-hour averages of sulfur dioxide. In those early years of monitoring a number of problems were detected with concentrations of pollutants exceeding state and federal standards. Sulfur dioxide, total suspended particulates and carbon monoxide exceeded the standards at several locations throughout the state. Control programs were implemented which resulted in eventual attainment status for all those areas that were not meeting the standards. In most cases where a local industry was identified as being responsible for the pollution a monitoring program was required of the industry to document existing levels and to show compliance with the standards.

Currently the Division has a staff of 24 with 15 of those positions dedicated to the support of airmonitoring activities. The primary responsibilities of the monitoring sections are still the same as above. However, the emphasis has shifted away from sulfur dioxide, carbon monoxide and total suspended particulates since those pollutants have been significantly reduced. Current monitoring efforts are primarily focused on ozone and the precursors of ozone, fine particulates and hazardous air pollutants. The early monitoring efforts included obtaining the data by hand resolving strip charts from each monitor and manually recording that data onto paper forms. Current monitoring includes the use of computers and sophisticated data loggers at each site that continuously record the output from several instruments and store that data in memory. All of the equipment is typically housed in a separate climate controlled monitoring shelter or is placed on the roof of a shelter or other secure building. The data is then retrieved from each site over phone lines and is stored electronically in computers at each office. That data is then reviewed and edited and after meeting all quality assurance requirements is electronically transmitted to the national EPA database for air monitoring data. Data from Maine and the rest of the country can be obtained from EPA's AirData web site.

Text Box: Interior of Monitoring Shelter at Castine The following section details some of the various pollutant monitoring programs that have been operated in the state and indicates some of the trends that have occurred over the years since monitoring began.