This is an old boiler at the marine base that was being worked on by some mechanics. Large boilers like this one have long metal tubes running along the inside from front to back. One end of several tubes is visible behind the blue "burner" assembly. The other end of the tubes is about 15 feet back at the rear of the boiler. This device burns more than 16,000,000 British thermal units (Btu) of natural gas per hour. The fire goes through the tubes and creates steam or hot water, which supplies heat to several nearby buildings.
Combustion of natural gas creates air pollution, which is our concern out at the base. We look at emission control systems, operation and maintenance logs, and other information, to quantify how much pollution each boiler creates and to check the base's compliance with air quality laws and regulations.