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Regulatory Information

Stop 06: Piping

Highlighted Topic:  Fugitive Air Emissions (Air Leaks)

Tour Stop 06

Pumps, valves, and piping often can be sources of small air leaks (as can other pieces of equipment, such as tanks, reactors, etc.).

The Clean Air Act covers not only air emissions from stacks, but also any "fugitive" emissions that may escape from piping, valves, tanks or other sources. This means you need to think about all the opportunities for solvents, volatile organics, or other chemicals to evaporate from storage locations, transfer stations, and work areas. Even vapor leaks are included.

Here are some of the possible sources of fugitive emissions:

  • vapor losses from storage containers
  • losses from pumps, valves, and fittings
  • losses during loading and unloading activities
  • losses from reactors, heat exchangers, separation tanks, centrifuges, or other process equipment
  • evaporation from open process tanks, wastewater treatment, or sewer systems
  • evaporation from accidental liquid spills or leaks
  • dust created during transportation or other activities.


Emissions levels from these sources must be included in the site-level air emissions inventory that will go into setting your site-wide permit limitations.  In addition, in some cases there are specific regulations that cover possible sources of fugitive emissions.  For example, there are specific New Source Performance Standards  to manage equipment leaks of VOCs and of benzene from containers or piping that hold those chemicals (Part 60 and 61 of the regulations).  There are also hazardous air standards that would also apply to any source of the pollutant - whether a stack or a fugitive source (National Emissions Standards for Hazardous Air Pollutants or NESHAPS, at Parts 61 and 63).

Other Regulatory Issues:

Pipes, valves and pumps can also be a source of liquid leaks.  In turn these liquid leaks can both generate air emissions (as the leak evaporates), and can cause hazardous waste or wastewater generation (as the leak is cleaned up or managed).   In addition, depending on the type and amount of leak, accidental release provisions under the Emergency Planning and Community Right to Know Act (EPCRA) may be triggered.  More details on these requirements is provided at the tour stop on  Truck and Train Loading.

Pipes, valves and pumps can also be the source of hazardous waste generation and/or wastewater generation during maintenance and cleaning activities.