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605 Confined Space Safety
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Confined Spaces in Pits

Even though a pit is typically open on top and over 4 feet deep, it can still be a confined space or permit-required confined space, most commonly due to exposure to hazardous atmospheres.

Work in pits are covered in the standard.

Pits can be completely underground or below grade, such as a utility vault within a sewer system or a pit within a pit in a wastewater treatment plant.

Pits are found in many environments. Examples include:

  1. sump pits
  2. valve pits or vaults (e.g., wastewater treatment plants, municipal water systems)
  3. electrical pits/vaults
  4. steam pits/vaults
  5. vehicle service/garage pits
  6. elevator pits
  7. dock leveler pits
  8. industrial chemical waste pits

Many of these spaces qualify as permit-required confined spaces.

Employers must take all necessary steps to keep workers safe in confined spaces, including following the OSHA Construction Confined Spaces standard. This standard applies to both new construction in a pit and alterations and/or upgrades. Among the pit-related tasks covered by the standard are:

  1. opening or closing valves during renovation work
  2. installing or upgrading pump equipment, cables, or junction boxes

Construction work can create confined spaces, even if there are none at the start of a project. Changes to the entry/exit, the ease of exit, and airflow could produce a confined space or cause one to become permit-required.

Knowledge Check Choose the best answer for the question.

5-6. What is the most common confined space hazard in pits?