Pennsylvania Underground Storage Tank (UST) Certification Practice Exam

The minimum of 2 feet of backfill requirement in non-traffic conditions is specifically pertinent to O/C tanks, or ordinary steel tanks that are often used for underground storage. The design and materials of O/C tanks necessitate sufficient backfill to provide structural support and protect the tank from soil pressure, ensuring that it maintains its integrity and does not collapse or deform under the weight of the surrounding earth.

The specified backfill depth also helps in reducing the potential for corrosion, especially in non-traffic areas where the risks are lower than in locations subject to vehicular loads. This guideline is essential for ensuring the longevity and functionality of the storage tank while minimizing environmental risks related to leaks or failures.

Other tank types, such as plastic or fiberglass tanks, are inherently lighter and often more resistant to deformation and corrosion; therefore, their backfill requirements may differ significantly. Steel tanks, while they do require adequate backfill to maintain stability, are most distinctly classified under the O/C category in terms of specific guidelines and regulations for installation in non-traffic areas.