California Designated Operator Practice Exam

How is rainfall accommodated in non-integral secondary containment systems?

1. Must accommodate 100% of primary containment

2. Must accommodate expected rainfall from a 24-hour, 25-year storm

3. Must have a roof to prevent rain from entering

4. Is not a requirement

The correct answer is: Must accommodate expected rainfall from a 24-hour, 25-year storm

The requirement for non-integral secondary containment systems to accommodate expected rainfall from a 24-hour, 25-year storm is rooted in environmental regulations aimed at preventing spills and leaks from contaminating the surrounding area. This standard ensures that the containment system is adequately designed to handle significant rainfall events, reflecting a commitment to environmental safety and protection. When preparing for potential heavy rain, understanding the implications of "24-hour, 25-year storm" is essential; this reference indicates a rainfall amount anticipated to occur once in 25 years, within a 24-hour period. By incorporating this design criterion, secondary containment can effectively manage not only the liquids held within the primary containment but also excess water from heavy rainfall that could otherwise lead to overflow or compromise the integrity of the containment system. This requirement helps to minimize risks associated with natural weather events, ensuring that any leaks or spills from the primary containment do not escape into the environment during such storms, thereby protecting ground and surface water quality. Other options do not fulfill this critical aspect of stormwater management, making the specified requirement essential for compliance and environmental protection.