A permanently installed pool is considered to be in the ground if its water depth is greater than how many inches?

• A. 36
• B. 42
• C. 48
• D. 60

Answer: (B)

Water depth is used to classify whether a permanently installed pool is considered in the ground for electrical code purposes. If the water depth is greater than 42 inches, the pool is treated as in the ground, which brings it under the more stringent in-ground pool requirements (bonding, GFCI protection for electrical equipment, and related clearances). This 42-inch depth acts as the boundary: pools deeper than this are in-ground; shallower pools are not. The other depths don’t define the boundary itself—36 is too shallow to meet the in-ground threshold, while 48 or 60 are depths that would still be in-ground if the water exceeds 42 inches, but the question asks for the boundary value, which is 42 inches.