Final answer:
The sump pit should be at least 8 inches in diameter and 15 inches deep, according to newer recommendations. An older rule of thumb suggested a smaller size of 5 side-to-side and 7-8 deep.
Step-by-step explanation:
The sump pit should not be less than 8 inches in diameter and 15 inches deep according to newer recommendations. An older rule of thumb suggested a smaller size of 5 side-to-side and 7-8 deep.