The floor base and foundation perimeter drain shall discharge by gravity or mechanical means into an approved drainage system that complies with the International Plumbing Code.
EXCEPTION: Where a site is located in well-drained gravel or sand/gravel mixture soils, a dedicated drainage system is not required.
This section implies that all drains located at the site—floor drains and perimeter drains—must properly discharge. Discharge can be through gravity—sloping of the drainpipes—or by mechanical means—such as a sump pump. The discharge must be delivered into a drainage system that is approved by the local authorities and is in accordance with the International Plumbing Code.
The only exception to this is if the site is located in an area that is well drained through gravel or a sand and gravel mixture.