Final answer:
The two types of drainage inspections are Visual Inspections, for examining accessible parts of the system, and CCTV Inspections, for assessing internal conditions of pipes.
Step-by-step explanation:
Types of Drainage Inspections
There are two main types of drainage inspections: Visual Inspections and Closed-circuit Television (CCTV) Inspections.
Visual Inspections
During a Visual Inspection, an inspector physically examines the accessible parts of the drainage system. This process typically involves looking for visible signs of damage, blockage, or wear and tear. This type of inspection is limited as it cannot assess sections that are not easily accessible or visible without excavation.
CCTV Inspections
CCTV Inspections involve inserting a camera into the drainage system to provide a live feed or recording of the drain's interior condition. This is a preferable method for inspecting underground or otherwise inaccessible pipes, as it provides a comprehensive view of the pipe's internal state, including any obstructions, damages, or defects.