A CCTV drainage survey is a process for examining the condition of drainage systems remotely with a camera system that records video footage and captures other useful data.
The technology has become an essential tool for inspecting and surveying underground drains, sewers, culverts and associated drainage assets safely, quickly and cost-effectively.
The techniques and equipment deployed to carry out CCTV drainage surveys can also be used to inspect above ground pipes, for example soil stacks, rainwater downpipes, industrial process pipes storage tanks, vertical chutes, and ducting systems.
What CCTV surveys are used for?
- As a remote access technology, CCTV drainage surveys allow data to be gathered safely, without operatives having to carry out confined space entries, which are potentially-hazardous.
- CCTV drainage surveys are vital to planned preventative maintenance (PPM) programmes, allowing asset owners to manage costs and avoid highly-damaging drain and pipe failures.
- They are used to investigate drain and sewer problems, such as blockages, poor flow rates and pollution incidents.
- They support construction projects – by identifying drain connectivity and allowing contractors to design appropriate drainage systems that meet regulatory controls.
- CCTV surveys are used to carry out pre-adoption condition inspections – allowing building contractors to show the condition of drainage assets before they are handed over to clients.
- They are used to support planned work to carry out pipe repairs, rehabilitation and replacement.
What CCTV surveys are used for?
CCTV surveys are often carried out in conjunction with the cleaning of pipes using high pressure water jetting, delivered by a jet vac tanker.
This is because a pipe may contain a significant amount of debris and material – silt, stones, tree roots, and fats, oils and grease (FOG).
If this material is not first removed, the CCTV camera may not be able to travel up the pipe or record unobstructed images of the pipe, which can later be viewed to assess its condition.
Types of CCTV drainage camera systems
Drainage specialists use robotic crawler cameras to survey pipes with diameters ranging from 150mm up to 2000mm.
The cameras have powerful LED lights that allow an operator, who controls the camera from a console in a specialist CCTV survey van, to record HD-quality video footage.
These cameras are combined with a rugged body fitted with an electric motor which drives wheels that can be interchanged to take account of varying conditions in pipes.
Robotic crawler cameras often have articulating arms, swivelling and rotating camera heads, and a zoom lens. This allows features within pipes to be viewed and filmed from many different angles and distances.
Different types of CCTV drainage surveys
Locating drain and sewer blockages
CCTV drainage cameras can be used to search for and find the cause of pipe blockages, then assess the best way to clear them. Before and after footage can be recorded as evidence that the work has been carried out and the pipe is clear and in good condition.
Drain and sewer inspections
CCTV cameras can be used to carry out quick and simple drain and sewer inspections, or asset condition surveys, as part of a PPM programme. This may not involve recording full drainage survey data or completing a full CCTV drainage survey report, which speeds up the inspection process and controls costs.