Engineering

Closed circuit television video sewer inspection is a proactive approach of preventative maintenance of the sewer system which minimizes disruption of sewer service to our customers. 

There are two major components to preventative maintenance: cleaning sewers and televising (video inspecting) sewers to identify defective pipes that need to be repaired or replaced.

Equipment

The sewer system is inspected and cleaned with a remote controlled unit on wheels with a camera mounted on top. The City has three different cameras for televising the City sanitary and storm sewer system.  Two are mainline camera units which pan and tilt.  The other unit is a Panoramo 360 mainline camera with a Structure Inspection (SI) Scan camera.

The pan and tilt video cameras provide a visual recording of the sewer; however, they only capture what the camera is directly pointing at. If needed, the operator can use the controller and manually rotate the direction the video camera is pointing.

The Panoramo 360 mainline camera takes millions of pictures in all directions instantaneously as the camera is being pulled through the sewer.  The end result of the Panoramo 360 mainline camera is a full video depiction of the sewer being televised at every angle.  The SI Camera (Structure Inspection Scan) records the condition of manholes.

Strategy

In accordance with the City Capacity, Manage, Operation and Maintenance (CMOM) program, Engineering Operations crews televise 10 percent of the total pipes in the City every year. That means that every sewer main in the City is televised at least every 10 years.

CCTV by Special Request

These are predominantly sewer mains identified by our cleaning crews to have potential problems that we will need to take a closer look at to determine if repairs are needed.

CCTV for Post Water Main Breaks

Sanitary and storm sewer mains that are close to a water main break are inspected to verify that the water main break did not impact the nearby sewer structures.

CCTV and SI Camera for Construction

Prior to the design of street reconstruction and resurfacing projects, pipes and manholes within the project area are recorded to confirm the condition and location of existing pipe connections. Post construction of street reconstruction/resurfacing and new road construction projects, pipes and manholes are recorded to ensure new structures are built properly without any sags or defects.  

On occasion, Engineering Operations may be contracted to perform CCTV of the sewer mains for other City agencies or the Madison Metropolitan Sewerage District (MMSD) contracts with the Sewer Utility.

Inspecting Private Pipes

The property owner is responsible for the sewer lateral from the house to the City sewer main. City staff does not have the staff available to televise homeowner’s laterals.  Homeowners interested in evaluating the condition of their sewer lateral should hire a sewer lateral cleaning service.  Most of these companies have the ability to perform this service.

Found in the Sewers