Manhole Inspections

Sometimes part of an I/I testing regime, and sometimes performed as a standalone, Manhole Inspection is another of our assessment services. Manholes can be found where a lateral drains into a main line, where there's a lengthy run of straight pipe, the pipe changes horizontal direction by more than 30°, or it changes diameter. They're usually round, and designed to allow man entry (hence the name) for access to cleaning or camera inspection work.

Service Overview

Experienced, knowledgeable technicians can utilize naked eye assessments or televise and record visual inspections, which reveal areas of concern and the general health of the structure.

Problem

Manholes are access points to sewer main lines, for inspection of sanitary infrastructure and the performance of essential repairs and cleaning work. However, these structures themselves, when physically deteriorated, can also become access points for trash, dirt, leaves and other debris, as well as inflow of unwanted stormwater.

Manholes also function as temporary storage vaults for stormwater that rises quickly in the system due to heavy rain events, preventing immediate flooding.

They are meant to remain covered by a hard, thick plate that can withstand foot and vehicle traffic, constant exposure to the elements, and rough handling. When those covers go missing, or there are too many flooding events, or the bench at the bottom of the manhole fills with debris, it can prevent the structure from performing this overflow prevention function properly, or even at all. If that happens, it's time for a professional manhole inspection.

Solution

Using both naked eye visuals and sometimes remote CCTV cameras, we look for and record the general condition of the riser (missing bricks or mortar), cracked concrete, evidence of root intrusion or other inflow and infiltration (I/I), and evaluate levels of hydrogen sulfide (H2S) corrosion. We may also, if requested, record an asset inventory including measurements, presence of or missing ladders or other access structures, missing cover, and any other data that could establish a baseline report for future reference.

Result

Post-inspection, these stormwater and sanitary conveyance asset assessments can be examined and structures prioritized for maintenance, repair and rehabilitation, which will return the systems to optimal performance.

Tools and Methods

Manhole inspection uses highly trained technicians who are NASSCO MACP Certified to perform naked eye and CCTV cameras specifically designed for the inspection of vertical structures to capture video data, record the condition/defects of the structure and provide detailed reports.