In performing manhole condition assessments, ICM field staff takes account of the following:
(a) General:
i. Manhole identification as provided by Client maps
ii. Address
iii. Location (pavement or easement)
iv. Size and condition of cover
v. Condition of ring and frame,
vi. Material
vii. Size of manhole
viii. Inlet and outlet pipe sizes.
(b) Structural
i. Condition of steps, cone, riser, bench and channel.
(c) Hydraulic
i. Inflow indicators
ii. Evidence of surcharging
iii. Clarity of flow
iv. Flow comparisons with adjacent manholes
v. Depth of flow
vi. Evidence of vermin
vii. Drop manhole (inlet/outlet).
(d) Engineering Parameters
i. Invert in elevations
ii. Invert out elevations
iii. Manhole rim elevations
iv. GPS Coordinates
To facilitate uniformity in the preparation of manhole condition assessment reports, a standardized industry standard inspection form is used by ICM.
The information obtained from the completed manhole condition assessment forms are reviewed for consistency and any missing or ambiguous information is revisited and updated based on field clarification. The data from accepted and completed forms can be used to determine the severity of the any defects and generate a ranking for each manhole asset based on structural integrity. In addition, an estimate of I&I potential for inspected manholes can be computed.