What we inspect

Any submerged asset in a treatment works. In service.

Above the water, everything is measured against a datum. Below it, acoustic imaging resolves what cameras cannot see. Every result is recorded against the asset.

Along the bridge of a settlement tank towards the centre column
01
Settlement tanks · PST and FST

The complete tank. One engineering assessment.

Scraper mechanism and structure, bridge geometry, drive and idler wheels, motor and gearbox, main bearing, scum and weir boards, centre and feed drums, pipework and floor profile. Eight-point level survey against the agreed datum.

Full scope ↓
Circular settlement tank
02
Storm tanks

Condition beneath stored storm water.

Submerged structure, cleaning mechanisms and mountings, walls, benching and floor profile, sediment depth and distribution, obstructions. Without emptying the tank.

Storm tank
03
Wet wells

No confined-space entry.

Pump casings and risers, pipework and supports, benching and structure, debris and ragging. Imaged from above with the pumps in service.

Wet well with pump risers
04
Aeration lanes and channels

Through turbulence.

Diffuser grids, droplegs and pipework, penstocks and gates, walls, floors and joints beneath aerated or flowing water. Lane kept in process.

Aeration lane

Scope on each asset subject to safe access and operating conditions

Sections A to G · above the water

Measured, not eyeballed.

Every item is referenced to a datum so the next inspection measures change.

AIDENTIFICATION & POSITIONING

Asset reference, coordinates, orientation, diameter, depth, wall and weir heights, water level, floor slope.

BSTRUCTURE & SETTLEMENT

Eight-point perimeter level survey, differential settlement, observable structural condition.

CBRIDGE GEOMETRY

Level, longitudinal and transverse inclination, alignment, deflection, handrails, connections, supports.

DDRIVE WHEEL

Condition, measured wear, contact surface, alignment, running condition.

EIDLER WHEEL

Condition, wear, alignment, contact condition, mechanical deterioration.

FMOTOR & GEARBOX

Leakage, lubrication evidence, noise, vibration, mountings, casing, operation.

GMAIN BEARING

Wear, lubrication, movement, noise, vibration, temperature where safe, fixings, mounting.

SSUBMERGED

Scraper mechanism and structure, scum and weir boards, centre and feed drums, duck's feet and pipework, acoustic floor profile.

Scraper bridge drive wheel on the tank wall

D · Drive wheel: measured wear and contact surface

Engineer taking a level reading on the bridge

B · Eight-point level survey against the datum

Beneath the surface

Every component identified, imaged, measured and graded.

Each component is given an identity, imaged, measured where geometry permits and graded good, monitor or act. An engineer interprets every capture.

Acoustic image of an intact scraper element
✓ GOODUniform profile · 2.47 m recorded
Acoustic image of a scraper element with partial loss
! MONITORPartial loss, approx. 20%
Acoustic image showing supports with the element absent
✕ ACTSupports present, element absent
Acoustic cross-section of the tank floor
FLOOR PROFILEWall to centre · slope 1.2°

PRAFIRA acoustic captures · illustrative examples