Pump Type

Maintenance frequency

Installation/ Capital Cost

Approx. Max. lift

Level Control

Energy Efficien-cy

Health & Safety

Electric Pumps

centrifugal (sewage type)

average

average inc. precast chamber

30m

external

average

Explosion rating applies, but risk exists from power supply distribution

progressive cavity

below average

above average inc. chamber

>30m

external

good

as above

borehole

average

below average no chamber cost - just b/h packing & lining

30m/ stage

external

good

Good - b/hs usually too small for man entry

Hydraulic Pumps

eductor

below average*

average (if compact site) otherwise pipe costs high with in and out (twin) pipes always req’d.

20m - 30m

external

poor

Good - avoids electricity distribution risks as all equipment can be locked away

Pnuematic Pumps (positive displacement & centrifugal)

floating piston

above average

above average

10m

self governing

best

As above

mechanically coupled push rod**

No information available

below average

50 ? approx.

submerged pressure transducer

good

As above

centrifugal - hydraulically driven

above average

average

up to 10m

not usually applied

average

Average to good