With OFWAT urging water companies to rethink pricing
strategies and with the current AMP 5 spending round and
Water Framework Directive (WFD) on the horizon,Simon
Lambert,general manager for Europe at NOV Mono,
explains why treatment works need to stretch their money
in many different ways

Due to be fully implemented by 2015,
the objective of the European WFD
is to integrate every aspect of the
control of water quantity and quality in the
water cycle across Europe, so that all parties
work to one timetable and objective. A
central concern is how water used for
industrial, commercial and domestic
purposes is treated and returned to the water
courses and, not surprisingly, upgrading the
effectiveness of treatment processes has been
a priority in the current five year
spending round.

The forthcoming AMP 5
spending round (from 2010)
is set to continue this
progress by focussing on
improving the lifetime costeffectiveness
of the treatment
processes. Following the
news that OFWAT has
ordered water companies to
rein in spending budgets
and cut bills, these
companies must hunt for
efficiencies in the supply
chain or face the prospect
of job losses across the
board. As such, treatment
works management will be encouraged to
focus on lifetime costs and their
improvement through better specification
and assessment of equipment.

Processing trends
Many treatment works are now
centralising certain duties to
improve efficiency and help
deliver cost savings, so it is
essential that all equipment,
and pumps in particular, can
handle the larger capacities
processed at main sites. In addition, pumps
are being put under more pressure by the
increase of non-disposable waste entering
the drains that needs to be processed. Items
such as facial wipes, cleaning cloths and
‘disposable’ toilet brushes are being flushed
into the sewers instead of being thrown in
the bin. For water and wastewater treatment
works this can cause serious ragging issues at
pump station collection. These inclusions are
particularly damaging to centrifugal pumps,
as the propeller vanes and shaft can be totally
entangled.

As key elements of the treatment process,
the performance of pumps has a
considerable bearing on the energy and cost
efficiency of a treatment works, as well as its
quality of discharge. As such, process and
maintenance engineers need to look at the
whole life cost and effective asset
management of their equipment.

Although centrifugal pumps have
traditionally been a familiar part of the
internal workings of wastewater treatment
transfers, progressing cavity pumps are
proving invaluable when it comes to
handling the more viscous media such as
filter cake and primary, secondary and
dewatered sludges. They have a hardened
steel rotor and resilient stator, which form
discrete cavities within the pump. This design
enables them to transfer difficult-to-handle
media, even types that appear non-flowing.

However, even with screens and grinders,
PC pumps can still suffer from ragging and
maintenance issues.With the forthcoming
AMP 5 spending set on improving the
lifetime cost-effectiveness of the treatment
processes, it is important that treatment
works pay attention to on-going
maintenance costs and their improvement
through better specification and assessment
of equipment and parts.

Often the cost of replacing spare parts
from OEMs can be expensive, but to provide
a solution to rising whole life costs, one of
the leading PC pump manufacturers has
developed a range of spare parts which offer
cost effective alternatives to OEM PC pump
parts. The range offers same day delivery on
stock items, with a dedicated aftermarket
team, making it an attractive offering for
engineers looking to control pump
maintenance costs without sacrificing high
quality service and parts. The range includes
rotors, stators, coupling rods, shafts,
pins/bushes, seals and drive train assemblies.

Fully assembled rotating
units are available, which
help to reduce operational
expenditure by
minimising assembly and
installation time, as well as
delivering cost savings,
because the complete unit
is purchased rather than individual
components.

Futureproofing treatment works
The next generation of PC pump parts have
been designed to ensure treatment works can
improve their processes and cope with the
increasing demands of a growing population.

The combination of the right pump and the
right maintenance approach will enable
them to meet the requirements of the
forthcoming AMP 5 spending round, as well
as the WFD, and importantly, help them to
safeguard funding while moving forward.