Project focus: water resource management
22 | APRIL 2015 | WWT | www.wwtonline.co.uk
• Innovations
● The qualities of the Lower
Greensand aquifer mean treated
water can be stored in a 'bubble'
which retains its integrity and the
water is still high quality when it
is pumped out
● The operational trial uses two
250m-deep production bore-
holes and a series of observation
boreholes for hydrogeologists to
model the aquifer's behaviour
● Water is pumped into the
aquifer at a rate of 3 megalitres a
day and out again at 5 megalitres
a day
need disinfection.
There is 10 times more storage
available underground in aquifers in
the Thames Water region than there is
above ground in reservoirs, and 70%
of the Thames Valley's drinking water
already comes from groundwater
sources; so it is not hard to see why
ASR has significant potential for
Thames. Jones says that the utility
has identified three possible similar
projects in the Lower Greensand, a
number which may increase as the
team learns more about the aquifer.
In the long term, there is also the
prospect of investigating ASR in other
aquifers such as the Cotswold Oolites.
Other water companies in the UK
to have investigated ASR include
Yorkshire Water, Wessex Water and
Severn Trent, although none have yet
progressed as far with it as Thames.
"The idea of ASR has become
popular again, mainly because
there's only a certain amount you
can do with demand management
to close the supply-demand gap,"
says Jones. "You could start looking
at desalination or effluent reuse, but
they are quite expensive. ASR can
help you fill a reasonably modest
sized gap in the supply-demand
balance much more cost effectively.
"ASR is a great innovative technique
which helps us make best use of
water resources while protecting
the environment and giving us water
supply resilience. It's a great thing for
storing water for larger, more severe
droughts that might very well be with
us in an uncertain climate change
future."
Thames Water's ASR project has
been shortlisted as a finalist in the 2015
Water Industry Achievement Awards:
waterindustryachievementawards.info
The rig for the borehole, which was drilled between September 2014 and January 2015
A series of observation boreholes are also needed as the schame is tested this year
