Australian Water Management Review Vol 1 2010 | Page 35

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the program will produce important fauna
data for urban wetlands in Brisbane, which
will be contributed to ecological journals
and databases.
“I’m told that since 1997, B4C has planted
260,000 native plants, protected 400
hectares of land and received the 2005
National River Prize at the International
River Symposium. Particularly for a group
based completely on volunteers, it’s a
remarkable effort and we’re pleased to
have assisted in their endeavours.”
A second group to have benefited
from the program is the Oxley Creek
Catchment Association (OCCA). The
Oxley Creek Catchment forms a pocket
of biodiversity within Brisbane’s southwestern suburbs, which is home to a
variety of flora and fauna.
OCCA used the grant to protect two of
its tributaries—Mayfly and Pennywort
creeks. Mayflies are aquatic invertebrates
found in healthy, clear waterways, while
the Pennywort is a rare plant found in
Brisbane waterways. The grant was
used to remove weeds that had choked
the waterway, revegetate degraded
areas using a number of tree planting
days and conduct educational programs
with local schools.
“The Oxley Creek Catchment Association
did a great job of bringing Oxley Creek
into the greater social consciousness,
while providing environmental benefits,”
Mr Davies said.
“Weed control and tree-planting days
enabled the community to gather in a
social and informal setting, where they
could share a common goal of restoring
a local creek. School education days
were also held, bringing the environment
into the consciousness of tomorrow’s
decision-makers.”
These initiatives are further enhancing the
environmental benefits the WCRW Project
is having on the region’s waterways
through its normal operations.
WaterSecure’s advanced water treatment
plants are not only the first of their kind in
Australia, they are also the first plants of
their kind in the world to address
environmental impacts on waterways
by further treating byproducts of the
treatment process before discharging
them.

“When the plants receive influent water it
undergoes pretreatment,” Mr Davies said.
“The plants use a flocculation-clarification
process, which removes suspended solids
and soluble phosphorus.”
Ferric chloride is added to the water and,
encouraged by gentle mixing, causes
solids to coagulate and form “floc”. The
flocculated solids are then separated from
the water in a high rate clarifier fitted with
lamella plates.
The ferric sludge produced is then
thickened, dewatered using a centrifuge
and disposed of in a landfill rather than
ending up in the Bremer or Brisbane
Rivers as it would have if the water
had been discharged from the source
wastewater treatment plants.
Water removed during pretreatment is
sent back to a wastewater treatment
plant and re-treated, further improving the
efficiency of the process. At its current
production rate, Bundamba Advanced
Water Treatment Plant is disposing an
average of 14 tonnes of sludge a day. At
full capacity, this would increase to about
25 tonnes a day.
The microfiltration and reverse osmosis
treatment processes produce backwash
and a concentrated discharge that
are further treated to reduce nutrient
levels before they are discharged into
the Brisbane River. Due to differences
in influent water characteristics, the
Bundamba and Luggage Point plants
use different techniques to manage
nitrogen levels.
The Bundamba Advanced Water
Treatment Plant uses a nitrificationdenitrification process to manage nitrogen
levels in reverse osmosis concentrate
(ROC) produced. The ROC is passed

into a nitrification tank where temporary
breakpoint chlorination is used to convert
ammonia to nitrogen gas, which is then
removed in the denitrification tank.
“Our project has been internationally
recognised for our engineering excellence
and construction innovations, and we’ve
won more than thirteen highly sought
after international, national and state
awards, including the 2009 Water ReUse
Project of the Year at the Global Water
Awards,” Mr Davies said.
“But the environmental recognition and
community grants have been one of the
most rewarding elements of our project.
“We will continue this work through
the operations phase and have already
started rolling out our Community
Support Program.”
WaterSecure has begun working with
Reverse Garbage, a Brisbane-based
not-for-profit that collects pre-consumer
waste otherwise destined for landfill from
businesses in south east Queensland. It is
then sold at low cost to the community, in
particular to schools and artists.
“We’ve partnered with Reverse Garbage
to host art workshops in schools located
near our assets that will be on the theme
of water and the environment. Their
focus on recycling and reuse perfectly
complements what we are doing at
Western Corridor.
“Community-based groups do an excellent
job of harnessing existing community
interest and transferring it into grassroots,
‘on-the-ground’ resources. It’s great
to support organisations that deliver
genuine benefits to the community and
environment, and it’s great to create an
environmental legacy.”