Media Release
July 28 2006
Water Reclamation: do or die
The wastewater treatment proposal for Toowomba is a necessary step in
dealing with the earth’s water crisis, says Professor J (Hans) van
Leeuwen, an expert in water reclamation technology.
“Water reclamation is not only a necessity; it’s a reality of life on
Earth,” Prof van Leeuwen says, visiting Professor with the
Water Science and
Systems Centre at UniSA.
"The whole planet is a closed biosphere and all water and air is
continuously recycled. In every glass of water, there are bound to be a
few drops that have already passed through the bodies of numerous
people, animals and dinosaurs. There is no other option. It's do or die.
"Water is already recycled through urban runoff, collected on streams
and rivers and down to the ocean, where it is eventually evaporated and
returned to the land as rain. This is nothing new, and everybody accepts
this as inevitable," he says.
Prof van Leeuwen points to more direct examples of using drinking water
which includes human waste.
"Discharging wastewaters into rivers that feed the supplies of
downstream users, including supply of drinking water, is an accepted
practice all over the world. This practice is called indirect potable
reuse. The public is generally not concerned about indirect reuse -- and
either view this as part of the natural cycle -- or hold on to some
mystical belief in natural purification during a period in natural
waterways."
Prof van Leeuwen says that while stringent measures control wastewater
treatment and effluent discharges to public streams, the quality is
typically nowhere close to that of drinking water.
“While there is some natural purification and certainly lots of
dilution, months of storage in lakes, or allowing it to run its course
for hundreds or thousands of kilometers, is no guarantee for quality and
safety.
“As soon as the water authorities come up with some imaginative scheme
to put wastewaters through extensive purification processes and then
release it in water sources, there will always be some political
movement or vocal minorities trying to mobilise against such measures,"
he says.
Professor van Leeuwen was one of the pioneers in providing the city of
Windhoek, Namibia, with reclaimed water for direct potable reuse. He
also lived in SE Queensland during the mid-90s, and is very familiar
with the situation in Toowomba. His continued research into improved
methods for water reclamation was incorporated in the design of the
improved integrated biological and physical-chemical treatment process
now in use in an expanded water reclamation plant in Windhoek.
He also helped in the design of an advanced wastewater purification and
reclamation process for South Caboolture, north of Brisbane in the late
90s. Although this water meets all quality requirements for drinking
water, it has not been used for this purpose.
"This is probably the result of political pressure and not based on
scientific logic and evidence," Prof van Leeuwen said.
"South Caboolture may also not need this water as a source of drinking
water, but by all the information I have at my disposal, reclaimed water
is the most economical option for additional water that will be required
in the Toowoomba area."
Prof van Leeuwen says that the processes being considered for the water
reclamation at Toowoomba are state of the art and the best available
technology for water reclamation currently available.
"The water reclamation plant would be one of the best, if not the best
in the world.
"Water reclamation has come a long way. The 1968 process originally
serving Windhoek, rather primitive according to modern standards, was
able to provide the city with up to 40 per cent of it drinking water
needs. Epidemiological studies conducted in Windhoek have never shown
any increase in either contagious diseases, cancer, birth defects or any
other adverse effect. In fact, the part of the city that then received
the recycled water, appeared healthier than the control population, but
this may have been the result of socio-economic factors," said Prof van
Leeuwen.
The Water Science and System Centre is a joint venture between UniSA and
SA Water.
Prof van Leeuwen is from Iowa State University. His visit is being
sponsored by ICE WaRM, the International Centre of Excellence for Water
Resource Management, headquartered in Adelaide.
Contact for interviews
-
Professor van Leeuwen office (08) 8302 5238 email
leeuwen@iastate.edu
He can also be contacted on (08) 8210 8000 (ask for room 1202)
Media contact
- UniSA - Rebecca Gill office (08) 8302 0096 mobile
0404 857 977 email
rebecca.gill@unisa.edu.au