|
Images:
Media release 31 August
Wastewater reuse:
are Australian children
at risk from playing in
their own backyard?
Four thousand families around
Sydney may be placing their young children at risk by spraying partially treated
sewage from their onsite aerated sewage systems on lawns where children play.
The sewage may
contain disease causing microorganisms such as viruses and Cryptosporidium
which can cause gastroenteritis in children who play in areas sprayed with
sewage.
Katrina Charles, a
PhD student in the School of Civil and Environmental Engineering at the
University of New South Wales and the Cooperative Research Centre for Water
Quality and Treatment, says the domestic wastewater is safe to use provided the
householder is aware of the risks and takes sensible precautions.
“Don’t spray the
wastewater on lawn areas where kids play and don’t spray it on vegetable
gardens” Ms Charles said.
“The best way to
reuse this wastewater is through an underground irrigation system where the
microorganisms become trapped and die in the soil but the water and nutrients
are still available for the garden.”
Ms Charles has
recently completed a study into the effectiveness of sewage treatment systems
used in unsewered areas around Sydney.
She found that the
disinfection used in these aerated treatment systems are not as effective as
disinfection in larger sewage treatment plants and only remove a small number of
disease causing microorganisms.
“Our results
indicate that a safer way to reuse the wastewater is through an underground
irrigation system.”
“These treatment
and irrigation systems start from about $11,000 for an average block. But the
value of water as a resource has never been plainer than in this drought. And
underground irrigation systems not only dispose of sewage safely but provide
water and nutrients for gardens.”
When there is an
infected person in the house, sewage may contain a high number of disease
causing microorganisms, including viruses, Cryptosporidium or bacteria.
For example rotavirus which can be transmitted by sewage is the most common
cause of severe gastroenteritis in young children worldwide.
Katrina was one of
15 early-career scientists who are presenting their work to the public and media
as part of Fresh Science 2004. Fresh Science is a national competition aimed at
getting the work of young scientists into public attention.
Images:
 |

Irrigation on a football field |

Large sewage sprinkler near a dam |
|
Environmental damage from over watering with
sewage |
|
|
 |
_small.JPG) |
 |
|
Sewage being used to water lawn |
Watering the mail with sewage |
Sprinklers near the vegie patch |
 |

Katrina in the lab
|

Laying irrigation pipe
|
|
Sampling for nutrients
|
_small.JPG) |
|
| |
Experimental site Goulburn boreholes |
|
|