Dr Martin Anda ETC Research Manager organised a tour of WA wastewater
treatment plants and onsite systems from July 25th to August 2nd with
the support of ETC colleagues John Hunt, Noraisha Oyama, Peter Stuart,
Chris Barker and Robert Hughes.
Dr Thamarat Koottatep,
Associate Professor in Environmental Engineering at the Asian Institute
of Technology, explained “Thailand embarked
on path of installing conventional centralised sewage treatment plants
using standard design parameters found in major Western texts such
as Metcalf and Eddy and this has largely failed us. The strength of
effluent reaching the plants is very low because of septic tanks already
on some houses and the entry of stormwater causing dilution. Thus the
plants are typically over engineered and also under utilised because
it is not possible to connect all houses designed for in the catchment.
Moreover, once the plants are handed over to local municipal authorities
it is difficult for them manage and maintain and sustain the recurrent
funding necessary. So after much expenditure by the Kingdom of Thailand
prevention of pollution to the environment has not been achieved. In
Bangkok we need more decentralised treatment technologies and in the
rural areas where there is more land available we can use lower technology
solutions such as lagoons and constructed wetlands.”
Mr. Adisak Thongkaimook,
Deputy Director General of the Pollution Control Department, Ministry
of Natural resources and Environment
who led the
tour explained “In Bangkok we have built 7 large sewage treatment
plants for a permanent population of 6 million plus 4 million itinerants
from rural areas. These plants will only serve 30% of the population.
The last 3 are now under construction but already we know they cannot
provide the pollution control solutions for the conditions experienced
in Thailand and typical Southeast Asia and other developing countries.
We are now keen to explore decentralised solutions. In the tour of
WA we look forward to learning of the local experiences in centralised
Vs decentralised and onsite systems.”
The main elements
of the tour were meetings with officers from the WA Departments of
Health and Environment, the Water Corporation,
wastewater researchers as well as numerous site visits around
Perth and to Dunsborough
in the southwest.
While WA is well
on the way to achieving effective pollution control in all its wastewater
management solutions, both centralised
and
onsite, it has done this at the expense of disposing of the
water and nutrients
without resource recovery. The current focus of the State Government
through the State
Water Strategy [www.ourwaterfuture.com.au] is particularly to see how the water can be recycled through large
schemes. Thus
the Thai visitors learnt much about these initiatives.
Dr Paul Van Buynder,
Principal Medical Consultant at the Department of Health, explained “One of our main concerns with recycled
wastewater is reliability of the treatment plant to deliver the required
water quality and disinfection so as to guarantee protection of public
health. This we believe is best managed by a large corporation such
as the Water Corporation with the necessary expertise”.
“Research
at the ETC may be 15 years ahead of current mainstream thinking” said
Professor Goen Ho where research is underway on new localised
treatment methods to recover both water, organic matter and nutrients
as on Integrated
Urban Water Management. This provides the basis of new
collaborative research between ETC and AIT into vermifiltration technologies
such
as Biolytix [www.biolytix.com] and constructed wetlands.
The collaboration will be commenced through initially supporting a
PhD student in each
institution to research a related topic. Later a workshop
will be organised at AIT in Bangkok where researchers, industry and
government officials
from around Southeast Asia and Australia can be meet to
further explore decentralised water management strategies.
Picture
1: The Thai delegation at Mundaring Weir.
Picture 2: The
Thai delegation at the Mundaring Wastewater Treatment Plant.
