The AILA Cultivate group organised a tour to the fascinating Western Treatment Plant in Werribee Victoria last month, led by Principal Biodiversity Scientist from Melbourne Water Will Steele.
– 105 square kms of WTP plant, built in 1896
– Treats 55% of Melbourne’s waste (shower water & sewerage etc.)
– Located in Werribee so mainly gravity fed as all downhill from Melbourne with only 2 pump stations (via 4.5m dia pipe)!
– Hoppers crossing pump is 8 stories high and super sci-fi
– And because sits in a rain shadow of the Otways ranges (ie lower rainfall to optimise evaporation)
Habitat & Ecological values:
– Agriculture and urbanisation in Victoria has threated wetland ecosystems, subsequently WTP has become an important substitute
– The “old sewage treatment lagoons” have been modified and now provide a world significant bird refuge due to the provision of: lots of water – even in drought, nutrients and space with limited people & foxes managed
– Ramsar listed wetlands as a major migratory bird path with thousands of rare and endangered bird species!!!!
– Research counts have shown up to 300,000 invertebrates/m square on intertidal mudflats
– The ecologists working at WTP can finely tune the water levels of the ponds to provide a variety of habitat types for different bird species/plants
– Flat treatment lagoons with rock beaching are gradually being regraded with planted banks and an undulating base to the ponds to create more variety water depth
Reshaped retention pond to provide habitat diversity
For $50/year you can apply for a key to access the prime bird watching areas. http://www.melbournewater.com.au/getinvolved/activities/Birdwatching/Pages/Apply-for-a-birdwatching-permit.aspx
1. Anaerobic pond – raw sewage is digested by anaerobic bacteria
2. Biproduct of bacteria is methane which is collected from under covers & powers 90% of the WTP!
3. Biosolids stockpiled from the ponds – not yet used from the WTP although used everywhere else in world (fertilisers, fuels or even concretes). Part of issue is they have stores from 1890s which include contaminants such as heavy metals (and they have not sorted by era).
4. Aerobic ponds/Stepped lagoons – nutrients consumed by aerobic bacteria, water evaporates
5. Class C water released into the bay
6. Some water is recycled, has been a valuable asset in times of drought
Great to see human infrastructure interventions with such a holistically positive outcome!
Piped to Hoppers Crossing
Stage 1, seagulls have first dibs
Methane gas captured from under the covers to provide electricity for WTP.