Western Treatment Plant

{{Short description|Ramsar site and sewage treatment plant in Victoria, Australia}} {{Use dmy dates|date=November 2019}} {{Use Australian English|date=August 2019}}

[[File:ISS016-E-12837 - View of Victoria, Australia.jpg|alt=Satellite image of the Western Treatment Plant on 26 November 2007.|thumb|Satellite image of the Western Treatment Plant on 26 November 2007.]]

The '''Western Treatment Plant''' (formerly the '''Metropolitan Sewage Farm''' or, more commonly and informally, the '''Werribee Sewage Farm''' or '''Werribee Poo Farm''') is a {{convert|110|sqkm|abbr=on|adj=on}} [[sewage treatment]] [[Physical plant|plant]] in [[Cocoroc, Victoria]], [[Australia]], {{convert|30|km|abbr=on}} west of [[Melbourne City Centre|Melbourne's central business district]], on the coast of [[Port Phillip Bay]]. It was completed in 1897 by the [[Melbourne and Metropolitan Board of Works]] (MMBW), and is currently operated by [[Melbourne Water]]. The plant's land is bordered by the [[Werribee River]] to the east, the [[Princes Freeway]] to the north, and [[Avalon Airport]] to the west.<ref>Observable from official Melway maps, http://www.street-directory.com.au/vic/melbourne</ref> It forms part of the [[Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar Site]] as a wetland of international importance. The Western Treatment Plant treats around fifty percent of Melbourne's sewage — about {{convert|485|ML|acre ft|disp=or}} per day — and generates almost {{convert|40,000|ML|acre ft|disp=or}} of [[recycled water]] a year.<ref name=MW-WTP>[http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/western_treatment_plant.asp Western Treatment Plant], Accessed 10 July 2012.</ref> (The [[Eastern Treatment Plant]] treats 40%.)

==History== ===The need for a solution=== The [[Victorian gold rush|discovery of gold in Victoria]] in 1851 led to Bendigo becoming the richest city in the world at the time<ref>Cervero, Robert B. (1998). The Transit Metropolis: A Global Inquiry. Chicago: Island Press. p. 320. {{ISBN|1-55963-591-6}}</ref> and therefore , Melbourne with a population of about 500,000 by the 1880s, also Australia's most populous.<ref>"The Snowy Mountains Scheme and Multicultural Australia". Atse.org.au. Retrieved 21 June 2010.</ref>

The rapidly expanding metropolis faced an increasing pollution problem. While it was described by British journalists as "Marvellous Melbourne" and "a city of magnificent intentions", it was also being dubbed "Marvellous Smellbourne" because of its primitive and [[unsanitary]] waste disposal methods. The majority of waste water from industries and homes, including [[chamber pots]] and overflowing [[cesspit]]s, ran into street channels and open drains which emptied into rivers and creeks, turning them into open sewers.<ref>{{cite web |title=History of Sewerage |url=http://www.melbournewater.com.au/content/sewerage/history_of_sewerage/history_of_sewerage.asp |publisher=Melbourne Water |access-date=2021-05-11 |archive-url=https://web.archive.org/web/20120119043906/http://www.melbournewater.com.au/content/sewerage/history_of_sewerage/history_of_sewerage.asp |archive-date=2012-01-19}}</ref> As a consequence, [[cholera]] and [[typhoid]] were rife.<ref>{{cite web |title=Melbourne's first sewage treatment plant |url=http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/history/history.asp |publisher=Melbourne Water |access-date=2021-05-11 |archive-url=https://web.archive.org/web/20120128165807/http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/history/history.asp |archive-date=2012-01-28}}</ref>

===Conception and planning=== In 1888, a [[Royal Commission]] was formed to come up with a solution to Melbourne's waste problems. The Commission's findings led to an ambitious plan for the construction of a [[sewerage]] system - a [[Combined sewer|system of pipes, sewers and drains]] built underground to carry [[sewage]] from homes and factories to a [[Sewage farm|sewage treatment farm]].<ref name=MW-HistWTP>http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/history/history.asp . Cannot be Accessed on 15 Sep 2018.</ref>

In 1892, the newly established [[Melbourne and Metropolitan Board of Works]] (MMBW) began buying land at [[Werribee]], chosen for its low rainfall and suitable soils. Western Treatment Plant (then known as Werribee Farm) began operations in 1897.<ref name=MW-HistWTP />

Eminent British engineer [[James Mansergh]] was appointed to advise on a suitable system, while local engineer [[William Thwaites (engineer)|William Thwaites]] was ultimately responsible for the design and implementation of the system. At a time when most cities dumped their untreated wastes directly into rivers and the sea, Mansergh advised treatment of Melbourne's sewage by broad irrigation with a capacity large enough able to deal with the expansion in population expected over 50 years. The system he conceived and which was implemented in only slightly modified form began with a water closet at every property which delivered the sewage by gravity through a network of underground sewers of increasing diameter to a steam [[Spotswood Pumping Station|pumping station]] at [[Spotswood, Victoria|Spotswood]] where it was forced up wrought iron rising mains to [[Brooklyn, Victoria|Brooklyn]] to begin its 25 kilometre journey along the Main Outfall Sewer to the sewage farm at Werribee.<ref name=VicHer>{{cite web | url=http://vhd.heritage.vic.gov.au/vhd/heritagevic/?timeout=yes#detail_places;11868 | title=VHD }}</ref>

===Main Outfall Sewer=== The Main Outfall Sewer was constructed in 1892-4 and was a vital link in the sewerage system of Melbourne which, when it was constructed in the 1890s, was the largest civil engineering project ever undertaken in Victoria. The sewer was constructed by seven contractors employing 1300 workers and cost £240,748.<ref name=VicHer />

The Main Outfall Sewer consists of a semicircular brick or concrete lined channel (in places arched over to form a circular tunnel with an earth covering) and three brick arched [[Aqueduct (bridge)|aqueduct]]s. It runs for approximately {{convert|27|km|mi|0|disp=or}} from the old pumping station in Spotswood (now part of [[Scienceworks (Melbourne)|Scienceworks Museum]]) to the Western Treatment Plant, spanning the suburbs of Brooklyn, Laverton North, Williams Landing, Hoppers Crossing and Werribee in the cities of [[City of Brimbank|Brimbank]], [[City of Hobsons Bay|Hobsons Bay]] and [[City of Wyndham|Wyndham]].<ref name=":0" />

The Main Outfall Sewer's function has now been entirely replaced by the more modern Western Trunk Sewer. The Main Outfall Sewer has been listed on the [[Victorian Heritage Register]] for being "of historical and scientific (engineering) significance to the State of Victoria."<ref name=VicHer />

The [[Federation Trail]] — a {{convert|23|km|mi|0|abbr=on}} cycling and pedestrian trail — runs mostly alongside the Main Outfall Sewer.

===Upgrades=== In 1996, a Port Phillip Bay Environmental Study by the [[CSIRO]] found that [[Port Phillip Bay]] could be damaged if [[nitrogen]] loads entering its waters continued to increase, and thus recommended a reduction in nitrogen loads going into the bay. In 2004, Melbourne Water completed a $160 million upgrade of the plant to reduce nitrogen loads. [[Recycled water]] [[irrigation]] replaced [[Sewage farm|sewage irrigation]] across the site. Land and grass filtration methods previously used were stopped.<ref name=MW-HistWTP />

===General=== Most of the [[Federation Trail]], a major arterial pedestrian and [[bicycle path]] that runs for 23-kilometres from [[Werribee]] to [[Altona North, Victoria|Altona North]], follows the heritage-listed Main Outfall Sewer.

"Greening the Pipeline" is a project aimed to transform approximately the pipeline into a 40-metre (43 yd) wide parkland in Melbourne's western suburbs to connect its communities.<ref name=":0">{{Cite web|url=http://greeningthepipeline.com.au/|title=Greening the Pipeline {{!}} A future vision for Melbourne|website=greeningthepipeline.com.au|language=en-US|access-date=2017-04-17|archive-date=19 May 2017|archive-url=https://web.archive.org/web/20170519162340/http://greeningthepipeline.com.au/|url-status=dead}}</ref> The pilot stage will be a 100m section in [[Williams Landing]].<ref>{{cite news|title=Greening the pipeline - Williams Landing parkland {{!}} Melbourne Water|url=https://www.melbournewater.com.au/what-we-are-doing/works-and-projects-near-me/all-projects/greening-pipeline-williams-landing|accessdate=5 January 2018|work=www.melbournewater.com.au|language=en}}</ref>

==Sewage treatment== ===System of treatment=== There are three modern [[lagoon]] systems at the Western Treatment Plant. A modern lagoon is typically made up of 10 large [[pond]]s, each of which can hold around 600 million litres of water. Sewage flows slowly through these ponds, allowing [[bacteria]] to break down the [[organic material]]. The water progressively becomes cleaner as it flows through each of the ponds. Two main types of ponds are used in lagoon treatment - [[Sewage treatment#Anaerobic digestion|anaerobic]] (without oxygen) and [[Sewage treatment#Aerobic digestion|aerobic]] (with oxygen) - both producing different types of bacteria needed to break down the sewage.<ref name=MW-STPro>{{Cite web |url=http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/sewage_treatment_process.asp |title=Sewage treatment - How it works today: Melbourne Water |access-date=10 July 2012 |archive-date=5 June 2012 |archive-url=https://web.archive.org/web/20120605010549/http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/sewage_treatment_process.asp |url-status=dead }}</ref>

===Electricity from biogas and odour control=== Using huge covers over the ponds, [[methane gas]] produced as a [[by-product]] of sewage treatment (known as [[biogas]]) is captured and turned into [[Biomass (energy)|renewable energy]]. The Western Treatment Plant generates 70,000 MWh annually which means that it sometimes exceeds its own need for electricity and exports it back to the grid.<ref>{{Cite web|title=Biogas {{!}} Melbourne Water|url=https://www.melbournewater.com.au/water-data-and-education/environmental-issues/how-we-generate-energy/biogas|access-date=2022-01-26|website=www.melbournewater.com.au}}</ref> Capturing and using biogas to generate electricity also means [[greenhouse gas]] and [[odour]] emissions are significantly reduced. Around 90% of odour emissions from the Western Treatment Plant have been cut since the first methane covers were installed in 1992.<ref name="MW-CEB">{{Cite web |url=http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/community_and_environmental_benefits.asp#5 |title=Melbourne Water : Sewerage : Western Treatment Plant : Community and Environmental Benefits |access-date=10 July 2012 |archive-date=14 June 2013 |archive-url=https://web.archive.org/web/20130614123202/http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/community_and_environmental_benefits.asp#5 |url-status=dead }}</ref>

===Water recycling=== A [[water recycling]] disinfection plant was built at the Western Treatment Plant in 2004. This plant treats Class C recycled water to Class A standard which means this water is suitable for a greater number of uses. In 2010/11, about 29.972 billion litres of recycled water was supplied from the Western Treatment Plant. Of this, about 28.051 billion litres of recycled water (mostly Class C) was used to [[irrigation|irrigate]] 85 km<sup>2</sup> of [[pasture]] for [[grazing]] 15,000 [[cattle]] and 40,000 [[sheep]] and [[Soil salinity control|manage soil salinity]] onsite, and to maintain the health of the Ramsar listed wetlands. A further 1.921 billion litres of recycled water (Class A) was supplied to [[Southern Rural Water]] and [[City West Water]] for offsite customers, such as the Werribee [[market garden]] area to grow [[vegetable]]s, and to [[Local government in Australia|local councils]] to irrigate [[playing fields|sports grounds]], [[park]]s and [[garden]]s.<ref name=MW-CEB />

The remaining treated effluent is discharged into Port Phillip Bay under an accredited [[Environment Protection Authority (Victoria)|EPA Victoria]] licence.<ref name=MW-WTP />

==Environment == [[File:Black Swan, Genesis - Flickr - birdsaspoetry.jpg|right|thumb|[[Black swan]] (''Cygnus atratus'') nesting at the Western Treatment Plant]]

In 1921 parts of Port Phillip Bay and Bellarine Peninsula including the Western Treatment Plant were declared a [[Animal sanctuary|sanctuary]] for [[Australian native animals|native animals]]. In 1983 the plant was declared a [[Ramsar Convention|Ramsar]] site, internationally recognised for its wetland habitat especially for waterfowl.<ref name=MW-HistWTP />

The Western Treatment Plant is one of Australia's best-known sites for recreational [[birdwatching|birding]], with about 270 species of [[bird]]s recorded there. On the south-western boundary lies the 1550 ha Murtcaim Wildlife Area, containing one of the last unmodified areas of [[salt marsh|saltmarsh]] on Port Phillip. The sewage treatment lagoons, [[Lake Borrie Wetlands|Lake Borrie]], creeks, saltmarsh, and coast host large numbers of sedentary and [[Bird migration|migratory]] [[waterbird]]s and [[wader]]s. It adjoins the [[Spit Nature Conservation Reserve]] and is one of the few wintering sites for the [[critically endangered]] [[orange-bellied parrot]]. Access to the Western Treatment Plant for birdwatching is by permit only; permits can be obtained from Melbourne Water.<ref name=MW-WTP/> The site is part of the [[Werribee and Avalon Important Bird Area]], identified as such by [[BirdLife International]] because of its importance for waterbirds as well as for orange-bellied parrots.<ref name=IBAfactsheet>{{cite web |author=[[BirdLife International]] |title=Important Bird Areas factsheet: Werribee and Avalon |url=https://datazone.birdlife.org/site/factsheet/werribee-and-avalon-iba-australia |access-date=20 January 2024}}</ref>

==See also== * [[Eastern Treatment Plant]] * [[Altona Treatment Plant]]

==References== {{Reflist}}

[[Category:Sewage treatment plants in Australia]] [[Category:Ramsar sites in Australia]] [[Category:Birdwatching sites in Australia]] [[Category:Water management in Victoria (state)]] [[Category:1897 establishments in Australia]] [[Category:Important Bird Areas of Victoria (state)]] [[Category:Industrial buildings in Victoria (state)]] [[Category:Sewerage infrastructure in Victoria (state)]] [[Category:Werribee]] [[Category:Buildings and structures in the City of Wyndham]]