Water and sewerage

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MelbourneHistory of Melbourne’s sewerage system

The history of sewage treatment in Melbourne is quite different from the history of water supply.

Prior to the establishment of any form of sewerage systems it was easy to get rid of some kinds of sewage. For example, once you had washed up, all you needed to do was throw the dirty water out the door.

For many years authorities avoided the responsibility of effectively removing and treating sewage. However, it soon became clear that the proper treatment of sewage from homes and from the growing industries of Melbourne was too important to ignore.

The Early Days - Marvellous 'Smellbourne'

In these early days the majority of sewage from houses, including kitchen, bathroom and laundry wastes, along with the contents of chamber pots, was emptied into open drains that flowed into street channels. This waste mixed with wastes from stables and industries made these open street channels extremely smelly.

Street channels were often wide enough to require small bridges that would allow pedestrians to cross them. They generally carried sewage to the nearest river or creek. As a result, natural watercourses became open sewers flowing to Port Phillip Bay.

The other method of waste disposal at this time was reserved for human wastes. In those days a toilet consisted of a bucket that was housed in a wooden structure commonly known as a pan closet toilet, middenstead or 'thunderbox'.

Thunderboxes

Disposing of human solid wastes caused problems. The early solution was to cart these solid wastes away to the tip rather than just wash them into open drains and street channels. 

Pan closet toilets, or 'thunderboxes' were emptied about once a week by a nightman (so called because he collected pans at night). Because the wastes stayed in a pan for up to a week, pan closet toilets were really smelly. As a result, they were generally built as far from the house as possible and a trip to the toilet involved a walk down the garden path.

As such a walk was not too inviting in the dark, people often used chamber pots at night (which were often emptied straight into street drains).In crowded city areas, the pan closet toilets generally backed onto a lane. Once a week the nightman would collect the pan by reaching through a small door in the back of the closet. He would then empty the pan into his own bucket and return it, uncleaned, to the closet.  The waste, called 'nightsoil' was then carted to the outer fringes of Melbourne where it was often used as fertiliser by market gardeners. However, as Melbourne grew the system began to break down. Nightmen couldn't keep up and by the 1880s Melbourne was ankle deep in its own wastes. Infectious diseases, such as typhoid, that were associated with these unsanitary conditions were on the increase and of great concern to the authorities.

Reticulation

The answer to all of Melbourne's problems with nightsoil and smelly open drains was to pipe sewage away in sewers. Although this was going to be very expensive it was the only solution that would work.

In 1889 an English engineer, Mr James Mansergh, was employed to draw up plans for Melbourne's sewerage system. Mansergh's plans were modified by the MMBW's first engineer-in-chief, Mr William Thwaites, and in May 1892 construction began on Melbourne's sewerage system.

This system was based on a network of main underground sewers that would carry sewage, via a massive pumping station at Spotswood, to a sewerage farm at Werribee. Unlike Sydney, which decided to pump its sewage out to sea with minimum treatment, the MMBW had decided to treat Melbourne's sewage at the Werribee sewerage farm before it was released into Port Phillip Bay. Despite a depression in the 1890s, by the turn of the century the Werribee sewerage farm was treating Melbourne's sewage.

Gradually underground sewers spread throughout Melbourne. The infamous thunderboxes, along with the attendant nightmen, were replaced by inside water-flushed toilets. Unlike modern toilets, which flush with a push of a button, early toilets had a high cistern located above the toilet that was flushed with the pull of a chain. The introduction of reticulated sewerage systems also meant that smelly open drains and street channels were no longer required.  As a final note, pan closet toilets are not necessarily things from the distant past. For example, the removal of the last three pan closet toilets in Frankston occurred in April 1991 and was hailed as 'a small milestone' in the city's history.

Septic tanks and the Eastern Treatment Plant

Reticulated sewerage was not seen as being appropriate for the more spacious outer suburbs and areas such as the Mornington Peninsula. Septic systems were widely used and replaced the nightman's weekly visit. Like toilets that were connected to a reticulated sewerage system, septic toilets had all the advantages of being flushed with water. 

In 1939, Mornington was the first town on the Mornington Peninsula to build a reticulated sewerage system. Construction of this initial system was the envy of other towns on the Peninsula. However, until late in the 1960s, Mornington was still the only town south of Mordialloc with a reticulated sewerage system.

By the early 1960s, problems of water pollution caused by the wastes from septic systems, led to the formation of a number of sewerage authorities in the district. These sewerage authorities soon began replacing septic systems with reticulated sewerage systems.

Finally, as Melbourne grew to the east and south, it was decided that Werribee could not handle processing the full load of Melbourne's sewage. As a result the MMBW built the Eastern Treatment Plant (ETP) at Carrum.

In 1975, ETP commenced operations and now treats 40 per cent of Melbourne's sewage. Sewage from this plant is screened and then undergoes primary and secondary treatment before the purified effluent is discharged into the environment.

Today Yarra Valley Water operates six Sewerage Treatment Plants located throughout its area of operation.