The cleaning and filtering of Water

[omoplata]

I have a very specific question.

 

The water in the aqueducts must have collected some dirt and debris on its long way. How was this water filtered and purified before consumption?

I can't find much information on this and would appreciate any input.

 

Thanks a lot

[Melvadius]

I have a very specific question.

 

The water in the aqueducts must have collected some dirt and debris on its long way. How was this water filtered and purified before consumption?

I can\'t find much information on this and would appreciate any input.

 

Thanks a lot

 

There are a number of books around which will give you much of this information, the best in my opinion probably A Trevor Hodges \'Roman Aqueducts and Water Supply\' although \'The Water Supply of the City of Rome\' by Frontinus describes things from the Roman viewpoint and is also worth a look.

 

[Holding reply follows...]

 

There is a general article elsewhere on this site.

 

However to try and answer your specific point from memory the simple answer is that the Romans drew their water supplies from a number of sources usually from either a river or underground source. The water was transported through aqueducts to where it was needed but would pass through one or more settling tanks which allowed the water to flow into the bottom and allow relatively clean water to flow out from the top of the tank with heavier contaminents dropping to the bottom of the tank.

 

I think they also made use of sand filters but even so some of the water supplied to Rome via aqueducts was not deemed by the Romans suitable for anything except possibly bathing. In areas of the city supplied inthis way I believe more use was made of local, sometimes household specific, supplies of water from cisterns or wells.

 

[Edit - expansion of answer]

 

Frontinus I.15 (Loeb - Frontinus Stratagems Aqueducts: - Aqueducts of Rome)

The intake of New Antonio is at the forty-second milestone on the Sublacensian Way. In the district of Simbruvium. The water is taken from the river, which, even without the effect of rainstorms, is muddy and discoloured, because it has rich and cultivated fields adjoining it, and in consequence loose banks. For this reason, a settling reservoir was put in beyond the inlet of the aqueduct, in order that the water might settle there and clarify irtself, between the river and the conduit. But even despite this precaution, the water reaches the City in a discoloured condition whenever there are rains.

 

Hodge Roman Aqueducts & Water Supply

 

Chapter 10 Urban Distribution –

Filtration

 

On arrival at the city the water had already been largely filtered, both by small setling chambers cut in the floor of the channel itself and by large settling tanks and reservoirs built…at intervals along the line of the aqueduct. By these means a good deal of the sediment had already been removed, though not by any means all, if there was a lot to start with.

 

Hodge goes on to mention that there were 'vast heaps of pebbles removed from the Anio Novus by the settling tank at the Villa Bertone, Capanelle'

 

and

 

It was common for such a settling tank to be provided at the end of an aqueduct’s run. All that was really needed was a large tank where the speed of the currentwould be sufficiently slowed in passing throuigh for impurities in suspension to settle to the botom, but we do find more elaborate arrangements. A common principle was to have two or more chambers so communicating that the water passed through all in turn, becoming progressively purer…

 

Hodge also mentions specific examples of filtration including a cistern at Ampuria (which had no aqueduct). The cisterns filter was made out of a circle of amphoras, which may originally have contained charcoal and sand.

 

There is also an actual aqueduct filter at Cirta (Constantine) in Algeria although Hodge notes that water was a rarer commodity there. This may explain the elaborateness of this particular system:

 

It was formed by a 60cm thick wall of sandbags built at an angle across the channel, here 1.5m wide. On the downstream side of this barrier were constructed a series of eight small channels, each 10cm wide, separated by planks, and running side by side along the floor of the conduit. They could be followed for a length of 12m, and bore traces of a fine white sand, which was apparently also what was inside the bags…

Edited April 20, 2010 by Melvadius

[Artimi]

thanks for the links and book references. I had never thought about the problems with impurities in the water brought by aqueducts.

Edited April 21, 2010 by Artimi

[omoplata]

Thank you very much

this really helps a lot

[Melvadius]

Thank you very much

this really helps a lot

 

Glad to help, I just trust that if it is for homework it will be suitably credited