NOTE UPON FUNGUS DEPOSITS IN UNFILTERED 
WATER MAINS 
By RUBERT BOYCE 
In i 899 I was requested by the Water Engineer of the City of Liverpool, Mr. Joseph 
Parry, to examine and report upon certain deposits which had gradually formed in the 
aqueduct conveying the unfiltered water trom Eake Vyrnwy to the filter becis at 
Oswestry, twenty-five miles distant. Jn consequence of this deposit, there had been 
a gradual falling-ofF of the quantity of water capable of passing through the pipe line 
in the twenty-four hours. It was therefore considered of primary importance to 
seek the cause of the retardation, and to suggest a remedy. There have been many 
well-recorded cases where deposits in unfiltered water have led to a very serious 
falling-off in the daily water supply, notable cases have occurred at Lille and Berlin. 
In these instances the water contained much iron, and the deposits were shown to consist 
largely of Crenotbrix polyspora (well-pest), a fungus in whose gelatinous sheath iron 
becomes deposited as ferric oxide. 
Not only do these deposits lead to a diminution in the capacity of the water 
mains, wells, and reservoirs, but by forming a sticky layer on the surface of the filter 
beds, they hinder the normal rate of filtration, and further, the particles of fungus 
may impart to the unfiltered water an appearance, which has been aptly compared to 
thin coffee, and which, without treatment, may render it useless for domestic purposes. 
The question of the associationship of large masses of some special organism 
with fluid containing special constituents has of late attracted considerable attention, 
and in a previous number of the Thompson Yates Laboratories Reports* I described 
the two species of ' Sewage Fungus,' Spbaerotilus and Leptomitus, which are to be found 
in dilute sewage waters, and which, by their bulk, may lead to the blocking of drains 
and to offensive secondary decomposition. Like the water fungus the sewage fungus 
has a gelatinous sheath in which oxide of iron is formed when iron is present in the 
dilute sewage, and therefore, like the Crenotbrix, the colour of the Leptomitus or 
Spbaerolitus is often brown ; but whereas when the sewage fungus dies the oxide is 
converted into a black sulphide with the production of the odours of decomposition. 
I have never seen in the fungus deposits in pure water the production of any bad- 
smelling compound, nor is there any black sulphide formed, no matter how long the 
deposit is kept ; on the contrary, the odour is rather pleasant, and the number of 
* Sewage Fungi, Rubert Boyce, vol. Ill, part I. 
