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The effect of storage on the coliform and Bacterium coli counts of water samples

Storage for six hours at room and refrigerator temperatures

Published online by Cambridge University Press:  15 May 2009

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This investigation has been concerned with the changes that occur in the coliform and faecal coli content of water samples on storage at room and refrigerator temperatures for 6 hr. as compared with those occurring after 24 hr. storage.

The examination was conducted by a 70-tube method using twofold diminishing volumes.

The percentages of samples showing a significant change corresponding to at least a doubling or halving of the coliform content on storage were: (a) at room temperature after 6 hr. 24.7%, and after 24 hr. 38.3%; (b) at refrigerator temperature after 6 hr. 25.0%, and after 24 hr. 33.9%. The percentages of samples showing a significant change in the faecal coli content on storage were: (a) at room temperature after 6 hr. 18.7%, and after 24 hr. 34.6%; (b) at refrigerator temperature after 6 hr. 10.4%, and after 24 hr. 25.0%. The changes were preponderantly decreases and most of the large changes occurred after 24 hr.

The investigation has shown that fewer changes occur after 6 hr. storage than after 24 hr. storage, and that storage for 6 hr. at refrigerator temperature is preferable to storage for 6 hr. at room temperature. Even so, some samples show significant changes after 6 hr. storage at refrigerator temperature; the coliform content is significantly altered in 25% of samples and the faecal coli content in 10% of samples.

Samples of water should, therefore, be examined as soon as possible after collection, certainly within 6 hr., and during the period of transport to the laboratory they should be kept cold, if possible by ice.

Type
Research Article
Information
Journal of Hygiene , Volume 51 , Issue 4 , December 1953 , pp. 559 - 571
Copyright
Copyright © Cambridge University Press 1953

References

Caldwell, E. L. & Parr, L. W. (1933). Amer. J. publ. Hlth, 23, 467.Google Scholar
Hoather, R. C. (1952). J. Instn Wat. Engrs, 6, 426.Google Scholar
Jones, G. E., Franklin, P. M. & Thomas, S. B. (1950). Proc. Soc. appl. Bact. 13, 108.Google Scholar
Report (1939). Ministry of Health, The Bacteriological Examination of Water Supplies. Rep. publ. Hlth med. Subj., Lond., no. 71. London: H.M.S.O.Google Scholar
Report (1952). Public Health Laboratory Service Water Sub-Committee. J. Hyg., Camb., 50, 107.Google Scholar
Taylor, C. B. & Collins, B. G. (1949). J. gen. Microbiol. 3, 32.Google Scholar
Whipple, G. C. (1901). Technol. Quart. 14, 21.Google Scholar