Study of Bacteriological Methods of Testing and Means of Disinfecting Water with Chlorine

Abstract

INCE the adoption of continuous feed chlorination of swimming pool water whereby residual chlorine contents of 0.2 to 0.5 p.p.m. may be maintained irrespective of the bathing load, bacterial quality comparable to drinking water has been obtained. In 1926, Stovall, Nichols, and Vincent 1 reported that the relationship between the bacterial purity of the water and the residual chlorine content as measured by the orthotolidine test was so satisfactory that this test could be depended upon as a measurement of sanitary quality. In the same year Mallmann2 observed such a close agreement in the bacteriological and the orthotolidine tests that he recommended the latter as the sole measurement of the sanitary quality of swimming pool water. Since then numerous reports have appeared showing the absence of Esckerickia coli in 50 c.c. of water in swimming pools maintaining a residual chlorine content of 0. 2 to 0. 5 p.p.m. There has been no occasion to question the reliability of these data, until-recently in a series of studies on swimming pools, the writers had occasion to test swimming pool water immediately after it was withdrawn from the pool. In 1930, Schoepfle 3 reported that pool side bacteriological tests and tests on the same stored samples tested later at the laboratory were practically the same. He concluded that the increment of pollution to the pool water due to swimmers seemed to be handled effectively by maintaining the residual chlorine within proper limits;

The use of inactivators in the evaluation of disinfectants

“…of 3 % solution per 170 ml. sample) to neutralize chlorine residues in water samples (Mallman & Cary, 1933 Reports on the toxic nature of sodium thiosulphate against, in particular, staphylococci (Kayser & van der Ploeg, 1965;Gross, Cofone & Huff, 1973) agree with unpublished results from this laboratory. The degree of inhibition will vary in different basal media.…”

Comparative Mammalian Cell Cytotoxicity of Water Concentrates from Disinfected Recreational Pools

“…Notwithstanding public pools, by 2007 the number of private swimming pools in the United States increased to 8.4 million . The disinfection of recreational pools has been practiced for many years, and is essential to prevent outbreaks of disease . Yet from a survey of public pools, a majority had management code violations that could lead to infectious disease .…”

A Bacteriologist Looks at Chlorine

“…MaIlman and Carey (19) found that with swimming pool waters the ortho-tolidine test does not closely follow the bacteriological relationship previously reported by Stovall, Nichols, and Vincent. Later MaIlman and Ardrey (20) reported that neither the starch-iodide nor the orthotolidine test gave accurate indications of relative germicidal activity of various concentrations of chlorine either in the presence or absence of organic matter.…”