Swimming Pool Water Treatment

Abstract

A BOUT forty years ago, the only places available for swimming jt'_ were the old swimming holes in the creeks or the sand beaches along the rivers and lakes. I can remember when I was a boy that every once in a while we would hear about boys or adults who had drowned while swimming in the river. Most of the accidents were caused by divers hitting submerged stumps, rocks, etc., and by weak swimmers wading into concealed deep holes called step-offs. As a result of these accidents, artificial pools were built to remove the hazard of step-offs, hidden stumps, and undertow. These pools were called fill-and-draw pools, that is, they were filled and then drained at the end of some definite period, such as a week or a month. The water in these pools was quite turbid and concealed disabled bathers, hence there continued to be a few deaths, although not as many as before. The fill-and-draw pools, however, had one distinct disadvantage, for they became a very good channel for spreading diseases. Hundreds of persons used the same water in the pool before it was changed, and as each person went into the pool, he carried in his quota of germs and body dirt. Consequently, infections developed easily, particularly ear infections. An attempt was made to alleviate the condition by adding fresh water daily, but this was not satisfactory. Then someone suggested that the difficulties caused by the cloudy water and by the multitude of germs in the water could be corrected by means of a system which would continuously purify the water. This system consisted of a pump which drew water from one point in the pool, forced it through filters to remove the dirt, sterilized it with chlorine or other germicide, and then returned it to the pool at