The minimum chlorine residual of the pool water shall be maintained at two-tenths (0.2) to five-tenths (0.5) parts per million or maintained with other disinfectant methods approved by the Texas Department of Health. However, chlorine residuals as high as one (1.0) part per million are not harmful and may be beneficial during heavy swimmer loads and as a deterrent to algae.
(1965 Code of Ordinances, Chapter 9, Article IV, Section 9-63)