1 The Effectiveness of Ozone-chlorine Treatment for Reducing Chloramine Concentration Compared to Chlorine Treatment in Swimming Pools and Whirlpools

Objectives: Chloramines are by-products of chlorine disinfected swimming pools and are hazardous to people if chloramines evaporate into the air. There is evidence that chloramines cause upper respiratory tract and eye irritation. It was suspected that ozone treatment in addition to chlorine disinfection will reduce chloramine levels in the pool. The following study compared chloramine concentration in a strictly chlorine disinfected swimming pool and whirlpool (C.G. Brown) in Burnaby, BC with an ozone-chlorine disinfected swimming pool and whirlpool (Killarney) in Vancouver, BC. The study also compared each pool and whirlpool to the 1.0 mg/L combined chlorine concentration limit in the B.C. Pool Regulation. Methods: Chloramine concentrations were determined by using a Hach Pocket Colorimeter 2 Analysis System which used a DPD method of analysis. Chloramine was determined by subtracting total chlorine by the free chlorine. Thirty pool water samples were analyzed based on two samples per pool per day for fifteen days. A two sample t-test was used to compare the ozone-chlorine treated pools with the chlorine only treated pools using the Mann-Whitney U test. A z-test was used to compare all types of swimming pools and whirlpools to the 1.0 mg/L limit