Natural warm water spa baths in rural Australia and public health risks

Australian artesian spa baths are popular recreational destinations for domestic and international visitors. Although Australia, and New South Wales in particular, have recreational water management guidelines (including natural waters and swimming pools), there are no specific management guidelines for artesian spa baths. Some regular visitors to artesian spa baths in Moree requested Council to cease chlorination in the belief that it reduced the health benefits of the geothermal water exposure. A weekly sampling study was conducted to test for the presence of pathogenic and indicator bacteria in untreated geothermal source water and to determine the effectiveness of the current chlorination system during the peak use period. Results indicated that the geothermal source water had no natural disinfection qualities and that disinfection is necessary at all times. Indicator bacteria were detected when low disinfectant levels were recorded in the artesian spa bath water. The chemical, thermal and pH qualities of the geothermal water suggests that chlorination alone may not be adequate during periods of high contamination and presents unique challenges to the standard disinfection regimes for swimming pools. These results indicate the need to develop or adopt management guidelines to define clearly the appropriate disinfection requirements for geothermal spa baths in Australia