A broader approach to recreational water quality assessment: Buenos Aires City case study

Abstract

In the last decade, the world population has become more urban than rural, but the human contact with nature is still a necessity for a proper physical and mental development. The urban green areas are a significant part of the urban heritage, providing fundamental ecosystem services. They give us the possibility of having social and cultural interaction surrounded by nature. Water is usually part of the landscape of these areas. The quality of the recreational water in urban green areas impacts on multiple factors like soil, vegetation, aquatic and terrestrial life and public health. A complete evaluation of this quality requires applying different methodologies simultaneously. Samples were collected at eight sites of Buenos Aires City in order to assess the quality of its recreational water. Results were compared with water quality standards in established legislation and were ranked by the National Sanitation Foundation Water Quality Index (NSF-WQI). Euphotic zone transparency was used as a parameter of the impact on aquatic life, measuring the Secchi depth. A test for fecal coliform bacteria was used as a risk indicator for human health. In accordance with the NSF-WQI ranking, the eight sampling sites have medium or bad water quality. Fifty percent of the sites exceeded the allowed count of coliform bacteria. According to established legislation, five of the studied sites were found to be unsuitable for primary, secondary or passive aquatic activities. Of the remaining sites, two were suitable for passive activities and only one qualified to be suitable for all kinds of aquatic activities. Secchi depth measures reveal a bad water quality for aquatic life at four of the analyzed sites.