Typifying cities to streamline the selection of relevant environmental sustainability indicators for urban water supply and sewage handling systems: a recommendation

Measuring performance and setting targets and benchmarks for the future entail the adoption of metrics or indicators. Sustainability is a multi-pronged objective encompassing social, economic, health, cultural, governance and environmental aspects. Indicators can be grouped under these categories. The selection of environmental sustainability indicators for a water and wastewater utility in a city needs to be based on concerns specific to the utility in question. The authors, in this paper, have recommended the classification of cities into city types based on specific attributes and identification of relevant environmental sustainability indicators, from a pool of 13 indicators, for these different city types. Having selected the relevant indicators, utilities can use them as tools to improve their environmental performance. The purpose is to not facilitate inter-utility comparisons within or across city types. Every utility would compare its environmental performance at a given point in time with what it was in the past. Towards the end, the paper also applies the methodology to nine cities across four continents—Europe (Oslo, Trondheim and Turin), Asia (the National Capital Territory of Delhi, Beijing, Tel Aviv and Male), North America (Sacramento) and South America (São Paulo). In all, 13 environmental sustainability indicators have been identified. Two cities—Oslo and Trondheim (both from Norway) belong to the same city type, while the other seven are different from each other in this regard. The number of relevant indicators ranged from 4 for Trondheim to 11 for Tel Aviv. The methodology is not restricted to urban water supply and sewage handling systems. It can be extended to other infrastructure systems as well—waste management, transportation, etc.