Pipelines account for the lion’s share of the lifetime costs of any typical urban wastewater collection. While the deterioration of pipeline is the obvious “frontline” reason to adopt asset management practices, a more overarching driver is the need to gravitate toward sustainable development and set short- and long-term objectives encompassing economic, social, and environmental goals. Optimizing the expenses and providing the required levels of service to customers are the twin targets of wastewater utilities. Oslo Vann og Avløpsetaten—the water/wastewater utility in the Norwegian capital, considered as case study in this paper, is sprucing up its data bank, rightly realizing that a very effective information management system is the spine of asset management.

Wastewater treatment plants, while performing the important function of treating wastewater to meet the prescribed discharge standards, consume energy and a variety of chemicals. This paper analyses the consumption of energy and chemicals by wastewater treatment plants in Oslo over eight years, and their potential environmental impacts. Global warming and acidification were the dominant impacts for chemicals and energy, respectively. Avoided impacts due to usable by-products – sludge, ammonium nitrate and biogas – play a key role in shrinking the environmental footprint of the wastewater plants. The scope for decreasing this footprint by streamlining energy and chemicals consumption is limited, however, considering that over 70% of the impact is accounted for by the eutrophication potential (thanks to the nitrogen and phosphorus which is discharged to the sink) of the treated effluent wastewater.

Water saving is not just the responsibility of the consumer. While demand-side management prescribes several good practices for water-consumers, the supplier also understands that leakage reduction on its part is a more effective mode of saving large quantities of water, by having to abstract, treat and supply less. It is not just water which is saved, but money spent on chemicals and energy expended on treatment and pumping. The economic aspect apart, this also means that there are possibilities of significant reductions of environmental impacts upstream in the chemicals production and energy generation processes. However, it is not an easy task to perform a comprehensive cost-benefit analysis, by taking into account all the direct and indirect costs and benefits. Benefits besides are not just multi-pronged but also distributed over time. In this paper, the author compares the direct costs incurred in rehabilitating old water pipelines in Oslo, with the direct benefits of leakage reduction which accrue therefrom, for the period 2011–2020. Avoided greenhouse gas emissions by virtue of savings in energy and chemicals are compared with the greenhouse gas emissions which occur due to the rehabilitation operations. It is seen that it often becomes difficult to justify rehabilitation economically, if the direct and indirect monetary benefits in addition those accruing from leakage reduction alone are not taken into consideration. Interestingly, the net savings in GHG emissions are significant, even over the 10-year study period.