RESUMO
The water sector could play a major role towards a Net Zero greenhouse gas (GHG) future if Scope 3 emissions were embraced and operationalised. Significant opportunities and challenges exist in tackling Scope 3 emissions including those associated with customer hot water use. Present GHG emission reduction practices predominantly focus on Scope 1 "within utility" and Scope 2 "purchased energy" emissions. In the urban water cycle, Scope 3 "indirect" emissions dominate, and water use is only one example of Scope 3 emissions. Over 90% of all water cycle GHG emissions can be attributed to water use in residential, industrial and commercial premises, collectively some 7% of global GHG emissions. One possibility is for water utilities to actively support efficient hot water use such as new ultra-low flow shower heads. Scope 3 opportunities also offer a range of cost-effective emissions-reduction opportunities, particularly when the wider perspective of "community value" is considered and not just a "business financial perspective". Hot water efficiency is additionally essential to Net Zero carbon futures, even with decarbonised grids, because most major Net Zero roadmaps require energy efficiency gains. Scientific and management advance needed includes: accounting methodologies, clear roles, collaboration, new business models, and clear definitions. The water sector has the opportunity to play a significant role in achieving Net Zero cities. The decision how much is yet to be made.
RESUMO
The provision of water and wastewater services to peri-urban areas faces very different challenges to providing services to cities. Sustainable solutions for such areas are increasingly being sought, in order to solve the environmental and health risks posed by failing septic systems. These solutions should have the capability to reduce potable water demand, provide fit for purpose reuse options, and minimise impacts on the local and global environment. A methodology for the selection of sustainable sewerage servicing systems and technologies is presented in this paper. This paper describes the outcomes of applying this methodology to a case study in rural community near Melbourne, Australia, and describes the economic and environmental implications of various sewerage servicing options. Applying this methodology has found that it is possible to deliver environmental improvements at a lower community cost, by choosing servicing configurations not historically used by urban water utilities. The selected solution is currently being implemented, with the aim being to generate further transferable learnings for the water industry.
