Would the municipal authority be able to provide you with information on the energy intensity of the recycled water supplied? Also, will the building be permanently on recycled water? What’s the strategy in place for ensuring this? Unfortunately for water, there is currently no LCI data for recycled water so it’s not an operational water option you can simply select.
One option is to use ‘desalinisation’ as a proxy however you’ll need to check if that’s comparable with recycled water. Desal is about 5 times more GWP intensive than the ‘general’ water supply and can go up to 21.6 times higher if it was compared with the Victorian water grid.
For example, this article estimates that recycling water requires about 0.4-1.0 kWh/m3 versus desal at 3-3.4 kWh/m3 of energy which is quite a significant difference. Therefore it would useful to find out if the plant supplying the recycled water comes out to about the same figures.