Hello Everyone,

I am seeking further clarifications and suggestions regarding the clacuation for the use of grey water for irrigation and rainwater for our project. We have a large retention pond where we will be collecting rainwater to purify for drinking and other potable water use. We also have a Waste water treatment plant that will treat our water and recylce it for irrigation and toliets.
The project is located in Phuket, Thailand. For 6 months of the year it is rainy season. The other 6 months are relatively dry. Irrigation demands on the grey water will be less if not zero some dry months.

We are trying to claim Non potable water used equal to the design case water total. The project is a net zero water project, no potable water from offsite. GBCI feedback is they would like to get more details on the calculations that determine the amoubt of non potable used. My engineers seem to not understand what is needed. Is there an online resource somewhere with examples of these calculations?

I am assuming we have to show two things. One would be a rain fall water balance chart thast would show the irrigation demands for a year (by month) with rainfall factored in. The other item would be a daily or monthly output of the grey water produced by the WWTP and how much gets used by irrigation. And to factor in any treated rainwater use if that is required in the hotter months of the dry season.

Any feedback on what is needed to document non potable water use and where I might find examples of this is appreciated. Thanks.