i was involved with ...

i was involved with development of a recycled water program at 2 new Las Vegas mega-casino projects in hopes of re-use if for the same purposes. Our first step was to test multiple waste water samples from a similar site at various times of the day and with different hotel occupancy levels. This determined the estimated average hourly volume of waste water and factored in seasonal changes due to the A/C cooling towers discharge. We also talked with a botanist regarding the acceptability of this water quality for sustaining plants. We initially found that the water could be remediated for toilets except that State regulations however prevented any use of any gray water in toilets at that time (1988).  In addition, cooling tower discharge to the casino waste water greatly increased dissolved solids (TDS) which our botanists stated made it unacceptable for plant irrigation unless it was pre-treated using expensive reverse osmosis equipment.  Hopefully this might help you in moving forward.