Your consultant is the correct person to suggest recycling possibilities, as he studies the entire situation at site.
Generally you can compare the test results with the limits prescribed by Pollution Control Board (as per their Consent) and accordingly utilize treated wastewater for gardening, toilet flushing, car washing and other such non-critical applications.
Practically, the wastewater needs to be crystal clear with a BOD value less than 10 mg/l for using it for toilet flushing.