Is water coming from non-rooftop safe for borewell recharge?

Hello all,

In our residents' assocation we have this debate regarding recharging the borewells with water both from rooftop and non-rooftop.

  1. Is it safe to let non-rooftop water into the borewell?
  2. And if yes, what filters would one need?
  3. Is this a standard practice?

The reason I am asking is that we have pipes coming down and the rooftop and non-rooftop water gets mixed. If we want to have "pure" rooftop water, we would need to separate the pipes.

Thank you very much in advance,