This question concerns a NH plumbing issue. I would like to install a Drain Saddle for a Reverse Osmosis System on a vent pipe. The code says "The discharge from a reverse osmosis drinking water treatment unit shall enter the drainage system through an air gap...". I think this means I can drain the RO waste into the vent pipe, but I would like other more learned opinions. I get a bit confused, because I don't think the RO system has a "flood level rim". I don't know if it matters, but the system is installed in the basement.