ASHP installation / mount point and draingage

[RFw3Duwrd7Yu]

I'm installing a 16kw air source heat pump next week, and need to put in a spot to anchor it. I'm wondering if people can comment on how they've installed them and what has worked? I'm aware this ASHP will put off a lot of water (60-100l a day) and there's an inlet for sewer/waste water (it's a combined one system) about 4ft away from the installation point I've chosen. Should I put down some combination of sand, gravel and top off with cement? Or just small cement bits for the footings for the ASHP mount points? And what about water drainage? I can run some 40mm pipe from top of the pad, or a kind of soakaway. I'm just not quite sure whether 100l is too much to just drain in place. The ASHP is downslope slightly from the sewer inlet which is only about 2" below ground, so it's likely I'd need to run pipes above ground from ASHP. Would love to hear what you've done, and what has worked - and photos if you have 'em!

Here's a photo of the site:

 

[conny]

Only suggestion I have is to construct a plinth for the unit to stand on to avoid unsightly, (and trip/damage hazard), pipes running across at ground level.