Dumping Backset/dunder

[IMALOSERSCUMBAG]

Looking for suggestions or issues with disposing your backset/dunder. I tend to make whiskey and rum. I have a septic system and have heard some say it's a bad idea because the low ph will kill the good bacteria and potentially harm the concrete in the tank. I have a 26 gallon boiler and my typical runs start with anywhere from 10-20 gallons so it's not like a gallon here or there. I do re-use for my next ferments but still can have quite a bit to dump. My thoughts:

Dump down drain and hope it really doesn't mess with my system......

I could set up a hose to run outside and dump in the yard. I'm afraid the ph would damage the lawn... not that I have a golf course but the wife may not like if I kill the grass. The other issue is Wisconsin winters. I'm thinking it would be a pain to run a hose when it's -20%%d.