Ok, so I am not going to pretend to know much about water softeners. I disclaim them for a reason. What I saw today raised a question however. The softener had a line running from it, through the attic, and into a vent pipe in the attic. Why? Thanks in advance.
Because the “Plumber” is an idiot. 
By the look of the tape it looks like electrican’s work.
It is a brine wast line that should be properly plumbed to a drain, and not cobbled together into a vent.
I was flabbergasted. The thing travelled uphill into the attic, and then another four feet into the vent. I just shook my head and thanked my lawyer for disclaiming them in the contract. Should I make a comment about it or what? I wouldn’t really have a clue what I’m talking about.
By the way, I hope you guys are busier than I have been. I need to get a new seo’er for my new site.
You do not disclaim the vent line Dylan, and it has been phucked up. 
Nice…If that line “popped” out that could be a huge mess when the system went into backflush mode.
ContactDominic he is an SEO god
The configuration noted in the photos is also technically a cross connection with potable water potentially in contact with non potable water. This is a common condition for water softener discharge lines terminating into a drain line without an air gap. I would call out the potential cross connection as well as the non professional workmanship.
Thank you gentlemen
Not to mention, the sewer is now venting into the attic through that open hole…