That's really terrible. You should report those folks to the BBB or someone. Of course after 11 years that crook has probably gone on to sell Kangi units or something. A water softener is absolutely useless against this water and as your iron is so low you don't need it for that either.
[Edit: but now I see there may be a question as to whether it actually does go through the softener. If it does then the softener is doing yeoman duty and I owe the Sears guy an apology]
But back to the main subject. How does this water taste? To make if from DI water you would add 0.9 grams of sodium bicarbonate and 0.1 grams of table salt. I can't imagine it tastes very good nor that beer made from it, especially a Kölsch, would either. And that's based just on the taste of the water. The RA on this is huge (535) and would pull pH up to the mid 6's in a Kölsch. That's going to have a detrimental effect on mash, boil and fermentation. The beer would come out pretty lifeless. Even an inexperienced judge wouldn't score it at 41.
Normally in well water the bicarbonate comes from respiring bacteria. The resulting carbonic acid dissolves limestone and you wind up with calcium bicarbonate and a low pH. Your pH is very high - in fact higher than WHO recommendations for potable water. I can't thing of a mechanism that would produce this water other than that you live over a deposit of natron. Has the health department approved this well?
Something doesn't compute here.
[Edit] No, it can't be fixed except by extreme dilution in which case why bother - just use RO. If it turns out it came through the softener (and it certainly looks as if it did) you had hardness of nearly 700 ppm as CaCO3 (and maybe some iron too). There are various ways to deal with that one of which, for brewing, is not a softener (unless it precedes an RO unit which, at this level of hypothetical hardness, it should).