I suggest you experiment with bottled water for your Keurig.
Do not use distilled water for coffee brewing. It does not contain the dissolved minerals required to extract the full flavours. Mind you, this probably applies more to specialty rather than commercial coffee, although, I'm sure it can still make a difference in the cup.
For a while, I would make my own water to match the city water of the roaster I get my beans from, but this got tiresome. I now use Third Wave Water to keep my water a constant.
https://thirdwavewater.com/
If you wanna dive deeper into this subject, there's a great book called Water For Coffee by Maxwell Colonna-Dashwood & Christopher Hendon.
City of Calgary water -
http://www.calgary.ca/UEP/Water/Page...-Overview.aspx
Water recipes -
https://baristahustle.com/blogs/bari...-water-recipes