Mineral content, hardness and pH of your water isn't really a big concern for extract brewing. These things do have an effect of the mash, but the mashing was already done for you by the extract manufacturer. As Kevmoron said, if it's okay to drink, it should be fine for an extract batch.
That said though, you sound unsure about it, so if you want to put your mind at ease, just buy some distilled water (preferable in this case to bottled spring water).
Stop using so much caramel malt. Your beer will thank you.
(yes, Carapils is a caramel malt...so is Special B)
pujwI HIq Mild Ale
KPA Khitomer Pale Ale