> Any recommendations/procedures re cleaning/sterilizing the water system?

If the tank LOOKS dirty, then get in there and scrub some.  If it
looks clean and you just want to sterilize it, then fill it 2/3s
full, add one cup of bleach, close it up, drive around a while,
run some through the water faucet, then drain it. Rinse and drain
and then let it dry out.

I do this once a year at most.  I have found that if I drain and
dry the tank after a trip, it stays clean and fresh.  If I leave
water in the tank between trips for 2-3 weeks, then it tastes
like plastic.  So I drain the tank after a trip and leave it
open for a couple of days until it is dry before I put the top
back on and the drain cap.

                                Richard A. Jones
                                Boulder, Colorado