Even if the caravan has what is sold as a filter at the pump's delivery point, there are metres of internal tubing for muck to culture, live its life out, die and then pass on to block the faucet (taps etc) filters.Makes you wonder how well the water is filtered as we are ingesting all that muck.
Add into that some of these "so called" supply filters if not drained and dried out or sterilised after use, then standing stagnant till the van is used again, makes a wonderful culture environment for lots of microbial activities. Another designed in source of debris to potentially break away and block faucet filters.
Much IMO will not be a serious health risk, but enough that I will not tolerate having any system filters, nor drink any unboiled water drawn from our caravan's water system; that need is simply from a portable small container with freshly, daily or more often if needed, drawn water.
This also avoids drinking in any of the plasticisers that potentially can leach from the systems tubing; IMO all things better avoided even if not a great risk.