Is there a chance it can get contaminated with bacteria? I worry about the water sitting in there.
First there has to be bacteria in the municipal water. The city does a pretty good job there,
Second there has to be organic matter for the bacteria to grow. Again, cities are good with that.
But even if you have bacteria in your water, a good RO system's pores should be smaller than a virus (really smaller than a prion) or it won't be able to remove metallic ions.
But let's assume after two years these assumptions fail because the filters get old. Replace the filters and flush the system with bleach.
My fear with RO are bad filters. I once had a Zero pitcher and it tasted bad, acidic. A few weeks later there was a recall that the RO membrane was leaking ionomers.
Moral of the story- trust your senses. If municipal water tastes bad, it's bad. If bottled water tastes bad, it's bad. If RO water tastes bad, it's bad.
Also consider what your holding tank and supply to the water, either through leaching, accumulation or simply time
But without a booster pump or if you've got a lower waste ratio either by restriction or piggyback ro membranes you'll have a lower rejection rate.
And that ignores the fact the you really need to be back flushing the membrane regularly and rejection rates are measured after 30 minutes of continuous running, ions migrate when it's idle so you have to throw away a lot of water at the start that you're probably not doing
My water is fairly heavily chlorinated where i live compared to my previous county.
Letting the glass of water sit in open for a few minutes after pouring helps with taste because the chlorine evaporates.