If one's family is Jewish but does not wash ritually in the morning and you are the only one who washes, would this make other things in the house ritually impure, like water for example? What do rabbinic sources say about this?
This would seem to depend on why we wash our hands in the morning. The Shulchan Aruch (OC 4:2) says it’s to remove “ruach ra’ah,” an “evil spirit,” from them - but what does that actually mean?
The Mishnah Berurah (4:1) quotes two opinions. The first is that of the Rosh, who says that the institution of Netilas Yadayim was because a person probably touched a part of his body that’s normally covered during the night.
The second is that of the Rashba, who explains that the reason we wash is because we’re considered a “new being” in the morning (and cites a passuk to that effect); therefore we wash our hands as we are created anew.
Please don’t ask me what either of these opinions mean; I’m not going to try to guess. But neither one actually talks about a state of tumah and taharah. Therefore the question is moot.
You’re not alone in this misconception; I’ve heard this repeated many times. I think it stems from confusion between washing in the morning versus washing for bread. In the latter case, tumah is a factor.
The Shulchan Aruch (OC 158:1) does say that one must wash over bread “even if he does not know of any tumah on them.” Mishnah Berurah (158:1) explains that there are two motivations behind this institution. One is because Terumah must be eaten in a state of purity, and in order to prevent any confusion, Chazal instituted that even non-Kohanim eating non-Terumah bread should wash their hands first. While Kohanim don’t eat Terumah nowadays, we still keep the Takanah so that, when the Beis HaMikdash will be rebuilt and the concern returns, we’ll be ready for it. The second reason is simply that a person’s hands should be clean and prepared for eating.
At least according to the first reason presented, when it comes to eating bread, impurity is indeed an issue. Perhaps it’s from here that people misunderstood washing in the morning to be for the same reason, when that washing is very different indeed.