The dunship was designed by Master Zhou in accordance with the latest standards, and before designing, he had visited several units' dunships across the river, so the living facilities on the dunship are quite complete.
There is electricity and running water.
There are restrooms for both men and women, and there's even a sewage hold.
However, extracting sewage requires a boat, and the boat needs to be equipped with a pump. Since it's not feasible to pump daily, the sewage would linger in the hold and definitely create an odor, and it cannot be discharged directly into the river.
After weighing his options, Xu Sanye finally decided to construct restrooms onshore and temporarily convert the dunship's male and female restrooms into washrooms for washing face, clothes, and even taking showers.
If you look at the blueprint, the small cabin between the two water rooms is designated for handwashing and freshening up, but now it has been turned into a "boiling water room."