

You can get conductive paint for RFI shielding. It’s very conductive, so make sure that the case can’t come in contact with any circuit boards or it will short out. Make sure the paint is compatible with the type of plastic you print the case out of too.
They also make ESD safe filament, but it’s $150+ a roll.
Fresh water doesn’t mean drinkable water, it just means not salt water. The desalination plant produces drinkable water.