Dirty water is the most common water in the game, and is drawn from the tainted lakes and rivers of the Capital Wasteland. Unlike purified water, this will give you radiation, which can be cured by a doctor (for a fee), by using RadAway, or by using My First Infirmary.
Dirty water can commonly be found in people's homes, first aid boxes, and in merchant inventories.
Dirty water differs in appearance from purified water. Dirty water is labeled "WATER", while purified water is labeled "H²O", the bottle is also grimier. The Pip-Boy icon for both is the same, however.
Dirty water has the same appearance as the Broken Steel add-on item aqua cura, apart from the writing on the side.