Systems and methods for treating contaminated water from gas wells by adding an inorganic coagulant and a low molecular weight polymer to the contaminated water to increase the size of solid particulates in the water and to thereby allow the solid particulates to be filtered or to otherwise be removed from the water are disclosed herein. While the inorganic coagulant can be any suitable coagulant, in some cases the coagulant is selected from aluminum chlorohydrate, polyaluminum chloride, aluminum sulfate, and ferric sulfate. Similarly, the polymer can comprise any suitable polymer, such as epi/dma, a condensation product of epichlorohydrin and dimethyl amine. The described systems and methods can clean the contaminated water so that the water can then be treated in a variety of other manners, which may include reverse osmosis, deionization, treatment with mixed bed deionizers, electro-separation, fraction distillation, distillation, and other suitable water cleansing processes.