A method of improving oil or gas well production has the steps of (a) collecting contaminated water having 0.15% or more by weight of the salts of Na, Ca, Mg, K, Cl, SO.sub.4 or CO.sub.3 or combinations thereof (b) separation processing the contaminated water to produce i.) a first separated liquid product having increased sodium chloride and decreased magnesium chloride and calcium chloride or combinations thereof than the collected water, and ii) a second solid or liquid product having decreased sodium chloride and increased magnesium chloride and calcium chloride or combinations thereof than the collected water, and (c) injecting the first liquid product into an oil or gas well formation to improve production.