Abstract: Methods for removing volatile organic substances from water employ flash vaporization techniques. The methods comprise providing water which contains volatile organic substances and is at a pressure of at least about 35 psig, releasing the water into a vacuum chamber maintained under a vacuum in the range of about 1 to about 5 psia, removing resulting vapors from the chamber, and collecting liquid water from the chamber. At least a portion of the volatile organic substances originally contained in the water are removed as vapors from the vacuum chamber.