Organic contamination of drinking water is basically caused by two general classes of organics; man-made synthetic organics and disinfection of naturally occurring organics (disinfection by-products). Many volatile and non-volatile synthetic organics at trace concentrations are being detected in surface and groundwaters. Contaminated groundwater usually contains two or more predominant organic compounds and several other identifiable ones at lesser concentrations. Surface waters, such as rivers, generally contain many organic compounds in low concentrations. The document summarizes the treatment technologies that EPA's Drinking Water Research Division (DWRD) is evaluating for removal of VOCs, SOCs, and disinfection by-products from water supplies. Carbon adsorption is effective for removing both VOCs and SOCs. Packed tower and diffused aeration are best suited for removing VOCs. Of the technologies that show promise and are being tested at the bench and pilot scales, conventional treatment with powdered activated carbon (PAC) is effective for removing a few of the SOCs, ozone oxidation is effective for removing certain classes of VOCs and SOCs, and certain reverse osmosis membranes and ultraviolet treatment are also potentially effective against VOCs and SOCs.