Trihalomethane Formation Potential of Filter Isolates of Electrolyte-Extractable Soil Organic Carbon.

This article focuses on a study which states that certain organic carbon moieties of soil origin in drinking source waters of Sacramento-San Joaquin Delta (Delta) in California, can react with chlorine to form trihalomethanes during the disinfection process. Organic carbon from soils may be collected from lysimeters and piezometers, or from drainage ditches and canals adjacent to the soils. At each sampling site, subsamples were collected from the surface layer between 0 and 0.3 m using an auger. Subsamples were then mixed and cleaned of rocks, undecomposed roots, and crop residue before being composited into 1-L mason jars. Increases in electrical conductivity of extractants generally decreased the quantity of extractable organic carbon. Two soils of contrasting texture and organic carbon contents were extracted using five extractants including deionized water and four sodium and calcium-based electrolytes. The extractable organic carbon was then separated into particulate, colloidal, fine colloidal, and soluble organic carbon to determine trihalomethane formation potential.