U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12,1999--Volume 2 of 3--Contamination of Hydrologic Systems and Related Ecosystems, Water-Resources Investigation Report 99-4018B

How DOC Composition May Explain the Poor Correlation Between Specific Trihalomethane Formation Potential and Specific UV Absorbance

By Miranda S. Fram, Roger Fujii, James L. Weishaar, Brian A. Bergamaschi, and George R. Aiken

This report is available in pdf format: Fram.pdf

ABSTRACT

Trihalomethane formation potential, ultra-violet light absorbance, and aromatic carbon content of dissolved organic carbon in natural water from grab sampling in watersheds across the USA and from detailed sampling in one watershed, the Sacramento-San Joaquin Delta, California, were examined in order to better understand the compositional nature of trihalomethane precursor material. Specific trihalomethane formation potential and specific ultra-violet light absorbance were not tightly correlated in either dataset, indicating that ultra-violet light absorbance cannot be used for accurate prediction of specific trihalomethane formation potential in drinking water derived from a broad spectrum of watershed types. Specific trihalomethane formation potential was not closely related to the aromatic carbon content of dissolved organic carbon isolates or to the partitioning of the dissolved organic carbon by nonionic macroporous resins, suggesting that neither of these measures are related to the compositional features of the dissolved organic carbon responsible for trihalomethane formation.