Orange County California groundwater characterization and treatability

Abstract

Groundwater in portions of Orange County exhibits a characteristic color attributed to the presence of naturally occurring organic matter. Dissolved organic carbon, largely in the form of humic and fulvic acids, is found at concentrations ranging from 0.3 mg/L to 14.4 mg/L. Organic rich strata is believed to be the source of dissolved organic carbon (DOC). Removal of DOC from groundwater is necessary to reduce water color and trihalomethane formation potential (THMFP). Organic carbon characteristics such as average apparent molecular weight and carboxylic acidity appear to effect groundwater treatability and THMFP. Increased organic carbon removal efficiency was realized with decreasing carboxylic acidity and lower apparent molecular weight organic carbon appears to contribute a greater amount of THMFP per milligram groundwater DOC. Alum coagulation was consistently more successful in removing DOC from solution while ozone oxidation achieved the greatest reduction in sample reactivity.