Organic Carbon and THM Formation Potential in Kansas Groundwaters

Abstract

Fifty wells in Kansas were sampled to determine the concentrations of total organic carbon (TOC) and trihalomethane formation potential (THMFP) associated with major aquifer systems. The mean TOC and THMFP concentrations were 1.03 ± 0.76 mg/L and 46.7 ± 39.5 μg/L, respectively; THMFP was very strongly correlated with TOC (r = 0.953). Only 8 percent of the THMFP concentrations exceeded 100 μg/L, but 56 percent exceeded 25 μg/L and 90 percent exceeded 10 μg/L, suggesting that many Kansas water utilities using groundwater might have difficulty meeting a substantially lower THM standard. Efforts to control THMs in Kansas groundwater supplies should focus on alluvial aquifers, particularly those with high concentrations of TOC, ammonium, iron, and manganese.