10.2190/JPMV-NJV2-GKRF-0UC1 JPMVNJV2GKRF0UC1 2 Trihalomethanes in Groundwater Systems 115 125 20020509 20020509 20020509 20020509 JPMVNJV2GKRF0UC1.pdf http://baywood.metapress.com/link.asp?target=contribution&id=JPMVNJV2GKRF0UC1 2 M. M. Varma A. Balram H. M. Katz Howard University, School of Civil Engineering, Washington, D.C. Aqueous chlorine reacts with certain precursors in water to form trihalomethanes which are suspected carcinogens-mutagens. In the past, much attention has been given to the formation of THM's in surface waters, but little attention has been given to groundwater systems. In this study, groundwater supplies in six small towns in Maryland were studied. Samples of both raw and finished water were collected and analyzed for THM's and for THM formation potential at ambient pH and at pH9. In raw water samples, the only THM detected was chloroform, and the highest concentration was 2.5 μg/ℓ. In finished water samples, chloroform concentrations were somewhat higher and no other species were detected, except for one supply where the chloroform concentration was 24.8 μg/ℓ and total THM's were 103.5 μg/ℓ, the difference being brominated compounds. Significant amounts of brominated compounds were found in only one other supply, but total THM's were relatively low. The results of THM formation potential generally followed the same pattern, and showed a slight increase in formation potential at higher pH. The results indicate that more attention needs to be given to monitoring groundwater supplies in small towns. R. D. Kloeffer, et al., Characterization of Organic Components in Municipal Water Supply, <i>Environ. Sc. and Technology, 6</i>:1036, 1973. P. R. Wood, et al., Treatment of Groundwater with Granular Activated Carbon, <i>J. AWWA, 71</i>:674, 1979. W. H. Glaze, et al., A Preliminary Survey of Trihalomethane Levels in Selected East Texas Water Supplies, <i>J. AWWA, 71</i>:509, 1979. J. J. Richard and G. A. Junk, Liquid Extraction for the Rapid Determination of Halomethanes in Water, <i>J. >AWWA, 69</i>:1, p. 62, January 1977. J. P. Mieure, A Rapid and Sensitive Method for Determining Volatile Organohalides in Water, <i>J. AWWA, 69</i>:62, 1977. M. M. Varma, et al., Analysis of Trihalomethanes in Aqueous Solution: A Comparative Study, <i>J. AWWA, 71</i>:389, 1979. Federal Register, National Interim Primary Drinking Water Regulations: Control of Trihalomethanes in Drinking Water, Fianl Pub., Federal Register No. 44FR68641, November 29, 1979.