Modelling spatial variation of total trihalomethanes (TTHMs) based on the quality of drinking water and parameters of distribution network showed three intervals (low, moderate, and high) for TTHMs abundance in various governorates in Kuwait. The majority of differences in TTHMs spreading were found between samples collected at Ahmadi, Jahra and Capital Governorate, as well as at Hawalli and Jahra. Spatiotemporal variations of TTHMs in household drinking water carried out by the self-organizing map (SOM) approach indicated that discontinuously sampled locations could be analyzed in a multivariate way in order to reveal the factors controlling the quality of water. In the group of analyzed variables, several mutual correlations were discovered; however, the highest relative abundance of TTHMs, and hence the correlation, was associated with dibromochloromethane (DBCM) and bromoform (BFM). The SOM-based classification helped to uncover the relationship between the THMs level and the distance from the supplying water treatment plant, and hence an indirect relation to its operational efficiency. The products of the Az-Zoor and the Shuaiba plants were of the best quality and contained the lowest levels of each of the four THMs as well as TTHMs. (C) 2009 Elsevier B.V. All rights reserved.