Trihalomethanes (THMs) are regulated disinfection by-products (DBPs), analyzed in drinking water due to their toxicological health effects. However, few data exist regarding the content of emerging THMs in drinking water which are present at very low concentrations. This study aimed to monitor hazardous and emerging THMs from drinking water supply in a residential area via solid phase microextraction using gas chromatography. Response surface methodology was employed to evaluate the role of salt concentration, temperature, desorption and extraction times on THMs formation as a result of raw water prechlorination. Maximum THM detection was achieved at 3.25 g Na2SO4 salt via 30 min extraction time at 80 °C along with 8 min of desorption time. The quantification results revealed the presence of total THMs in all drinking water samples, while most of the sites (88%) exceeded the permissible limit set by USEPA. Among I-THM, chloroiodomethane was found to be dominant as detected in 79% of samples.