Increase of population and urban, industrial and agricultural activities, has led to groundwater and surface water pollution. A major part of human's health, is affected by the quality of drinking water which, in turn, is affected by the pollution of groundwater and surface water. Researches show that excessive increase and decrease of fluor and total hardness of water can cause health problems. This research aimed to determine the amount of hardness and fluor of drinking water in the district of Ghochan, north of Khorasan, Iran. Therfore, 11 wells, 1 qanat, 2 reservoirs, and Tabarakabad dam were selected in the district of Ghochan. The samples were collected in three stages from winter 2008 to summer 2009. Total hardness of water and fluor were analyzed and the results were compared to national and international standards for drinking water. The results show that total hardness of sample were in the high level. The amount of total hardness of all water resources were 102.4 to 925 mg/L based on Calcium Carbonate (Standard WHO: 500 mg/L). The highest amount was observed in the old city sector and city center reservoirs as well as the new wells in the eastern part of the city. It was also seen that the dam water and the mixing reservoirs had a relatively acceptable hardness. The highest amount of hardness in the period of study was from the wells of Norooz and Bagh Behesh and also the qanat of Reza Abad, 804, 703 and 702 mg/L, respectively. Regarding the direction of groundwater movement, declivity of the area and the city, the reason for such high amount was the geological formations of the area. The amount of fluor in the most cases was approximately at minimum permissible level and fluctuated between 0.42 to 1.66 mg/L (Standard ISIRI: 0.6 to 1.7 mg/L). It was concluded that the drinking water in the city of Ghochan is generally very hard and the amount of fluor in the most cases was at minimum permissible level. However, regarding the fact that high quality water and low quality water were mixed and then used by people, no serious problem was seen. The analysis of the drinkability of Ghchan's water based on Sholer's diagram also confirmed that the drinkability of water is relatively acceptable. Using Lanjiler and Risener yardsticks also showed that both new and old water reservoirs of Ghochan have the potential of deposition more than corrosion. Key Words: Total Hardness , Fluor, Drinking Water
