Water used for the drinking purpose should be free from any contamination like Arsenic, Nitrite, Iron etc presence of Arsenic can affect millions of people. Arsenic is one of the most hazardous substances found in underground water. It is very difficult to detect the presence of Arsenic in the groundwater and a lot of research is going on in this regard.This paper presents Arsenic hazard map includes known Arsenic-affected areas and previously unaffected areas. Ranchi is capital of Jharkhand state situated at 23.36-degree North to 85.33-degree East. Tropic of Cancer is passing through the city at 23.4-degree North. Ranchi city has a population of about 1.073 million as per 2011 census. This paper presents the arsenic mapping of the Ranchi city. With the help of multivariate interpolation it is found that the maximum value of Arsenic is 212.998 microgram per liter near Tunki Tola. The minimum value of Arsenic is below desired level (BDL) at Sidhu Kanhu Park. This result can be used to aware the people to stop using or installing any new borewell in the Arsenic affected area

Keywords : QGIS, Arsenic, Contamination, Groundwater, BDL.