Environmental concerns have been raised because of a garbage disposal facility (GDF) constructed near Çavuşlu Stream in Giresun, Turkey. This article proposes a fully validated ICP-MS technique to investigate the impacts of the GDF on the water quality of the stream and provide a human health risk estimation. Water sampling was carried out at four different stations and in tap water since the stream is the primary source of drinking water for the inhabitants of the town. Quantification of selected toxic metals (As, Pb, Cd, Hg, Sb, Al, and Ni) in conjunction with the essential and other elements (Se, Cu, Fe, Mg, Mn, Zn, and Co) was performed by the use of the previously validated ICP-MS method. Once water quality index (WQI), heavy metal pollution index (HPI), and heavy metal evaluation index (HEI) were computed, the health risk assessment was studied according to the US EPA's method. Although the stations (2, 3, 4, and tap water) showed excellent water quality, station-1, which is the closest one to the facility, was classified as poor water quality. Lifetime cancer risk (LCR) was only significant both for adults and children in station-1. In addition, low risk regarding non-carcinogenic health hazards was found for children. The results indicate that the facility decreases the water quality of this stream and is possibly responsible for LCR. In conclusion, the ecological environment and human health should be protected by further monitoring the effect of the GDF on the ecological system.