Groundwater has a wide range of social effects and is essential to daily livelihood, agriculture, and the economy of a nation. However, groundwater quality is still susceptible to contamination and is frequently disregarded until it significantly deteriorates. Alongside this, the impact of contaminated water intake is a serious issue, particularly in human health. In this perspective, the present study has evaluated "groundwater quality" and associated health hazards in a semi-arid fluoride enriched fringe area of the Chhotanagpur plateau and alluvial Gangetic Plain. To achieve the objective of this study, water samples were collected from deep tube wells located in different parts of the study area to measure hydrochemical parameters through laboratory analysis. For groundwater quality modeling, an objective-weighting approach i.e. "Entropy-weighted water quality index (EWQI)" along with four learning algorithms i.e., "boosted regression tree (BRT)", "support vector regression (SVR)", "maximum-entropy (Max-Ent)" and "random forest (RF)" were applied. The "Human Health Hazard Index" was used for optimal human health risk evaluation provided by "U.S. Environmental Protection Agency". The performance evaluation of predicted EWQI-RF has shown the highest r2 i.e., 0.911, followed by EWQI-MaxEnt (r2 = 0.891), EWQI-SVR (r2 = 0.862), and EWQI-BRT (r2 = 0.818). The area under the curve (AUC) value i.e. 0.887 in validation also indicates RF is the best optimal model for water quality assessment in this area. The best-fitted model i.e., RF demonstrates that groundwater quality zones of this area occupy 18.5%, 12% and 43.1% for very low, low, and very high quality, respectively. The outcome of this study provides a fruitful strategy to achieve "sustainable development goal (SGD)" 6 through regional water resources management and fluoride risk management.