Mining activity has been the main support for the economy in Folldal, Hedmark, during more than two centuries due to the extraction of copper, zinc and sulfur that rebounded in the industrial and social development of the region. The depletion of the ore lead to a new direction in the activity of the village, turning into the tourism associated with the visit of the old mine and its protection to keep the original buildings, galleries and mine tailings. However, the exposure and subsequent oxidation of the mine wastes produces acid mine drainage, which is discharging into the river Folla with high concentrations of heavy metals that are toxic and trigger serious environmental damage. The absence of life in the Folla river downstream of Folldal center has been manifested by authorities and there are projects ongoing trying to find a solution and restore the aquatic conditions in Folla. Therefore, this study assesses the impact of acid mine drainage in the groundwater environment and its possible contribution to Folla river. The groundwater flow and quality was investigated integrating field data with the numerical models MODFLOW and PHREEQC in order to simulate the hydrological and geochemical observations and the effectiveness of a limestone drain as a possible remediation solution. The groundwater level in the study area shows variations, ± 1m, through the hydrological year due to arid winters and humid summers. The hydrogeological numerical model reproduces these changes with a mean error of 1.4m. Heavy metals in groundwater present a concentration trend versus depth. Groundwater in the mine tailings up to 6 m deep is heavily polluted, 20 µg/L Cd, 250 µg/L Co, 1500 µg/L Cu; while at 10 m depth is HCO32- rich and has very low concentration of heavy metals, 0.02 µg/L Cd, 1.31 µg/L, Co 3 µg/L Cu. The combination of water balance and hydrochemistry indicates that currently the groundwater input of sulfate, copper and zinc into the river Folla procedding from the Folldal mine area is 2000 t/yr, 9t/yr and 16t/yr, respectively. This represents the 30% of the total yearly contamination transport in Folla. The geochemical simulation revealed that an anoxic limestone drain would remove more than 75% of Cu and Zn from groundwater and the pH would increase from 4 to 6.5. Therefore, two limestone barriers, 100-150m long, are suggested in the main mine tailings areas, in the proximity of Folla river.