This paper is the result of environmental geological survey engineering.

Objective As an important water conservation area of the Middle Route of the South-to-North Water Diversion Project, the study of groundwater quality in Ankang Basin is very important for regional ecological security and drinking water safety. This basin is situated between the Qinling Mountains and the Daba Mountains. The shallow groundwater consists primarily of pore water in unconsolidated rocks and bedrock fracture water, making it susceptible to disturbance by surface activities.

Methods Through collecting 37 shallow groundwater samples and employing integrated approaches including descriptive statistics, correlation analysis, Positive Matrix Factorization (PMF) modeling, and USEPA health risk assessment models, this study systematically examined the concentration characteristics, pollution sources, and health risks of heavy metals in the basin's groundwater.

Results The mean concentrations of heavy metals followed the order: Fe>Mn>Cu>Ni>Pb>As>Co>Cr(Ⅵ)>Cd>Hg. Notably, Fe, Mn and Pb concentrations at specific locations exceeded the Class III limits of China's Groundwater Quality Standards. PMF source apportionment identified three primary contributors: industrial and mining activities (56%), combined agricultural and domestic pollution (29.65%), and mineral weathering (14.35%). Health risk assessment revealed that As and Ni were the predominant carcinogenic risk factors, while non-carcinogenic risks remained relatively low overall, though the potential risk of Mn warrants attention. Drinking water intake emerged as the primary exposure pathway, with children demonstrating significantly higher health risks than adults.

Conclusions The northwestern and southeastern basin regions are priority areas for targeted management due to elevated risk levels.