Anthropogenic influences on dissolved organic matter transport in high arsenic groundwater: Insights from stable carbon isotope analysis and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.

•Terrestrial DOM account for 54.2%–85.5% of groundwater DOM.•Irrigation using canal water inputs aliphatic and tannin-like DOM to groundwater.•Recharge from irrigation leaches aromatic DOM from sediments into groundwater.•Reuse of CRAM-like DOM might be an additional DOM source to groundwater.