Multi-Evidence Identification of Distinct Recharge–Discharge Systems Across the F2 Fault in a Closed Coal Mine

connections is essential for zoned pollution control in closed coal mines. This study examined two outlets, S1 and S2, 174 m apart in the Chunjingwa closed coal mine area, Shanxi Province, China. Discharge dynamics, hydrochemistry, hydrogen–oxygen stable isotopes, and a goaf pumping test were combined. S2 showed 9.7 times the discharge variation of S1 and responded more rapidly to rainfall. Most contamination indicators had higher median exceedance levels at S2; isotopically, S1 overlapped with goaf boreholes ZK2 and ZK3, whereas S2 was heavier. During pumping, S1 discharge fell by about 91% and partially recovered, whereas S2 remained stable. The evidence identifies two distinct recharge–discharge systems on opposite sides of F2 and indicates limited cross-fault hydraulic communication at the tested scale and duration. F2 is interpreted as a structural divide, not a uniformly impermeable fault. S1 is regulated mainly by goaf-water storage to the south, whereas S2 is dominated by shallow-catchment, rapid-infiltration recharge to the north. The framework provides a practical alternative to artificial tracer tests for outlet-scale source identification and zoned remediation.