Vacuum-enhanced extraction uses one of two engineering configurations at the extraction well: 1) a vacuum pump connected to a siphon tube, or 2) a total-liquids pump with a separate vacuum pump connected to the well head. This paper presents a conceptual model and three semi-analytical solutions that describe the simultaneous flow of the three fluids in subsurface strata to the extraction well for either configuration and is suitable for short-term pilot test analyses.  The constant drawdown analytical solution of Jacob and Lohman (1952) closely approximates groundwater flow to such a well.  Assuming the aquifer has a constant aquifer transmissivity and storativity, groundwater yield will decline over time. These two aquifer parameters are modified to derive analogous fluid transmitting and storage parameters for the subsurface air and free-phase LNAPL. The constant drawdowns for the three fluids in the extraction well are related to the vacuum pressure applied and the position of the liquids pump intake or liquid pumping level(s) relative to the static fluid tables.  When the drawdown is specified for each fluid inside the extraction well and hydraulic parameters are known in adjoining strata, the flow of each fluid to the well can be calculated along with the drawdowns in fluid heads for each, as a function of radial distance from the well.  Conversely, pumping test data from multiphase extraction and monitor wells can be used to back calculate the controlling hydraulic parameters of the adjoining strata for each fluid.  Calculations and field observations show that the upconing of fluid potentiometric surfaces (groundwater and LNAPL) are offset by drawdowns when free LNAPL and water are being withdrawn under vacuum.   A case study shows that, when the pump intake is set a short distance below the static water table, vertical smearing of the LNAPL is minimized and its recovery is maximized.