Multimedia environmental models based on fugacity (Mackay,2001) have been widely employed to quantitatively describe the fate and transport of PAHs Fugacity models quantify the mass of chemicals transferred across different bulk media (e.g., air, water, sediment, soil, etc.) and their sub-compartments, and determine the chemical's concentration profiles in them based on mass-balance calculation. Fugacity models have been used to estimate the fluxes of PAHs from soil to sediment (lang et al., 2008). However, as fugacity models usually do not have a detailed description of water flow, soil erosion and chemical enrichment, the modeling results could provide very limited support to managing the NPS pollution. Wang et al. (2011) evaluated the fate of PAHs in Songhua River (Northeast china) by integrating an 1-D hydraulic model with a Level-IV fugacity model. But the surface runoff and sediment processes were not explicitly modeled. Another relevant study (Lou et al., 2007), although not on PAHs, jointly used HSPF ( a classic NPS pollution model) and a Level-IV fugacity model for trichloroethylene (TCE). But the HSPF model provided runoff simulation to the fugacity model, and its water quality module was not activated. An innovative approach to incorporate the fugacity concept in modeling the NPS pollution of PAHs (and other chemicals alike) has yet to be found.