A new analytical model for transport of multiple contaminants considering remediation of both NAPL source and downgradient contaminant plume in groundwater

•Analytical model considering remediation of both NAPL source and downgradient contaminant plume.•Contaminant-dependent retardation factors for contaminant and degradation byproduct.•Effects of contaminant-dependent retardation factors on plume migration are investigated.•Developed model is applied to illustrate the effectiveness of various remedial efforts.