BACKGROUNDMost experts acknowledge that low aqueous solubility results in low mass recovery rates using pump-and-treat (P&T), making such systems ineffective for coal tar (a multi-component NAPL) recovery. It is proposed to increase the apparent aqueous solubility of coal tar by orders of magnitude as an enhancement to conventional P&T schemes (or P&T-E'), increasing coal tar recovery rates, reducing the pore volumes and time required for complete recovery, thus translating into cost savings. RESULTSBatch test results of aqueous solutions containing anionic surfactant, co-solvent, and electrolyte are presented that were studied for both compatibility with a field-obtained coal tar and effectiveness at solubilizing the coal tar above its aqueous solubility. Seven surfactants were tested at room temperature (23C) in aqueous solutions containing the surfactant with co-solvents and electrolytes. The most promising surfactant solution solubilized upwards of 40 000 mg L-1 coal tar. A 1-D column test resulted in 97% recovery using the promising surfactant. CONCLUSIONSP&T-E could significantly increase coal tar solubility without causing the formation of a rate-limiting, solid-like film and offers a promising approach for the remediation of coal tar from the subsurface. (c) 2013 Society of Chemical Industry