Quantitative determination of dioctyl the phthalate [bis (2-ethylhexyl) phthalate, DEHP] pollutant in soil and surface water near the "ERG" Factory of Synthetic Polymers located in Wąbrzeźno (Toruń District) has been carried out. Results confirm a high concentration of DEHP in the soil (max. 45 g/kg of air-dry soil). DEHP was also found in the water and bottom muds of Sitno Lake, near Wąbrzeźno (max. 82 mg/kg in wet mud, 0.65 ppm in surface water). Quantification was done using reversed-phase high performance liquid chromatography (RP-HPLC).