Integrated approach for evaluation of pollution level of underground water in the vicinity of a municipal landfill

The aim of this work was the evaluation of the pollution level of underground water samples collected in the vicinity of a large city landfill in the Pomeranian province (Poland), opened before 1990 and being not water-tight. An integrated monitoring approach comprising chemical analysis and biological toxicity testing has been applied. The toxicity was measured applying the acute toxicity test with the bioluminescent bacteria Vibrio fischeri, and the acute and chronic toxicity tests with crustacean Daphnia magna. The results of ecotoxicological tests were compared to those of available physicochemical tests. An attempt was also made to identify the volatile and semi-volatile organic compounds responsible for the observed toxicity effects, and GC-MS analysis indicated the presence of several substances. The most polluted samples were also found to be the most toxic ones. However, the identity of potential problematic chemicals cannot be revealed by biotests and, therefore, chemical analyses and biotests should be used in combination.