Wastewater treatment plant efficiency and contaminant levels in a Mediterranean coastal area: a comprehensive inventory and assessment
Résumé
The contamination of estuarine and coastal waters raises the question of risk assessment,
management and remediation, all of which require a good knowledge of the contamination present. Most studies focus on specific species in samples from a given site, but few examine the presence of multiple contaminants at once. Here we considered 7 nonmetallic inorganics, 32 metals and metalloids, 4 chlorobenzenes, 16 PAHs, 8 PCBs, 34 organochloride pesticides and 239 other pesticides or pesticide metabolites, 12 pharmaceuticals and 2 others, in sea water, sediments, and in urban wastewater before and after treatment. Our study sites included a reference station, a harbor, a coastal bay and a treated wastewater outlet plume. Our results provide insight into the current contamination levels and the
efficiency of the wastewater treatment plant for a wide range of contaminants. Although some organic contaminants remained at concentrations above the limit of reporting in the treated water, the dilution effect in the plume was sufficient to bring most of the organic contaminants studied below detectable levels, except for 17α-ethinylestradiol, which was the most commonly detected contaminants. This finding underscores the insufficient reduction of endocrine disruptors by current wastewater treatment.