Effects of a sewage treatment plant outlet pipe extension on the distribution of contaminants in the sediments of the Bay of Vidy, Lake Geneva, Switzerland.
In 2001, the municipality of Lausanne extended the outlet pipe of the sewage treatment plant into the Bay of Vidy (Lake Geneva, Switzerland) as a measure to reduce bacterial water pollution and sediment contamination close to the lake beaches. The aim of the present study was to assess the impact of this measure. Lake bottom sediments were collected and analyzed for grain size, organic matter, organic carbon, nitrogen, phosphorus, heavy metals and hydrophobic organic compounds to evaluate their concentration and spatial distribution. Our results demonstrate that, compared to results obtained before the outlet pipe prolongation, the surface area of highly contaminated sediments was reduced by one third after the pipe extension. However, contaminant concentrations are still high and the accumulation of pollutants may represent a significant source of toxicity for benthic organisms. One concludes that contaminant reduction at the source will be necessary for a further improvement.
Poté
John
J
University of Geneva, Institute F.-A. Forel, 10 Route de Suisse, CP 416, 1290 Versoix, Switzerland. john.pote@terre.unige.ch
Haller
Laurence
L
Loizeau
Jean-Luc
JL
Garcia Bravo
Andrea
A
Sastre
Vincent
V
Wildi
Walter
W
D019015:Geologic Sediments / Q000737:chemistry*; D012722:Sewage; D013557:Switzerland; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis*
D012722:Sewage; D014873:Water Pollutants