D10: Impact of Contaminants - Hydromod

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Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas EUROLAKES D10: Impact of Contaminants FP5_Contract No.: EVK1-CT1999-00004 Version: 4.0 Date: 25/07/01 File: D10-vers.4.0.doc Page 74 of 136 ing herbicides are still proved in the lake water. Although their concentration is low and below the threshold value for drinking water is their presence undesired [CIPEL 2000d]. More than 800 industry plants are registered but the situation is not serious because all have their own treatment plant or are connected to a sewage treatment plant. It seems that concerning the micro-pollutants like e. g. pesticides and heavy metals no important problems exist. But it is more difficult to made an exactly estimation because only few measurements are made. According to the amounts of the measured parameters in the different compartments like natural habitats, sewage treatment plant effluents, industrial discharges and sewage sludge there are great differences. Because of this it is difficult to estimate the true influence of the industry to the natural habitats of the Lake Geneva catchment. The control of certain micro-pollutants having an negative effect to the biocenosis already in low concentrations are not part of the regular monitoring program yet [CIPEL 200d]. The amounts of mercury, lead, cadmium, chrome, copper, manganese and iron measured in the water of Lake Geneva are very low and the requirements concerning the drinking water and the habitat for fishes are warranted. Investigations concerning pesticides and NTA and EDTA are also made. Very low amounts of herbicides, atrazine, simazine and terbutylazin are measured. These concentrations are below the standard for drinking water. The registered reduction of mercury charges in fish could be affirmed. The mercury and PCB concentrations in fish are harmless. On the basis of a standard-table to rate the content of metal in mussels (species Dreissena) the following propositions can be made: — Concerning cadmium, they are extremely burdened at the river banks near Bouveret, Thonon, Meillerie and near Dranse and Hermance, medium burdened at other locations, — There is a medium burden with chrome, copper, zinc and nickel at every location but some are near the level polluted, — Concerning lead there is a medium burden for Versoix, Promenthouse, Venoge, Lutry, Vidy and Thonon, other locations are not burdened [CIPEL 2000b]. Between 1995 and 1997, 22 flowing waters have been explored. The biological water quality deteriorate top down. This impairment is caused by several anthropogenic ascendancies. Although certain impairments caused by nutrients and organic material are reduced by sewage treatment other replace them. For example pesticides, alluvial matters and degradation of shore vegetation. The water quality of only one third of the investigated Waadt's rivers is acceptable at their inflow into Lake Geneva [CIPEL 2000b]. A Swiss exploration about the influence of sewage treatment plant effluents (three of the treatment plants are in the Lake Geneva catchment) shows that such effluents have in some cases a negative effect to the development of fishes [CIPEL 2000d]. During the use of pesticides these products are proved in rivers. In certain cases these concentrations could be a threat to the biological condition of water bodies. Therefore
Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas EUROLAKES D10: Impact of Contaminants FP5_Contract No.: EVK1-CT1999-00004 Version: 4.0 Date: 25/07/01 File: D10-vers.4.0.doc Page 75 of 136 regularly controls and investigations about the sources of these substances are necessary [CIPEL 2000d]. Measurements and Investigation Programs Concerning Pollutants in Lake Geneva DDT and metabolites: In twelve feeders of Lake Geneva the o,p'- and p,p'-isomers of DDT, DDD and DDE have not been found in 1997. The detection limits of these substances are between 0.05-0.1 µg/l. In a older study of 1979 the concentrations of DDT and its metabolites (p,p'-isomers) were measured in the sediments of Lake Geneva. The upper 2 cm of the sediment contained concentrations between 0.5 and 49 µg/kg dry weight of DDT and metabolites. This load was mainly composed by p,p'-DDD and p,p'-DDE, p,p'-DDT was only found sporadically. In 1982/1983 samples from the estuaries (Mündungsregionen) of the most important feeders and from sediments of Lake Geneva were tested. In every sediment sample of Lake Geneva p,p'-DDT was found in medium concentrations of 4.2 µg/kg dry weight and maximum values of 14.4 µg/kg. In the sediments of the estuaries concentrations up to 22 µg/kg were detected. In the water of Lake Geneva no isomers of DDT or its metabolites were measured at a detection limit of 0.05-0.1 µg/l [BÄTSCHER et al. 1999]. Between 1984 and 1993 the concentrations of p,p'-DDE in some fish species were proved and showed a decreasing tendency. The existing data are insufficient to derive a general decreasing tendency from that [BÄTSCHER et al. 1999]. PCB: Surface sediments from the estuaries of important feeders are investigated between 1982 and 1990 to their PCB-load. The total concentrations of most of the samples were between 25 and 200 µg/l dry weight. A consistent temporal trend of the PCBload could not be found. In 1978 the total load with PCB in the sediment of Lake Geneva has a medium concentration of 43 ± 28 µg/kg dry weight and 1983 at 47 ± 24 µg/kg dry weight. In 1979 between 20 and 540 µg PCB/kg dry weight were found in 15 sediment samples. From a perennial measuring program PCB-data of Lake Geneva are available permitting predications about the temporal trend (zeitlicher Verlauf) of the load.1995 Dreissena polymorpha living in the estuary of 12 investigated feeders of Lake Geneva were tested to their PCB-load. At 11 locations the total concentrations were between 100 and 500 µg PCB/ kg dry weight. The highest values were measured with approximately 2500 µg PCB/kg dry weight in mussels from the Venoge estuary [BÄTSCHER et al. 1999]. Lindane, Endosulfan and Vinclozolin: Between 1992 and 1996 twelve feeders of Lake Geneva have been explored but lindane (γ-HCH) was found in any flowing water at a detection limit was 50 ng/l. Samples showed that no HCH (α, β, γ, δ) were detected at detection limits of 50-100 ng/l [BÄTSCHER et al. 1999]. In 1995/1996 twelve feeders of Lake Geneva have been explored but endosulfan was not measured at a detection limit of 50 ng/l [BÄTSCHER et al. 1999]. Vinclozolin have never been detected in the water of Lake Geneva during several measuring campaigns between 1992 and 1995. The detection limit was 100 ng/l [BÄTSCHER et al. 1999]. Antifouling Compounds: Antifouling paints prevent or retard the growth of algae, bacteria and shellfish on ships’ hulls. However, organotin compounds are among the
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