title: Assessment of the groundwater ecosystem

XXXVIII IAH Congress Groundwater Quality Sustainability Krakow, 12–17 September 2010 Extended Abstracts Editors: Andrzej Zuber Jarosław Kania Ewa Kmiecik University of Silesia Press 2010 abstract id: 210 topic: 2 Groundwater and dependent ecosystems 2.6 Groundwater in eco-hydrology title: Assessment of the groundwater ecosystem author(s): Thomas Struppe Struppe & Dr. Kuehn Umweltberatung GbR, Germany, [email protected] Stephan Kuehn Struppe & Dr. Kuehn Umweltberatung GbR, Germany, [email protected] Christoph Charlé Protekum Umweltinstitut GmbH, Germany, [email protected] keywords: groundwater, community, ecosystem, microbial, threshold Krakow, Poland 2010 2. Groundwater and dependent ecosystems INTRODUCTION The role of organisms in the groundwater ecosystem for the global turnover of materials and energy is not known. Estimations that 6–40% of the bacterial biomass of the earth is living subterranean (Griebler, Lüders, 2008), show that the biomass of this ecosystem has great importance. The groundwater ecosystem plays a role in the global carbon and nitrogen cycles and has importance for the quality of drinking water resources and surface water. The groundwater ecosystem is characterized by geological, geochemical and hydrological conditions as abiotical factors. Under the given circumstances a typical biocoenosis is built, which is fundamentally different from those in surface waters. Due to the darkness in the groundwater biotop there are no primary production by photosynthesis. Nutrients are not produced on site but yielded from outside. The area groundwater is largely anaerobic. The quality of groundwater in Germany are assessed only by chemical criteria, at which toxicological aspects for humans stood in front as standards (Geringfügigkeitsschwellenwerte — no deterioration clause). A groundwater damage occurred when these human toxicological standards were exceeded. In surface waters the quality is detected since a long time by indicator organisms. This time research projects deal with the transfer of this system to groundwater and to find some indicator organisms in groundwater. The EC groundwater directive (2006/118/EC) demands “Research should be conducted to provide better criteria for ensuring groundwater ecosystem quality”. INDICATOR ORGANISMS IN GROUNDWATER Due to the anaerobic conditions in the groundwater biotop the diversitiy of microorganisms is much higher than the diversity of invertebrates. Invertebrates needs oxygen for their life and are not able to exist in anaerobic deeper groundwater. Investigations to detect indicator organisms like crustaceans or nematods in groundwater for an assessment of biocoenosis can only be used in groundwater areas under aerobic conditions. The research of this groundwater invertebrates are just beginning so this time neither an sufficient amount of species nor the knowledge of their pretension to habitats and environmental conditions are present. There is a lack of bioindicators for groundwater habitats. Another problem is the sampling technique. The conditions in the well water are different from the environment. So it is necessary to use a sampling technique that collects organisms of the representative groundwater area. This is much easier for microorganisms than for invertebrates, because one can use a radial pump with high through flow according to the DIN/ISO. This makes possible one sampling of groundwater for chemical and micro- and molecularbiological investigations. The results of the KORA project show that emissions out of landfills into the groundwater have an influence of the ecosystem. The DGGE-fingerprints of bacteria in groundwater influenced by landfill emissions differ, dependent from the concentrations of the emissions, significantly from those of the not influenced ones (Struppe, 2006). So an assessment of the groundwater ecosystem has to refer to main and can only refer to microorganisms. METHODS In this investigation the groundwater microbiocoenosis in the area of nine German landfills are characterised by DGGE-Fingerprints and DNA-Microarrays. The DGGE-Fingerprints were done XXXVIII IAH Congress 2.6. Groundwater in eco-hydrology as described by Kilb (1999) and Eschweiler (1999). Parallel the emissions from the landfills into the groundwater are determined. The sample was taken according to the DIN 38 402 T13 with a Grundfos MP1-pump when the in situ parameters show constant values and the volume of the well tube was exchanged three times. Relative high through flow (10–12-L/min.) provides that sessile microorganisms will be teared from aquifer material and registered. The groundwater sample then were anaerobically filtered and the DNA was extracted, cleaned amplified by PCR and then separated by denaturing gel electroohoresis (DGGE). The DGGE-Fingerprints were compared by Sørensen-indices and Cluster analysis. The resulting dendrograms show the similarity between wells at one landfill. For more information an additional quantification of the bacteria was done using fluorescent dyes. There is a definition of groundwater damage by Kerndorff et al. (2006), which we used too for influence definition (Fig. 2). To define not influenced groundwater, the background concentrations have to be detected. This is done by adding the 84.1%-percentiles of the groundwater main ions (Na, K, Ca, Mg, Fe, Mn, HCO3, NO3, NH4, Cl, SO4, TOC) of numerous groundwater (Schleyer, Kerndoff, 1992). The sum is 760 mg/L. So groundwater with concentrations of groundwater main ions <800 mg/L are defined as not influenced (neutral wells). RESULTS 5004 5003 5001 4007 4125 5002 The results show that the landfills cause groundwater damages or at least an increase compared to the upstream. Normally the concentrations downstream are higher at the border of the landfills and were decreasing with distance. A dendrogram of the Sørensen-indices of a landfill shows that the microbiocoenosis of two wells is separated from the others (Fig. 1). 1 2 3 4 5 6 0 -0,1 -0,2 -0,3 -0,4 -0,5 -0,6 -0,7 Similarity -0,8 -0,9 -1 -1,1 -1,2 -1,3 -1,4 -1,5 -1,6 -1,7 -1,8 -1,9 7 Figure 1. Clusterdendrogram of Sørensen-Indices from wells of a landfill. One well (5003) is added to the neutral well (5004) the others are separated from the neutral well. The concentrations of the main ions in the separated wells ranged from 1100 mg/L up to Krakow, Poland 2010 2. Groundwater and dependent ecosystems more than 2500 mg/L. The well 5003 has a concentration of maximal 600 mg/L and the neutral well 390 mg/L. At all landfills it can be shown that downstream wells with concentrations of main ions below 900 mg/L in clusterdendrograms of the DGGE-Fingerprints are added to the neutral wells. If the concentrations of main ions are higher than 1200 mg/L the changes in the groundwater microbiocoenosis compared to those of the neutral wells are so significant that the wells are separated in clusterdendrograms (Tab. 1). Table 1. Addition and separation of wells in clusteranalysis of Sørensen-Indices. Landfill Wells added to the neutral well Groundwater main ions [mg/L] Wells separated from the neutral well Groundwater main ions [mg/L] 1 5003 599 4007, 5001, 4125, 5002 1088–2839 2 none 4653, 4654, 4010*, 4024*, 4042* 942–960 (533–940)* 3 4010, 4024, 4042 — 533–940 4003, 4011, 5008, 5009 1089–1788 4 4019, 5006 969–1015 4002, 4012, 5007, 4001 998–4368 5 none 6 none — DE16, DE II, DE VI, DE VIII 1303–1673 — GWM 8, GWM 9, GWM 12 1733–5400 7 none 1634–5189 MA2a, MA16 — W08/029, W08/032 8 260–1174 GWM 18 3652 9 P5/01, P4/01 787–808 none * wells are added at landfill 3 to the neutral well. Wells with concentrations between 900 and 1200 mg/L are sometimes separated from neutral and sometimes added to the neutral well. So this is similar to the groundwater damage definition by Kerndorff et al. (2006) (Fig. 2). Figure 2. Thresholds for assessment of groundwater and groundwater ecosystem damages. It is possible to define a threshold of non-toxic emissions, which causes significant differences in the groundwater ecosystem. Of special interest is that the threshold of 900 mg/L is the same for a groundwater damage and for not influenced groundwater microbiocoenosis. These changes in assembles of groundwater microorganisms can cause in two effects. First there are toxic effects of other components in the emissions, which lead to a decrease of bacterial diversity and amount. Second there are adaptations of the bacterial settlement to the emissions, which lead to an increase of bacterial amounts, caused by better nutrition situation downstream of landfills. XXXVIII IAH Congress 2.6. Groundwater in eco-hydrology Quantifications of bacteria at the investigated landfills show that both effects can be observed. At one landfill the amount of bacteria near the landfill is lower than some 50 meters away, although the concentration of the main ions is higher. This is caused by pesticide containing emissions (Fig 3). At the other landfills the amount of the bacteria show an increase downstream, which is decreasing with distance and concentration of the main ions and nutrients. Figure 3. Amount of bacteria in groundwater of a landfill. SUMMARY AND CONCLUSIONS A significant change of groundwater biocoenosis caused by non toxic landfill emissions is possible. Above a threshold of 1200 mg/L main ions in groundwater the assemblage of microorganisms changes. This is an adaptation to the nutrient offer and coupled with an increase of the amount of bacteria in groundwater. This adaptation and increase is leading to natural attenuation effects. If the change is caused by toxic emissions the abundance of the bacteria decreases. This is of great importance for the assessment of groundwater biocoenosis. A change in groundwater micorbiocoenosis together with a decrease of the amount of microorganisms is considered as a damage. On the other hand an adaptation leading to natural attenuation is a “positive damage” in microbiocoenosis which reduce the geochemical damage. This is a difference to the assessment of surface water. The DGGE fingerprints allows only the comparison between influenced and not influenced groundwater microbicoenoses. The fingerprints give no information about the species behind the bands in the gel but they detect species, so local differences are emphasized to much. Desiderable are an evidence about the biodiversity in groundwater habitats. This will be possible by using DNA-microarrays which can differentiate groups of microorganisms with respect to their dependence on metabolism. The outlined investigation could be improved by using DNA-microarrays and is a field proved standard for the description of the groundwater ecosystem quality. ACKNOWLEDGEMENT The authors wish to thank the BMBF for funding KORA TV 4.1 (FKZ.:0330501) and for funding the following project PRONABAC (FKZ: 033 R040 A). REFERENCES Eschweiler B., 1999: Charakterisierung der mikrobiellen Besiedlung von Grundwässern unterschiedlicher Beschaffenheit mittels molekularbiologischer Methoden (PCR, DGGE). Veröffentlichungen des Inst. f. Wasserforschung GmbH Dortmund und der Dortmunder Energie und Wasserversorgung GmbH, Nr. 57, Dortmund. Krakow, Poland 2010 2. Groundwater and dependent ecosystems Griebler C., Lüders T., 2008: Microbial biodiversity in groundwater ecosystems. Freshwater Biology, Blackwell Publishing Ltd. Kerndorff H., Kühn S., Minden T., Orlikowski D., Struppe T., 2006: Schutzgutspezifische Bewertung von Grundwasserkontaminationen durch Altablagerungen mit dem Ziel einer passiven Sanierung mittels natürlicher Selbstreinigungskräfte (NA). Altlastenspektrum 15, Heft 1/2006, pp. 9–20. Kilb B., 1999: Analyse mikrobieller Lebensgemeinschaften in anaeroben Grundwassersystemen mittels molekulargenetischer Methoden. Veröffentlichungen des Instituts für Wasserforschung GmbH in Kooperation mit der Wasserwerke Westfalen GmbH, der Westfälische Wasser- und Umweltanalytik GmbH und der Dortmunder Energie und Wasserversorgung GmbH, Heft 59, Dortmund. Schleyer R., Kerndorff H., 1992: Die Grundwasserqualität westdeutscher Trinkwasserressourcen. Groundwater quality of Western Germany drinking water ressources — VCH Verlag, Weinheim, New York, Basel, Cambridge, 249 p. Struppe Th., Kühn St., Kerndorff H., 2006: Development of molecular genetic research methods for the ecological evaluation of groundwater. Proc. of the Hydro Eco 2006 Conference, Karlovy Vary, 11.–14 Sept. 2006. XXXVIII IAH Congress International Association of Hydrogeologists AGH University of Science and Technology 2-vol. set + CD ISSN 0208-6336 ISBN 978-83-226-1979-0