Conflicts in the Colbitz-Letzlinger Heide between Military Use and Drinking Water Protection

Country / Region: Germany / Saxony-Anhalt

Begin of project: January 1, 1992

End of project: July 31, 2014

Status of project: July 31, 2014

Investigation area

Background:
The groundwater resources in the Colbitz-Letzlinger Heide are used to supply drinking water to the city of Magdeburg and the adjacent districts to the north in the Magdeburger Börde and the Altmark. The groundwater in the approx. 980 km² area between Uchte, Tanger, Ohre, Milde and Secantsgraben, are exploited by the waterworks in Colbitz (drinking water for Magdeburg), Haldensleben, Gardelegen and Schernebeck. The central part of the Colbitz-Letzlinger Heide has been used as a military training ground since 1934 (up to 1945 as an artillery test firing range used by the company Krupp, then by the Wehrmacht, and subsequently by the Soviet army until 1993).

The German Armed Forces are now in charge of the area and are building a battle training centre for the army in the Altmark military training area. The military use of the area in the past caused soil contamination in areas including explosion and firing ranges, washing facilities, barracks, fuel depots and test facilities. Immissions involved a range of contaminants (e.g. heavy metals, explosive residues, mineral oils) and are therefore suspected to be present in the raw water of the water catchments at the edge of the military training area.

The Colbitz-Letzlinger Heide is not only used for the abstraction of drinking water and as a military training area: some parts are designated nature protection areas or have the status of “temporarily protected”. There is therefore a general conflict of interest between the military, the water industry and environmental protection. A long-term groundwater monitoring programme is a fundamental requirement for the amicable resolution and regulation of the various interests.

Monitoring well and landscape

The use of large parts of the old military training area as a battle training zone in a way which complies with the current environmental protection regulations was tied to the results of detailed hydrogeological investigations and reports. The Federal Institute for Geosciences and Natural Resources (BGR) was engaged by the German Federal Ministry of Defence (BMVg) to assess, implement and evaluate hydrogeological investigations concerning various aspects including geology, hydrogeology, hydrochemistry, remote sensing, surface geophysics, borehole geophysics, drill sites, the construction of observation wells, and land surveys. The investigations are carried out in close collaboration with the Ministry for Agriculture and the Environment of the State of Saxony-Anhalt, the State Geological Survey and Mining Inspectorate, the Countryside Commission and the State Construction Authority.

Work phases:
The whole military training area and its surroundings have been investigated in detail since 1992 in various work phases. 176 groundwater observation wells were installed at 56 sites in the military training area to investigate the hydrogeological structures, measure groundwater levels, and extract water samples. Pumping tests were conducted at 11 observation wells to determine the hydraulic parameters. Surface geophysical surveys were conducted to document the geological information. The monitoring network includes the new observation wells as well as those belonging to the water resources management and the State of Saxony-Anhalt in the vicinity of the military training area.

Water levels were measured at around 650 observation wells between 1993 and 1998. At the same time water samples were collected and analysed to determine standardised inorganic and organic parameters and use-related organic parameters (including chemicals used in explosives).

Sampling a monitoring well

Groundwater monitoring was continued in 1998 in the form of long-term monitoring realised in various measuring and sampling campaigns. The first phase of the long-term groundwater monitoring was concluded in 2006 with a summary report covering the four previous campaigns. Based on these results the long-term monitoring was modified in 2007. There is a measuring grid in the centre of the training area with 30 locations and annual measurements for mapping groundwater quality in the area directly used by the military and a monitoring network to control the border of the training area with 36 locations and biannual measurements. The hydrogeological investigation consists of three complementary components: The monitoring, the hydrogeological database and the groundwater modelling.

Results:
All of the important hydrogeological data in the area was compiled within a central database as part of the investigation programme. 20 hydrogeological sections were drawn up using the results of the new data points and the older data.

The base of the freshwater-bearing multiaquifer formation is the Mid-Oligocene Rupel Clay. In the southern part of the Colbitz-Letzlinger Heide this lies directly beneath thick Quaternary, primarily sandy formations of Elsterian and Saalian glacial deposits. The Elsterian glacial till in this multiaquifer formation forms a discontinuous aquitard between the lower and upper aquifers. These aquifers are further subdivided by other sealing interbeds. The upper multiaquifer formation is used intensively for drinking water abstraction. The oldest known aquifers in this sequence are the fine and medium-grained sands of Upper Oligocene to Lower Miocene age. These are the deepest aquifers in the freshwater-saturated overburden which is only present to the north of the Gardelegen Fault. A locally significant perched aquifer, with perched groundwater in part, is present in the southern part of the military training area.

Hydrogeological cross section

The periodically produced water table contour maps define in detail the groundwater flow from large parts of the military training area to the water catchments at the Colbitz, Haldensleben, Schernebeck and Gardelegen waterworks. The depth of the water table in the terminal moraines is over 60 metres. The groundwater level measurements show local differences in pressure between the Saalian glacial aquifers and the Elsterian aquifers.

The hydrochemical investigations indicate that the groundwater is locally contaminated as a result of military activities. Most of the military facilities and activities were in the area covered by the perched aquifer. This is where the German Armed Forces Contaminated Sites Remediation Programme is looking in detail at the contaminant immissions. The results of this programme will be taken into consideration when evaluating the groundwater monitoring data. Because the water table is deep in most cases, any contaminated percolating water spends high residence times within the formations overlying the aquifers. In addition, the flow times of potential contaminated groundwater to the interconnected abstraction wells is relatively high, at a few decades to a few hundred years.

A regional computer model for groundwater flow and mass transport was elaborated for the whole area of investigation covering the Altmark military training area to simulate water management scenarios and to generate forecasts.

Literature:

• ERTL. C., MAIWALD, U. & WINTER, P. (2006): Hydrogeologische Begutachtung der Colbitz-Letzlinger Heide. Grundwasser-Dauermonitoring auf dem Truppenübungsplatz Altmark, 1. - 4. Kampagne (1998-2005). - Unpublished report, arch. no. 1109006, 104 p., 8 ann., 4 app.; Berlin.
• ERTL, C., MAIWALD, U. & WINTER, P. (2005): Hydrogeologische Begutachtung der Colbitz-Letzlinger Heide - Grundwasser-Dauermonitoring auf dem Truppenübungsplatz Altmark - 3. Kampagne 2003. - Unpublished report, arch. no. 0125406; 3 Bd., 65 p., 4 ann., 37 app.; Berlin.
• ERTL, C., NESTLER, J. & HIMMELSBACH, Th. (2013): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 6. Kampagne 2012. Unpublished report, arch. no. B 30132-01, 88 p.; Berlin.
• ERTL, C., NESTLER, J. & HIMMELSBACH, Th. (2012): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 5. Kampagne 2011. Unpublished report, arch. no. B 30132-01, 81 p.; Berlin.
• ERTL, C., NESTLER, J. & HIMMELSBACH, Th. (2010): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 4. Kampagne 2010. - Unpublished report, arch. no. 1066010, 73 p.; Berlin.
• ERTL, C., NESTLER, J. & HIMMELSBACH, Th. (2010): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 3. Kampagne 2009. - Unpublished report, arch. no. 1011610, 70 p.; Berlin.
• ERTL, C., NESTLER, J. & WINTER, P. (2008): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 2. Kampagne 2007. - Unpublished report, arch. no. 1103708, 90 p.; Berlin.
• ERTL, C., NESTLER, J. & WINTER, P. (2008): Nutzungsbegleitendes Grundwassermonitoring auf dem Truppenübungsplatz Altmark, 1. Kampagne 2007. - Unpublished report, arch. no. 1022008, 99 p.; Berlin.
• KRAMPE, K. & SCHWALBE, E. (1997): Weiterführende hydrogeologische Untersuchungen - Grundwasser-Monitoring - auf dem Truppenübungsplatz Altmark. Abschlussbericht. - Unpublished report, arch. no. 2025934, 95 p., 2 app.; Berlin.
• KRAMPE, K. & SCHWAMM, G. (1999): Truppenübungsplatz Altmark / Wasserschutzgebiet Colbitz. Schutzbedürftigkeit des Einzugsgebietes der Grundwasserfassung Cröchern - Trinkwasserschutzzone III B. - Unpublished report, arch. no. 0119614; 19 p., 6 fig., 5 app.; Berlin.
• KRAMPE, K. & SCHWAMM, G. (1994): Hydrogeologisches Gutachten für den Truppenübungsplatz Magdeburg in der Colbitz-Letzlinger Heide. Abschlußbericht Teil I-III. - Unpublished report, arch. no. 2024873; Berlin.
• KRAMPE, K., SCHWAMM, G., GOSSEL, W. & LANGKUTSCH, U. (2001): Hydrogeologische Begutachtung der Colbitz-Letzlinger Heide - Grundwasser-Dauermonitoring - auf dem Truppenübungsplatz Altmark. Kampagne 1998/1999, Eröffnungskampagne. - Unpublished report, arch. no. 0121036; 144 p., 2 app.; Berlin.
• SCHWAMM, G., LANGKUTSCH, U., GOSSEL, W. & WINTER, P. (2002): Hydrogeologische Begutachtung der Colbitz-Letzlinger Heide - Grundwasser-Dauermonitoring - auf dem Truppenübungsplatz Altmark. 2. Kampagne 2001 - Unpublished report, arch. no. 0122348, 136 p., 2 app.; Berlin.

Promotion / document number:

Federal Ministry of Defence (BMVg), contract no.: 030/S 1124/010