A procedure to define natural groundwater conditions of groundwater bodies in Germany

Abstract

Commissioned by Germany's Working Group of the Federal States on Water Problems (LAWA) the authors developed a procedure to define natural groundwater conditions from groundwater monitoring data. The distribution pattern of a specific groundwater parameter observed by a number of groundwater monitoring stations within a petrographically comparable groundwater typology is reproduced by two statistical distribution functions, representing the "natural" and "influenced" components. The range of natural groundwater concentrations is characterized by confidence intervals of the distribution function of the natural component. The applicability of the approach was established for four hydrochemically different groundwater typologies occurring throughout Germany. Based on groundwater monitoring data from 7920 groundwater monitoring stations, 15 different hydrochemical parameters were evaluated for each groundwater typology. For all investigated parameters the range of natural groundwater concentrations has been identified. According to the requirements of the EC Water Framework Directive (article 17) (WFD) this study is a basis for the German position to propose criteria for assessing a reference state for a "good groundwater chemical status".

Occurrence of nitrate in Tanzanian groundwater aquifers: A review

“…Background concentrations of nitrate in different aquifers vary depending on geological formations and current and past vegetation cover (ECETOC 1988;Foster et al 1999;West 2001;Limbrick 2003;Wendland et al 2005). Natural sources of nitrate in the groundwater include leaching and oxidation of nitrogenous compounds incorporated in rocks (Holloway and Dahlgren 2002) and fixation by leguminous plants and microorganisms (Edmunds and Smedley 1996).…”

“…According to Holloway and Dahlgren (2002), rock nitrogenous compound concentrations range from trace levels to above 200 mg-N/kg in granites and may exceed 1,000 mg-N/kg in some sedimentary and meta-sedimentary rocks. In many aquifers, background concentration of nitrate is less than 1 mg/l (West 2001;Wendland et al 2005). However, due to variation in geochemical and historical vegetation cover, higher background concentrations have been reported elsewhere (Burkart and Kolpin 1993;Eckhardt and Stackelberg 1995;Mueller 1995;Foster et al 1999;Limbrick 2003).…”

Assessment of background levels of trace metals in water and soil from a remote region of Himalaya

“…Use of a single value, regardless of the spatial variations could give rise to either overestimation or underestimation of metal contamination and the associated risk. Nevertheless, it is important to assess the background concentration which is essential for risk assessment and regulation of metals in water/soil systems (Wendland et al 2005;Zhao et al 2007;Marandi and Karro 2008;Vencelides et al 2010). In the analyses of soil geochemical data, the relationship of selected elements with Fe or Mn has been used to estimate their background concentrations assuming that the soils in a sub-set from remote areas were uncontaminated.…”

From submarine to lacustrine groundwater discharge

“…Analogous to N, groundwater-P might be increased due to fertilizers, atmospheric deposition, manure and sewage (500 to 5000 µg P L -1 ; Wendland et al 2005;Kunkel et al 2005). The mineralization of naturally present organic matter might also increase P concentrations.…”