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Contract n° SSPI-2004-006538

BR B R ID I D G G E E

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Research for Policy Support

D10: Impact of hydrogeological conditions on pollutant behaviour in groundwater and related ecosystems.

Volume 1 - Appendices

Due date of deliverable: March 2006 Actual submission date: May 2006

Start date of the project: 1^st January 2005 Duration: 2 years Organisation name of lead contractor for this deliverable: BRGM

Project co-funded by the European Commission within the Sixth Framework Programme (2002-2006)

Dissimination level PU Public

PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission

Services)

CO Confidential, only for members of the consortium (including the Commission Services)

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Deliverable D10 3 / 199

General Content

Volume 1

Chapter 1: Introduction

Chapter 2: Techniques used to collect and process the data Chapter 3: Methodologies used for GWB delineation

Introduction General comment

Delineation of groundwater bodies Aquifer Typology

Interaction with surface waters Assessment of pressures Assessment of vulnerability Risk assessment

Open questions Concluding Remarks References of chapter 3

Chapter 4: Concepts for characterisation of aquifer regarding transport and attenuation of pollutants

Generalities

Typology of aquifers

Characterisation of attenuation between source of pollution and receptor Chapter 5: Hydrogeological processes

Importance of aquifers in the context of the WFD Concept of the aquifer control on pollutants

Attenuation of the pollutants according to aquifer typology

Synthesis and perspective of use of information on hydrogeological processes Appendices: in a separate volume

Chapter 6:Natural Background Levels. State of the art and review of existing methodologies

Introduction

Methodologies to determine the natural background level State of the art on natural background levels

Conclusions References

Appendices: in a separate volume

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D10: Hydrogeological conditions - volume 1

4 / 199 Deliverable D10

Volume 2

Chapter 7: Groundwater/surface water interactions Introduction

Aim

Types of surface water systems Chemical/substance concerns

Processes and controls at catchment scale Processes and controls at local scale Discussion

Conclusions References

Chapter 8: Groundwater/dependant terrestrial ecosystems interactions Introduction

Aim

Types of water dependent terrestrial ecosystems

Linking landscape location and water transfer mechanisms

Processes and controls on the groundwater system and the GWDTE.

Chemical /substance concerns Review of methods

Discussion Conclusions

Volume 3

Chapter 9: Impact of quantitative alteration on groundwater quality What means change of quantitative status? Synthesis

Quantity related aquifer responses and triggered processes with impact on groundwater quality

Matrix Actions/quantity impact/triggered processes/quality parameter influenced Assessment of quantitative impacts on quality

Annex Task 2.3 partnerships: contribution of each partner

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Volume 1

Appendices of chapters 5 and 6

Statistical characteristics from the participant

countries and their groundwater bodies

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Deliverable D10 7 / 199 We have synthesised in a table form some characteristics according to the responses on the questionnaires and to some bibliographic references.

In this table we have presented following information:

Name of countries and occasionally the region (Belgium and United Kingdom);

Number of Water Basin District;

Country or region surfaces;

Population;

Number of GWB;

Average surface of GWB;

Range and median of GWB;

A last column “specific point” emphasizing some particularities.

Remark

The average surface of GWB gives the result of the whole surface of GWBs divided by the country surface. It is just an indicative value. Thus this calculation procedure is correct only if all GWB are shallow GWB covering the whole countries. In France the GWBs are covering the whole country surface, but the deeper, covered GWBs are added. Thus, the country surface is 646,321km², but the total surface of GWBs is 1,094,514km². Otherwise, in Finland, only 4,1% of the country surface is related to the identified GWBs.

We have also expected to provide further information about other parameters but the available knowledge at that work stop didn’t allow it:

Number of points for groundwater monitoring;

Percentage of groundwater withdraw in the drinking water balance;

Systematic typology of GWBs.

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Appendix of chapter 5

Contributions from partners

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Appendix 5.1

Contribution from EA and BGS (United Kingdom)

Lithological type of the aquifer: Sandstones

General information on the location of the specific aquifer considered as example

The Permo-Triassic sandstones form the second most important aquifer in the UK, supplying around 25% of licensed groundwater abstractions in England and Wales. The sandstones outcrop in the south-west, central, north-east and north-west of England and in the Vale of Clwyd in Wales. The total outcrop area is around 9,000km².

Geometrical settings

In general the Permo-Triassic sandstones lie within the onshore extensions of a number of major offshore sedimentary basins. They have variable and often substantial thicknesses; for example the Sherwood Sandstone Group is up to 600m thick in Lancashire and around the northern edge of the Cheshire Basin the Permo-Triassic sandstones approach 1,000m in thickness. In south Nottinghamshire the Sherwood sandstone Group is around 90m thick, increasing to around 180m thick further north in Yorkshire. In the south-west and north-east of England the sandstones dip to the east and become confined down dip by the Mercia Mudstone Group.

Geological settings

The Permo-Triassic sandstone aquifers include breccias, aeolian dunes and fluviatile clastic deposits. Fluviatile deposits largely form the important Sherwood Sandstone Group aquifer which was created when basins initiated in the Permian continued to subside, causing thick clastic deposits to spread diachronously across the older rocks, deposited by a major braided river system. A number of cycles of gradational grain size occur within the sequence and as a whole the grain size tends to decrease upwards.

Intrinsic physical/hydrogeological properties

The total porosity of the sandstones is very variable, ranging from less than 5% to 35%, with a median value (from BGS core data) of 26%. The sandstones are commonly layered and highly anisotropic (layered heterogeneity). Therefore while the long-term specific yield is commonly of the order of 0.1, the unconfined storage coefficient measured from pumping test data is often much lower. Measured intergranular hydraulic conductivities range from 10^-6 to 20m/d with a median value of around 0.5m/d. Transmissivity data from pumping tests range from less than 1m²/d to over 50,00m²/d, with a median value of around 200m²/d.

Fracture flow is considered to be important on a local scale.

Information on the cover

Downdip from outcrop the Sherwood Sandstone Group is commonly confined by the Mercia Mudstone Group which acts as an aquitard, although there is often considerable interlayering of sandstones and mudstones at the junction. Permian Marls in the form of the Aylesbeare Mudstone Group in the south-west and the Manchester Marl in the north-west act as aquitards, confining the Permian sandstones.

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Flow condition

The mean annual replenishment of the Permo-Triassic sandstones has been estimated to be 1,442x10⁶ m³.

Other Sandstones

In addition to the major Permo-Triassic sandstone aquifers of England and Wales another important aquifer for water supply is the Lower Greensand, a Cretaceous aquifer found in the south-east of England. Other sandstone aquifers include the Coal Measures, the Millstone Grit and Devonian sandstones

Physico-chemical conditions

Permo-Triassic Sandstone

The Permo-Triassic Sandstone is a silicate aquifer with a small percentage (typically 1^–4wt%) of carbonate minerals, including dolomite. It is an oxidised red-bed sandstone with abundant iron oxides (particularly haematite) both in the matrix and as grain coatings. The concentration of organic matter is typically very low (0.07wt% or less).

Although considered a non-carbonate aquifer, carbonate reactions dominate the major-ion chemistry of the groundwaters. These are buffered at near-neutral pH with Ca-HCO3

dominating. Redox processes play an important role in controlling many elements in the confined parts of the aquifer. In some areas (e.g. East Midlands), the aquifer dips gently eastwards and in the east is covered by a thick sequence of Mercia Mudstone. Here, a smooth downgradient geochemical evolution of water chemistry can be observed from the unconfined aquifer in the west to the confined aquifer in the east. Along the flow line, increasing borehole depth and groundwater residence time lead to increasing temperature and evolution of chemical composition as a result of mineral dissolution and a change from oxic to anoxic groundwater conditions. In the deepest parts of the aquifer in the East Midlands, there is evidence for the presence of older formation water. In other areas, fracturing and patchy drift cover lead to more variable and less clear-cut spatial patterns in chemical composition. In some fractured parts of the aquifer, there is evidence for cross- formational groundwater flow (Griffiths et al., 2002; Shand et al., 2002; Tyler-Whittle et al., 2002; Griffiths et al., 2003; Griffiths et al., 2005; Smedley et al., 2005).

Other sandstones

Other sandstones include the red-bed Devonian sequences of part of Wales and the Welsh Borders, the Carboniferous Millstone Grit of northern England, the Jurassic Bridport Sands of southern England, the greensand lithologies of Cretaceous age in southern England and poorly-consolidated sands of Tertiary age in southern England. These have variable compositions, with differing non-silicate components. Red-bed Devonian sandstones are dominantly oxic with abundant iron oxides. Greensand deposits in southern England appear to be relatively pure sandstones but with relatively abundant glauconite and a number of other clays. They also contain occasional phosphate minerals and pyrite. Carbonate mineral content is typically around 1wt%. The Tertiary sands also contain variable amounts of carbonate as well as occasional pyrite.

As the sandstone lithologies of the UK are variable, so too is the chemistry of the groundwaters. The processes controlling groundwater chemistry within them are often poorly understood. Almost all contain carbonate in varying proportions and where present this has an important buffering effect on groundwater chemistry. Red-bed Devonian sandstones of Wales and the Welsh borders have groundwaters of variable pH but for the most part these are well-buffered with near-neutral values. The groundwaters abstracted from them are usually shallow and oxic. Carboniferous Millstone Grit groundwaters are influenced by both

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Deliverable D10 13 / 199 carbonate and silicate mineral reactions. They have varying redox conditions because of heterogeneous lithologies and overlying drift deposits. Some are reducing with evidence of denitrification and with high Fe and Mn resulting from dissolution of Fe and Mn oxides. Ca- SO₄ waters occur in some areas, probably as a result of pyrite oxidation. Jurassic Bridport Sands groundwaters have Ca-HCO₃ compositions but with evidence of ion exchange giving rise to Na-HCO₃ waters in some parts of the aquifer. Greensand deposits of southern England are unconfined along the sandstone outcrop but are confined below Tertiary clays in the central London Basin. Downgradient changes occur in groundwater chemistry as a result of redox processes, ion exchange and groundwater residence time. Downgradient, the groundwater evolves from Ca-HCO₃ to Na-HCO₃ types, reflecting the influence of ion exchange. Where solid carbonate is sparse or absent, groundwaters can be locally acidic.

Some groundwaters in the deep confined Lower Greensand appear to be palaeowaters of likely Pleistocene age. Tertiary sands of southern England also contain groundwater showing evidence of the importance of carbonate reaction. These too are of Ca-HCO₃ type although ion exchange down the flow gradient has resulted in Na-HCO₃ compositions in some confined groundwaters. Oxidation of pyrite appears to have affected groundwater chemistry in some unconfined parts but in a few anoxic groundwaters, sulphate reduction is likely to have occurred. In all the unconfined sandstone aquifers, nitrate concentrations are relatively high (typically >3mg L^-1 as N) as a result of pollution from agricultural and other sources (Shand et al., 2003; Moreau et al., 2004; Neumann et al., 2004; Shand et al., 2004; Abesser et al., 2005).

Physico-chemical processes

See spreadsheet

References

Allen D.J., Brewerton L.J., Coleby L.M., Gibbs B.R., Lewis M.A., MacDonald A.M., Wagstaff S.J. and Williams A.T. 1997. The physical properties of major aquifers in England and Wales.

British Geological Survey Report WD/97/38, Environment Agency R&D Publication 8.

Monkhouse R.A. and Richards H.J. 1982. Groundwater resources of the United Kingdom.

Commission of the European Communities. Th. Schafer, Hannover.

Grey D.R.C., Kinniburgh D.G., Barker J.A. and Bloomfield J.P. 1995. Groundwater in the UK.

A strategic study. Issues and research needs. Groundwater Forum Report FR/GF 1.

Abesser, C., Shand, P., and Ingram, J. 2005. Baseline Report Series: The Millstone Grit of Northern England. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/015N; Environment Agency Report NC/99/74/22.

Abesser, C., Shand, P., and Ingram, J. 2005. Baseline Report Series: The Millstone Grit of Northern England. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/015N; Environment Agency Report NC/99/74/22

Griffiths, K., Shand, P., and Ingram, J. 2002. Baseline Report Series: The Permo-Triassic Sandstones of west Cheshire and the Wirral. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/02/109N; Environment Agency Report NC/99/74/2.

Griffiths, K., Shand, P., and Ingram, J. 2005. Baseline Report Series: The Permo-Triassic Sandstones of Liverpool and Rufford. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/xxxN; Environment Agency Report NC/99/74/19.

Griffiths, K., Shand, P., and Ingram, J. 2003. Baseline Report Series: The Permo-Triassic Sandstones of Manchester and East Cheshire. British Geological Survey and Environment

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Agency, Keyworth and Solihull. BGS Report CR/03/265C; Environment Agency Report NC/99/74/8.

Moreau, M., Shand, P., Wilton, N., Brown, S., and Allen, D. 2004. Baseline Report Series:

The Devonian aquifer of South Wales and Herefordshire. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/04/185N; Environment Agency Report NC/99/74/12.

Neumann, I., Cobbing, J., Tooth, A.F., and Shand, P. 2004. Baseline Report Series: The Palaeogene of the Wessex Basin. British Geological Survey and Environment Agency, Keyworth and Solihull. CR/04/254N; Environment Agency Report NC/99/74/15.

Shand, P., Ander, E.L., Griffiths, K.J., Doherty, P., and Lawrence, A.R. 2004. Baseline Report Series: The Bridport Sands of Dorset and Somerset. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/04/166N; Environment Agency Report NC/99/74/11.

Shand, P., Cobbing, J., Tyler-Whittle, R., Tooth, A.F., and Lancaster, A. 2003. Baseline Report Series: The Lower Greensand of southern England. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/03/273N; Environment Agency Report NC/99/74/9.

Shand, P., Tyler-Whittle, R., Morton, M., Simpson, E., Lawrence, A.R., Pacey, J., and Hargreaves, R. 2002. Baseline Report Series: The Triassic Sandstones of the Vale of York.

British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/02/102N; Environment Agency Report NC/99/74/1.

Smedley, P.L., Neumann, I., and Brown, S. 2005. Baseline Report Series: The Permo- Triassic Sandstone aquifer of Shropshire. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/061N; Environment Agency Report NC/99/74/20.

Tyler-Whittle, R., Brown, S., and Shand, P. 2002. Baseline Report Series: The Permo- Triassic Sandstones of South Staffordshire and North Worcestershire. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/02/119N;

Environment Agency Report NC/99/74/3.

Lithological type of the aquifer: Limestones

General information on the location of the specific aquifer considered as example :

the Jurassic limestones, Magnesian Limestone and Carboniferous Limestone are three important aquifers in England, with the Carboniferous Limestone important in Wales;

the Jurassic limestones outcrop as part of a broad band of Jurassic rocks trending south- west-north-east from the Dorset to the Yorkshire and Cleveland coasts. They often form scarps, with incised valleys. The Magnesian Limestone aquifer occupies a narrow north- south outcrop from Sunderland to Nottingham. The main aquifer in the Carboniferous Limestone is well developed in the hills of the southern Peak District of Derbyshire, the Mendip Hills, North and South Wales and north-west Yorkshire.

Geometrical settings

Jurassic limestones – The Jurassic sediments (clays, shales, sandstones and limestones) are up to 15.00m thick, and generally dip gently eastwards. Within these the limestones aquifers occur in sequences of relatively thin beds which rarely extend over large areas.

Outcrop area around 3,500km².

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Deliverable D10 15 / 199 Magnesian Limestone – this reaches thicknesses of 200m where it crops out in Durham. The aquifer dips to the east. Outcrop area around 1,500km².

Carboniferous Limestone – found in a variety of settings. For example in the Mendips it flanks a series of hills and reaches thicknesses of over 600m. In South Wales it outcrops around the periphery of the South Wales coalfield, where its northern outcrop runs in arc of over 100km. Outcrop area around 3,500km².

Geological settings

Jurassic limestones – Occur in a complex series of Jurassic deposits lain down in three different depositional environments; deep shelf, shallow shelf and marginal marine to non- marine, resulting in a variety of sediment types. Sedimentation was also controlled by a series of platforms and highs separating depositional basins and shelves. Stratigraphically complex.

Magnesian Limestone – deposited in marine conditions in two provinces, Durham (north) and Yorkshire (south). In the north the aquifer is separated into three; Lower and Middle limestones locally separated from the Upper limestone by marls and siltstones. In the south the limestone is divided into two, again separated by marls and siltstones.

Carboniferous Limestone – significantly affected by structure. For example the Mendip hills are a series of en-echelon periclines with the Carboniferous Limestone surrounding Silurian and Devonian cores. In South Wales the Limestone is preserved around the edges of the major South Wales Coalfield Syncline.

Intrinsic physical/hydrogeological properties

Jurassic Limestones – Limited data are available. Porosities vary, depending on the type and location of the limestone, the total range is around 2-30%, with means around 14-19%. The intergranular hydraulic conductivity tends to be very low, with means of the order of 10^-4m/d.

However, as a result of solution-enlarged fractures transmissivities can be high, although storativities are low. Locally, some karstic features have been noted.

Magnesian Limestone – only limited core data are available. These suggest porosities in the range 1-30%, with a median value of around 15%. Hydraulic conductivities vary over six orders of magnitude, with a mean of around 10^-4m/d. As a result of fracturing, good transmissivities are found, and there is some intergranular storage. Some karstification has been noted.

Carboniferous Limestone – Intergranular porosities are very low, normally around 1% or less (few data), and intergranular permeability is also thought to be very low. However the limestone is commonly highly karstified and is an important aquifer.

Information on the cover

Jurassic Limestones – generally confined to the east of the outcrop by Jurassic clays.

Magnesian Limestone – generally confined to the east of outcrop by Permian Marls.

Carboniferous Limestone – away from outcrop overlain by various strata.

Flow conditions

Rapid groundwater flows can occur in these aquifers as a result of their fractured nature.

Mean annual replenishment: Magnesian Limestone – 248x106m³; Carboniferous Limestone – 971x10⁶m³.

Physico-chemical conditions

Other limestones in the UK are much less pure than the Chalk with higher and variable amounts of clay and other material. Organic matter content has been poorly documented.

Lawrence and Foster (1986) reported concentrations in the range 0.01–0.07wt% in oxidised

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areas of the Lincolnshire Limestone of eastern England, rising to 0.1% in unaltered parts of the aquifer.

Groundwater chemistry is dominated by carbonate reactions with pH being well-buffered and Ca-HCO₃ dominating the major ions. In the confined aquifer of the Cotswolds Oolite aquifer, ion exchange processes appear to be important with increasing dominance of Na-HCO₃ ions.

Redox processes are influential where the limestones are covered by poorly permeable deposits. There is evidence for denitrification in the confined limestone aquifers. Some deep groundwaters have saline waters that are likely to reflect mixing of groundwater with older saline formation water (Neumann et al., 2003; Cobbing et al., 2004; Abesser et al., 2005;

Griffiths et al., 2005).

Physico-chemical processes

See spreadsheet

References

British Geological Survey Report WD/97/38, Environment Agency R & D Publication 8.

Grey D.R.C., Kinniburgh D.G., Barker J.A. and Bloomfield J.P. 1995. Groundwater in the UK.

Abesser, C., Shand, P., and Ingram, J. 2005. Baseline Report Series: The Carboniferous Limestone of Northern England. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/xxxN; Environment Agency Report NC/99/74/22.

Cobbing, J., Moreau, M., Shand, P., and Lancaster, A. 2004. Baseline Report Series: The Corallian of Oxfordshire and Wiltshire. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/04/262N; Environment Agency Report NC/99/74/14.

Griffiths, K.J., Shand, P., and Peach, D.W. 2005. The Lincolnshire Limestone. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/xxxN; Environment Agency Report NC/99/74/23.

Lawrence, A.R., and Foster, S.S.D. 1986. Denitrification in a limestone aquifer in relation to the security of low nitrate groundwater resources. Journal of the Institution of Water Engineers and Scientists, Vol. 40, 159-172.

Neumann, I. Brown, S., Smedley, P.L., and Besien, T. 2003. Baseline Report Series: The Great and Inferior Oolite of the Cotswolds District. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/03/202N; Environment Agency Report NC/99/74/7.

Lithological type of the aquifer: Chalk

General information on the location of the specific aquifer considered as example

The Chalk aquifer is the most important in the UK, providing around half of the licensed groundwater abstractions in England and Wales. The Chalk outcrops generally in a broad band in the southern and eastern part of England from Dorset in the south to Yorkshire in the north-east and underlies eastern and southern England except in the Weald where it has

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Deliverable D10 17 / 199 been removed by erosion. At outcrop Chalk typically forms ‘downland’ with rounded hills and gentle slopes. The total outcrop area of the aquifer is around 21,000km².

Geometrical settings

In East Anglia and northwards the Cretaceous Chalk varies in thickness from around 100m near to the western outcrops to over 400m near to the coast. In southern England the Chalk is generally between 200m and 400m thick, less in the London area and in general terms it tends to dip towards to eastern and southern coasts.

Geological settings

The Chalk is a very fine-grained soft white limestone. Although it is 98% pure CaCO₃, it contains flint and marl horizons, which can have important effects on groundwater flow, as can interspersed hardgrounds. In southern England the Chalk is currently commonly divided into ten lithostratigraphic units and into four units in its northern outcrop. The lowest units are marly, with flints restricted to overlying material. The northern part of the aquifer was strongly affected by glaciation, with the southern area was subjected to periglacial influences.

Intrinsic physical/hydrogeological properties

The total porosity of the Chalk is generally high, with an overall mean of around 35%, although values between 3 and 55% are found. However, as the pore throat size is normally less than 1 micron most of the pores do not drain under gravity and the specific yield is very low. The small pore size also results in a very low intergranular hydraulic conductivity, commonly of the order of 0.001m/d. Transmissivities of the Chalk however are often high in valleys, and in the southern Chalk outcrop often exceed 1,000m²/d, falling to a few tens of m²/d under interfluves. This is because most saturated flow in the Chalk occurs through solution-enlarged fractures, normally occurring within the top few tens of metres of the aquifer. The Chalk acts in a karstic manner in parts, usually close to the edge of overlying Palaeogene deposits.

Information on the cover

In parts of the south and East the Chalk is covered by Tertiary and Quaternary deposits and in some areas (e.g. the London Basin) is naturally confined beneath thick clays. The unsaturated zone of the Chalk under interfluves can reach several tens of metres in thickness.

Flow conditions

The annual replenishment of the Chalk aquifer is estimated to be in excess of 4,600x10⁶m³ annually.

Physico-chemical conditions

The Chalk is usually a pure carbonate but with locally higher clay content in the marls and hardgrounds. Some of the hardgrounds are phosphatised. Organic matter content is typically

<0.01-0.1wt% but can be higher in the marl bands (Pacey, 1989).

Groundwater in the Chalk is strongly influenced by carbonate dissolution reactions and is therefore buffered at pH close to neutral with Ca and HCO₃ as the dominant ions. Redox processes have a major impact on groundwater quality and confined parts of the Chalk are typically reducing with respect to nitrate, Fe and Mn. Pollution from agricultural, industrial and domestic sources can be significant in the unconfined parts of the aquifer; parts confined by thick clay have been less vulnerable. Saline groundwaters occur in coastal areas. Where overlying deposits are absent, thin or permeable, the saline component appears to be recently infiltrated seawater. Where covered by thick clay layers, saline groundwater in the Chalk reflects infiltration of older (pre-Flandrian) seawater (Edmunds et al., 2002; Shand et

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al., 2003; Smedley et al., 2003; Ander et al., 2004; Smedley et al., 2004; Ander and Shand, 2005).

Physico-chemical processes

See spreadsheet

References

British Geological Survey Report WD/97/38, Environment Agency R & D Publication 8.

Grey D.R.C., Kinniburgh D.G., Barker J.A. and Bloomfield J P. 1995. Groundwater in the UK.

Ander, E.L., and Shand, P. 2005. The Chalk and Crag of north Norfolk and the Waveney Catchment. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/05/xxxN; Environment Agency Report NC/99/74/21.

Ander, E.L., Shand, P., Lawrence, A.R., Griffiths, K.J., Hart, P., and Pawley, J. 2004.

Baseline Report Series: The Great Ouse Chalk aquifer, East Anglia. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/04/236N;

Edmunds, W.M., Doherty, P., Griffiths, K.J., Shand, P., and Peach, D. 2002. Baseline Report Series: The Chalk of Dorset. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/02/268N; Environment Agency Report NC/99/74/4.

Pacey, N.R. 1989. Organic matter in Cretaceous chalks from eastern England. Chemical Geology, Vol. 75, 191-208.

Shand, P., Tyler-Whittle, R., Besien, T., Peach, D.W., Lawrence, A.R., and Lewis, H.O. 2003.

Baseline Report Series: The Chalk of the Colne and Lee River Catchments. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/03/69N;

Smedley, P.L., Griffiths, K., Tyler-Whittle, R., Hargreaves, R., Lawrence, A.R., and Besien, T.

2003. Baseline Report Series: The Chalk of the North Downs, Kent and East Surrey. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/03/033N; Environment Agency Report NC/99/74/5.

Smedley, P.L., Neumann, I., and Farrell, R. 2004. Baseline Report Series: The Chalk aquifer of Yorkshire and North Humberside. British Geological Survey and Environment Agency, Keyworth and Solihull. BGS Report CR/04/128; Environment Agency Report NC/99/74/10

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verable D1019 / 199

Aquifer

type Parameter Units Min Max n Process Importance Factors controlling effectiveness of processes SEC uS/cm 343 26800 497 Saline intrusion, mixing with older water,

agricultural or other pollution inputs, mineral dissolution

Large area of Chalk in England, importance of processes varies from region to region

Proximity to coast, hydraulic continuity with other rock formations, landuse

SO4 mg/L <5 1290 589

Saline intrusion, mixing with older water, agricultural or other pollution inputs, mineral dissolution

Cl mg/L 9 10700 589 Saline intrusion, mixing with older water, agricultural or other pollution inputs

NH4-N mg/L <0.003 12 526 Biodegradation, reduction, pollution inputs

Biodegradation dominates in confined aquifers with overlying clay deposits

NO3-N mg/L <0.002 38.8 589 Pollution inputs, reduction

Large area of Chalk in England, importance of processes varies from region to region; where high pollution dominant

Denitrification significant in confined aquifers

As ug/L <0.4 62.5 374 Mineral dissolution, reduction, sorption/desorption reactions Confinement by overlying clay, As distribution in solid phase

Cd ug/L <0.05 3.93 433 Sorption/desorption Not known

Hg ug/L <0.005 2.3 300 Possibly pollution Highest concentration observed in unconfined aquifer

Chalk

Pb ug/L <0.07 14.8 441 Sorption/desorption Not known

SEC uS/cm 207 20500 167 Mineral dissolution, mixing with older formation water, pollutant inputs Groundwater residence time, confinement of aquifer, hydraulic properties (fractures etc) SO4 mg/L <0.2 1160 296

Mineral dissolution, mixing with older formation water, pollutant inputs, sulphate reduction

Varies from aquifer to aquifer

Confinement of aquifers, groundwater residence time

Cl mg/L <10 6250 304 Mineral dissolution, mixing with older formation water, pollutant inputs Confinement of aquifers, groundwater residence time

NH4-N mg/L <0.003 11.3 293 Pollutant inputs, biodegradation, reduction Confinement NO3-N mg/L <0.003 46.1 279 Pollutant inputs, reduction, biodegradation Confinement

As ug/L <0.5 25.1 100 Sorption/desorption probably Confinement, local mineralogy Cd ug/L <0.05 0.59 115 Sorption/desorption probably Mineralisation ?

Hg ug/L <0.01 0.8 110

Other limestone

Pb ug/L <0.1 19.5 115 Sorption/desorption probably Mineralisation ?

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20 / 199 Deliverable D10 D10: Hydrogeological conditions - volume 1

Aquifer

type Parameter Units Min Max n Process Importance Factors controlling effectiveness of processes SEC uS/cm 64 27,000 630 Mineral dissolution, saline intrusion, mixing

with water from other formations, pollution inputs

Large area of aquifer, significance varies regionally

Borehole depth, groundwater residence time, confinement by clay deposits, fracture geometry

SO4 mg/L <4 1,790 644

Mineral dissolution (especially

gypsum/anhydrite), saline intrusion, inputs from other formations, pollution inputs, sulphate reduction (locally)

Borehole depth, groundwater residence time, confinement by clay deposits, aquifer mineralogy, fracture geometry

Cl mg/L <10 10,000 650 Saline intrusion, inputs from other formations, pollution inputs

Borehole depth, groundwater residence time, confinement by clay deposits, fracture geometry NH4-N mg/L <0.003 38.6 628 Pollution inputs, biodegradation, reduction Pollution probably dominant Confinement of aquifer, landuse

NO3-N mg/L <0.002 72 629 Pollution inputs, reduction Pollution dominant Confinement of aquifer, landuse As ug/L <0.5 355 341 Sorption/desorption, mineral dissolution,

reduction

Sorption reactions probably dominate

Confinement of aquifer, groundwater residence time, mineralisation

Cd ug/L <0.05 42 461 Probably sorption/desorption Mineralisation Hg ug/L <0.01 1 224 Probably sorption/desorption Not known

Permo-Triassic Sandstone

Pb ug/L <0.1 6,650 461 Sorption/desorption, mineral dissolution, air pollution, possibly point-source

pollution Mineralisation, local landuse SEC uS/cm 46.6 3,870 251 Mineral dissolution, ion exchange, sorption/desorption, saline intrusion,

pollution inputs

Groundwater residence time, aquifer confinement, landuse

SO4 mg/L <0.2 259 391 Mineral dissolution (including pyrite oxidation), saline intrusion, pollution inputs, reduction

Aquifer confinement, landuse, pyrite content, groundwater flow rate

Cl mg/L <10 1,290 396 Mineral dissolution, saline intrusion, pollution inputs Aquifer confinement, landuse NH4-N mg/L <0.003 2.23 364 Agricultural/domestc pollution inputs, biodegradation Borehole depth, landuse NO3-N mg/L <0.003 42.7 377 Agricultural/domestc pollution inputs, natural

organic matter Pollutant inputs significant Borehole depth, landuse

As ug/L <0.5 20 200 Mineral dissolution, sorption/desorption, reduction Aquifer confinement Cd ug/L <0.05 0.674 199 Sorption/desorption probably, acid water in some areas Carbonate content of sandstone

Hg ug/L <0.1 0.2 146 Unknown Barely detectable

Other sandstone

Pb ug/L <0.1 8.6 197 Sorption/desorption probably, mineral diss possibly, pollution inputs

possibly, acidic water Carbonate content of sandstone

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Appendix 5.2

Contribution from IGME (Spain)

Lithological type of the aquifer: Plana de Castellón

It is a granular porosity aquifer. It extends over 464 square kilometres, and the maximum height above sea level is 130 metres. These hydrogeological systems have common characteristics from the point of view of the physical model and relation to surface water, being common the presence of marshlands. Contamination processes include introduction of nitrogen in the aquifer due to agricultural practices and salinization due to seawater intrusion.

General information on the location of the specific aquifer considered as example

Along the Mediterranean coast of Spain there is a number of aquifers with an appreciable quantity of water resources. Exploitation of such aquifers implies nearly 50% of groundwater extraction in Jucar river Basin, located in Autonomous Community of Valencia. From the point of view of morphology, two areas can be separated. A coastal plain, near the coast line, between sea level and 20m above sea level, with low relief. Second one is an erosion surface from the coastal plain up to the mountains.

Geometrical settings

The aquifer extends over a coastal strip of 464km², located between sea level and a maximum height of 130m.

Geological settings

Coastal plain is made up of fluvial, colluvial and marine Plioquaternary sediments. These sediments consist of gravel and sand and conglomerates embedded in a clay matrix. This sequence leans on Mesozoic materials (that conform a second aquifer) or alternatively on Terciary sediments of low permeability.

Intrinsic physical/hydrogeological properties

Main productive formations are detritic sediments corresponding to Mio-quaternary aquifers of coastal plains. Transmisivity has a range of values between 500 and 1,200m²/day, with minimum below 200m²/day at the edges. Values as high as 6,000m²/day can be found, generally related to Mijares, Palancia, Turia and Júcar rivers bed. Permeability is in the order of 30-120m/day and average specific flow in productive wells is 10l/s/m (IGME, 1988).

Storage coefficient is between 2 and 15%, but frequent values vary between 10 and 12%.

Information on the cover

This aquifer belongs to a multilayered system, embedded into a clay-limestone matrix. It is a multilayered aquifer, unconfined aquifer. Sediment thickness increases from the edges to the coast line, and average thickness goes from 50 to 150m. Maximum thickness is located in plains with more superficial development, generally in areas near the main rivers that cross the plain, and the coast line, with figures up to 270m near Mijares river.

Flow conditions

Inputs: Recharge by rain infiltration: 50hm³/year River flow losses: 36hm³/year

Lateral inflow from other aquifers: 90hm³/year Recharge by irrigation returns: 100hm³/year

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Outputs: Springs: 36hm³/year Pumping: 201hm³/year

Discharges into the sea: 39hm³/year Average annual recharge: 276hm³/year

Physico-chemical conditions

In the coastal plain the climate is a typical littoral mediterranean one. Average annual temperature ranges from 16.5 to 17.5ºC. Conductivity varies between 2,200 and 3,500µS/cm. Bicarbonates are in the range of 100-380mg/l. In soil, clay content is in the order of 0.4-4.5%, organic matter is 2-45% and pH 7-8.9. Eh range is -20 -250. Groundwater pH goes from 6 to 8.

Physico-chemical processes

Pollutant/substances: Chloride

Observed range of concentration: 10 - 900mg/l Origin of the substance/pollutant: anthropogenic

Processes Importance Factors controlling

effectiveness of processes Remarks Seawater intrusion Locally high Intrinsic properties, pumping out

Pollutant/substances: Nitrate

Observed range of concentration: 5 - 500mg/l Origin of the substance/pollutant: anthropogenic

effectiveness of processes Remarks Agricultural practices High Infiltration, intrinsic properties

Pollutant/substances: Sulphate

Observed range of concentration: 100 - 970mg/l

Origin of the substance/pollutant: natural, anthropogenic

effectiveness of processes Remarks Seawater intrusion Locally high Intrinsic properties, pumping out

Pollutant/substances: Mercury

Observed range of concentration: 0 - 10µ/l

Origin of the substance/pollutant: anthropogenic, natural?

effectiveness of processes Remarks Industry pollution,

natural background Locally high Intrinsic properties, geology

Lithological type of the aquifer: Onda

It is a limestone aquifer. It extends over 230 square kilometres, and the maximum height above sea level is 900 metres. Main productive activity is agriculture and industry does not exist. Contamination processes include introduction of nitrogen in the aquifer due to agricultural practices and salinization due to natural evaporitic materials.

General information on the location of the specific aquifer considered as example

Ther are two aquifers, with thickness of 100m the deepest and 50-60m the superficial one.

Frequently both aquifers are in contact, and then there is only one aquifer.

Geometrical settings

The aquifer is located in West direction of Plana de Castellón. It is a mountain area with heights from 160 to 900m above sea level

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Geological settings

The system consists of Muschelkalk limestones and dolomites. Sediments. Pervious formation at the bottom is Buntsandstein materials.

Intrinsic physical/hydrogeological properties

Hydraulic Main productive formations are limestones corresponding to Muschelkalk.

Transmisivity has a range of values between 200 and 400m²/day, with maximum in discharge areas up to 2,000m²/day.

Information on the cover

Flow conditions:

Inputs: Recharge by rain infiltration: 30hm³/year Lateral transfers: 9hm³/year

Outputs: Springs: 2hm³/year Pumping: 10-21 hm³/year

Discharges into Mijares river: 12-15hm³/year Lateral transfers: 4-13hm³/year

Average annual recharge: 39hm³/year

Physico-chemical conditions

In the area the climate is a typical mediterranean one. Average annual temperature ranges from 16.5 to 17.5ºC.

Physico-chemical processes

Pollutant/substances: Sulphates and magnesium Observed range of concentration: 511 – 603 Origin of the substance/pollutant: natural

effectiveness of processes Remarks Salinization Locally high Intrinsic properties, pumping out

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Appendix 5.3

Contribution from fz-Jülich and HLUG (Germany)

Characterisation of German aquifer typologies (examples)

Frank Wendland, Hans – Gerhard Fritsche & Ralf Kunkel

Aquifer type: Glacial sand and gravel deposits in Germany

General information on the location of the specific aquifer considered as example

Country: Germany; region, landscape or surface morphology: North German Lowland

Geometrical settings

Horizontal extension: ca. 130,000km²; variation of the top of the aquifer below the surface:

variable, 0-50 m; thickness: < 10 - > 100m.

Geological settings

Glacial deposits consisting mostly of sand and gravel in various combinations, but also including clay, silt, cobbles and boulders. The glacial deposits were deposited during several advances and retreats of continental ice sheets in the Pleistocene. Glacial ice and meltwater from the ice laid down several types of deposits. Till, which is an unstratified, unsorted mixture of material that ranges in particle size from clay to boulders, was deposited under the ice or directly in front of the ice sheet. Likewise tills are no productive aquifers. Outwash deposits, by contrast, generally consist of stratified sand and gravel that form productive aquifers.

Intrinsic physical/hydrogeological properties

Total porosity: up to 40%; effective porosity: 5-25%; hydraulic conductivity: ca. 10^-3 up to 10^-5m/s; groundwater velocity: <0.05m/d up to 23m/d.

Information on the cover

Thickness of the unsaturated zone: 0 - > 50m; type of the covering layers: sandy and loamy soils above unconsolidated glacial deposits. Protection property of the covering layers varying.

Flow conditions

Precipitation: ca. 500-800 mm/a; potential evapotranspiration: ca. 550-600mm/a; origin of the recharge: percolation water; possible variation of recharge/discharge: < 50-200mm/a;

BFI: between 0.2 (groundwater table near sites) and 0,8 groundwater table far sites);

characteristic residence time between location of recharge and discharge: 1 - > 200 years.

Physico-chemical conditions and physico-chemical processes, which result in the observed NBLs

(see figure 1 on NBLs).

The general solution content of around 1,000 (µS/cm) reflects the petrografic as well as the hydromechanical conditions, i.e. intergranlar porosity allowing a good dissolving of minerals and a long groundwater residence time due to shallow hydraulic gradients. For many parameters (e.g. Na, K, SO₄, Cl) the solution content decreases with increasing depth. This is striking on first sight as in general it can be expected that the solution content will rise with increasing depth due to the longer residence times of groundwater. This behaviour can be

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explained however by the ubiquitous input of anthropogenic substances from the surface (e.g. fertilizers) with the percolation water.

Parameter N Na mg/l 2019 K mg/l 2002 Mg mg/l 3307 Ca mg/l 3337 Fe mg/l 2097 Mn mg/l 2809 HCO3 mg/l 3369 SO4 mg/l 3387 Cl mg/l 3533 NH4 mg/l 3154 NO2 mg/l 1050 NO3 mg/l 3034 PO4 mg/l 1705 DOC mg/l 2720 LF µS/cm 2237 O2 mg/l 951 H µg/l 3401 pH - 3401 F mg/l 546 Br mg/l 309 J mg/l 174 Ag µg/l 59 Al ^µg/l ⁷⁰⁸ As µg/l 594 B µg/l 696 Ba µg/l 208 Bi µg/l 37 Cd µg/l 656 Co µg/l 194 Cr µg/l 736 Cu µg/l 848 Hg µg/l 533 Li µg/l 304 Ni µg/l 743 Pb µg/l 818 Sb µg/l 1 Se µg/l 128 Si mg/l 466 Sn µg/l Sr µg/l 364 Zn µg/l 813

Komponentensep.

10. P 50. P 90. P 6,9 16,2 38,1 1,0 1,9 3,8 3,4 8,7 22,2 27,1 71 153 0,06 0,7 8,0 0,06 0,3 1,4 28,9 150 351 7,0 36,4 189 12,2 32,6 87 0,011 0,03 0,1 0,004 0,02 0,06

0,1 0,3 0,9 0,01 0,04 0,11 1,0 3,0 8,8 226 474 993 0,2 1,0 6,0 0,01 0,03 0,2

6,8 7,5 8,2

9,1 50,7 283 0,3 1,1 4,4 14,3 58 233

0,1 0,2 0,3

0,6 1,1 2,3 1,0 3,1 10,1 0,03 0,10 0,29

1,9 5,0 13,3 0,84 1,9 4,3

1,2 15,1 196

Figure 1 - Natural background levels in Pleistocene gravels and sands in Germany at sampling depths

<10m (N: number of sampling sites) (Kunkel et al., 2004).

With regard to the redox status, the distribution of the parameters O2, Fe(II), Mn(II), NO3, DOC show, that in general this hyderogeologic unit can be regarded as carrying reduced groundwater. Due to the long groundwater residence times and high redox reactivity of the subsurface, a complete use of the oxygen reaching the aquifers with the percolation water, is attained. An indicator for this is the decreasing DOC and the fact, that nitrate is present in very few samples only, while there is a general trend towards high Fe(II) and Mn(II) concentrations.

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Deliverable D10 27 / 199 Aquifer type: Fluviatile terrace deposits of major streams in Germany

(Example: Lower Rhine Valley)

General information on the location of the specific aquifer considered as example

Country: Germany; region, landscape or surface morphology: Upper and lower Rhine Valley, Prealpine river valleys of Danube and adjacent rivers

Geometrical settings

Horizontal extension: ca. 35,000km² (total), 6,500km² (Lower Rhine Valley), variation of the top of the aquifer below the surface: variable, 0-50m; thickness: 30-50m.

Geological settings

The fluviatile terrace deposits of major streams are fluviatile deposits delivered from the Alps and the South and Central German low mountains. Petrographically this hydrogeological unit consists primarily of siliceous material, which is not very soluble, but limestone, dolomite and other constituents are also present. In the aquifers of the foothills of the Alps the latter are even the primary minerals. The aquifer materials are commonly segregated by size into lenses and beds, which can affect the movement and availability of water. Beds and lenses of sand, gravel or mixtures of the two yield large amounts of water.

Intrinsic physical/hydrogeological properties

Total porosity: up to 50%; effective porosity: 10-30%; hydraulic conductivity: ca. 10^-2 up to 10^-4m/s; groundwater velocity: 0.1 - 15m/d.

Information on the cover

Thickness of the unsaturated zone: 0 - > 50m; type of the covering layers: loamy soils (e.g.

loess, alluvial clays) above unconsolidated fluviatile deposits. Protection property of the covering layers varying, but in principle quite high.

Flow conditions

Precipitation: ca. 500-750 mm/a; potential evapotranspiration: ca. 500-550mm/a; origin of the recharge: percolation water, occasionally infiltration of surface waters; possible variation of recharge/discharge: <100-300mm/a; BFI: 0.8 (groundwater table far sites); characteristic residence time between location of recharge and discharge: < 5 years.

Physico-chemical conditions and physico-chemical processes, which result in the observed NBLs

(see figure 2 on NBLs in the Lower Rhine Valley).

As the aquifers are predominantly deep below from the land surface, the input of dissolved materials from the unsaturated zone can be rather high. Hence, although the most common mineral in the aquifers is quartz, the total solution content is around 900 to 1,000 (µS/cm). As an example, in table 2 the NBL concentration ranges of the Lower Rhine valley is shown.

The Fe^-, Mn^-, O₂^- and SO₄ – data show, that the groundwater of the Lower Rhine valley can be classified as predominantly oxidized. Hence the groundwater of the Lower Rhine Valley displays high NO₃ and O₂, but low Fe^- and Mn- concentrations. The Na^-, K^-, Mg^-, Ca^-, and HCO_3-concentrations are quite high. The reason for this might be the covering loess soils. As the portion of carbonate minerals in the hydrogeologic unit is rather high, the concentrations of the related ions (Ca, Mg, HCO₃) is too. The high K-contents reflects on the ubiquitarious influence of agricultural activities (K-containing fertilizers).

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Figure 2 - Natural background levels in Fluviatile terrace deposits of major streams in Germany with the example of the Lower Rhine Valley (N: number of sampling sites) (Kunkel et al., 2004).

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Deliverable D10 29 / 199 Aquifer type: Triassic Sandstones in Germany

General information on the location of the specific aquifer considered as example

Country: Germany; region, landscape or surface morphology: hills, midlands.

Geometrical settings

Horizontal extension: ca. 30.000km²; variation of the top of the aquifer below the surface:

variable, from 10-50m; thickness: <10->100m.

Geological settings

In Germany, sandstone aquifers are parts of complexly embedded sequences of various types of clastic sedimentary rocks, predominantly from the Triassic epoch. The sandstones display a red colour, which is due to the arid-continental deposition conditions and gave this epoch its name (Bunter Sandstone comes from the German for "coloured sandstone", where it is now known as “Buntsandstein”). In general the sandstone aquifer systems consist of layered rocks differentiated vertically into fine-grained, low-permeability rocks such as shale or siltstone, and more permeable predominantly sandstones.

Intrinsic physical/hydrogeological properties

The average intergranular porosity of sandstone aquifers generally doesn’t exceed 10%.

Thus, most of the porosity in these consolidated rocks consists of secondary openings such as joints, fractures, and bedding planes. Groundwater movement in sandstone aquifers primarily is along bedding planes, but the joints and fractures cut across bedding and provide avenues in the sandstones as well as in the interbedded shale and siltstones for the vertical movement of water between bedding planes.

Hydraulic conductivity: ca. 5 x 10^-5 up to 5 x 10^-6m/s; groundwater velocity: <0.1m/d up to

>10m/d depending on hydraulic gradient. Due to more pelitic layers, the alternate bedding in the Lower Bunter is less than in the Middle Bunter. In middle and northern Germany, the Upper Bunter (Röt) is consisting of shales and siltstones and therefore very low permeable.

Information on the cover

Thickness of the unsaturated zone: 0->50m; type of the covering layers: sandy and loamy soils, mostly with small thickness above weathered sandstone and the aquifer. Mostly medium protection property.

Flow conditions

Precipitation: ca. 500-1,000mm/a; potential evapotranspiration: ca. 450-550mm/a; origin of the recharge: percolation water; possible variation of recharge/discharge: <50-<150mm/a;

BFI: 0.4-0.6; characteristic residence time between location of recharge and discharge:

<10 years in the upper regions of the aquifer, several 100 years in lower regions.

Characteristic physico-chemical conditions and physico-chemical processes, which result in the observed NBLs

(see figure 3 on NBLs)

The sandstone sequences are in general characterized by a high significance for water management issues. Due to the silicatic rock attribute, however, the waters have in many cases low TDS and are threatened by acidification due to thin and buffer-poor soils. Thus more than 50% of all samples display an electric conductivity of less than 250µS/cm and a pH less than 7.0 (see table 2).

Due to the relative high permeability of the sandstone aquifers and the steep hydraulic gradients, the residence time of the groundwater is generally shorter compared to the groundwater in the unconsolidated rock units. Groundwater recharge has been calculated to

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represent about 50% of the total runoff (Bogena et al., 2003), which is a good indication of the water-yielding capacity of the aquifer that provides the base flow. The Fe, Mn, O₂ and SO₄ concentrations show that the groundwater of the sandstone aquifers can be classified as predominantly oxidized. Thus, low Fe and Mn concentrations coincide with high O₂ and NO₃ concentrations. Although Ca is usually the major cation, Na and Mg are relevant as well. On milliequivalent basis, SO₄ is the major anion instead of alkalinity.

Parameter N Na mg/l 1617 K mg/l 1574 Mg mg/l 1629 Ca mg/l 1625 Fe mg/l 1552 Mn mg/l 1620 HCO₃ mg/l 1604 SO4 mg/l 1622 Cl mg/l 1632 NH₄ mg/l 1477 NO2 mg/l 1909 NO₃ mg/l 1644 PO₄ mg/l 439 DOC mg/l 453 LF µS/cm 1491 O₂ mg/l 1599 H µg/l 1630 pH - F mg/l 910 Br mg/l 196 J mg/l 116 Ag µg/l 378 Al µg/l 1376 As µg/l 669 B µg/l 522 Ba µg/l 542 Bi µg/l 195 Cd µg/l 1013 Co µg/l 335 Cr µg/l 1000 Cu µg/l 520 Hg µg/l 784 Li µg/l 363 Ni µg/l 1038 Pb µg/l 1019 Sb µg/l 305 Se µg/l 414 Si mg/l 670 Sn µg/l 210 Sr µg/l 390 Zn µg/l 684

Komponentensep.

10. P 50. P 90. P 1,9 5,5 16 1,3 2,1 3,6 1,9 6,5 22 5,0 11,3 26 0,002 0,02 0,09 0,001 0,004 0,07 6,4 25 95 5,3 18 58 4,0 8,3 17,4 0,001 0,004 0,01 0,002 0,004 0,009 2,2 7,5 26

78 237 692 4,9 8,1 10,8 0,03 0,07 0,19

6,7 7,1 7,6 0,03 0,07 0,2

2,2 9,3 39,0 0,3 1,0 3,1 6,2 11,8 22 26 95 350

0,007 0,05 0,41

0,14 0,53 2,0 0,32 0,91 2,6 0,03 0,05 0,08

0,05 0,48 4,4 0,002 0,04 0,75

0,29 0,50 0,87

3,9 8,1 17

Figure 3 - Natural background levels in Triassic Sandstones in Germany (N: number of sampling sites) (Kunkel et al., 2004).