1.7 Groundwater

The WFD requires that initial characterization Figure 1.7.1 of the location and boundaries of all groundwa- Map indicating loca- ter bodies be carried out in connection with the N tion and boundaries Article 5 report. In addition the initial charac- of aquifers in Odense terization must identify the pressures on the River Basin. groundwater bodies and the character of overlying strata, and must identify those groundwater bodies for which there are directly dependent surface water ecosystems or terrestrial ecosystems. If the initial characterization reveals that spe- ciﬁ c groundwater bodies are at risk of failing to meet the environmental objectives set, these groundwater bodies have to be characterized further. Among other things, their geological and hydrogeological characteristics have to be described. In addition, the chemical composition of the groundwater has to be characterized, as has groundwater recharge and exchange of water between the groundwater body and associated surface systems.

0 5 10 km 1.7.1 Initial characterization

This section describes the initial characterization of aquifers and groundwater abstraction in Table 1.7.1. From Table 1.7.2 it can be seen that Odense River Basin. Subsequently a single aqui- 20 aquifers are smaller than 15 km2, and that 12 fer has been selected for further characterization, of these are smaller than 5 km2. Table 1.7.1 would including subdivision into groundwater bodies. seem to indicate, moreover, that the majority of Odense River Basin is covered by aquifers. This Aquifers is not the case, however, in that the parts of the The location and boundaries of the aquifers aquifers that lie outside Odense River Basin are within Odense River Basin are illustrated in Fig- also included in the total aquifer area. Moreover, ure 1.7.1. The aquifers are included if just part of several aquifers may very well overlap in places, the aquifer lies within Odense River Basin, even separated by impervious clay layers. if only a limited part. As mentioned earlier, a number of the aquifers A summary of the aquifers is shown in Table are only partly located within Odense River Ba- 1.7.1 based on the data for the individual aquifers sin. For example, the major part of aquifers 3, 7N shown in Table 1.7.2 (Fyns Amt, 2000b). Due to and 39 are located outside the basin. These rela- the large range in aquifer size it makes a consider- tively large aquifers comprise approx. 50% of the able difference whether one considers the mean water resource. Abstraction from these aquifers or the median values, as is also apparent from is limited seen in relation to their size, however.

Max Min Median Mean Total Table 1.7.1 Statistics for all aqui- Aquifer area (km2) 187 0.4 9.8 29.7 1 009 fers encompassed by Odense River Basin. Aquifer resource (106 m3) 1 472 0.6 30 146 4 956

Waterworks abstraction in 1998 (103 m3) 4 173 0 152 565 18 627

Total abstraction in 1998 (103 m3) 5 628 0 161 772 25 498

Odense PRB Odense Pilot River Basin 43 1.7 Groundwater ) 3 m 0 1 0 0 1 6 33 82 30 83 90 49 38 161 307 644 188 108 603 281 256 109 157 253 516 160 1 220 1 576 5 628 4 173 1 072 3 378 3 041 1 260 (10 tion in 1998 Total abstrac- Total ) 3 m 0 0 0 0 0 0 6 56 97 13 72 30 83 90 49 34 294 273 188 591 274 256 855 152 253 515 130 1 217 1 246 1 585 4 173 1 800 3 041 1 260 (10 Waterworks abstraction in 1998 1998 in abstraction DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DS DG DS, IS BK, PK PK, BK DS, DG DS, DG DS, DG DS, DS DG, DG DS, DG DS, DG DS, Geology Geology U U C C C C C U C C C C C C C C C C C C C C C C, A A C, A C, U, C U, C U, C U, C U, C U, C U, C U, C U, C U, type Aquifer ) 3 m 6 7.5 9.6 0.6 8.1 9.0 9.6 5.1 3.6 28.2 68.4 16.8 21.6 59.7 18.0 51.3 45.9 64.2 7.05 8.25 63.3 30.9 129.6 223.5 112.5 582.6 148.5 13.95 13.05 821.7 626.4 163.8 111.15 1 472.4 472.4 1 (10 Resource ) 2 4.7 5.6 7.2 2.5 9.3 2.9 4.7 5.5 3.2 0.4 2.7 3.9 0.6 3.2 1.7 1.2 28.8 24.7 74.5 25.0 11.4 33.0 19.9 17,5 11.4 10.2 21.4 21.1 10.3 Area (km 122.7 186.9 182.6 139.2 A1 A1 A1 B1 A1 B2 B1 B1 A1 A3 A1 A1 A3 A2 B2 A1 B2 A3 A2 B2 A2 B2 B3 B1 B1 B1 B2 C2 C2 C1 C2 C1 C2 C2 C1 C1 class Cover layer 3 3 5 3 3 9 5 7 3 5 1 3 3 9 9 3 3 3 7 7 7 7 3 7 5 7 5 5 7 7 7 7 7 9 model Layer in geological 3 5 6 8 9 12 16 17 18 20 23 24 27 35 39 40 41 42 44 45 46 50 60 63 65 66 90 91 93 1V 7N 1Ø 102 105 Aquifer number Aquifer name/identity Tarup-Årslev Tarup-Årslev Langeskov Gislev Ringe-Ryslinge Nyborg Odense near complex Aquifer Holmehave Frøbjerg Vissenbjerg-Blommenslyst Korinth Arreskov Lake at Aquifer Aquifer north of Espe Limestone aquiferOdense – Deep aquifer at Holmehave Stenstrup-Lunde Kværndrup Lake Søndersø aquifer Odense Northern Seden-Bullerup Hasmark Mesinge Munkebo aquifer – upperpart Munkebo aquifer – lower part Morud Vester Hæsinge Tommerup at Aquifer Trunderup Broby Bøge Fruens at aquifer Deep Sanderum of north Aquifer Brylle of north Aquifer Aquifer northwest of Lake Søndersø Kappendrup

Table 1.7.2 Description of the individual aquifers encompassed by Odense River Basin. DS: Late-glacial meltwater sand; DG: Late-glacial meltwater gravel; BK: Danien bryozo limestone; PK: Selandien greensand limestone; IS: Interglacial freshwater sand.

Odense 44 PRB Odense Pilot River Basin 1.7 Groundwater

Class Description Cover layer class Description Table 1.7.3 Classiﬁ cation of cover A The cover layer thickness exceeds A1 A considerable part of the cover layer layer classes. 15 m in less than 25% of the total is less than 5 m thick. area of the aquifer. A2 There are no significant areas where the cover layer is less than 5 m thick, and heavy clay is not present to any great extent above the aquifer. A3 Heavy clay occurs above the aquifer. B The cover layer thickness exceeds B1 Areas are present where the cover 15 m in more than 25% of the total layer is less than 5 m thick. area of the aquifer. In addition, the B2 The cover layer is never less than 5 cover layer is less than 15 m thick in m thick, and only insignificant areas more than 5% of the total area of the of heavy clay occur above the aquifer. aquifer. B3 Significant deposits of heavy clay above the aquifer. C The cover layer thickness exceeds C1 There are no significant deposits of 15 m in more than 25% of the total heavy clay above the aquifer. area of the aquifer. In addition, the C2 Significant deposits of heavy clay cover layer is less than 15 m thick in above the aquifer. less than 5% of the total area of the aquifer.

A geological layer model has been established tion to the aquifers and the degree of exploitation in which layer 1 represents the unsaturated zone, vary considerably. layers 3, 5, 7 and 9 are the water-bearing layers (aquifers), with layer 3 uppermost and layer 9 Groundwater potential lowermost. Layers 2, 4, 6 and 8 are the inter- A potential map for the primary water table has mediate impervious layers, of which layer 2 is been prepared from sounding data (Figure 1.7.2). uppermost. The cover layer classes refer to the As this is primarily based on soundings from the distribution of the cover layer overlying the aqui- primary water table, it is possible that a second- fer (Table 1.7.3). The aquifer types are as follows: ary water table closer to the surface might exist U: Unconfi ned; C: Confi ned; and A: Artesian. locally. As areas without aquifers have also been Certain aquifers contain several types, including assigned a water table, the potential lines cannot both unconfi ned and confi ned. be utilized to accurately determine the magni- With a number of the aquifers it is apparent tude or direction of groundwater fl ow. that abstraction amounts to less than the mini- mum requirement of 10 m3/day for drinking Aquifer protection water, e.g. aquifers 12, 27, 91 and 102. They are Clay thickness above the aquifer nevertheless included because it is as yet unclear The thickness of the clay overlying the indi- whether groundwater fl ow in these aquifers vidual aquifers is indicated in Figure 1.7.3. The affects terrestrial ecosystems or surface water clay thickness map is not complete for the whole ecosystems. Moreover, the intention is that it of Odense River Basin, however. This is due to should be possible to abstract water from these the fact that well density is too low in some areas aquifers for the drinking water supply. For this to permit estimation of the thickness of the clay reason these four aquifers are also designated as above the aquifer, and that no aquifer is present protected areas (see Section 2). in some areas. In all, 34 aquifers have been characterized. These consist of both unconfi ned, confi ned and Nitrate-vulnerable abstraction areas artesian aquifers, primarily glacial meltwater It is estimated that approx. 303 km2 of Odense sand or gravel aquifers, but also some Tertiary River Basin is vulnerable to nitrate contamina- limestone aquifers. Some are located near the sur- tion (Figure 1.7.4). This fi gure encompasses the face and some are very deep with a very variable areas where groundwater recharge takes place cover layer thickness. As a consequence, infi ltra- and where the aquifer is already contaminated

Odense PRB Odense Pilot River Basin 45 1.7 Groundwater

Figure 1.7.2 (left) Map indicating groundwater potential for the primary water 0 table shown in metres 0 above sea level.

1 5 Figure 1.7.3 (right) 0 0

6 5 1 6 0 Map indicating clay 0 5 0 5 25 45 0 thickness above aqui- 40 3 3 0 fers. 50 5 Over 30 m 5 1 Under 15 m

0 15–30 m 2

Unknown 3 0 3 35 5 clay thickness

0 3

8 9 8 5 0 9 1 0 0 5 4 0 5 7 0 10 5 5 45 0 6 7 5 0 6 0 5 5 675 750 5 3

5 4

5 0 5 5 6 0

0 5 10 km 0 5 10KM

Figure 1.7.4 (left) Map indicating areas vulnerable to nitrate N N contamination.

Figure 1.7.5 (right) Map indicating soil type distribution at a depth of 1 m. Glacial meltwater gravel Glacial meltwater silt Glacial meltwater clay Glacial meltwater sand Post-glacial freshwater clay Post-glacial freshwater gyttja Post-glacial freshwater sand Post-glacial freshwater peat Post-glacial marine gravel Post-glacial marine silt Post-glacial marine sand Glacial moraine gravel Glacial moraine clay Glacial moraine sand 0 5 10 km 0 5 10 km Lake Late-glacial freshwater gravel Late-glacial freshwater clay Late-glacial freshwater sand

Odense 46 PRB Odense Pilot River Basin 1.7 Groundwater

Soil type Area % of Table 1.7.4 (left) 2 even if only a limited part. (km ) area A number of groundwater abstraction areas are Soil type distribution at a depth of 1 m Glacial moraine gravel 9.8 0.9 only partly located within Odense River Basin within Odense River (Figure 1.7.6). These only account for a limited Glacial moraine clay 679.5 65.5 Basin. part of the total amount abstracted, however. Glacial moraine sand 1.8 0.2 The total area of the groundwater abstraction areas is 441.2 km2. Several of the abstraction ar- Glacial meltwater gravel 17.5 1.7 eas are more or less coincident. Glacial meltwater clay 7.3 0.7 In addition to waterworks, groundwater is also abstracted by a large number of farms, Glacial meltwater sand 138.5 13.4 market gardens, industrial enterprises and small Post-glacial freshwater gyttja 40.3 3.9 waterworks (Table 1.7.5). In addition, there are

Post-glacial freshwater clay 1.9 0.2

Post-glacial freshwater sand 6.3 0.6 Permits in Abstraction in Table 1.7.5 (right) Category 3 3 3 3 10 m 1998 in 10 m Abstraction permits Post-glacial freshwater peat 57.0 5.5 Public waterworks 29 090 20 288 and groundwater Post-glacial marine gravel 2.8 0.3 abstraction in Odense Market gardens, 9 458 4 112 River Basin. Post-glacial marine clay 10.9 1.1 farms, etc. Industry 12 520 3 512 Post-glacial marine sand 11.4 1.1 Institutions 146 102 Late-glacial freshwater gravel 0.6 0.1 Minor waterworks 291 59 Late-glacial freshwater clay 1.6 0.2 (2–9 households) Private wells, 1 228 1 228 Late-glacial freshwater sand 49.6 4.8 assessed

with nitrate, or areas where there is poor geological protection against nitrate contamination.

Soil type maps Figure 1.7.6 The distribution of soil type at a depth of 1 m is Map indicating loca- summarized in Table 1.7.4 based on the soil type N tion of groundwater distribution map shown in Figure 1.7.5. abstraction areas The greater part of Odense River Basin is located within or en- covered by moraine clay, while a smaller part compassed by Odense River Basin. is covered by glacial meltwater sand and post- glacial organic-rich soil types. The distribution is uneven in that glacial meltwater sand is more frequent in the western and southern parts of the basin while the late-glacial freshwater sand is more frequent in the northeastern part. The post-glacial organic-rich soils are primarily seen around the River Odense ﬂ oodplain and in ad- joining ﬂ oodplains.

Abstraction and groundwater abstraction areas The ﬁ gures for groundwater abstraction are from 1998. Since then the amount of water abstracted by waterworks has decreased slightly, as has the total abstraction permit allocation. The groundwater abstraction areas have been included if just 0 5 10 km part of the area lies within Odense River Basin,

Odense PRB Odense Pilot River Basin 47 1.7 Groundwater

numerous private wells that supply individual In these areas there is a good chance that surface households. Within Odense River Basin, approx. water ecosystems or terrestrial ecosystems are di- 550 groundwater abstraction permits have been rectly dependent on upwelling from groundwa- granted to farms, market gardens, institutions, ter bodies. These areas are described as upwelling industries and waterworks supplying 2–9 house- areas, and among others include Kulemose Bog, holds. Together with the water abstracted from Stavis Stream, parts of the River Odense and private wells, this accounts for approx. 1/3 of the parts of Ulvebæk Brook. In connection with the total groundwater abstraction in Odense River further characterization of aquifer 8 (see below), Basin. a more detailed map of upwelling areas has been drawn up for that aquifer. Monitoring Under the provisions of the WFD, groundwater Conclusion bodies from which more than 36 500 m3/year is The overall assessment is that in view of the pres- abstracted for drinking water must be monitored. sure of land use and nutrient loading described in As this is the case for most aquifers it is conclud- Sections 3 and 4 and of the geological conditions ed that monitoring will have to be carried out at described in this section, many of the aquifers most of the aquifers listed in Table 1.7.2. are at risk of failing to meet the objective set and must therefore be considered to be threatened. Upwelling The aquifers therefore need to be characterized The areas where the groundwater potential lies further in order to more precisely determine the above ground surface are shown in Figure 1.7.7. magnitude of the risk.

Table 1.7.6 Contaminant Objective Limit value cf. Remarks Groundwater quality Groundwater Directive objectives and limit Nitrate 25 mg/l 50 mg/l The limit value applies to all ground- values for nitrate and water bodies apart from those in areas pesticides. vulnerable to nitrate contamination 1 according to Directive 91/676/EEC . In these areas Article 4 (1)(c) of the WFD applies. Pesticides and pesticide Non-detectable 0.1 µg/l metabolites

Figure 1.7.7 (left) Map indicating location of upwelling areas and watercourses. Watercourse

Upwelling area

Figure 1.7.8 (right) Map indicating location and boundaries of aquifer 8 and urban areas. Urban areas

Aquifer 8

0 5 10 km 0 5 10 km

Odense 48 PRB Odense Pilot River Basin 1.7 Groundwater

Layer Area Resource Geology Waterworks Total Infiltration Groundwater Utilization Table 1.7.7 in Fyn (km2) (106 m3) abstraction in abstraction (mm) recharge per (%) Description of aquifer 8. model 1998 (103 m3) in 1998 year (103 m3) (103 m3)

5 186.9 582.6 DS 1 585 5 628 100 18 691 30

1.7.2 Further characterization

Due to resource constraints, it was decided to re- strict further characterization to a single aquifer Figure 1.7.9 – No. 8, the aquifer complex near Odense. Map indicating cover The characteristics of the aquifer are summa- layer thickness above aquifer 8. rized in Table 1.7.7, and its location and boundaries are illustrated in Figure 1.7.8. As a ﬁ rst step the aquifer was subdivided into groundwater bodies. Thereafter the individual groundwater bodies were characterized. The analysis method followed was that outlined in the horizontal guidance document “Identiﬁ cation of water bodies”.

Subdivision into groundwater bodies Subdivision into groundwater bodies was based on a survey of the aquifers. In order to determine 02.5 5 to what extent the aquifer should be subdivided km into a number of groundwater bodies, the follow- ing aspects were assessed: Accumulated clay thickness 15-30m Accumulated clay thickness <15m • Geology Accumulated clay thickness >30m • Groundwater chemistry Unknown clay thickness above aquifer • Flow direction/potential. Figure 1.7.10 Geology Map indicating soil Aquifer 8 is an aquifer complex comprised of type distribution above several smaller contiguous aquifers in meltwater aquifer 8 at a depth of sand. The complex was deposited at approxi- 1 m. mately Danish Zero Level with a general thick- Glacial meltwater gravel ness of 10 m. A belt of the aquifer around Odense Glacial meltwater silt is as much as 35 m thick, though, and in this area Glacial meltwater clay it reaches down to -30 m below Danish Zero Glacial meltwater sand Level. Moreover, geophysical mapping (TEM) Post-glacial freshwater clay indicates that the aquifer is up to approx. 20 m Post-glacial freshwater gyttja thick in the vicinity of Nørre Søby. The aquifer Post-glacial freshwater sand complex is covered by an approx. 10 m thick Post-glacial freshwater peat layer of moraine clay. The individual aquifers are Post-glacial marine gravel both unconfi ned and confi ned. Their boundaries Post-glacial marine silt to the north and south are uncertain, while those Post-glacial marine sand to the west and east are reasonably well defi ned. Glacial moraine gravel The aquifer complex is the most extensive in Glacial moraine clay Fyn County, and is probably in hydraulic con- tact with the regional Northern Odense Aquifer Glacial moraine sand (No. 40) to the north and possibly with the Vis- Lake Late-glacial freshwater gravel senbjerg-Blommenslyst Aquifer (No. 16) to the 0 2.5 5 km northwest and the Holmehave Aquifer to the Late-glacial freshwater clay west. It is provisionally assigned to layer 5 in the Late-glacial freshwater sand

Odense PRB Odense Pilot River Basin 49 1.7 Groundwater

Table 1.7.8 Area Type 2 % to analyse the potential data. The groundwater Distribution of cover (km ) potential map composed using the model is layer thickness above Clay thickness unknown 46 25 shown in Figure 1.7.14. Comparison of this with aquifer 8. the previously established potential map shows Clay thickness <15 m 97 52 that the two maps are in good agreement. The Clay thickness 15–30 m 41 22 ﬁ gure shows that aquifer 8 can be subdivided into a number of smaller areas on the basis of poten- Clay thickness >30 m 2 1 tial data for the primary water table.

Groundwater bodies geological layer model. Based on the above it is concluded that the aqui- The distribution of cover layer thickness above fer needs to be subdivided into six groundwater aquifer 8 is shown in Figure 1.7.9 and Table bodies in order to be able to characterize them in 1.7.8. a uniform manner, namely groundwater bodies The distribution of soil types within aquifer 8 8-1 to 8-6 (Figure 1.7.14). The subdivision was is indicated in Table 1.7.9, while the location of initially based on groundwater chemistry data. soil types within aquifer 8 is illustrated in Figure Final subdivision was made with the help of the 1.7.10. modelled potential map. Table 1.7.10 indicates In the southeastern part of the aquifer clay which of the groundwater bodies differ from the cover above the aquifer is thicker than in the re- expected natural state. mainder of the aquifer. Moreover, meltwater and From Table 1.7.10 it can be concluded that freshwater deposits predominate in the south- the problem facing the six groundwater bodies western part in contrast to glacial deposits in the differs. Thus it is not possible to group two or remainder of the aquifer. more of the groundwater bodies on the basis of their chemical properties. They are therefore Groundwater chemistry described individually. In order to assess the need to subdivide aquifer 8 into groundwater bodies an analysis of the Description of groundwater bodies groundwater chemistry data was made encom- The characteristics and status of each of the six passing: groundwater bodies into which aquifer 8 has been subdivided are described below. • Nitrate • 2,6-dichlorbenzamid (BAM) Geology • Conductivity. The area and geology of each groundwater body is shown in Table 1.7.11. In this connection, a simple model was established (Triangular irregular network model). Hydrogeological conditions The model is based on interpolation between The hydrogeological properties of each of the original data points in a network of triangles. groundwater bodies are summarized in Table These models are shown in Figure 1.7.11 (ni- 1.7.12. The hydraulic conductivity is based on the trate), Figure 1.7.12 (2,6-dichlorbenzamid) and geological description of the groundwater body. Figure 1.7.13 (conductivity). The reason that the Negative values for the depth of the groundwa- individual maps do not encompass the same area ter table indicate that the groundwater potential is that not all three of the selected parameters are lies above ground surface. analysed for in each of the selected wells. The resultant maps show that clear aggrega- Clay thickness above the groundwater bodies tions are apparent for certain parameters. For The distribution of clay thickness above the in- example, raised nitrate concentrations are seen dividual groundwater bodies is shown in Table in groundwater bodies in the southwestern and 1.7.13 based on the clay thickness map for aquifer northeastern areas, while lower concentrations 8. are seen in the northwestern and southeastern areas. Raised BAM concentrations are seen in the Effects of groundwater on surface water eco- northern part of the area. systems Groundwater affects both the quantitative and Flow direction/potential qualitative status of surface water ecosystems. A triangular network model was also established In this section an attempt is made to identify

Odense 50 PRB Odense Pilot River Basin 1.7 Groundwater

Figure 1.7.11 (left) Nitrate concentration 8-1 8-1 map based on well measurements. The map was composed 8-3 using a triangular 8-3 8-2 8-2 irregular network model. The locations 8-4 of the wells used for 8-4 the triangulation are indicated. 8-6 8-6 8-5 8-5 Figure 1.7.12 (right) 2,6-dichlorbenzamid (BAM) concentration 02.5 5 map based on well km measurements. The map was composed using a triangular Site of analysis Site of analysis irregular network over 50 mg/l over 10.0 µg/l 44-50 mg/l model. The locations 1.0-10.0 µg/l of the wells used for 39-44 mg/l 0.1-1.0 µg/l 33-39 mg/l 0.05-0.1 µg/l the triangulation are 28-33 mg/l 0.01-0.05 µg/l indicated. 22-28 mg/l 17-22 mg/l 11-17 mg/l 6-11 mg/l 0-6 mg/l

0 Figure 1.7.13 (left) 40 4 5 Conductivity map 1 0

3 5 8-1 5 8-1 based on well meas- 0 5 urements. The map

0 3 was composed using a triangular irregular 8-3 8-3 8-2 8-2 network model. The

5 locations of the wells 1 used for the triangula- 8-4 8-4 tion are indicated.

5 3 8-6 8-6 8-5 8-5 Figure 1.7.14 (right)

3 2 5 0

0 4 Groundwater poten- 4

30 6 tial map composed 5

0 0

5 5 using a triangular

0 2.5 5 0 2.5 5 2 irregular network 40 3 5 45 5 km km 5 50 7 model. The locations 55

0 5 6 of the data points used for the triangulation Site of analysis Measurement points Potential line are indicated. Subdivi- over 1930 µS/cm sion of the aquifer into 1750-1930 µS/cm Interpollated potential map groundwater bodies is 1580-1750 µS/cm 15 m 30 m 1400-1580 µS/cm also indicated. 1230-1400 µS/cm 5m -6 m 1050-1230 µS/cm 10 m 50 m 870-1050 µS/cm 20 m 45 m 700-870 µS/cm -5 m 520-700 µS/cm 35 m 350-520 µS/cm 0m 40 m 25 m 55 m

Odense PRB Odense Pilot River Basin 51 1.7 Groundwater

Table 1.7.9 Area surface water ecosystems that are dependent on Soil type 2 % Soil type distribution (km ) groundwater. within aquifer 8. Glacial moraine gravel 0.1 0.0 The areas in which the groundwater potential lies above the ground surface were determined Glacial moraine clay 114.8 61.7 from terrain altitude relative to Danish Zero Glacial moraine sand 0.1 0.0 Level in combination with potential data for the primary water table. These areas were compared Glacial meltwater gravel 2.7 1.5 with the areas known from the soil type distri- Glacial meltwater clay 0.2 0.1 bution map to consist of post-glacial freshwater sediments. From Figure 1.7.15 it can be seen that Glacial meltwater sand 29.5 15.9 by far the majority of the upwelling areas are Glacial variable moraine layer 0.0 0.0 located in areas with post-glacial freshwater sediments. From Table 1.7.14 it can also be seen that Post-glacial freshwater gyttja 10.5 5.7 the percentage of each groundwater body that consist of upwelling areas varies considerably. Post-glacial freshwater clay 1.0 0.5

Post-glacial freshwater sand 1.5 0.8 Conclusion Based on the groundwater chemistry data it Post-glacial freshwater peat 14.0 7.5 seems appropriate to subdivide aquifer 8 into Late-glacial freshwater gravel 0.5 0.3 six groundwater bodies in order to be able to describe status. Late-glacial freshwater clay 0.5 0.3 The characterization revealed that fi ve of the Late-glacial freshwater sand 10.5 5.6 groundwater bodies are at risk of failing to meet the objective. This aspect is more closely exam- ined in Section 4.1, where the groundwater chemical status (environmental effect) is described for the individual groundwater bodies. The environ- Table 1.7.10 Groundwater Nitrate BAM Conduc- mental pressures on the individual groundwater Subdivision of aquifer body tivity bodies are described in Section 3.4.1. 8 into groundwater 8-1 bodies on the basis of groundwater chemis- 8-2 try. The grey, shaded 1.7.3 Provisional establishment of objec- areas indicate where 8-3 tives the water chemistry differs from the expect- 8-4 The WFD does not directly specify criteria for ed natural state. 8-5 assessing the quality of the groundwater. The criteria have been subsequently specifi ed in the 8-6 Groundwater Directive. In Fyn County an objective has been set re- garding the pesticide content of the groundwater, namely that pesticides and pesticide metabolites may not be present in the groundwater. Among Table 1.7.11 Groundwater Area 2 Geology other things, the background for this objective body (km ) Area and geology of the is that it must be possible to base the drinking individual groundwa- Quaternary meltwater 8-1 15.09 water supply on uncontaminated groundwater. ter bodies of aquifer 8. sand/gravel Fyn County has also set an objective for the Quaternary meltwater 8-2 34.51 sand/gravel nitrate content of the groundwater, namely that Quaternary meltwater the nitrate content may not exceed 25 mg/l in 8-3 24.53 sand nitrate-contaminated groundwater zones in the Quaternary meltwater identifi ed groundwater bodies. 8-4 29.06 sand These objectives differ from the criteria es- Quaternary meltwater tablished for assessing good chemical status of 8-5 55.74 sand groundwater in the Groundwater Directive, Quaternary meltwater 8-6 27.98 namely 0,1 µg/l for pesticides and their relevant sand metabolites, and 50 mg/l for nitrate. The objectives and the limit values for good status are shown in Table 1.7.6.

Odense 52 PRB Odense Pilot River Basin 1.7 Groundwater

Groundwater Distance from the terrain to Hydraulic conductivity (m/s) Annual varia- Source of Table 1.7.12 body the primary groundwater tion in ground- groundwater Hydrogeological prop- table (m) water level (m) recharge erties of the individual Mean Max Min Mean Min-Max groundwater bodies of aquifer 8. 8-1 6.0 29.3 -9.0 5.0E-3 5.0E-5–1.0E-2 No data Precipitation

8-2 5.9 27.1 -14.6 5.0E-3 5.0E-5–1.0E-2 0.5–2 Precipitation

8-3 5.7 24.4 14.7 5.0E-4 5.0E-5–1.0E-3 0.5–2 Precipitation

8-4 2.4 22.0 -12.8 5.0E-4 5.0E-5–1.0E-3 0.5–2 Precipitation

8-5 2.8 23.3 -9.5 5.0E-4 5.0E-5–1.0E-3 0.5–2 Precipitation

8-6 3.4 32.9 -8.7 5.0E-4 5.0E-5–1.0E-3 0.5–2 Precipitation

Groundwater body 8-1 8-2 8-3 8-4 8-5 8-6 Table 1.7.13 Distribution of clay Area % Area % Area % Area % Area % Area % thickness above the individual groundwater Clay thickness unknown 6.1 40.2 12.9 46.2 7.1 29.1 0.7 2.3 14.5 26.0 12.9 46.2 bodies of aquifer 8. Clay thickness <15 m 8.0 53.2 10.0 35.7 12.3 50.2 21.7 74.5 21.2 38.0 10.0 35.7

Clay thickness 15–30 m 1.0 6.6 5.0 18.0 5.1 20.8 6.3 21.6 19.3 34.6 5.0 18.0

Clay thickness >30 m 0.0 0.0 0.0 0.1 0.0 0.0 0.5 1.6 0.8 1.4 0.0 0.1

Ground- Area Area with up- % area with Table 1.7.14 (left) water body (km2) welling (km2) upwelling Distribution of up- 8-1 15.1 0.9 5.7 welling areas in the individual groundwater 8-2 34.5 2.7 7.7 bodies of aquifer 8.

8-3 24.5 2.3 9.4 Figure 1.7.15 (right) 8-4 29.1 5.5 18.9 Map indicating areas of aquifer 8 where the pri- 8-5 55.7 8.5 15.3 mary water table lies above ground level, as 8-6 28.0 7.1 25.4 well as areas consisting 8 186.9 27.0 14.4 of post-glacial freshwater sediments.

Post-glacial freshwater sediments 0 2.5 5 km Upwelling area

Odense PRB Odense Pilot River Basin 53 Photo: Bjarne Andresen, Fyns Amt Seden Strand and Odense Fjord.

Odense 54 PRB Odense Pilot River Basin