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Classification of Groundwater Resources for Regional Planning with Regard to their Vulnerability to Pollution
1101 Quality of Grouridwater, Prowedm . of an International Symposium,Noordwijkefiout, The Netherlrmds, 23-27 March 1981, W. van Duijvenbooden, P. GlmbXgm and H. van Lelyveld (Eds.), Shdier in Enyironmcntal Science, Volume 17 Q M e r Scihntific Publishing Company -Printed in The Netherlmh
CLASSIFICATION OF GROUNDWATER RESOURCES FOR REGIONAL PLANNING WITH REGARD TO THEIR VULNERABILITY TO POLLUTION
H. VIERHUFF Fed. Institute f o r Geosciences and Natural Resources, Hannover (G. F. R. )
ABSTRACT A s part of the project "Grundwasservorkommen in d e r Bundesrepublik Deutschland" (Groundwater r e s o u r c e s in the Fed. Rep. of Germany), c a r r i e d out in 1977178 by the Bundesanstalt fiir Geowissenschaften und Rohstoffe (federal geological survey) in cooperation with the s t a t e geol. surveys and other relevant institutions, t h r e e maps of the Fed. Rep. of Germany were compiled dealing with the most important c h a r a c t e r i s t i c s of groundwater r e s o u r c e s needed f o r national and regional planning: availability, suitability and vulnerability to pollution.
In the approach used t o classify the vulnerability of the groundwater resources, we focussed on the natural r e a s o n s f o r the vulnerability of groundwater r e s o u r c e s f r o m the geological point of view: 1) the degree of the protection against pollution f r o m the surface by the
overlying s t r a t a (main aspect), 2 ) the potential of purification of polluted groundwater in the aquifer.
The F e d e r a l Ministry of Raumordnung, Bauwesen und Stadtebau undertakes studies t o obtain basic knowledge f o r regional and national planning (Bundesraumordnungsprogramm,
F e d e r a l Planning Programme).
One of these studies was the project "Grundwasservorkommen in d e r Bundesrepublik Deutschland" (Groundwater r e s o u r c e s in the Fed. Rep. of Germany), c a r r i e d out in 1977178 by the Bundesanstalt fiir Geowissenschaften und Rohstoffe (federal geological survey) in cooperation with the state geol. surveys and other relevant institutions.
1102
T h e aim w a s t o p r o v i d e a s i m p l i f i e d b u t c o m p r e h e n s i v e p i c t u r e of t h e m a j o r g r o u n d w a t e r o c c u r r e n c e s . T h e y w e r e t o b e c h a r a c t e r i z e d i n t e r m s of t h e i r m o s t i m p o r t a n t f e a t u r e s n eed ed f o r n a t i o n a l a nd r e g i o n a l pla nning: a va ila bility, s u i t a b i l i t y and v u l n e r a b i l i t y t o pollution. D u r i n g t h e f i r s t s t a g e of t h e p r o j ect , a t t e m p t s w e r e m a d e t o e v a l u a t e t h e g r o u n d w a t e r r e s o u r c e s b y c o m b i n i n g t h e s e t h r e e s y s t e m s of p a r a m e t e r s a nd t o find o n e s i m p l e scale of criteria. B u t t h i s did not w o r k b e c a u s e of m a n y r e a s o n s which c a n n o t d i s c u s s e d h e r e i n detail. T h e r e f o r e , t h r e e m a p s of t h e F e d e r a l R epublic of G e r m a n y w e r e c o m p i l e d ( s c a l e 1 : 1 000 000) d e a l i n g with the m o s t i m p o r t a n t c h a r a c t e r i s t i c s of groundw a t e r r e s o u r c e s men t i o n ed a b o v e a s n eed ed f o r pla nning p u r p o s e s . C o m m o n t o all t h r e e m a p s is t h e c l a s s i f i c a t i o n an d d e m a r k a t i o n of t h e g r o u n d w a t e r o c c u r r e n c e s
a c c o r d i n g t o t h e i r p o t e n t i a l an d the g e n e r a l a p p r o a c h . For i n s t a n c e , i n all t h r e e m a p s the areas a r e same w h e r e t h e g r o u n d w a t e r p o t e n t i a l is low a n d s u i t a b l e o n l y f o r l o c a l u s e. T h e s e areas w e r e not c o n s i d e r e d as i m p o r t a n t f o r t h i s kind of s t u d y a n d w e r e not d e a l t with f u r t h e r . T h i s p a p e r d e a l s with t h e t h i r d m a p which s h o w s t h e v u l n e r a b i l i t y of t h e g r o u n d w a t e r o c c u r r e n c e s t o pollution. T h e aim of t h i s s p e c i a l m a p is t o s h o w how g r o u n d w a t e r resources d i f f e r with r e s p e c t to t h e v u l n e r a b i l i t y of w a t e r t o pollution, b e c a u s e t h i s a f f e c t s t h e a s s e s s m e n t not only of t h e g r o u n d w a t e r r e s o u r c e s t h e m s e l v e s , but a l s o of t h e g r o u n d s u r f a c e f o r a n y kind of u s e which m ig h t p o l l u t e t h e g r o u n d wat er .
One of t h e m a i n a s p e c t s i n c h a r a c t e r i z i n g t h e v u l n e r a b i l i t y of g r o u n d w a t e r is t h e t y p e of a q u i f er , i. e. m a i n l y w h e t h e r i t is a p o r o u s a q u i f e r , a h a r d - r o c k
t y p e a q u i f e r with f a u l t s a n d f i s s u r e s , o r a k a r s t i c a q u i f e r . An e x a m p l e of a m a p w h e r e m a i n l y t h i s a s p e c t of t h e v u l n e r a b i l i t y of groundw a t e r r e s o u r c e s has b e e n t a k e n i n t o a c c o u n t is t h e K a r t e d e r Verschmutzungsgefahrdung d e r G r u n d w a s s e r -Vorkommen i n N o r d r h e i n - W e s t f a l e n ( 1 9 7 3 ) (Ref. No. I). A s e c o n d a s p e c t of t h e v u l n e r a b i l i t y t o pollution is the l o c a t i o n of t h e a q u i f e r with r e s p e c t t o t h e h y d r o l o g i c a l c y c l e : g r o u n d w a t e r flowing f r o m the i n f i l t r a t i o n
area t o w a r d s t h e b a s e l e v e l an d f i n al l y r e e m e r g i n g i n t o t h e s u r f a c e w a t e r m a y a c c u m u l a t e p o l l u tan t s o n t h e way. T h e s e a c c u m u l a t i o n s w ill b e greatest at t h e point of r e e m e r g e n c e i n t o t h e s u r f a c e w a t e r s .
1103
Consequently, alluvial valley f i l l may be regarded as the aquifers with the highest degree of vulnerability. This hydrological point of view received the highest priority in the C a r t e de vulnerabilit’e A la pollution des nappes d’eau souterraine de la F r a n c e (1970) (Ref. No. 2). The third aspect of the vulnerability takes into account the characteristics of the unsaturated zone o r the confining l a y e r s (thickness, permeability, type of rock and soil).
In a study for regional planning in the a r e a Nurnberg-Furth (Ref. No. 3), the approach used t o classify the vulnerability of the groundwater r e s o u r c e s took a l l three aspects, type of aquifer, hydrology, c h a r a c t e r i s t i c s of the overburden, into consideration. Additionally, these c r i t e r i a were combined with o t h e r s according to the c u r r e n t and potential groundwater development and the c u r r e n t groundwater protection measures. W e could not use any of the approaches mentioned above. We wished to show only the conditions as found in nature with no reference to groundwater use o r planning. Also, the hydrological situation does not play such an important role in Germany as it does in F r a n c e because of our m o r e humid climate and the generally good possibilities f o r filtration and dilution by groundwater flow in alluvial sediments. W e tried to focus on the natural reasons f o r the vulnerability of groundwater
r e s o u r c e s from the geological point of view: 1) the degree of the protection against pollution f r o m the surface by
the overlying strata, 2 ) the potential of purification (effects of sorption, chemical interaction,
dilution) of polluted groundwater in the aquifer. The degree of the protection against pollution f r o m the surface which is regarded to be the main aspect is defined in f i v e classes. C r i t e r i a are the hydrogeological regime, geology and pedology of the unsaturated rock, depth of groundwater o r thickness of the confining layer, (Fig. 1).
1104
I
Productive aquifer
I
Kind of
aquifer
Kmd of unsaturated rock
Depth of unsaturatod lO"O
Vulnerability
Fig. 1. Classification of vulnerability of groundwater o c c u r r e n c e s with r e s p e c t to the protection against pollution f r o m the surface. The data a r e taken f r o m geological and pedological m a p s and a r e supplemented on t h e b a s i s of hydrogeological knowledge of t h e region. K a r s t i c aquifers, o t h e r h a r d - r o c k aquifers, and porous a q u i f e r s are differentiated f o r t h e second aspect. Our approach t r i e s to combine t h e s e two a s p e c t s but not t o mix them. T h e
c h a r a c t e r i s t i c s of t h e overburden f o r m i n g t h e main group of c r i t e r i a a r e symbolized by coloured a r e a s , while t h e type of the a q u i f e r is shown by s y m b o l s s u c h as dots and lines. G r e e n a r e a s signify little d a n g e r of pollution o r effective protection, while r e d areas symbolize high vulnerability. I n t e r m e d i a t e d e g r e e s of vulnerability a r e indicated by yellow and orange. The s y m b o l s f o r t h e type of aquifer a r e r e d f o r k a r s t i c a q u i f e r s and g r e y l i n e s f o r h a r d r o c k and g r e y d o t s f o r porous aquifers. The density of t h e s e two g r e y s y m b o l s are printed t o give different intensities. Thus, t h e c o l o u r s f o r one group of s y m b o l s c a n i n t e r f e r e with t h o s e of a n o t h e r and e i t h e r intensify o r weaken the c h a r a c t e r i z a t i o n of t h e vulnerability.
1105
The concept and all draft m a p s w e r e discussed with the hydrogeological e x p e r t s of t h e f e d e r a l states. During t h e s e discussions we w e r e able t o make u s e of the experience and i d e a s of o u r colleagues, which improved t h e approach and helped u s to finally obtain a n acceptable picture. REFERENCES 1 Geol. Landesamt Nordrhein-Westfalen (H. BOLSENKOTTER und H. D. HILDEN): K a r t e d e r Verschmutzungsgefahrdung d e r Grundwasservorkommen in Nordrhein-Westfalen, 1973. 2 BRGM, Directibn du Service Gbologique National (M. ALBINET): C a r t e d e Vuln'erabilit'e B la Pollution d e s Nappes d'Eau s o u t e r r a i n e de la France, 1970. 3 Lehrstuhl fiir Raumforschung, Raumordnung und Landesplanung, Technische Universitat Miinchen (H. KIEMSTEDT): Wissenschaftliches Gutachten zu okologischen Planungsgrundlagen i m Verdichtungsraum Niirnberg-FurthErlangen-Schwabach, 1977, pp 227, maps. 4 D e r Bundesminister f u r Raumordnung, Bauwesen und Stadtebau (H. AUST, H. VIERHUFF, W. WAGNER): Grundwasservorkommen in d e r Bundesrepublik Deutschland, 1980, p 64, 3 maps.
CLASSIFICATION OF GROUNDWATER RESOURCES FOR REGIONAL PLANNING WITH REGARD TO THEIR VULNERABILITY TO POLLUTION
H. VIERHUFF Fed. Institute f o r Geosciences and Natural Resources, Hannover (G. F. R. )
ABSTRACT A s part of the project "Grundwasservorkommen in d e r Bundesrepublik Deutschland" (Groundwater r e s o u r c e s in the Fed. Rep. of Germany), c a r r i e d out in 1977178 by the Bundesanstalt fiir Geowissenschaften und Rohstoffe (federal geological survey) in cooperation with the s t a t e geol. surveys and other relevant institutions, t h r e e maps of the Fed. Rep. of Germany were compiled dealing with the most important c h a r a c t e r i s t i c s of groundwater r e s o u r c e s needed f o r national and regional planning: availability, suitability and vulnerability to pollution.
In the approach used t o classify the vulnerability of the groundwater resources, we focussed on the natural r e a s o n s f o r the vulnerability of groundwater r e s o u r c e s f r o m the geological point of view: 1) the degree of the protection against pollution f r o m the surface by the
overlying s t r a t a (main aspect), 2 ) the potential of purification of polluted groundwater in the aquifer.
The F e d e r a l Ministry of Raumordnung, Bauwesen und Stadtebau undertakes studies t o obtain basic knowledge f o r regional and national planning (Bundesraumordnungsprogramm,
F e d e r a l Planning Programme).
One of these studies was the project "Grundwasservorkommen in d e r Bundesrepublik Deutschland" (Groundwater r e s o u r c e s in the Fed. Rep. of Germany), c a r r i e d out in 1977178 by the Bundesanstalt fiir Geowissenschaften und Rohstoffe (federal geological survey) in cooperation with the state geol. surveys and other relevant institutions.
1102
T h e aim w a s t o p r o v i d e a s i m p l i f i e d b u t c o m p r e h e n s i v e p i c t u r e of t h e m a j o r g r o u n d w a t e r o c c u r r e n c e s . T h e y w e r e t o b e c h a r a c t e r i z e d i n t e r m s of t h e i r m o s t i m p o r t a n t f e a t u r e s n eed ed f o r n a t i o n a l a nd r e g i o n a l pla nning: a va ila bility, s u i t a b i l i t y and v u l n e r a b i l i t y t o pollution. D u r i n g t h e f i r s t s t a g e of t h e p r o j ect , a t t e m p t s w e r e m a d e t o e v a l u a t e t h e g r o u n d w a t e r r e s o u r c e s b y c o m b i n i n g t h e s e t h r e e s y s t e m s of p a r a m e t e r s a nd t o find o n e s i m p l e scale of criteria. B u t t h i s did not w o r k b e c a u s e of m a n y r e a s o n s which c a n n o t d i s c u s s e d h e r e i n detail. T h e r e f o r e , t h r e e m a p s of t h e F e d e r a l R epublic of G e r m a n y w e r e c o m p i l e d ( s c a l e 1 : 1 000 000) d e a l i n g with the m o s t i m p o r t a n t c h a r a c t e r i s t i c s of groundw a t e r r e s o u r c e s men t i o n ed a b o v e a s n eed ed f o r pla nning p u r p o s e s . C o m m o n t o all t h r e e m a p s is t h e c l a s s i f i c a t i o n an d d e m a r k a t i o n of t h e g r o u n d w a t e r o c c u r r e n c e s
a c c o r d i n g t o t h e i r p o t e n t i a l an d the g e n e r a l a p p r o a c h . For i n s t a n c e , i n all t h r e e m a p s the areas a r e same w h e r e t h e g r o u n d w a t e r p o t e n t i a l is low a n d s u i t a b l e o n l y f o r l o c a l u s e. T h e s e areas w e r e not c o n s i d e r e d as i m p o r t a n t f o r t h i s kind of s t u d y a n d w e r e not d e a l t with f u r t h e r . T h i s p a p e r d e a l s with t h e t h i r d m a p which s h o w s t h e v u l n e r a b i l i t y of t h e g r o u n d w a t e r o c c u r r e n c e s t o pollution. T h e aim of t h i s s p e c i a l m a p is t o s h o w how g r o u n d w a t e r resources d i f f e r with r e s p e c t to t h e v u l n e r a b i l i t y of w a t e r t o pollution, b e c a u s e t h i s a f f e c t s t h e a s s e s s m e n t not only of t h e g r o u n d w a t e r r e s o u r c e s t h e m s e l v e s , but a l s o of t h e g r o u n d s u r f a c e f o r a n y kind of u s e which m ig h t p o l l u t e t h e g r o u n d wat er .
One of t h e m a i n a s p e c t s i n c h a r a c t e r i z i n g t h e v u l n e r a b i l i t y of g r o u n d w a t e r is t h e t y p e of a q u i f er , i. e. m a i n l y w h e t h e r i t is a p o r o u s a q u i f e r , a h a r d - r o c k
t y p e a q u i f e r with f a u l t s a n d f i s s u r e s , o r a k a r s t i c a q u i f e r . An e x a m p l e of a m a p w h e r e m a i n l y t h i s a s p e c t of t h e v u l n e r a b i l i t y of groundw a t e r r e s o u r c e s has b e e n t a k e n i n t o a c c o u n t is t h e K a r t e d e r Verschmutzungsgefahrdung d e r G r u n d w a s s e r -Vorkommen i n N o r d r h e i n - W e s t f a l e n ( 1 9 7 3 ) (Ref. No. I). A s e c o n d a s p e c t of t h e v u l n e r a b i l i t y t o pollution is the l o c a t i o n of t h e a q u i f e r with r e s p e c t t o t h e h y d r o l o g i c a l c y c l e : g r o u n d w a t e r flowing f r o m the i n f i l t r a t i o n
area t o w a r d s t h e b a s e l e v e l an d f i n al l y r e e m e r g i n g i n t o t h e s u r f a c e w a t e r m a y a c c u m u l a t e p o l l u tan t s o n t h e way. T h e s e a c c u m u l a t i o n s w ill b e greatest at t h e point of r e e m e r g e n c e i n t o t h e s u r f a c e w a t e r s .
1103
Consequently, alluvial valley f i l l may be regarded as the aquifers with the highest degree of vulnerability. This hydrological point of view received the highest priority in the C a r t e de vulnerabilit’e A la pollution des nappes d’eau souterraine de la F r a n c e (1970) (Ref. No. 2). The third aspect of the vulnerability takes into account the characteristics of the unsaturated zone o r the confining l a y e r s (thickness, permeability, type of rock and soil).
In a study for regional planning in the a r e a Nurnberg-Furth (Ref. No. 3), the approach used t o classify the vulnerability of the groundwater r e s o u r c e s took a l l three aspects, type of aquifer, hydrology, c h a r a c t e r i s t i c s of the overburden, into consideration. Additionally, these c r i t e r i a were combined with o t h e r s according to the c u r r e n t and potential groundwater development and the c u r r e n t groundwater protection measures. W e could not use any of the approaches mentioned above. We wished to show only the conditions as found in nature with no reference to groundwater use o r planning. Also, the hydrological situation does not play such an important role in Germany as it does in F r a n c e because of our m o r e humid climate and the generally good possibilities f o r filtration and dilution by groundwater flow in alluvial sediments. W e tried to focus on the natural reasons f o r the vulnerability of groundwater
r e s o u r c e s from the geological point of view: 1) the degree of the protection against pollution f r o m the surface by
the overlying strata, 2 ) the potential of purification (effects of sorption, chemical interaction,
dilution) of polluted groundwater in the aquifer. The degree of the protection against pollution f r o m the surface which is regarded to be the main aspect is defined in f i v e classes. C r i t e r i a are the hydrogeological regime, geology and pedology of the unsaturated rock, depth of groundwater o r thickness of the confining layer, (Fig. 1).
1104
I
Productive aquifer
I
Kind of
aquifer
Kmd of unsaturated rock
Depth of unsaturatod lO"O
Vulnerability
Fig. 1. Classification of vulnerability of groundwater o c c u r r e n c e s with r e s p e c t to the protection against pollution f r o m the surface. The data a r e taken f r o m geological and pedological m a p s and a r e supplemented on t h e b a s i s of hydrogeological knowledge of t h e region. K a r s t i c aquifers, o t h e r h a r d - r o c k aquifers, and porous a q u i f e r s are differentiated f o r t h e second aspect. Our approach t r i e s to combine t h e s e two a s p e c t s but not t o mix them. T h e
c h a r a c t e r i s t i c s of t h e overburden f o r m i n g t h e main group of c r i t e r i a a r e symbolized by coloured a r e a s , while t h e type of the a q u i f e r is shown by s y m b o l s s u c h as dots and lines. G r e e n a r e a s signify little d a n g e r of pollution o r effective protection, while r e d areas symbolize high vulnerability. I n t e r m e d i a t e d e g r e e s of vulnerability a r e indicated by yellow and orange. The s y m b o l s f o r t h e type of aquifer a r e r e d f o r k a r s t i c a q u i f e r s and g r e y l i n e s f o r h a r d r o c k and g r e y d o t s f o r porous aquifers. The density of t h e s e two g r e y s y m b o l s are printed t o give different intensities. Thus, t h e c o l o u r s f o r one group of s y m b o l s c a n i n t e r f e r e with t h o s e of a n o t h e r and e i t h e r intensify o r weaken the c h a r a c t e r i z a t i o n of t h e vulnerability.
1105
The concept and all draft m a p s w e r e discussed with the hydrogeological e x p e r t s of t h e f e d e r a l states. During t h e s e discussions we w e r e able t o make u s e of the experience and i d e a s of o u r colleagues, which improved t h e approach and helped u s to finally obtain a n acceptable picture. REFERENCES 1 Geol. Landesamt Nordrhein-Westfalen (H. BOLSENKOTTER und H. D. HILDEN): K a r t e d e r Verschmutzungsgefahrdung d e r Grundwasservorkommen in Nordrhein-Westfalen, 1973. 2 BRGM, Directibn du Service Gbologique National (M. ALBINET): C a r t e d e Vuln'erabilit'e B la Pollution d e s Nappes d'Eau s o u t e r r a i n e de la France, 1970. 3 Lehrstuhl fiir Raumforschung, Raumordnung und Landesplanung, Technische Universitat Miinchen (H. KIEMSTEDT): Wissenschaftliches Gutachten zu okologischen Planungsgrundlagen i m Verdichtungsraum Niirnberg-FurthErlangen-Schwabach, 1977, pp 227, maps. 4 D e r Bundesminister f u r Raumordnung, Bauwesen und Stadtebau (H. AUST, H. VIERHUFF, W. WAGNER): Grundwasservorkommen in d e r Bundesrepublik Deutschland, 1980, p 64, 3 maps.