Environmental Isotopes in the Hydrological Cycle
Principles and Applications

VOLUME V: MAN'S IMPACT ON GROUNDWATER SYSTEMS
by 
Klaus-Peter Seiler  GSF-Institute of Hydrology, Neuherberg Germany
Contributing Authors
E.Müller, A.Hartmann, P.Trimborn, GSF-National Research Centre, Neuherberg, Germany
F.Decarli, J.Alvarado Rivas, Ministerio del Ambiente y de los Recursos Naturale Renovables (MARNR) Caracas, Venezuela
A. Jiriez, University of  Muta, Jordan
I. Sajjad, Pakistan Institut of Nuclear Technology, Rawalpindi, Pakistan

Preface
CONTENTS
1	POLLUTION SUSCEPTIBILITY OF AQUIFERS AND POLLUTION ASSESSMENT	  1
	1.1	Introduction			  1
	1.2	Role of groundwaters in human and ecosystem sectors	  2
	1.3	Transport potential of discharge components	  4
	1.4	Rock properties and the susceptibility of aquifers to contaminants	  6
	1.5	Reactive behaviour of pollutants in aquifers	  8
	1.6	Microbial activities in aquifers		10
	1.7	Dynamics of groundwater in aquifer systems	11
	1.8	Contaminant sources		19
		               

2	GROUNDWATER EXPLOITATION AND OVEREXPLOITATION	21
	2.1	Groundwater abstraction from deep wells in the Molasse Basin of S. Germany	28
		2.1.1	Introduction		28
		2.1.2	The TNL in the study area	28
		2.1.3	Hydrodynamic flow field in the vicinity of deep wells	30
	2.2	The origin of saline ground waters in the area of the Valenci  lake, Venezuela	32
		2.2.1	Introduction		32
		2.2.2	Hydrogeologic overview		33
		2.2.3	The origin of groundwaters	34
			2.2.3.1	Hydrochemistry and isotopes E. and SE of the lake	34
			2.2.3.2	Groundwater W. and N. of the lake	36
		2.2.4	Water balance for the study area	37               

3	IRRIGATION AND THE IMPACT ON GROUNDWATER QUALITY	41
	3.1	The impact of irrigation on percolation in dry lands with various sediments	43
		3.1.1	Experimental boundary conditions and performance	44
		3.1.2	Discussion of results on percolation	45
		3.1.3	The contribution of irrigation and channel waters in the area
			between Chenab and Ravi, Punjab, to groundwater logging	53
	               

4	IMPACT OF URBANISATION ON GROUNDWATER	55
	4.1	Groundwater management below the city of Caracas, Venezuela	56
		4.1.1	Geology of the Caracas valley	57
		4.1.2	Water balance and the origine of groundwaters beneath the city	58
		4.1.3	Stable isotope concentrations in the groundwater	58
		4.1.4	Dynamics of the groundwater	59
		4.1.5	Contaminants in the groundwater	61               

5	IMPACT OF LAND USE ON GROUNDWATER QUALITY	65
	5.1	The role of sediment facies in storage and disintegration of agrochemicals
		in the karst of South Germany		66
		5.1.1	Introduction		66
		5.1.2	The malm carbonates of the Franconian Alb	67
		5.1.3	Results of tracer experiments	67
		5.1.4	The dilution of dye tracers	68
		5.1.5	Tritium in groundwaters from bedded and reef facies	70
		5.1.6	Fate of nitrates in the reef facies	71
		5.1.7	Bacterial populations in the underground	71
		5.1.8	Laboratory denitrification experiments	73               

6	SAMPLING OF WATER - QUANTITIES, METHODS, POINTS OF ATTENTION	77
	6.1	Well construction and sampling		77
	6.2	Sampling devices			79
	6.3	Sampling quantities and water storage	80
	6.4	Sampling of seepage waters		81               

7	OUTLOOK TO FURTHER APPLICATIONS		85               

REFERENCES	87               

LITERATURE	95               

IAEA PUBLICATIONS		97               

CONSTANTS	100               

SYMBOLS AND UNITS	101               

SUBJECT INDEX	103