An Isotope and Geochemistry Approach
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nm u Ottawa L'Universite canadienne Canada's university run FACULTE DES ETUDES SUPERIEURES L^^l FACULTY OF GRADUATE AND ET POSTOCTORALES U Ottawa POSDOCTORAL STUDIES L'Univer&itO canadienne Canada's university Martin Suchy "AUTEnRDElATHlSETXUTHbRWTHE^S" M.Sc. (Earth Science) GRADE/DEGREE Faculty of Science FACULTE, ECOLE, DEPARTEMENT / FACULTY, SCHOOL, DEPARTMENT Nitrate and Ammonium Transformation and Fate in Groundwater of an Agricultural Watershed : An Isotope and Geochemistry Approach TITRE DE LA THESE / TITLE OF THESIS Ian Clark CO-DIRECTEUR (CO-DIRECTRICE) DE LA THESE/THESIS CO-SUPERVISOR Frances Pick Frederick Michel Gary W. Slater Le Doyen de la Faculte des etudes superieures et postdoctorales / Dean of the Faculty of Graduate and Postdoctoral Studies Nitrate and Ammonium Transformation and Fate in Groundwater of an Agricultural Watershed: An Isotope and Geochemistry Approach Martin Suchy Thesis submitted to the Faculty of Graduate and Postdoctoral Studies University of Ottawa In partial fulfillment of degree requirements for a Masters of Science (M.Sc.) in Earth Sciences Ottawa-Carlton Geoscience Centre and University of Ottawa Ottawa, Canada UMUUL u Ottawa L'Universiie canadienne Canada's university © Martin Suchy, Ottawa, Canada, 2010 Library and Archives Bibliotheque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-79695-5 Our file Notre reference ISBN: 978-0-494-79695-5 NOTICE: AVIS: The author has granted a non L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par Nnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation. without the author's permission. In compliance with the Canadian Conformement a la loi canadienne sur la Privacy Act some supporting forms protection de la vie privee, quelques may have been removed from this formulaires secondaires ont ete enleves de thesis. cette these. While these forms may be included Bien que ces formulaires aient inclus dans in the document page count, their la pagination, il n'y aura aucun contenu removal does not represent any loss manquant. of content from the thesis. 1+1 Canada TABLE OF CONTENTS LIST OF FIGURES Hi LIST OF TABLES v ABSTRACT vii RESUME ix ACKNOWLEDGEMENTS xii 1.0 INTRODUCTION 1 1.1. Background 1 1.2 Scope of Work 1 1.3 Objectives 3 2.0 LITERATURE REVIEW 4 2.1 Introduction 4 2.2 Nitrogen Dynamics 4 2.2.1 Isotope Fundamentals 6 2.2.2 Isotope Fractionation 6 2.2.3 Transformation Processes 7 2.2.4 Nitrogen Sources 14 2.2.5 Fertilization 16 2.2.6 Groundwater Investigations 17 2.3 Carbon Dynamics 18 2.3.1 Dissolved Inorganic Carbon 18 2.3.2 Dissolved Organic Carbon 20 2.4 Stable Isotopes of Water 21 2.4.1 Isotope Fractionation 21 2.4.2 Relationship of 8 180 -8 2H in Precipitation 22 2.4.3 Spatial and Temporal Variations in Precipitation 23 2.4.4 Isotopic Composition of Groundwater 24 3.0 STUDY AREA 26 3.1 Location and Topography 26 3.2 Climate 27 3.3 Land Use 28 3.4 Geology 30 3.4.1 Surficial Geology and Soils 30 3.4.2 Bedrock Geology 33 3.4.3 Structural Geology 35 3.5 Hydrology 35 3.6 Hydrogeology 36 3.6.1 Bedrock Aquifer 36 i 3.6.2 Surficial Aquitard 37 3.6.3 Groundwater Quality 41 4.0 METHODOLOGIES 42 4.1 Site Selection 42 4.2 Installations 42 4.2.1 Lysimeters 44 4.2.2 Piezometers 44 4.2.3 Meteoric Stations and Rain Collectors 45 4.2.4 Survey 46 4.2.5 Test Pit Excavation 46 4.3 Field Measurements 46 4.3.1 Water Levels 47 4.3.2 pH and Temperature 47 4.3.3 Conductance 47 4.3.4 Oxidation-Reduction Potential (Eh) 48 4.3.5 Dissolved Oxygen 48 4.4 Sample Collection and Handling 48 4.4.1 Groundwater 48 4.4.2 Precipitation 49 4.4.3 Sampling QAQC 50 4.5 Analytical Methods 50 4.5.1 Oxygen and Hydrogen Isotopes of Water 50 4.5.2 Aqueous and Isotope Carbon Composition 51 4.5.3 Major Ions and Nutrients 51 4.5.4 Nitrogen and Oxygen Isotopes of Nitrate 52 4.5.5 Nitrogen Isotopes of Ammonium 54 5.0 RESULTS AND DISCUSSION 56 5.1. Stable Isotopes in Precipitation 56 5.1.1. Precipitation Data 56 5.1.2. Meteoric 8180 and 52H Values 58 5.1.3. Summary and Conclusions 63 5.2. Background Site - Natural Vegetation 64 5.2.1. Field Measurements 64 5.2.2. Groundwater 5180 and 52H 66 5.2.3. Geochemistry, Nutrients and Isotope Composition 67 5.2.4. Summary and Conclusions 69 5.3. Site 1 - Agricultural Field 71 5.3.1. Field Measurements 72 5.3.2. Vadose and Groundwater 5180 and 52H 74 5.3.3. Geochemistry 78 5.3.4. DIC and DOC 80 5.3.5. Nitrate and Ammonium 83 5.3.6. Summary and Conclusions 86 u 5.4. Site 2 - Agricultural Field 86 5.4.1. Field Measurements 88 5.4.2. Soil Test Pit 90 5.4.3. Vadose and Groundwater 5180 and 52H 91 5.4.4. Geochemistry 95 5.4.5. DIC and DOC 96 5.4.6. Nitrate and Ammonium 100 5.4.7. Summary and Conclusions 105 5.5. Site 3 - Agricultural Field 107 5.5.1. Field Measurements 108 5.5.2. Vadose and Groundwater 8180 and 82H 111 5.5.3. Geochemistry 114 5.5.4. DIC and DOC 116 5.5.5. Nitrate and Ammonium 119 5.5.6. Summary and Conclusions 124 6.0 CONCLUSIONS 126 6.1 Recharge Environment 126 6.2 Nitrogen Dynamics 127 6.3 Recommendations 128 REFERENCES 130 Appendix A: Climate Data - Environment Canada 142 Appendix B: Laboratory Methods 159 Appendix C: Precipitation Data 175 Appendix D: Isotope and Geochemistry Results and Statistics 178 Appendix E: Raisin River Discharge Data - Environment Canada 253 Appendix F: Sample Symbol Legend 256 LIST OF FIGURES Figure 1.1: Location of the Raisin River watershed within Eastern Ontario, Canada 2 Figure 2.1: The Nitrogen Cycle 5 Figure 2.2: Biochemical and physiochemical nitrogen transformations 8 Figure 2.3: The distribution of three DIC species according to pH and molar concentration 18 Figure 2.4: Ranges of organic and inorganic 513C values from terrestrial reservoirs 19 Figure 3.1: Location of the Raisin River watershed in Eastern Ontario, Canada 26 Figure 3.2: Regional topography 27 Figure 3.3: Regional land use 29 Figure 3.4: Surficial Geology of the region 31 Figure 3.5: Physiographic units of the region 32 Figure 3.6: Soil classification for the region 33 in Figure 3.7: Bedrock Geology and faults of the region 34 Figure 3.8: Shallow Bedrock Aquifer potentiometric surface and groundwater flow direction 37 Figure 3.9: Hydraulic conductivity of overburden sediments (Surficial Aquitard) 38 Figure 3.10: Surficial aquitard potentiometric surface and groundwater flow direction 39 Figure 3.11: Average annual recharge to the overburden and contact bedrock aquifers 40 Figure 4.1: Research site locations 43 Figure 5.1: Mean monthly total precipitation data from EC Cornwall Station 57 Figure 5.2: Event-weighted 8180 distribution for stations M2 and M5 60 Figure 5.3: Amount-weighted mean monthly 8180 distribution 61 Figure 5.4: Event-weighted precipitation 82H and 8180 values 62 Figure 5.5: Background Site - Monthly water level fluctuations 66 Figure 5.6: Background Site - 8180 and 82H for event-weighted precipitation and groundwater 67 18 15 Figure 5.7: Background Site - 8 0No3 vs. 8 NN03 plot 70 Figure 5.8: Site 1 - Location map of sampling points and local land 72 Figure 5.9: Site 1 - Monthly water level fluctuations 73 Figure 5.10: Site 1 - Mean monthly precipitation and groundwater 8180 values 76 Figure 5.11: Site 1 - 82H and 8180 for weighted mean monthly precipitation and groundwater 78 13 Figure 5.12: Site 1 - Depth vs. DIC concentrations and S CDiC values 82 13 Figure 5.13: Site 1 - Depth vs. DOC concentrations and 8 CDOc values 82 15 Figure 5.14: Site 1 - Depth vs. nitrate and ammonium concentrations and S NN03 values 84 18 15 Figure 5.15: Site 1 - 8 0N03 vs. 8 NN03, plot 85 Figure 5.16: Site 2-Location map of sampling points and local land 88 Figure 5.17: Site 2 - Monthly water level fluctuations 89 Figure 5.18: Site 2 - Test pit horizontal and vertical cross-sections 91 18 Figure 5.19: Site 2 - Temporal plot vs. mean monthly precipitation and S 0H2o values 94 Figure 5.20: Site 2 - 82H and 8180 for monthly-weighted precipitation and groundwater 95 13 Figure 5.21: Site 2-Depth vs.