THE UNIVERISTY OF CALGARY Controls on the chernistry of the Bow River, southern Alberta, Canada by Stephen E. Grasby A DISSERTATION SUBMlTTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF =OR OF PHlLOSOPHY Department of Geology and Geophysics Calgary, Alberta March, 1997 O Stephen E. Grasby 1997 Acquisitions and Acquisitions et Bibliographie SemMces- se~kesbibiiograptiiques The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distniute or sell reprod&, prêter, distri'buer ou copies of Merthesis by any means vendre des copies de sa thése & and in any fonn or format, malQng quelque detea sous quelque this thesis avaiiable to interested forme qye ce soit pour mettre des persons. exemplaires de ce~tethèse à la disposition des personnes intéressées. The author retains ownership of the L'auteur caoserve la propriété du copyright in Merthesis. Neither droit d'auteur qui protège sa thèse. Ni the thesis nor substantial extracts la théSe ni des extraits substantiels de fkom it may be printed or otherwise ceile-ci ne doivent être imprimés ou reproduced with the author's autrement reproduits sans son permission. ABSTRACT Integrated chernical and stable isotope analyses were used to defhe the controls on the dissolved inorganic load in the Bow River, and thereby eiucidate the chernical and hydrologie dynamics of the nver. The dominant sources of ions in the nver are amiospheric deposition and rock weathering. The input by weathe~gis largely controiied by dissolution of carbonate and evaporite minerais. Calgary is the most significant point source input dong the river- Effluent fiom the sewage treatment plants loads Na, K, and Cl to the nver. Cation activity ratios are strongiy controiied by exchange on smectite. Smectite is absent in the nver, suggesting that activity ratios are an iaherited signature of ground water. Stable isotope data indicate that discharge in the fail and winter is fed by groundwater. The high discharge event in the spring is a mixture of snowmelt and displaced groundwater. Summer discharge is fed by rainfall. Despite seasonal variations in the TDS load, element ratios are constant, suggesting that the chemistry of snowmelt and raid" are altered by the same processes controiling groundwater chemistry. This suggests snowmelt and rab faU must pass through the ground before becoming discharge. S1*O,, data indicates dissolved sulfate undergoes a complex redox history before reaching the river, implying that the water transporting the sulfate passes through the anoxic zone before becoming discharge. Therefore, the Bow River is largely fed by ground water. The chernical denudation rate for the Bow River at Banff is 678 kg/ha/y. The denudation rate for the basin as a whole is 340 kg/ha&. Loading fiom Calgary accounts for 8 to 92 of the mass flux out of the basin in the spring and fdand 25% of the mass flux in the summer. 1 am gratefiil to my supe~sorIan Hutcheon, and to Roy Krouse, who were both encouraging and supportive of my work. They were never too busy to sit down and talk about my research. Funding for this pmject was provided by research grants to 1. Hutcheon and H.R. Krouse. This work was assisted by the cooperation of several agencies. Chernical data for the Bow River at Lake Louise and Ban€f was supplied by the Water QwLty Branch of the Water Survey of Canada. The Wakr Survey of Canada and Trans-Alta Utilities provided discharge data for the Bow River and tributaries. Aiberta Environment provided precipitation chemistry. Parks Canada provided groundwater data for Banff National Park. Several people at the University of Calgary helped me complete this project. 1 am gratehil to Maria Miehailescue, Jesusa Pontoy-Overend, and Nenita Lozano for teaching me how to nui the mass spectrometers, as weii as for feeding me. Maurice Shevaiier not only helped in the lab, but also solved ali my computer problems. Pat Michad ran cation andysis. The 'Pudes" provided many hours of stimulahg arguments about geochemistry. matched by many hours of playing Doorn. Marian Johuson assisted in collecting water samples, as well as distracthg me with ski trips. Once again, thanks to Teresa for her support and patience. TABLE OF CONTENTS ABSTRAa ACENOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES CHAPTER 1 Introduction BACKGROUND PROJECT DEFINITION OBJEcmms FIELD AND LABORATORY METHODS CEIAPTER 2 Overview of the Bow River Basin GEOGRAPHY CLIMATE GEOLOGY ANTaROPOGENIC WATER USE CHAPTER 3 Meteonc verms groundwater inputs to the Bow River INTRODUCTION O AND H ISOTOPE COMPOSI'MONS OF PRECIPITATION AND GROUNDWATER O AND H ISOTOPE COMPOSITIONS OF WATERS IN THE BOW mRBASIN VARIATIONIN THE SCABLE ISCJIDPE COMPOSlTlON OFTRlBUTARlES - THE '-" CONïTNENTALEFFmT CATIONS FOR PALEO-CWMATE STUDIES 6180AND 6D OF THE BoW RIVER - THE SOURCE OF DWHARCX ~WNSIREAMVARIATION IN 6D CONCLUSIONS CHAP'iZR 4 Chemical weathering of the Rocky Mountains INTRODUCTION METHODS CONTROLS ON THE CHEMISTRY OF THE BOW RIVER CORRKIWG IQRNON-WEATHEWG COWNENTS WEATHERINGREACIIONS CO~OLLINGRIVER CHEMISIRY THERMODYNAMICCONIROLSONFWERCHEMISTRY -CAL DENUDATiON RATE CONCLUSIONS CEAPTER 5 Chernical dynamics of the Bow River INTRODUCTION CHEMICAL CaARACTERISTICS OF POINT SOURCE INPUTS CHEMICAL CHARACTERISTICS OF TEIE BOW RIVER CONTROLS ON TBE MAJOR ION CHEMISTRY OF TBE BOW RIVER CHLmcDE SODIUM SULFUR CALCIUMAND MAGNESIUM BICARBONATE CHEMICAL DENUDATION RATE SUMMARY IMPLICATIONS FOR BASIN HYDROLOGY CaAPFER 6 Tracing anomalous TDS in Nose Creek INTRODUCTION TBE NOSE CREEK BASIN RESULTS AND DBCUSSION SOURCE OF NOSECREEK WA'IER INORGANECHEM~~~RY OF NOSE CREEK WATER OXUGEN AND HYDROGEN SOTO OPE conmsmo~sOF NOSECREM WATER SOURCES OF SULFATE CONCLUSIONS CEiAPTER 7 Conclusions REFERENCES APPENDIX 1 Sâmple Locations APPENDIX 2 Chernical and stable isotope data for the Bow River APPENDLX 3 Chcmical data for springs and shallow ground water APPENDIX 4 Chernical and stable isotope data for Nose Creek Table 2-1 Average annual flow for the Bow River and major aibutaries. Table 2.2 Licensed and actual water use for the Bow River for 1991. Table 3.1 Isotope &ta for spcings in the Bow Basin. Table 4-1 Chioride normaliseci eqyivalents ratios for precipitation. Table 4.2 Mean mual wet and dry deposition rates for the Bow Basin. Table 4.3 Dominant weathering reactiom anticipated for the Bow Basin. Table 4.4 Ca and Mg bearing minerals that may occur in sedimentary rocks Table 4.5 Calculated beidellite activities for smectite in equilibrium with Bow River water at Banff and Lake Louise. Table 4.6 Long term denudation rate for the Bow Basin. Table 4.7 Chernical deaudation rates for world rivers, and world average rate. Table 5.1 Chemisüy of storm sewer discharge, sewage effluent, and irrigation return flow. Table 5.2 Calculated beidellite activities for mectite in equiliirium Bow River water at Banff. Table 5.3 Total monthly discharge and flux of TDS for the Bow River at Banff, Carseland, and Hays. Table 6.1 Flow data for Nose Creek. LIST OF FIGURES Figure 1.1 Location of study area and sampling locations. Figure 1.2 Discharge for the Bow River at Calgary, showing sampling periods. Figure 2.1 ~ajorweather systems for the Bow River Basin. Figure 2.2 Physiographic Regions of the Bow River Basin. Figure 2.3 Mean annual precipitation and evapotmnspiration for the Bow River Basin. Figure 2.4 Composite monthly discharge for the Bow River at Batlff. Figure 2.5 Monthly average mual precipitation for Calgary. Figure 2.6 Geology of the Bow River Basin. Figure 2.7 Dowmtream variation in discharge of the Bow River. Figure 3.1 Variation in the stable isotope composition of precipitation from the five main weather systems that bring moisture to the Calgary area Figure 3.2 m> and 6"O of tributaries versus the distance of their confluence dong Bow River. Figure 3.3 6D and Sf8Oof tributaries versus distance of the headwaters of the tributaries hmthe Great Divide. Figure 3.4 Schematic illustration of mixing relationship of westerly and easterly winds over the Rocky Mountains. Figure 3.5 Plot of SD versus 6% for ail samples coilected dong the Bow River. Figure 3.6 Plot of 6D versus 618~. Figure 3.7 Plot of m> versus 6180best fit iines for each sample set from the Bow River. Figure 3.8 Discharge versus temperature, measured at Banff. Figure 3.9 Plot of 6D versus 6180for the tributaries dong the Bow River. Figure 3.10 Downstream variation in 6D. Figure 4.1 Geology in the headwaters of the Bow River basin. Figure 4.2 Discharge venus TDS for the Bow River at Banff, 1978 - 1995. VlIl Figure 4.3 Composite plot of monthly TDS measurements at Banff, 1978 - 38 1995. Figure 4.4 Temqdiagram showing major cation and mion composition of the Bow River at Lake Louise and Bd. Figure 4.5 Cumulative plot of mon- Cl concentrations at Banff and Lake Louise. Figure 4.6 Na+K vs. Cl for Banff. Figure 4.7 Major ion composition of the Bow River and rivers draining a variety of Lithologies throughout the world. Figure 4.8 Ca+Mg vs. HCO,. Figure 4.9 Ca+Mg vs. HCO, + SO,. Figure 4-10 Discharge vs. SO,/total anions. Figure 4.1 1 Plot of log a~ala(~)~versus log a~g/a(~)~for Bow River water. Figure 4.1 2 Plot of log aCa/a(W2 venus log aMg/a(H)' for Bow River water with calculated phases boundaries superimposed. Figure 4.13 Plot of log aNa/H versus log aKM- Figure 4.14 Plot of a) log a~a/a(~)~versus log a~g/a(~)~,and b) log aNfl versus log aK/H for groundwater.