Case Study: Intermediate Field Mixing for a Bank Discharge in a Natural River
Publication: Journal of Hydraulic Engineering
Volume 135, Issue 1
Abstract
The intermediate field mixing characteristics of the Gold Bar Wastewater Treatment Plant effluent into the North Saskatchewan River at Edmonton were evaluated. This region may be considered to be the early part of the transverse mixing region where local channel characteristics are important. An extensive field study was conducted to delineate the bathymetry of the study area and evaluate the mixing characteristics by means of a steady state dye test. The topographic and limited velocity results of the field study were used to create and validate a depth-averaged hydrodynamic model of the study reach in order to extract streamtube information. The results from the hydrodynamic model were used to interpret the mixing characteristics of the study reach as well as extract channel characteristics. From the analysis it is evident that the distribution of effective transverse mixing coefficient is highly dependent on local river conditions. The use of the hydrodynamic model to extract channel characteristics provided a reasonable estimate of mixing characteristics without requiring detailed field velocity data. The trade-off is more detailed bathymetry data is required to have a realistic model. Plume averaged channel characteristics rather than cross sectional averaged were shown to produce more realistic transverse mixing coefficients. Assumed Gaussian profile distributions were successfully applied suggesting that for a bank discharge if the maximum bank concentration and mass flux are known this technique could be applied.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The field work described herein was funded by the City of Edmonton and was carried out with the help of S. Edwini-Bonsu, H. Fouli, D. Healy, T. Kowalczyk, S. Lovell, A. Mowad, Z. Mustaffa, K. Van der Vinne, and C. Zhao. Some equipment for the field study was supplied by the Department of Fisheries and Oceans. C. Albers provided technical advice for the dye test and A. Burrows assisted with the hydraulic modeling. Research funding for the first author were provided by the Natural Sciences and Engineering Research Council of Canada and the Informatics Circle of Research Excellence.
References
Beltaos, S. (1980). “Transverse mixing tests in natural streams.” J. Hydr. Div., 106(HY10), 1607–1625.
Boxall, J. B., and Guymer, I. (2003). “Analysis and prediction of transverse mixing coefficients in natural channels.” J. Hydraul. Eng., 129(2), 129–139.
Cochrane Engineering Inc. (1997). “Near field mixing of outfall discharges in the North Saskatchewan River.” Prepared for the City of Edmonton, Cochrane Engineering Inc., Edmonton, Alberta.
Dow, K. E. (2003). “Intermediate Field Mixing of Wastewater Effluent in the North Saskatchewan River at Edmonton Alberta.” MSc thesis, Department of Civil and Environmental Engineering, Univ. of Alberta, Edmonton, Alberta.
Elhadi, N., Harrington, A., Hill, I., Lau, L., and Krishnappan, B. G. (1984). “River mixing—A state of the art report.” Can. J. Civ. Eng., 11, 585–609.
Fischer, H. B., List, E. J., Koh, R. C. Y., Imberger, J., and Brooks, N. H. (1979). “Mixing in inland and coastal waters.” Academic Press, New York.
Golder Associates Ltd. (1994). “Modelling of mixing of wet weather discharges in the North Saskatchewan River, Edmonton to the Saskatchewan border.” Prepared for the City of Edmonton, Golder Associates Ltd., Calgary, Alta., Canada.
Golder Associates Ltd. (1995). “Joint industry—Municipal North Saskatchewan River study.” Prepared for City of Edmonton, Golder Associates Ltd., Calgary, Alta., Canada.
Ghanem, A., Steffler, P., Hicks, F., and Katopodis, C. (1995). “Two dimensional finite element model for aquatic habitats.” Water Resources Engineering Report 95-S1, Department of Civil Engineering, University of Alberta.
Holley, E. R., Siemons, J., and Abraham, G. (1972). “Some aspects of analyzing transverse dispersion in rivers.” J. Hydraul. Res., 10(1), 27–57.
Lau, Y. L., and Krishnappan, B. G. (1977). “Transverse dispersion in rectangular channels.” J. Hydr. Div., 103(HY10), 1173–1189.
Lau, Y. L., and Krishnappan, B. G. (1981). “Modeling transverse mixing in natural streams.” J. Hydr. Div., 107(HY2), 209–226.
Milne, G. D., Stanley, S. J., Smith, D. W. (1993). “Residual chlorine decay in a broad, shallow river.” Water Resour., 27(6), 993–1001.
Montes, S. (1998). “Hydraulics of open channel flow.” ASCE Press, Reston, Va.
Putz, G. (1996). “Dynamic two-dimensional river quality modeling.” Ph.D. thesis, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alta., Canada.
Putz, G., and Smith, D. W. (1998). “Verification of a transient input, two-dimensional, river mixing model.” Can. J. Civ. Eng., 25(1), 51–66.
Putz, G., and Smith, D. W. (2001). “Field measurement and modeling of two-dimensional river mixing.” Water Supply, 1(2), 57–65.
Rutherford, J. C. (1994). “River mixing.” Wiley, West Sussex, England.
Smith, D. W., Putz, G., Gerard, R. (1983). “Wastewater outfall and lume characteristics Fort Simpson, N.W.T.” Report Prepared for Department of Local Government, Government of the Northwest Territories; Issued as Environmental Engineering Report No. 83-2, Department of Civil Engineering, University of Alberta, July 1983.
Steffler, P. M., Bai, B., and Katopodis, C. (1996). “Application of GIS in modeling river characteristics.” Proceedings of the Annual Conference of the Canadian Society of Civil Engineers, Edmonton, Alta., C. Ward, ed., 252–262.
Van der Vinne, G. (1991). “Low Flow, Open Water Tracer Dye Studies on the North Saskatchewan River, Edmonton to Saskatchewan Border.” Report No. SWE-02 Prepared for Alberta Environment, Environmental Research and Engineering Department, Alberta Research Council, Edmonton, Alta., Canada.
Webel, G., and Schatzmann, M. (1984). “Transverse mixing in open channel flow.” J. Hydraul. Eng., 110(4), 423–435.
Yotsukura, N., and Sayre, W. W. (1976). “Transverse mixing in natural channels.” Water Resour. Res., 12(4), 695–704.
Information & Authors
Information
Published In
Copyright
© 2009 ASCE.
History
Received: Jul 10, 2006
Accepted: Jun 5, 2008
Published online: Jan 1, 2009
Published in print: Jan 2009
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.