Prediction of Post-Closure Water Balance for Monolithic Soil Covers at Waste Disposal Sites in the Greater Accra Metropolitan Area of Ghana

  • Kodwo Beedu Keelson
Keywords: water balance model, landfill cover, landfill closure, waste disposal site, Ghana


The Ghana Landfill Guidelines require the provision of a final cover system during landfill closure as a means of minimizing the harmful environmental effects of uncontrolled leachate discharges. However, this technical manual does not provide explicit guidance on the material types or configurations that would be suitable for the different climatic zones in Ghana. The aim of this study was to simulate and predict post-closure landfill cover water balance for waste disposal sites located in the Greater Accra Metropolitan Area using the USGS Thornthwaite monthly water balance computer program. Five different cover soil types were analyzed under using historical climatic data for the metropolis from 1980 to 2001. The maximum annual percolation and evapotranspiration rates for the native soil type were 337 mm and 974 mm respectively. Monthly percolation rates exhibited a seasonal pattern similar to the bimodal precipitation regime whereas monthly evapotranspiration did not. It was also observed that even though soils with a high clay content would be the most suitable option as landfill cover material in the Accra metropolis the maximum thickness of 600 mm recommended in the Ghana Landfill Guidelines do not seem to provide significant reduction in percolation rates into the buried waste mass when the annual rainfall exceeds 700 mm. The findings from this research should provide additional guidance to landfill managers on the specification of cover designs for waste disposal sites with similar climatic conditions.


S. Twumasi-Ankrah, J. Holm and E. Oppong, “Evaluation of landfill cover design options for the Greater Accra Metropolitan Area using the HELP Model,” BSc. Project Thesis, Department of Civil Engineering, Kaaf University College, Ghana, 2012.

Ghana Environmental Protection Agency, “Ghana landfill guidelines,” July 2002.

Washington State Department of Ecology, “Solid Waste Landfill Design Manual,”, July 12, 2012.

Ireland EPA, “Landfill Site Design,”, July 6, 2012.

P. Rushbrook and M. Pugh, “Solid waste landfills in low and middle income countries – A technical guide to planning, design and operation,” World Bank Technical Publication 426, Washington D.C., Feb. 1999.

K. Berger, “Water Balance of Capping Systems,”, July 12, 2012.

R. Schroeder, P. Dozier, T. Zappi, B. McEnroe, J. Sjostrom and R. Peyton, “The Hydrologic Evaluation of Landfill Performance (HELP) engineering documentation for version 3,” EPA/600R-64/168b, U.S. Environmental Protection Agency Risk Reduction Laboratory, Cincinnati, Ohio, 1994.

D. Fenn, G. Hanley, and K. DeGeare, “Use of water balance method for predicting leachate generation from waste disposal sites,” Report No. EPA/530/SW-168, http:/, July 5, 2012.

H. Obeng, “Soil classification in Ghana, in: selected economic issues No. 3,” Centre for Policy Analysis, Accra, Ghana, 2000.

United States Department of Agriculture, Soil Taxonomy. A basic system of soil classification for making and interpreting soil surveys. 2nd Edition, Agriculture Handbook, no. 436, Washington D.C., U.S.A., 1999.

G. McCabe and S. Markstrom, “A monthly water balance model driven by a graphical user interface,” U.S. Geological Survey Open-File Report 2007-1008, http:/, July 2, 2012.

W. Harmon, “Estimating potential evapotranspiration,” Journal of the Hydraulics Division, American Society of Civil Engineers, vol. 87, pp. 107–120, Dec. 1961.

K. Keelson, “The Ghana hydro-database project - IT applications in water resources engineering and management,” 1

st GIMPA School of Technology Workshop on Information Technology and Systems, Accra, Ghana, Jan. 31, 2012.

Accra Metropolitan Assembly, “Rehabilitation, closure, bid evaluation, construction supervision and contract management of the Oblogo No.1 and Mallam No.1 dumpsites in Accra,” Draft Design Report, Accra, Ghana, Aug. 2011.

United States Environmental Protection Agency, “Design and Construction of RCRA/CERCLA Final Covers,” EPA/625/4-91/025,, July 6, 2012.

United States Department of Energy, “Alternative landfill cover,” Innovative Technology Summary Report,, July 12, 2012.

United States Environmental Protection Agency, “Evapotranspiration Landfill Cover Systems Fact Ssheet,” EPA 542-F-

-015,, July 6, 2012.

S. F. Dwyer, “Water balance measurements and computer simulations of landfill covers,” Ph.D. dissertation, University of Mexico, Albuquerque, New Mexico, USA, 2003.

B. A. Gross, “Water balance evaluations for monitored evapotranspirative cover systems at three sites in the semi-arid and arid Southwest USA,” Ph.D. dissertation, University of Texas at Austin, Texas, USA, 2005.

V. L. Hauser, D. M. Gimon, J. V. Bota, T. A. Howell, R. W. Malone and J.R. Williams, “Models for Hydrologic Design of Evapotranspiration Landfill Covers,”, July 6, 2012.

W. H. Albright, G. W. Gee, G. V. Wilson and M. J. Fayer, “Alternative cover assessment project Phase 1 Report,” Publication No. 41183,, July 6, 2012.

United States Environmental Protection Agency, “Case Studies on Ground Water and Surface wWater Contamination from Municipal Solid Waste Landfills,” EPA/530-SW-88-040,, July 6, 2012.

Interstate Technology and Regulatory Council, “Technical and Regulatory Guidance for Design, Installation, and Monitoring of Alternative Final Landfill Covers,”, July 6, 2012.

How to Cite
K. B. Keelson, “Prediction of Post-Closure Water Balance for Monolithic Soil Covers at Waste Disposal Sites in the Greater Accra Metropolitan Area of Ghana”, Int. j. eng. technol. innov., vol. 4, no. 2, pp. 96-106, Apr. 2014.