Groundwater Quality Analyses along Kenyan Coastal Region, Case Study of Kilifi County

Year 2019, Volume: 6 Issue: 1, 1 - 14, 12.04.2019

Mary Makokha

https://doi.org/10.30897/ijegeo.466933

Abstract

The Kenyan coast is a semi-arid region frequently faced with severe water scarcity especially
during prolonged drought and a rapid population growth. Groundwater
provides 50% of the water demand and most sources are poorly drilled,
over-abstracted and abandoned. The aquifers occur in sedimentary formations of
fluvial and lacustrine origin. There is a need to have a groundwater  monitoring system in place; therefore this
study analyses selected physico- chemical and microbial parameters using both
laboratory and field methods. Arc-GIS 9.3, SURFER were used to generate
thematic maps for some tested parameters. Results indicate pH values within
acceptable range of 6.5 – 8.5, though shallow wells in Malindi were acidic,
this atrributed to the heavy industries prevalent in the area. Electric
conductivity (EC) was above the set standard of 1500µS/m indicating high
dissolved ions present especially in Magarini where salt mining is done. Total
dissolved solids (TDS) of up to 500mg/L suitable for drinking water was only
found during the wet season. Turbidity of less than 5 NTU was established in
most areas.  Chlorides and salinity
levels exceeded 250mg/L pointing to the saltwater intrusion problem that is a
challenge along Kenyan coastal aquifers  
Boreholes and shallow wells had a total hardness ranging from 50mg/L
-150mg/L indicating the water was ranging from being slightly hard to hard
water. Escheriria coli was present in
almost all the boreholes and shallow wells indicating the need to treat water
before use. Water Quality index (WQI) calculation indicate that groundwater is
unsuitable for human consumption in dry season.

Keywords

Groundwater, boreholes, water quality

References

• Anon, J. 1996. Proposed amendments to the Hawaii Administrative Rules Chapter 11-54-08, Recreational Waters. in Water Quality Standards, pp. 54–86, Department of Health, State of Hawaii.
• Anon J. 2000. Rural water sources under the microscope SA. Water Bulletin 26(3) 18-21
• APHA. 2005. Standard Methods for the Examination of Water and Wastewater, 20th edition, American Public Health Association. New York. Retrieved from https://www.mwa.co.th/download/file_upload/SMWW_1000-3000.pdf
• Bertram J., &Balance R. 1996. A Practical guide to the design and implementation of freshwater, quality studies and monitoring programmes. Published on behalf of United Nations Environmental Programme (UNEP) and World Health Organization (WHO), E & FN spoon publishers. 172 –177, 192-196. Retrieved from; http://www.who.int/iris/handle/10665/41851.
• Bordalo, A. A., Nilsumranchit, W . and Chalermwat, K. 2001. Water quality and uses of the Bangpakong River (Eastern Thailand). Water Resources 35(15), 3635-3642. doi.org/10.1016/S0043-1354(01)00079-3
• Charterjee C. & Raziuddin M. 2002. Determination of water quality index (WQI) of the degraded river in Asonol Industrial area, Raniganj, Burdwan, West Bengal, Nature Environment and Pollution Technology, 1(2), 181-189.
• Chukwunenyoke, A.U.,& Igboekwe, U.,M. 2012. Characterization and quality assessment of groundwater in parts of Aba Metropolis Southern Nigeria, Scholars Research Library. 4, 1949-1957.
• Department of Water Affairs and Forestry (DWAF), 1996. South African water quality guidelines; Volumes 1 and 2. Domestic use: The Government Printer, Pretoria, South Africa. Retrieved from: www.dwa.gov.za/iwqs/wq_guide Pol_saWQguideFRESH_vol1_Domestic use.PDF
• Foster S., & Tuinhof, A. 2000. Kenya: The Role of Groundwater in the Water Supply of Greater Nairobi. Accessed September 24, 2018 from https://waterfund.go.ke/watersource/
• Gebrehiwot, A. B., Tadesse, N., & Jigar, E. 2011. Application of water quality index to assess suitablity of groundwater quality for drinking purposes in Hantebet watershed, Tigray, Northern Ethiopia. ISABB Journal of Food and Agricultural Sciences, 1(1), 22-30.
• Government of Kenya (GoK). 2008. Vision 2030 Medium Term Plan, Strategy for National Transformation 2008-2012: Accelerating Equitable Economic and Social Development for a Prosperous Kenya. Government of Kenya, Nairobi, Government Printer, Kenya, 396. Retrieved from:https://vision2030.go.ke/2008-2012/
• Grabow N.A, Kfir R. & Grabow W.O.K. 1991. A most probable number method for the enumeration of Legionella bacteria in water. Water Sci Technol 24 (2): 143-147. doi.org/10.2166/wst.1991.0046
• Kannan, N., & Sabu , J. 2009. Quality of Groundwater in the shallow Aquifers of a Paddy Dominated Agricultural River Basin, Kerala,India., International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering, 52, 475-493. Retrieved from: https://scholar.waset.org/1307-6892/3883
• Laluraj, C.M., & Gopinath, G. 2006. Groundwater chemistry of Shallow Aquifers in the Coastal Zones of Cochin, India. Environ Monit Assess 117, 45 doi.org/10.1007/s10661-006-7675-5Louise E. 2005. A psychosocial analysis of the human-sanitation nexus. Dellström Rosenquist, Journal of Environmental Psychology. 25 (3) 335-346.
• Macdonald A., Davies J., Calow R & Chilton J. 2005. Developing groundwater: A guide for rural water supply. ITDG Publishing, Warwickshire. doi.org/10.3362/9781780441290
• MPCA. Minnesota Pollution Control Agency; 2008. Turbidity: Description, impact on water quality, sources measures- general overview. Retrieved from https://www.pca.state.mn.us/sites/default/files/wq-iw3-21.pdf
• Momba M.N.B & Mnqumevu B.V. 2000. Detection of faecal coliforms and heterotrophic plate count bacteria attached to household containers during the storage of drinking groundwater in rural communities. WISA; Biennial Conference and Exhibitions. Sun City, 28 - 1 June 2000 South Africa.
• Momba M.N.B, Malakate V.K., & Theron J. 2006. Abundance of phathogenic Escherichia coli, Salmonella typhimurium and Vibrio cholerae in Nkonkobe. Drinking water sources. Journal of Water Health, 4, 289- 296. doi 10.2166/wh.2006.011
• National Environment Management Authority (NEMA), 2006. Environmental management and coordination of water quality regulations Nairobi, Kenya. Retrieved from https://www.nema.go.ke › Home › Laws and Guidelines › Gazetted Regulations.
• Navaraj, P. S., & Krishnammal, S. 2012. Evaluation of water quality and its quotient factor in Therkutheru village, Madurai, India. Journal of Environmental Science and Water Resources, 1, 216 - 222.
• Ocheri, M.,& Ahola , O. 2007. Seasonal variation in physio-chemical characteristics of Rural groundwater of Benue State, Nigeria. Journal of Asian Scientific Research, 2(10):574-586.
• Onyancha C., Khaemba A., & Sabuni., B. 2010. Aquifer storage and recovery and surface basins for a greener Kilifi District, Nile Water Sci. Eng. J., 3 (3) 26-33.
• Otieno R O., Ndunda E., & Makokha M. 2015. Seasonal variations of physico-chemical and microbiological characteristics of groundwater quality in Ruiru, Kiambu county, Kenya. International Journal of Scientific and Research Publications. 5(12), 412-423.
• Nsubuga, F.B., Kansiime, F., & Okot O., J. 2004. Pollution of protected springs in relation to high and low density settlements in Kampala Uganda. Physics and Chemistry of the Earth. 29, 1153– 1159
• Sayyed, J A & Bhosle, A., B. 2011. Analysis of Chloride, Sodium and Potassium in groundwater samples of Nanded City in Mahabharata, India. , European Journal of Experimental Biology,1(1), 74-82 .
• Reza R., & Singh G. 2010. Assessment of ground water quality status by using water quality index method in Orissa, India. World Appl. Sci. J. 9 (12), 1392-1397.
• UNICEF/WHO. 2012. Progress on drinking water and sanitation: WHO/UNICEF Joint Monitoring Program for water supply and sanitation. UNICEF, New York. Retrieved from : https://www.unicef.org/media/files/JMPreport2012.pdf
• United States Environmental Protection Agency, (USEPA), 2012. Current drinking water standards. United States Environmental Protection Agency. Washington, DC. Accessed on 25 September from: https://www.epa.gov/dwstandardsregulations
• UN-Water / World Water Assessment Program. 2006. Kenya national water development report. 2nd UN World Water Development Report; Water, A shared responsibility. Retrieved from: www.unwater.org/publications/water-shared-responsibility
• World Health Organization (WHO), 1996. Guidelines for drinking water, health criteria and other supporting information, Geneva, Switzerland. Retrieved from www.who.int/whr/1996/en/
• World Health Organization (WHO), 2004. Guidelines for drinking water quality, Vol. 1. Recommendations (3rd Edition).WHO, Geneva. Retrieved from: www.who.int/water_sanitation_health/dwq/GDWQ2004web.pdf
• World Health Organization WHO. (2006). Guidelines for drinking water quality: First Addendum to 3rd Edition, vol. 1. Geneva. WHO press, 515. Retrieved from www.who.int/whr/2006/
• World Health Organization WHO (2011). Guidelines for drinking water quality. 4th Edition. WHO press, 564. https://apublica.org/wp-content/uploads/2014/03/Guidelines-OMS-2011.pdf