OR/15/009 Appendix

Lapworth D J, Carter R C, Pedley S and MacDonald A M. 2015. Threats to groundwater supplies from contamination in Sierra Leone, with special reference to Ebola care facilities. British Geological Survey Internal Report, OR/15/009.

Area	Geology	Sample sites (n)	Results from selected water quality parameters*		Sampling time frame	Conclusion and sources of contamination	Reference
2Bombali, Sierra Leone	Granitic Basement	Wells (60)	FC 0-80, mean 16.6 SEC 38-554 NO3 25-280 Turb, and other majors, pH <6.5		Single study during the wet season May- June 2010	Wells contaminated with FC, 60% above. Who standards. Low pH concern for corrosion.	Ibemenuga and Avoaja (2014)
3Njala, Sierra Leone	Granitic Basement	Springs and wells (8)	FC 50-39k, mean 3.2k FS 5-2k		Monthly Wet and dry season sampling	Increased contamination during the onset of dry season and at the start of rainy season	Wright (1986)
3Moyamba, Sierra Leone	Granitic Basement	Springs and shallow wells (13)	FC 15-251k FS 12-63k, mean 501 SEC 7.6-206, mean 30 Turb, pH 5-6.5		Transition from dry to wet season, multiple sampling occasions	Increase risk during onset of wet season sustained risk during dry season for wells. No sanitation, open defecation practiced.	Wright (1982)
3Bo, Sierra Leone	Granitic Basement	Wells (33) lined and unlined	FC 0-75, mean 19.6 NO3 0.5-28, mean 7.7 PO4 0.01-11.5, mean 1.7 SEC 39-1281, mean 362		Wet season	Distance from field significant predictor of FC, not distance from toilet/PL	Jimmy et al. (2013)
3Conakry, Guinea	Volcanic rocks, fissured	Wells (69)	Mod.wells FC 370-1x105 FS 90-9k NO3 2-46 NH4 0.06-7 Cl 17-130 F 0-0.16 Turb. 1-70	Trad. wells FC 50-2 x105 FS 150-2 x104 NO37-51 NH4 0.01-8 Cl 8-284 F 0.0.38 Turb. 1-63	Dry season April-May 1994	Widespread contamination by nitrate and FC linked to poor sanitation and well construction	Gélinas et al. (1996)
2Various. Ivory coast	Basement	Boreholes (230)	NO3 mean 69	1981 and 1982	High nitrate (up to 200 mg/L) linked to domestic pollution and deforestation	Faillat (1990)
2Bolama City, Guinea Bissau,	Sandy soils and Cenozoic–Modern sediments	Wells (28)	SEC 27-326, mean 136 Turb. 1-26, mean 6.5 TC 0-23000, mean 2306 FC 0-5000, mean 410 Fecal Enterococci 0-850, mean 74 NO3 0.9-55.3, mean 16.6 NH4 0.01-1.37, mean 0.11 NO2 0.03-0.13, mean 0.04 Cu, Fe, Cr, As,	July 2006	80% of wells contaminated with FC linked to widespread use of PL	[file:///W:/PP/GraphicCommunications/Graphic%20Design/Live_Jobs/2014%20Reports/2015/15009/OR15009.docx#_bookmark8 Bordalo and Savva-] Bordalo (2007)
2Cotonou, Benin	Quaternary to mid Pleistocene sandstone	Dug wells in upper aquifer in densely populated area (379)	SEC 320-1045 Mn 0.06-0.19 NO3 10.4-118 PO4 <0.05-21.6 SO4 3.14-86.3	May 1991, August 1991 and April 1992	High P and K concentrations in upper aquifers linked to anthropogenic pollution	Boukari et al. (1996)
1Kumasi, Ghana	Precambrian Basement	Hand-dug wells (10)	TDS 6-230, mean 113 NO3 0-0.968, mean 0.16 PO4 0.67-15, mean 7.8 TH 8-103, mean 54 TC and EC <20	N/A	Water quality survey showed that water quality parameters were within WHO drinking water guideline values	Nkansah et al. (2010)
3Kumasi, Ghana	Precambrian Basement	Borehole and wells in peri-urban communities (9)	Fe 0.001-0.955 Mn 0.018-0.238 Pb 0.005-0.074 TC 3-16.8×106 FC 1.5-4.37×104 Enterococci 1.3-53.5	Monthly between Dec 2000 and Jan 2001	Poor quality overall, contamination linked to proximity to PL and refuse tips as well as livestock	Obiri-Danso et al. (2009)
3Ilesha, Nigeria	Basement	Wells (86)	Mean results: NO3 35 Cl 34 SO4 2.8	Single survey	Evidence of anthropogenic impact on water quality degradation using PCA	Malomo et al. (1990)