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) |