FEIR for Boitshepi Landfill Site .pdf - Zitholele.co.za

August 2010 458848• Soil depth;• Soil texture (Field determination);• Wetness;• Occurrence of concretions or rocks; and• Underlying material (if possible).Regional DescriptionThe region is underlain by colluvial and alluvial soils overlying shale and sandstone bedrockof the Ecca Group, Karoo Super group (refer to Figure 11 for regional geology and Figure 12for regional soil type delineation). The Ecca group consists mainly of shales, with thicknessvarying from 1,500m in the south, to 600m in the north. Since shales are very dense, theyare often overlooked as significant sources of ground water.The Daspoort quartzite of the Pretoria Group outcrops to the north of the region. Topsoil inthe region essentially consists of brown and grey, loose to medium dense, clayey sandwhich extends to an average depth of 0.5m. Some portions of the region’s topsoil areunderlain by orange mottled light grey, firm sandy clay with occasional gravel, cobbles andboulders, while some areas are underlain by brown, clayey sand containing abundant gravel,cobbles and boulders of colluvial origin. On the other hand, a small portion of the region isunderlain by orange, very strongly cemented soft to hard rock, hardpan ferricrete. The clay isof alluvial origin. The transported alluvial and residual soils are underlain, at an averagedepth of 1.5m, by residual mudrock and sandstone over the portions and also by residualquartzite.Site DescriptionThe surface area of study area has been fairly extensively disturbed by the removal of soilfor use as cover for the solid waste. The study area is underlain by transported and residualsoils developed over shale bedrock belonging to the Vryheid Formation, Ecca Group, KarooSupergroup and by quartzite bedrock belonging to the Daspoort Formation, Pretoria Group,Transvaal Supergroup. No rock outcrops were encountered in the immediate vicinity of thesite.SensitivitiesSeventeen test pits were excavated across the site for the proposed extension of theBoitshepi Waste Disposal Site using a Cat 428 backactor. The test pits were for thepurposes of describing the soil and bedrock formations.Minor to strong inflow of perched ground water seepage was encountered in some 80% ofthe test pits at depths ranging from 0,4m to 2,1m below surface. The design of undergroundstructures such as basements or buried tanks if not correctly implemented could affect theground water.ZITHOLELE CONSULTING