Water, Sewage & Effluent March-April 2018 | Page 13

Groundwater relief for Middelpos school A school in the drought-stricken western Karoo, Middelpos Primary School, was landed with an R18 000 water bill in February this year. A more sustainable plan had to be made. Case study by SRK “We began drilling the borehole in the school yard on 16 March 2017 and completed it on the same day.” Water Sewage & Effluent March/April 2018 innovations Chris Esterhuyse, SRK in March last year to identify a potential drill site on the school property. Esterhuyse points out that there were no prominent geological features linked to the occurrence of groundwater on the school property and nothing could be identified from satellite imagery. “However, detailed surface geological mapping of the area revealed a narrow joint system that intersects the property, and we selected a drill site there,” he adds. On another property, adjacent to the town, a second, backup drill site was selected on a prominent east- west striking dolerite dyke; this was considered the most promising of the two drill targets. “We began drilling the borehole in the school yard on 16 March 2017 and completed it on the same day,” says Esterhuyse. “We were pleased when fresh groundwater was intersected at 34 metres below ground level (mbgl) with a measured drill stem blowout yield of 2.8 litres per second.” The borehole was completed to a final depth of 50mbgl and a water sample submitted to UIS Analytical Services in Kimberley for quality analysis. L ocated in the small town of Middelpos between Calvinia and Sutherland in the Northern Cape, Middelpos Primary School and its hostel were subject to the water restrictions in the Hantam Local Municipality — but clearly could not afford the water it needed. Through a provincial Department of Education programme to alleviate the water crisis in schools, RE Construction was awarded the tender to provide a solution. Bernie de Jongh of RE Construction approached SRK Consulting, a firm of consulting engineers and scientists, to site a water supply borehole within the school property to alleviate the water challenge. De Jongh explains that there was an existing borehole at the hostel, but owing to numerous sewage pits in the vicinity, the water quality was unsuitable for human consumption. However, he points out, the school is upstream of the town and the likelihood of finding potable groundwater in this area was an option and considered to be fairly good. SRK principal hydrogeologist Chris Esterhuyse visited the area 11