Civil Engineering June 2021 | Vol 29 No 5

Civil Engineering June 2021 35 full funding for this project is still needed. The Department of Water and Sanitation did however provide intermediate funding to the value of approximately R40 million. These funds were utilised to upgrade the Calvinia Water Treatment Plant and to complete the Calvinia North Wellfield, which is already supplying an additional 8 ℓ/s to the town. Calvinia Water Treatment Plant Upgrade Calvinia receives seasonally variable water from either surface water sources (Karee Dam), or from groundwater sources. During early winter the raw water is sedi- ment laden and highly turbid, but later in the season algal blooms are predominant with related taste and odour problems. To counter these issues, the new treatment plant was planned to provide the fol- lowing new facilities: Q Q Four rapid gravity filters with com- bined air-water scour capability Q Q Conversion of existing clarifiers to conical Dortmund type clarifiers Q Q Dissolved air flotation (DAF) facility for removal of algae Q Q New chemical dosing facility to allow the use of multiple coagulants Q Q New chlorine dosing facility for disin- fection with calcium hypochlorite Q Q New plant room housing the clear water pumps, backwash pumps, air scour blowers, DAF recycle pumps, air compressors and the saturation vessel Q Q New electrical switchgear and fully automated operation and control system. Construction of the Calvinia Water Treatment Plant upgrade commenced in March 2020 and was completed in May 2021. The contract was awarded to Messer’s CSV Construction for a total contract value of R36 million. Parallel to the work at the water treatment plant, the construction of the Calvinia North Wellfield commenced in January 2021 and was completed in May 2021. The project comprised the following works: Q Q Equipping of five new borehole pumpstations Q Q Construction of 3 km of 11 kV over- head electrical powerline Q Q Construction of 7.8 km of 110 mm diameter rising main pipelines Q Q Electrical switchgear, instrumentation and telemetry. The project was awarded to Messer’s JVZ Construction for a total value of R 6 979 555,65. The upgrade of the Calvinia Water Treatment Plant and the completion of the Calvinia North Wellfield will help enormously with the future water supply to Calvinia. The larger project to develop some 37 ℓ/s at the Kreitzberg Wellfield south of Calvinia still needs to be imple- mented in the near future and is vital for the town’s long-term water security. CONCLUSION The severe drought experienced in the Hantam Region over the past seven years has had a severe impact on water supply to the towns of Loeriesfontein, Brandvlei and Calvinia. The Northern Cape office of the Department of Water and Sanitation has been exemplary in its support to the Hantam Municipality. Infrastructure to the value of R300 million has been constructed in this municipality since 2017 and should provide these towns with a secure supply of water for the next 15 to 20 years. All that remains now is to complete implementation of the Calvinia Project and for the Hantam Municipality to properly maintain this infrastructure for the advantage and future supply to the Hantam communities.  Figure 9 Refurbished clarifier at the Calvinia Water Treatment Plant Figure 10 Aerial view of the completed Calvinia Water Treatment Plant