MUNICIPAL FOCUS | NELSON MANDELA BAY
Nooitgedacht Low Level Water Supply Scheme achieves ‘first water’ Aerial view of the Nooitgedagt WTW
Nooitgedacht Low Level
Water Supply Scheme achieves ‘first water’ The Nooitgedagt/ Coega Low Level Supply Scheme (NCLLS) increases the supply of treated water (sourced from the Gariep Dam) from 70 Mℓ/day to 210 Mℓ/day for Nelson Mandela Bay Municipality (NMBM). The first water flowed through the new Phase 3 module on 31 March. By Kevin McRae
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IMIESA April 2022
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t first, the NCLLS was to be implemented as a single project under multiple contracts; however, due to funding constraints, the scheme had to be implemented in phases. Phase 1: On completion (1993), Nooitgedagt Water Treatment Works (WTW) had a capacity of 70 Mℓ/day and a hydraulic peak capacity of 84 Mℓ/day. A fourth pump was added to the pump station, boosting pumping output to 92 Mℓ/day with three pumps operating and one pump on standby. In 2008, two additional pulsator clarifiers were built, increasing the capacity of Nooitgedagt WTW to 100 Mℓ/day. Additional sludge lagoons and a 10 Mℓ balancing reservoir at Olifantskop Farm were constructed. There was also the implementation of bulk electrical supply to the WTW, and the rising (1 200 mm) and gravity (1 400 mm) mains from the WTW to Motherwell and the Coega Industrial Development Zone (IDZ).
Phase 2: This included the low-lift pump station building, as well as the construction of the western bank with six additional filters, and pumping equipment, electric and control systems for the low-lift scheme. Phase 3: This comprised a complete stand-alone 70 Mℓ/day treatment module at Nooitgedagt WTW, a 45 Mℓ balancing reser voir at Olifantskop Farm, installation of cathodic protection systems on both the original Nooitgedagt to Mother well highlevel pipeline and the low-level pipeline built under Phase 1. The building of various bulk pipelines and rehabilitation of structures, as well as the replacement of certain valves and fittings on the Mother well to Chelsea pipeline were also included. This is the last significant milestone for the Nooitgedagt/Coega Low Level Supply Scheme project that commenced with construction in 2010. Interestingly, the original scheme was also built under emergency drought conditions. Back then, while Nooitgedagt WTW was under construction, the Grassridge Reser voir was used as an emergency treatment works where settling and chlorination took place. In order to maximise the water supply to NMBM while Phase 3 was under construction, the Grassridge emergency treatment works was again put into use and upgraded with improved treatment and chlorination systems.
