Nooitgedagt Coega Low Level Scheme (NCLLS)
The Nooitgedagt Water Treatment Works (WTW) is located in the Sundays River Valley some 35km north of Port Elizabeth and is the largest water treatment plant supplying Nelson Mandela Bay Municipality. Raw water is supplied from the Gariep Dam via transfer tunnels, rivers, weirs and canals.
AfriCoast was appointed as Lead Consultant for the Project Management, planning, and administration of the entire NCLLS. In addition AfriCoast was also responsible for the design and implementation of contracts for the upgrading and extensions to the Nooitgedagt WTW, 10Ml and 45Ml bulk storage reservoirs at Olifantskop Farm, cathodic protection of more than 100km of bulk steel pipelines and the rehabilitation of the Chelsea – Motherwell link pipeline.
The project was originally designed and tendered as a single phase under multiple contracts with an estimated cost of R747 million. It subsequently changed to a phased project due to a lack of funding. Final project cost is R1.3 Billion.
Phase 1 was completed in 2016 and included 15 new sludge ponds, an effluent return pump station, installation of mechanical and electrical equipment to an existing 35 Ml pulsator clarifier, an automated raw water strainer and upgrade of the bulk electrical supply at Nooitgedagt WTW. The first phase furthermore included construction of a 1300mm diameter rising main to Olifantskop, a 10Ml reservoir at Olifantskop, booster pump stations at Motherwell and Standford Road and a 1500mm diameter gravity pipeline from Olifantskop to Motherwell.
Phase two added six additional filters at to the WTW and a new Low Lift pump station was constructed to pump water through the newly constructed Nooitgedagt/Coega Low Level Scheme pipeline to the reservoir at Olifantskop. Phase 2 was completed in 2017.
- Phase three entails the construction of a complete new 70Ml/day stand alone water treatment module comprising of a flash mixer, two flocculation channels and settling tanks, six new filters with clearwell below, upgrading of filter pumps, blowers and electrical system, interlinking pipework, upgrading of SCADA and telemetry systems, construction of a 45Ml reservoir at Olifantskop, AC Mitigation and Cathodic protection of bulk steel pipelines and rehabilitation of Grassridge to Chelsea pipeline.
On the 30th of March 2022 Nooitgedagt started producing an increase of 70ml by providing 210ml a day a figure extended from a previous 140ml to meet the current and estimated future potable water demand.
AC Mitigation and Cathodic Protection of Existing Pipelines
The pipeline routes for both the high and low level pipelines required additional corrosion protection due to the aggressive soil types encountered. The Cathodic Protection (CP) previously installed under the High Level Scheme (1993) had to be integrated with the Low Level pipeline as well as all the steel pipelines between the Motherwell and Stanford Road Booster Pump Stations.
The works include continuity bonding, ground beds, impressed current transformer rectifiers and installation of isolation kits where required.