A contractor has been hired to begin repair work on two major pipelines carrying raw water from the Nagle Dam to the Durban Heights Water Treatment Plant for treatment and supply of potable water to the eThekwini Metro.< /p>
Following the appointment of the contractor, the next steps will be to establish a site to direct the work from and provide Umgeni Water with a detailed project implementation plan.
Two pipelines were severely damaged in the April floods at Wushini, Inanda, Durban. These two pipelines and two others transport raw water to the water treatment plant in Durban Heights. The two undamaged pipelines continue to deliver water to the Durban Heights facility.
Due to the temporary shutdown of the two damaged pipelines, Umgeni Water had to use three shaft pumps to pump water from the Inanda Dam to the to transport the plant in order to improve the raw water supply. Additional water is also being routed through the Nagle Dam-Durban Heights facility’s two working pipelines.
There is currently a shortfall in the facility’s raw water supply and consequently reduced production and supply of Drinking water (drinking water). The shortfall amounts to an average of 40 to 50 million liters per day. The shortfall will remain in place until the two pipelines are repaired and returned to service.
The repair of the two pipelines is expected to be a 10-12 be a month-long project. One of the pipelines is made of steel and the other is made of concrete. They are under high pressure and transport large volumes of raw water.
Status of drinking water production on June 3rd:< p>The Northern Region: The Hazelmere Water Treatment Plant outside Verulam was producing 60 million liters (60 ml/d) of potable (potable) water on Friday. This is 15 million liters less than the average daily production of 75 million liters and is due to repairs being carried out at the factory to the Aquatan roof liner on Reservoir 2’s floating deck, which was damaged during the April rains this year.
The reduced production was necessary due to a partial shutdown of the plant for the work to be carried out. The work should be completed last Friday, after which production is to be ramped up to 75 million liters.
The municipalities of eThekwini Metro and iLembe District Municipality, as well as a private sector entity, Siza Water, are served by the Hazelmere plant. Meanwhile, as the work progresses, customers have continued to effectively manage and deliver to consumers the reduced amounts of water fed to them. Umgeni Water would like to thank customers for their cooperation and support in this regard.
Durban Central, Durban South, Durban North and Durban Inner West: Two Water treatment systems are used by the eThekwini Metro to network these areas. They are Durban Heights and Wiggins.
Durban Heights: On June 3, an average of between 490 million liters and 500 million liters of drinking water per day was produced and delivered to eThekwini Metro. The community in turn serves North, South, Central and Inner West Durban. Currently, between 40 and 50 million liters of drinking water per day are short of the amount of drinking water that Umgeni Water is contracted to supply with eThekwini Metro.
This is due to the temporary closure of two pipelines – 1 and 2 – which, along with pipelines 3 and 4, transport raw water from the Nagle Dam to Durban Heights for treatment. Lines 1 and 2 were badly damaged in the April floods. To increase supply, three wave pumps are used to transfer raw water from the Inanda Dam and additional water is transferred through pipelines 3 and 4.
A shortage of raw water and accompanying lack of drinking water supply remains. After the two pipelines have been repaired and put back into operation, the plant will be supplied with the full amount of raw water. The restoration of the two pipelines is estimated to take 10 months.
Wiggins: On June 3, drinking water production averaged .327 million liters. Production has been rising steadily since the weekend of May 28-29 after raw water turbidity issues began to surface from Thursday, May 26 due to heavy rains in the previous week and poor water quality in the catchments. At this point a decision was made to reduce inflows and production to avert the possibility of producing drinking water that does not meet SA National Standards (SANS) 241 for drinking water quality
Of the 327 million liters produced as of June 3, about 325 million liters were delivered to eThekwini Metro. Umgeni Water is contracted to deliver 301 million liters per day.
The average daily production for the whole of May was 305 million liters, of which an average of 298 million liters was delivered to eThekwini Metro daily. As a result, in May there was a supply deficit compared to the contractually agreed amounts of an average of three million liters per day.
The Inanda Dam becomes very cloudy (muddy) water and the treatment processes at the Wiggins plant are not capable of treating this water at a 100% production rate. Hence the reduction in the amount of water produced while this problem still persists. Umgeni Water has introduced a new chemical to try to treat this water at the plant’s full production capacity.
The goal is to reach 100% production in the shortest possible time and when the nephelometric turbidity unit (NTU) reaches 100. NTU is used to measure the degree of turbidity in water and on May 26th it peaked at 400. Since then it has started to decrease and on June 3rd the NTU level reached 150 which is manageable for treatment purposes . Once full production is achieved and sustained, the shortfall to contracted levels will be eliminated.
The Wiggins system also post-supplies to Amanzimtoti Waterworks via the South Coast Augmentation for eThekwini Metro for distribution Amanzimtoti and beyond south within its borders.
Shami Harichunder is Corporate Stakeholder Manager of Umgeni Water.