Online Reporter
Remember Deketeke
Municipal Correspondent
THE rehabilitation of Morton Jaffray Water Treatment Works has entered its final phase, with engineers now working on the plant’s critical clarifiers, which are central to the purification process.
The ongoing works, which are envisaged to result in the production of 500 megalitres of water per day, are also expected to improve the efficiency of the treatment process and increase the volume of potable water.
Project engineer for Consolidated Water Industries Shelton Kwashirai said the clarifiers were at the heart of the water purification process, and their rehabilitation would complete the major cycle of works at Morton Jaffray.
“What you are seeing here is a process where we are rehabilitating the clarifiers. The clarifier is a critical component in water production. This is where most of the activity that we do on a water treatment plant happens,” he said.
“So, we are now left with this component to complete the whole cycle of water treatment at Morton Jaffray.”
The works include removing accumulated sludge, debris and dirt from the clarifiers before replacing pipework and installing new baffles.
Eng Kwashirai said six clarifiers were scheduled for rehabilitation under the final phase, collectively adding about 450 megalitres of capacity once the works were completed.
“The activities that we are seeing here is the dislodging process where we are removing all the debris and the dirt that had remained in the clarifier for some time,” he said.
“As you can see, the guys are busy now. We are removing all the sludge that had occupied the clarifier, the dislodging, and then we are going to redo the pipework, the baffles.”
A major component of the rehabilitation is the replacement of asbestos-cement (AC) baffles with glass-reinforced plastic (GRP) baffles.
Eng Kwashirai said the GRP technology, being introduced from France, would replace the old AC baffles, which contain asbestos and are no longer considered suitable for use in potable water treatment.
“The baffles are the critical component that ensures the efficiency of this clarifier. The baffles we used to have were AC baffles that are made of asbestos, and asbestos has been declared non-food grade worldwide,” he said.
“The baffles that we are currently introducing are going to be GRP baffles. With GRP, it means we have now moved into the modern way of doing things.”
He said the new baffles were expected to have a longer lifespan and improve the efficiency of the clarification process.
“They have got a longer longevity in terms of their guarantee and performance. We are also expecting to improve our performance to around 95 percent when we start to do the actual water purification,” Eng Kwashirai said.
Improved clarification, he said, would also increase the amount of water that could be processed daily.
“With the baffles, now we are saying we are going to improve on our efficiency in this clarifier. The time that we retain water is going to significantly improve,” he said.
“This means that at least we meet the demand of water in a day and meet the cycles that we need to do per minute and per hour so that at least the outward benefit is an increase in the production of water on a daily basis.”
The completion of the clarifier rehabilitation is expected to mark the final phase of the Morton Jaffray rehabilitation programme as authorities work towards restoring the plant to its targeted capacity of 500 megalitres per day, which would significantly strengthen Harare’s water production capacity.
