Wastewater treatment works being upgraded

GEORGE NEWS - George Mayor Leon van Wyk visited the Outeniqua Wastewater Treatment Works (OWWTW) on Monday 25 October to review the construction works underway to upgrade and the plant and extend its capacity.

This project had been delayed, initially due to contractual matters and again later with the challenges introduced by Covid-19 lockdown.

Certain materials had to be imported and international travel restrictions due to the pandemic resulted in material shortages. The construction programme was revised to allow for new interim deadlines while still aiming to complete the project within the approved project timelines.

"This significant upgrade is essential for the ongoing growth we are experiencing throughout George and the increased capacity from 15Ml/d to 25Ml/d will provide us with the ability to continue with construction activity and development to move forward at a fair pace going into the future," said Van Wyk.

Two of four new aerators have been installed on the old works' carousel-activated sludge biological reactor. Each has a 130kW motor on top of the gearbox, which is connected below the concrete slab to an aerator. This combination adds air to the water to dissolve oxygen for bacterial growth in the water to enable aerobic biological treatment of the sewage.

The concrete platforms and beams had to be rehabilitated and retrofitted with carbon strips to provide additional reinforcement that would allow for the new heavier aerators to be installed on the existing platforms. Two of the four new aerators are already operational and the concrete remedial work is underway on the two remaining bays to allow the installation of the other two new aerators.

Inside the new skip handling building with new mechanical equipment visible in the background. From left are Gerard de Swardt (municipality); Jannie Koegelenberg (RHDHV); Luvoyo Dondolo (Khubeka Construction); Leon van Wyk (mayor); Irwin Ross (Khubeka Construction); and Dion Kuter (WPCP).

The construction of this mechanical, electrical and instrumentation works contract is being executed in three distinct components, i.e. the inlet works, the carousel (refurbishing of the existing 15Ml/d reactor) and completing the equipping of the new 10Ml/d reactor.

All of these components are due for completion in February 2023, while the first two components are expected to be fully operational by May 2022. For the most part, the civil engineering construction is nearing completion and only some roadworks remain.

The waste skips for screenings and grit will be housed inside the new skip handling building, after the screenings and grit has been washed and compacted, to allow for air collection from the building and to pass this air through the odour control system, where the air is to be treated to a less odorous state before being released back into the environment through the chimney.

The new 10Ml/d reactor is the main component for the provision of additional capacity at the plant. The component was also constructed in phases and the civil engineering structures, including the concrete structures of the reactor and settling tanks, the building to house the blowers and the motor control centre, were completed previously.

On site are, from left: Mayor Leon van Wyk; RHDHV project manager Jannie Koegelenberg; WPCP contracts manager Dion Kuter; and George municipal project manager Gerard de Swardt.