The uMgungundlovu district municipality in Pietermaritzburg, KwaZulu-Natal, is planning to upgrade its Mpophomeni sewerage infrastructure from six-million litres a day to three-million litres a day at a cost of R160-million, by 2019.
The Department of Water Affairs has approved the Mpophomeni Sanitation Scheme, which includes the six-million-litre- a-day treatment works for the Mpophomeni and Khayelisha areas, as well as an additional 25% capacity for future expansion.
The project is currently undergoing its environmental-approval process, which includes the water quality assessments of the streams the treated effluent will flow into; the impact assessments of the Umgeni river system, such as a river reserve determination to establish if the river will cope with the effluent; geohydrological assessments of site impacts; and a storm water management plan.
The five-year project will begin subject to the environmental approval, which is expected to be granted in October.
The project also includes the construction of infrastructure to discharge sewage from Khayelisha, two new main sewers within Mpophomeni and additional smaller sewer refurbishments to existing units such as digesters, inlet works and clarifiers, which will eliminate identified sewage pollution within Mpophomeni.
Effluent delivery systems, including an artificial wetland effluent polishing system at the treatment works, will also be included in the budget.
The old Mpophomeni sewage treatment works was discontinued in 2001 as it discharged effluent that progressively polluted near the Midmar dam, located near Howick and Pietermaritzburg. It was replaced with a sewage-pumping scheme that included transfer to the Howick Treatment Works, which was upgraded to cope with the addi- tional load. The infrastructure, including 11 km of pumping mains and sewers, has reached its full capacity.
The feasibility study of the upgrade is being undertaken by consulting and engineering services provider Royal HaskoningDHV, whose water principal associate, Peter Sibanda, hopes that the project will tackle negative health and social issues that occur as a result of the pollution in the Midmar dam.
“We are hoping for a positive impact from this project once the water is treated and discharged downstream of the Midmar dam. With less pollution, the area can expect to develop recreational activities and continue its sporting heritage, such as the yearly swimming race, the Midmar Mile,” Sibanda states.
The project will also provide employment for the local communities in the area, as soon as construction begins.
The project also expects to implement the digestion of sludge, which will separate the effluent’s solids and liquids – the solids can be used to generate electricity and gas.
Sibanda reveals that the electricity can be used to run some of the processes in the treatment works.