South Africa’s municipalities need to develop an integrated master plan to address delivery constraints of the country’s wastewater treatment plants, says consulting engineering firm WSP Parsons Brinckerhoff Africa technical director Leon Saunders.
He points out that municipalities in metropolitan areas, such as Cape Town, Johannesburg and Tshwane, are keeping pace with the growing demand for treated water. However, towns in municipalities outside South Africa’s major metropolitan areas, known as category B municipalities, require the most attention.
Saunders asserts that wastewater treatment plants in category B municipalities are in danger of breaking down, owing to demand exceeding plant capacity, the complexity of some modern technologies and a lack of sufficiently trained operators, as well as poor maintenance.
“Most of the plants in South Africa are 30 to 40 years old, many of which are receiving upgrades to improve plant capacity. However, this does not always help and municipalities need to consider developing an integrated plan to determine which areas have the greatest need for development, and how much water and sanitation capacity they require. This will enable municipalities to have a clear goal in mind to deal with the current problems,” he states, adding that decentralised solutions are sometimes more appropriate, as pumping raw wastewater is expensive and requires high maintenance infrastructure, such as pipelines and pumpstations.
“The need for simple and effective plants, which are energy efficient and low maintenance, has never been greater. Plants which deliver high- quality treated water consistently with semiskilled operators could be the way forward, as water from such plants could easily be used for irrigation or even for reuse in industrial applications,” Saunders states.
He suggests that municipalities need a two- to three-year lead time to highlight and prioritise the various issues facing wastewater treatment plants in the country. He adds that this time should also be used to determine which existing plants need to be extended through additional capacity and which areas require the construction of new plants.
“It will not be efficient to develop large wastewater treatment plants at category B municipalities, particularly those in rural areas, because populations are scattered over a large geographical area,” Saunders says.
He asserts that proper wastewater treatment facility management and maintenance require urgent attention. Municipalities need to include facility management into their maintenance plan, which involves determining the requirements that will keep a plant operational.
“Facility management also involves determining what needs to be repaired or replaced before there is a breakdown, which will ultimately extend the life of a plant.
“Municipalities need to continuously improve and replace parts at wastewater treatment plants,” Saunders avers, noting that plants need to regularly maintain inlet works, as grit and rags that have not been removed can significantly shorten the life span of mechanical equipment.
He concludes that municipalities, particularly category B municipalities, should focus on preventive or scheduled maintenance rather than reacting to equipment failure, as they often lack the finances to deal with major equipment failures.