In response to the ongoing challenges faced by dysfunctional sewer networks in South Africa, experienced Civil Engineer Chris Nganga Kimaru. has developed a groundbreaking solution – the Manhole Protector Grid (MPG). This innovative device promises to address critical issues in the country’s sewerage systems, promoting climate-resilient infrastructure and improving public health and environmental outcomes.
The MPG is a patented device designed to prevent blockages in underground sewer and stormwater networks by creating a resilient semi-permeable barrier inside sewer manholes. Positioned below the cover slab and above the pipeline, the MPG filters out foreign objects, preventing them from entering the sewer pipes and causing blockages that lead to sewage spillages.
Typically, sewer networks comprise of underground pipelines and manholes conveying sewage from properties both businesses and residential, to the nearest wastewater treatment plant. The MPG can be installed in both new and existing sewer manholes across South Africa and other regions facing similar challenges.
The MPG is now available for deployment and is already gaining recognition for its potential to revolutionise sewer infrastructure management.
Constructed from durable, non-corrosive materials, the MPG can be easily retrofitted into existing sewer manholes or included in new installations. Equipped with GSM and Sigfox-enabled IoT sensors and gateways, the MPG continuously monitors sewage flow rates, transmitting data to a management platform with an early warning system. This system alerts authorities to potential blockages, enabling proactive maintenance and reducing the risk of sewage spillages.
The use of this sewer flow data within the broader water balance analysis will also contribute to municipalities’ task of reducing non-revenue water, helping improve revenue collection.
The MPG can decrease incidents of sewage blockages by up to 70%, leading to significant maintenance cost savings. By preventing blockages, the MPG helps maintain well-functioning sewer networks, crucial during climate change-induced events like increased precipitation and flooding.
The MPG mitigates public health risks by reducing sewage spillages that contaminate water sources, and it helps protect aquatic ecosystems and soil quality. The Green Drop and Blue Drop reports (2023) released by the Department of Water and Sanitation a few months ago highlight the sanitation crisis which is exacerbating the water crisis.
By retaining sewage within the pipelines ensuring it reaches wastewater treatment plants, the MPG enhances opportunities for water reuse and recycling, especially important for water-scarce regions.
Dysfunctional sewer networks are a pervasive issue in many developing countries, including South Africa, primarily due to vandalism, improper disposal of rubbish, other unwanted objects and refuse into the manholes. The improper disposal of solid objects into manholes and the theft of manhole cover lids for scrap value lead to frequent blockages and sewage spillages. These incidents not only threaten public health and water security but also contribute to environmental degradation and climate change.
Acknowledging the MPG’s potential to address a critical issue in sewage network protection and wastewater management, Dr John Okedi, Senior Lecturer from the University of Cape Town’s Civil Engineering Department expressed his support and approved the MPG pilot project for a research master’s program.
The MPG has potential to address the manhole challenges while contributing to job creation. In South Africa alone, around 750,000 manholes are at risk of vandalism. The installation process is labour-intensive, focusing on building the capacity of local SMMEs and youth during the construction and maintenance phases. This approach will create numerous employment opportunities, engage the community, and enable us to manage multiple sites simultaneously, thereby facilitating swift progress.
Commenting on this breakthrough innovation founder and inventor of MPG Kimaru said: “The problem we are addressing is widespread in developing countries across Sub-Saharan Africa, Asia and Latin America. Additionally, the MPG speaks to sustainable development goals as identified by the United Nations.
“With MPG we are addressing a problem that is solvable. We envision a future where MPG will be an essential component of manholes during the design and construction of sewage networks. This will ensure that the long-term functionality of sewage networks is maintained and benefits such as lower maintenance costs, less environmental degradation, better healthcare outcomes and reduced greenhouse gases emissions are realised.”
He adds: “This innovative technology not only enhances the efficiency and sustainability of our sanitation infrastructure but also optimises the functionality of manholes as a key cog in the wastewater conveyance system. We should imagine a city where manholes are working and contributing to lower water and sanitation infrastructure maintenance costs and harnessing the untapped potential of wastewater flow in reducing the carbon footprint. We are looking forward to partnerships that will enable us to have influence on this societal challenge,” said Kimaru.
Following on South Africa’s 2024 national general elections, a recent study by the South African Human Rights Commission examined the state of sanitation services in the country and its impact on electoral behaviour. The findings revealed that inadequate sanitation services contribute to voter dissatisfaction and influence voter turnout trends.
