County banks on Japanese tech to end garbage crisis

A putrid stench characteristic of a poorly managed solid waste welcomes us to the Kang’oki dumpsite in Thika, Kiambu County. Trash, blown farther afield by wind or maybe a deluge, litter the adjacent upcoming residential neighbourhood. Here, Marabou storks and stray dogs scavenge over the mounts of trash.

Slurry oozes out on the floor of the mountainous heaps of garbage forming dirty streams where none should be flowing, compromising public health and the environment. About 1,240 metric tonnes of garbage is received here daily from all the urban areas in the county.

In 2016, Kiambu, one of the counties making up Nairobi Metropolis, started the process of containing this ghastly mess, albeit on a trial basis. It made history by becoming the first on the continent to pilot a landfill based on the ‘Fukuoka method’. The method involves mechanisms where waste water is quickly removed from waste materials. The process leads to faster decomposition of waste material, improves quality of the waste water and reduces emission of methane gas. While most of the world’s landfills are anaerobic, this semi-aerobic method ensures significant reductions in greenhouse gas emissions.

Built on a one-hectare land on the southern end of the over 200-acre-dumpsite, like a relic, the Kang’oki landfill site in Thika remains as impeccable as it was on the day activity was abandoned here the same year (2016).

This corner of the dumpsite is pristine and quiet. Seemingly unsullied. It is a delightful contrast to the unsightly rolling hills of garbage in the distant background.

It is hard to believe there is trash here at all. But garbage collected for three days is contained here. Compacted, buried and cemented with a layer of soil. Because the process involves covering the compressed garbage with a clean layer of soil, the now disused grounds remain clean and have since grown green with Kikuyu grass.

“It might seem inconceivable, but six years ago we cleared hills of accumulated waste here, compacting it to create concave chambers in the ground. And then we had 100 (10-tonne) trucks emptying garbage here for three days using the Fukuoka method,” explains the county’s Environment assistant director and landfill manager at Kang’oki dumpsite Monicah King’ori.

She observes that the method involves a simple low-cost semi-aerobic landfill disposal technology for solid waste originating in Fukuoka City, Japan in the 1960s. Ms King’ori was one of 12 Kiambu county officials trained on the method in Japan between 2015 and 2018. “We did a taster in 2016 with Prof Matsufuji Yasushi, the innovator of the method, but had to stop since what we were disposing of here included valuable waste that could get a second life. As a country we’re trying to embrace a circular economy,” she observes. “Also, unsorted, the garbage would ultimately take a lot more space. Yet the method is about saving space, too. The 100 trucks of garbage were easily compacted into a one-meter layer of one of the cells.” 

Constructed in the open, the Fukuoka landfill constitutes a series of carved-out ten by ten square feet cells where the trash is emptied, compacted and then buried with a layer of soil at the end of each day. Kang’oki has eight such chambers, with extension capacity as need arises. It has waste water treatment incorporated into the design.

Air pollution

“The semi-aerobic landfill has the potential to reduce air pollution and greenhouse gas effects by between 40 to 70 per cent, thus addressing climate change. The soil cover also helps prevent fires and keep away flies and insects as well as scavengers,” notes Ms King’ori.

Dumpsites are one of the key contributing sources of methane into the atmosphere as well as heavy metals such as zinc, lead, copper, nickel, chromium and cadmium in the environment.

Constructed with funding from the Swedish Government under a UN Habitat programme supporting urban improvement, the United Nations Environment Programme, technical support from Japan through JICA, Fukuoka University and Jomo Kenyatta University of Agriculture and Technology, the project was built as a prototype for other Kenyan counties and training center for African cities through the African Clean Cities Platform, towards solving Africa’s waste problems.

According to Dr Ayub Macharia, director, Environmental Education and Awareness Unit in the Ministry of Environment, having mapped all the waste value chains in the country in readiness for the operationalisation of the Sustainable Waste Management Bill, 2021, which lays emphasis on a transition to circular economy and segregation of waste at source, residual waste expected to end up in the dumpsites will be five per cent of all generated waste. “We’ll have two streams. Wet organic and recyclable waste. Kenya’s garbage will have two receptacles; a composting facility and a material recovery facility provided by the county governments,” he observed during a recent Kenya-Japan Waste Management Symposium at the Embassy of Japan in Kenya.

But even with the new law, Japan Ambassador to Kenya Ken Okaniwa observes that “a lot of issues still need to be addressed as the country moves into implementation such as a culture change in the way individuals interact with waste….to promote cleaner cities and reduce the burden of county governments needing to use enormous resources and land in the sector while generating new industries and jobs in the energy and recycling sectors.”

Kiambu is now working to revive the Fukuoka project as it struggles to contain waste volumes following the decommissioning of all other dumpsites in the county including Gioto-Kiambu, Gacharage-Ruaka and Bibirioni-Limuru, Gatundu. This is after they were declared full.

Last September, the county requested JICA for an expert from Japan to help them revive the project that is billed to have significant environmental and space saving benefits. Solid waste management advisor Kentaro Hotta, who arrived in the county 10 months ago to assist with the resuscitation, is expected to get systems running by November.

According to Kiambu Environment Executive David Kuria, these preparations are a precursor to the Sustainable Solid Waste Management Bill, which was passed on July 14, 2022, by the Senate and is currently awaiting the President’s assent to become law.

“The county has an upcoming policy in draft stage in line with the anticipated law requiring segregation at source with no garbage allowed here if it is co-mingled—the biggest problem we’re facing right now with the implementation of Fukuoka,” said the official during a recent tour of the dumpsite.

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