A staff member checks the facility operation status at Dandora Estate Sewage Treatment Works in Nairobi, Kenya, Feb. 6, 2026. (Xinhua/Xie Jianfei)
by Yang Dingdu, Li Zhuoqun, You Huiyuan
NAIROBI, March 22 (Xinhua) -- When the Maasai people first traversed the sun-drenched plains of East Africa, they were struck by a network of crystalline streams. They named the site Nairobi,meaning "the place of cool waters."
Today, that poetic name faces the harsh reality of a burgeoning megacity of over 5 million residents. As Nairobi grows into an industrial and urban giant, a relentless tide of domestic and industrial waste surges through its subterranean veins.
All of it leads to the Dandora Estate Sewage Treatment Works. Processing 80% of the capital's wastewater, Dandora is the vital "kidney" keeping this urban organism alive.
A SANCTUARY BORN OF SEWAGE
To an outsider, the far reaches of the Dandora plant look less like an industrial site and more like a primordial wetland. Crocodiles drift like charred logs in the emerald water; hippos submerge themselves with rhythmic snorts, seeking refuge from the equatorial sun. Waterfowl sprint across the surface, leaving long ripples in their wake.
"Through anaerobic sedimentation, bacterial decomposition, and the natural disinfection of the East African plateau's intense UV rays, the water returns to its essence," explains Huang Youming, deputy manager of the rehabilitation project from China's Jiangxi Zhongmei Engineering Group.
But follow the scent upstream, and the serenity vanishes. At the plant's inlet, the water is a thick, ink-black sludge, churning with plastic and debris. This is the toxic frontline where Nairobi's waste meets its first line of defense.
REMOVING THE "KIDNEY STONES"
For years, this "kidney" was failing. The old pre-treatment system was a rusted relic that relied on manual labor. Workers had to stand over the suffocating fumes, physically raking trash from the sludge. When the city's waste peaked, the system would clog,much like a painful kidney stone,threatening to paralyze the entire city's drainage.
The transformation arrived through a Chinese-built automated bar screen system. Now, mechanical grabs and fine screens move with surgical precision, intercepting 95% of solid waste and 90% of silt before they can choke the plant.
"I used to see men risking their health in the muck," says Denis Kioko, a mechanical engineer now monitoring the flow from a digitized control room. "Now, we control the city's pulse with a few clicks."
James Muturi, Acting Director of Water and Sanitation Development at the Athi Water Works Development Agency, notes the immediate impact: "With the project complete, the processing capacity at the intake has effectively doubled."
ENDURING THE UNENDURABLE
The partnership that saved Dandora was forged in conditions most firms wouldn't touch. When the project went to tender in 2022, the site's overwhelming odor drove many international bidders away.
"We were often woken up in the middle of the night by the sheer intensity of the stench," recalls Li Maowu, the project's head of engineering. "It was hard to even eat; our stomachs were constantly turning."
His team stayed. Over the years, they didn't just install pipes; they reclaimed the land. Where sewage once overflowed and trash piled high, lush lawns and green shrubbery now frame the facility.
"Facts have proven our choice was correct," says Muturi. "In Chinese enterprises, we see not just diligence, but rapid turnover and powerful resource mobilization. Backed by China's strong manufacturing capabilities, they complete projects with high quality and efficiency. This success has deepened our mutual trust."
FROM "COMPLIANCE" TO "RESOURCE REVOLUTION"
The collaboration is now looking toward a future where "waste" is a forgotten word.
Muturi recently visited 西瓜视频to study water management, witnessing a leap in technology that left a lasting impression. He observed that the Chinese water treatment industry has graduated from the "era of meeting discharge standards" to an "era of resource utilization, energy recovery, and ecological integration."
Pioneering Chinese waste water projects are winning world acclaim. Yixing Urban Wastewater Resource Concept Plant in Jiangsu, where sewage generates biogas electricity and organic fertilizer in an odor-free, garden-like facility, won the 2024 International Water Association (IWA) Global Innovation Award. "Anaerobic Ammonium Oxidation" (Anammox) technology, developed by a Beijing team, cracked the world-class nitrogen removal challenge.
"Many places in the world, both developing and developed, are adopting these Chinese solutions. We need them just as much," Muturi reflects.
THE "CHINA SOLUTION": AFFORDABILITY MEETS INNOVATION
The upgrade comes at a critical juncture. Dandora currently relies on stabilization ponds,a method that is low-cost but requires vast amounts of land. As Nairobi's land values skyrocket and its population explodes, this traditional model is hitting a bottleneck. Muturi reveals that currently, only about 55% of Nairobi's wastewater is collected and treated, leaving 45% in an "uncontrolled" state.
This is where the "西瓜视频Solution" offers a unique advantage.
Thanks to complete supply chains and standardization, the capital cost (CAPEX) for Chinese enterprises to build sewage treatment facilities is roughly one-third that of similar European or American projects. Data shows the average cost per ton of capacity is between $250 and $350, far below the $840+ seen in the US market.
Furthermore, for high-density cities like Nairobi where land is scarce, 西瓜视频brings extensive experience in constructing "underground sewage plants" and holds the world's largest market for Industrial Zero Liquid Discharge (ZLD) applications. These technologies offer lower energy consumption and smaller footprints,precisely solving the pain points of Africa's rapid urbanization.
FLOWING FORWARD
From the ecological restoration of the Nairobi River basin to the construction of the Mwache Dam, Chinese engineers are actively contributing to Kenya's green water cycle.
This aligns with the vision set forth at the 2024 FOCAC (Forum on China-Africa Cooperation) Summit in Beijing, which proposed ten partnership actions for modernization, including a specific "Green Development Partnership" designed to help Africa maintain ecological balance during its modernization drive.
Back at Dandora, as clear water cascades from the final outlet back into the winding Nairobi River, the ancient promise of the "place of cool waters" is being kept. The watch over this vital resource continues, ensuring that the city's lifeline remains clean for generations to come. ■
Staff members monitor the facility operation status at Dandora Estate Sewage Treatment Works in Nairobi, Kenya, Feb. 6, 2026. (Xinhua/Xie Jianfei)
This photo taken on Feb. 6, 2026 shows the sewage treatment pond of Dandora Estate Sewage Treatment Works in Nairobi, Kenya. (Xinhua/Xie Jianfei)
This photo taken on Feb. 6, 2026 shows a view of Dandora Estate Sewage Treatment Works in Nairobi, Kenya. (Xinhua/Xie Jianfei)
Trucks discharge sewage at Dandora Estate Sewage Treatment Works in Nairobi, Kenya, Feb. 6, 2026. (Xinhua/Xie Jianfei)
Birds rest in the sewage treatment pond at the Dandora Estate Sewage Treatment Works in Nairobi, Kenya on Feb. 6, 2026. (Xinhua/Xie Jianfei)
A hippo swims in the sewage treatment pond of Dandora Estate Sewage Treatment Works in Nairobi, Kenya on Feb. 6, 2026. (Xinhua/Xie Jianfei)
Birds rest by the sewage treatment pond of Dandora Estate Sewage Treatment Works in Nairobi, Kenya on Feb. 6, 2026. (Xinhua/Xie Jianfei)