An old quarry eight kilometres east of Nairobi city centre was converted into the Dandora Municipal Dump Site in the 1970s. Although the city council declared the 30-acre unfenced site full in 2001, Dandora remains the principal rubbish heap for most of the garbage generated by the Kenyan capital's 3.5m inhabitants.
Between 850 and 2,000 metric tonnes of trash are disposed here every day.
The lower figure is from a report made in 2012 by advocacy group Concern World- wide; the higher figure emerged from a study carried out at Dandora in 2007 by the UN Environment Programme (UNEP).
All day a stream of garbage trucks - some belonging to the city council, some to private garbage collection companies - offload here.
Dumping is unrestricted, and the sprawling site contains every conceivable type of waste - industrial, agricultural, domestic and medical - all piled together into mountains of trash.
The dump's smell, which hits your nostrils from as far as a kilometre away, is made worse whenever the city council's bulldozer - only one operates here routinely - moves already-rotting waste deeper into the site. Once a week, city council officials set a section of the dump site on fire, releasing foul-smelling smoke and fumes into the air.
The dump is surrounded by the low-income settlements of Baba Dogo, Dandora, Kariobangi North and Korogocho. Many of the residents of these poor and densely populated neighbourhoods try to eke out a living by scavenging this unnatural landscape for its "treasure": much of the waste at Dandora is recoverable and sellable. Scrap metal, empty glass bottles, tin cans, plastics, polythene, rubber - all fetch a price in the city's market for waste plastic and scrap metals.
But despite the economic opportunity that it represents, Nairobi's garbage - that which finds its way to Dandora, and that which does not - presents serious, some- times life-threatening dangers.
For Mbaluti Mulili, the story starts at 4:30am every day, when he leaves his shack in the heart of the Mukuru Kwa Njenga slums, south of Nairobi, to get to the nearest bus stop by 4:45am. A minute later and the only source of his income - a rickety green garbage truck - will leave without him.
Garbage collection is a profitable business in Nairobi. It attracts thousands of formal and informal entrepreneurs. Mr Mulili works for garbage.com, one of the largest private collection companies, which has lucrative contracts with many middle- and upper-class residential estates.
He rides on the back of the truck, hanging on tight, loading the truck with sacks full of waste from the city's more affluent areas. But Mr Mulili has learnt to make an extra coin on the side, too. Before the truck makes its way to the Dandora dump, its final destination, he ferociously rummages through the day's haul for plastic and glass bottles, polythene bags, bottle tops, buckets and basins.
Mr Mulili - and many other garbage collectors like him - sells what he can to a middleman for $0.05 a piece. The middleman will then sell it to recyclers for $0.17. Scrap metal is sold for $1.50/kg. "From selling scrap, I can make as much as $3.40 on a good day. This, plus my monthly $70 salary, helps me raise my family [of seven]," the 35-year-old father said.
Garbage collectors are not the only people in Nairobi making a living off what other people throw away. People carrying dirty sacks on their backs and scavenging in dump sites and bins are a common sight in the city. The rubbish is often their only source of income.
Nairobi provides a fertile ground for such scavengers. Once popularly known as the "Green City in the Sun", the Kenyan capital is choking in mounds of uncollected and poorly disposed garbage. The Nairobi county government - backed by a UN study conducted in 2007- claims that the garbage that finds its way daily to the Dandora dump is only a quarter of all the rubbish generated by Nairobi's inhabitants every day.
The rest is heaped along city roads and in the narrow passageways of informal settlements, where it lies rotting or is washed into drains or downstream by rain. Waste management in slum areas is almost non-existent. Many residents in these parts have never seen a garbage truck.
The National Environmental Management Authority (NEMA) issued official guidelines on waste collection and management in 2006. The guidelines empower the environmental body to license transporters, incinerators, landfills, composters and recyclers. These rules, however, are seldom followed.
Although NEMA sometimes cancels the licences of rogue garbage collectors and takes collection companies to court for haphazard dumping, it has done little to bring order to the city's rubbish business.
Scavenging in Nairobi is not always simple. At Dandora it is particularly dangerous. Cartels, said to be connected to influential businessmen and senior politicians, control the dump.
These syndicates use street boys armed with guns and other crude weapons to collect kickbacks from licensed and unlicensed garbage collectors. They have literally zoned off the dump site. No member of a rival group is allowed into the other's territory.
"The Dandora dump site has been infested by armed gangs," said John Munene, a police officer at Molem police station, located about three kilometres from the dump. "It is like they are protecting a goldmine. Locals never venture into the dump site for fear of being killed."
The garbage lords hire street boys to dig through the garbage in search of recyclable products. So lucrative is the trash business that it is now characterised by assassinations and other forms of violence. In mid-October 2013, one of Dandora's most feared rubbish barons, popularly known as "Daddy", was stabbed to death by people believed to be from a rival gang who wanted to control his section of the dump.
Daddy's killing sparked off fierce gun battles between his followers and their rivals. When the guns fell silent, two lives had been lost. It took the intervention of Nairobi Senator Mike Sonko to restore calm around the dump site. The street urchins surrendered five guns after the lawmaker pledged a prize of $600 for every gun surrendered.
But the armed scramble for garbage is not Dandora's only problem. UNEP commissioned a study in 2007 on the dump site's effects on the health of children and adolescents living near it. Half of the 328 children and adolescents aged between two and 18 examined for the study had lead concentrations in their blood exceeding inter- nationally accepted levels.
Almost half of the children tested were suffering from respiratory diseases, including chronic bronchitis and asthma. The report found that Dandora residents are exposed to heavy metals and toxic substances through soil, water and air.
Moreover, 42% of the soil samples recorded lead levels almost ten times higher than what is considered unpolluted soil. "We had anticipated some tough and worrisome findings, but the actual results are even more shocking than we had imagined at the outset," said Achim Steiner, UNEP executive director, in the report.
"The Dandora site may pose some special challenges for the city of Nairobi and Kenya as a nation. But it is also a mirror to the condition of rubbish sites across many parts of Africa and other urban centres of the developing world," he said.
Blood and urine samples analysed by the UNEP study showed alarming levels of heavy metals, especially lead, mercury and cadmium. Lead and cadmium levels found on the dump site were 13,500 parts per million (ppm) and 1,058 ppm respectively.
The average natural abundance of cadmium in the soil is between 0.1 to 0.5ppm, while that of lead is between 50 and 400 ppm. "High levels of lead in the blood cause anaemia and kidney failure, while too much mercury leads to gastrointestinal and respiratory tract irritation," said Dr Joshua Marinyiny, a respiratory specialist working in Nairobi. "The effects of cadmium include kidney damage and irritation of the lungs."
A health centre run by St John's Catholic Church and Informal School in the nearby Korogocho slums treats more than 9,120 people per year on average for respiratory problems, said Japhet Oluoch, an accountant and freelance journalist who works for the church.
Plans to relocate the dump site after the Nairobi county government declared it full in 2001 were never realised. That year the Kenyan environment ministry pro- posed creating a new dump site at abandoned quarries in Kayole, another poor residential area 13km east of the city centre. The ministry has routinely blamed its failure to implement this plan on local politicians, whom it accuses of convincing residents to reject the move.
Another proposal, from the environment ministry and the Nairobi city council, to transfer the dump to Ruai - 27km east of the Nairobi central business district - was helved in April 2012 because the Kenya Airports Authority said it would attract birds and put airplanes at risk. The Nairobi county government is yet to identify an alternative location for a new dump site.
In 2004 cabinet ministers and civic leaders rejected a $40.4m deal between the government and Jacorossi Impresse, an Italian firm, that would have established a waste recycling plant at the Dandora dump site, on the grounds that local leaders and residents had not been consulted.
St John's Catholic Church has always advocated recycling because "taka ni pato", or "trash is cash" in Swahili, Mr Oluoch said. The church has presented a case for decentralised solid waste management, he said. It calls for dividing Nairobi into eight regions, each equipped with a waste- collection and sorting point where entrepreneurs can buy rubbish for onward recycling. The rest would be discarded at the Dandora dump site for treatment.
"Only unrecyclable waste from the collection and sorting points should be disposed at Dandora, and all health and environment issues put into consideration to ensure that lives are not affected by the continued encroachment of the dump site into mainstream neighbourhoods," Mr Oluoch said. The Dandora dump site should be fenced and only those certified to work there should be allowed entry, he added. The government initially resisted looking into any issue related to the dump site, Mr Oluoch said.
But several government ministers and officials from environmental agencies have in recent years visited the site to speak with locals, collectors, sorters and garbage collection companies.
The environment ministry's department of climate change and NEMA held a meeting at the dump site in 2011 and agreed to develop a solid waste management policy. Former president Mwai Kibaki's government issued an international tender for the decommissioning of the dump site shortly after this meeting.
No progress, however, has been made. While the government dithers, Nairobi's garbage collectors, like Mr Mulili, will continue to eke out a meagre living despite the health hazards and the deadly gangland competition.