Home / Environment / From raw to artificial bone: How Catholic Diocese of Nakuru is contributing to water safety
Esther Photo: Esther Wanja, the Programme's Project Officer with a sample of bone char. The programme has been using the bone char technology for years now to filter fluoride from water.
Esther Photo: Esther Wanja, the Programme's Project Officer with a sample of bone char. The programme has been using the bone char technology for years now to filter fluoride from water.

From raw to artificial bone: How Catholic Diocese of Nakuru is contributing to water safety

By Kioko Kivandi

In 1984 Kenya was hit by a severe drought. The country’s food banks were severely stressed just as were its water sources.

Writing about it in July that year, Allan Cowell, a New York Times journalist noted that rain clouds would gather in the morning but by noon they would all vanish, “like a promise betrayed by the seasons”.

It is because of this that the Catholic Diocese of Nakuru (CDN) – whose vastness stretches from Nakuru to Baringo regions – felt obliged to supply water to communities in hard hit areas, especially, those in Baringo.

“We started drilling boreholes in Baringo,” says Hillary Korir, the Diocesan Caritas Director. Unfortunately the water from the boreholes was worsening the situation.

“When we conducted tests we realized that it had very high levels of fluoride. It’s like we were giving people poison.”

The consumption of high levels of fluoride can lead to dental fluorosis – a condition in which teeth lose their milky colour and slowly turn brown. While this can be embarrassing from a social point of view, severe cases can lead to loss of the teeth all together.

The World Health Organization (WHO) recommends a fluoride content of not more than 1.5 mg per liter in water that is used for cooking and drinking. Research has established that ground water sources in the Rift Valley (the region in which Nakuru and Baringo are found) can have fluoride levels of up to 50 mg per liter of water.

“We discovered that we were denying people opportunities,” Korir says.

Apart from dental fluorosis, over consumption of water with the chemical contaminant can lead to skeletal fluorosis – a condition where someone’s bones are damaged and become too painful to even support them.

It is because of this that in 1998 the diocese launched a programme on water quality whose mandate was to research, develop and implement a technology that would reduce the fluoride levels in water to the WHO recommended guidelines.

The challenge then was to have a technology that would not only serve this task but also be simple enough to be a ‘do-it-yourself’ among the target communities. So the diocese decided to use the bone char technology.

Bone Char Technology

Bone char technology involves the use of raw bones to siphon fluoride from water. The bones are burnt at very high temperatures for close to two weeks, they are crushed, sieved, cleaned, and put in containers through which water is run as the fluoride ‘sticks’ to calcium, a chemical found in bones.

Since its inception this technology has seen hundreds of households supplied with low-cost family sized filters. These filters are also fitted with ceramic candles to take out bacterial contaminants.

And apart from the family sized filters the diocese has had the same technology applied in bigger tanks that supply water to communities.

But bone char had a low uptake of fluoride and it was not easy to regenerate. Thus the diocese devised a new model that involved the use of pellets rich in calcium and phosphorus that are mixed with the bone char and put in the water filters.

“This elongated the life span of the bone char three times,” discloses Nancy Wanjiku, a Laboratory Manager of the programme that has since grown to become a fully-fledged company – the Nakuru Water Defluoridation Company.

However, just like the bone char, the pellets were also difficult to regenerate and this is how the diocese devised the use of an artificial bone or the hydroxyl-apatite model (HAP).

 Hydroxyl-apatite (HAP) model

This involves the industrial production of an artificial bone that serves the same purpose as the bone char; its trade name is ‘Fluorolith’.

Wanjiku says, this technology which is more than two years since it was introduced, has a higher fluoride uptake than the first two.

“HAP is made from calcium hydroxide and phosphoric acid feed grade. This is usually put in containers that can withstand some pressure,” she adds.

The project's plant that in which the artificial bone is made. This is the latest technology that the programme is employing to filter fluoride from water.
The project’s plant that in which the artificial bone is made. This is the latest technology that the programme is employing to filter fluoride from water.

Thus this technology is unlike the first two that only depend on gravity. It is also much more industrialized, can be used in places whose water sources have very high levels of fluoride and is easy to regenerate since the diocese has an automated regeneration system that is fast and efficient. This makes the HAP technology much better than the first two.

Need for water safety policies

Apart from Kenya, the diocese has implemented water quality projects in South Sudan, Tanzania, and Ethiopia.

Such projects have been necessitated by the rising demand of water among communities that has seen an increase in the use of underground water sources which unfortunately, have high fluoride content in some regions. The rising demand has partly been pushed by increase in populations and changes in climate change that have seen depletion of surface water and a drop in rain water.

According to Esther Wanja, the programme’s Project Officer, since communities are unable to sustain their demand using surface water, there is need to put more emphasis on the quality of underground water sources.

“We need policies that track on chemical contaminants,” she says as her colleague Wanjiku adds that provision of quality water should be given the same priority as water supply.

“Sometimes you find that there is no enough water, leave alone quality water. So supply is always prioritized.”

It’s been a long journey; from an awakening call of a dry spell to the provision of ‘poisoned’ water, and finally, to the provision of quality water. As the diocese lives to fulfill its vision of a “fluorosis free society” it also hopes that one day communities will embrace its slogan on water quality dabbed “my water, my esteem”.

About shitemi khamadi

Shitemi is the Kenya Monitor Managing Editor. He trains journalists on basics of journalism, storytelling, conflict sensitive journalism and devolution.

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