Nature's Voice Our Choice

Drought, Increased Desertification, and Falling Water Tables Have Led to Mass Migration from Rural Areas into the Cities in Search of Work

 A Growing Problem

In the desert village of Ksar Terchane, in the Northern Adrar Region of Mauritania, West Africa, water is the most valuable resource. Villagers live on less than 2 liters (1/2 gallon)/day including drinking, cooking, bathing, and washing dishes and clothes. Traditionally desert nomads, Mauritanians have become experts in water conservation; not a drop is wasted.
+ When thirsty you drink milk
+ Dishes are washed without soap so that the goats can drink the left over water
+ Bathing is done with a (teapot), permitting a decent bath with only a liter of water.
However in the late 70's drought and increased desertification began to alter their lifestyle, first requiring settlement in oasis villages in order to find water and grow food. Later, as wells dried up, grazing forage for goats ceased to exist, firewood became impossible to find, and as the hot desert winds became relentless, many began to migrate to the cities in search of work.

The capital, Nouakchott, has grown from a population of 50,000 to over 1 million in the last 20 years. As a Peace Corps Volunteer, I traveled from Ksar Terchane to the capital city every few months and witnessed this transformation. I watched as one by one, families from the village loaded up all their belongings in the back of a taxi, tied the goats on top, and headed off to Nouakchott with the promise of a better life in a place which many of them had never visited. As I watched, I couldn't help thinking of "The Grapes of Wrath".

Like many large cities in the developing world the population growth does not match the infrastructural growth. Therefore, the majority of the population lives in shanty towns on the peripheries of Nouakchott.  Although their environment has changed, the need to conserve water has not. For the majority of these families living on the peripheries of Nouakchott, access to running water does not exist and buying water in barrels is 10 times more expensive than tap water in the city's center; thus making agriculture production nearly impossible. Market gardeners previously tapped into the city's main line that pumps water from an aquifer 60 km (37 miles) east of Nouakchott. However, increase demand in Nouakchott's affluent neighborhoods required the city to regulate and prohibit this activity. In addition to the problem of potable water access, peripheral neighborhoods have become the dumping grounds for waste water (from septic tanks that have been pumped from affluent neighborhoods). This waste water was once dumped at the edge of town, however as the city grew and the price of fuel rose, the trucks began dumping in open lots in the shanty towns.  This area is also the dumping grounds for solid waste, these areas have become waste swamps filled with mosquitos, odors, and disease - a health hazard nightmare.  The poorest of these neighborhoods is called 'Kebbah' which in Hassaniya language means ‘garbage’.  The wrath is felt daily by these former villagers who once enjoyed the beauty and cleanliness of open spaces.

This problem in not specific to Nouakchott, it exists throughout the developing world in large cities that have an influx of people searching for ways to survive after their lands have become uninhabitable due to desertification, deforestation, erosion, soil salinity, and depleting water resources.

A Solution That Works

In November, 2003, motivated by an idea from former US Ambassador to Mauritania, John Limbert, we I started a local Nonprofit Organization called Nature's Voice - Our Choice with the goal of developing a system that could treat waste water using aquatic plants found in the nearby Senegal River. The goal was to create a pilot project that could:
+ be duplicated in peripheral neighborhoods
+ be constructed locally with minimal expense
+ function using only manual labor
+ be operated and maintained by local women
+ treat domestic waste water to World Health Organization standards for irrigation of vegetables for human consumption.

Mauritanian Women Operate and Maintain a Waste Water Treatment System Which Provides Them with Irrigation Water for Producing Vegetables

We partnered with the owner of a local apartment complex who agreed to let us use the lot adjacent to his complex as an experiment in "What is possible", in exchange for finding a solution to his waste water problem. 

The oldest method of waste water treatment is aerobic decomposition through natural processes (flow of water over rocks and plants, through sand, and in streams wherebacteria break down the waste). Natural aerobic decomposition of wastewater is a long process, but it is possible to recreate nature.  How? By constructing basins filled with aquatic plants and constructed wetlands. There are numerous types of aquatic plants that  can be used in wastewater treatment; however, for this project we chose water lettuce and water hyacinths for the basins and cattail and bulrush for the wetlands due to their proven effectiveness in other experimental projects and availability in the nearby Senegal River. Water lettuce and Water Hyacinths are buoyant and grow on the surface of fresh water streams, rivers, and lakes. The plant roots provide an ideal environment for aerobic bacteria to grow.  The contact of waste water with large surface areas of aerobic (good) bacteria is the process of aerobic decomposition during secondary treatment. For irrigational purposes, recycled water may be used after secondary treatment. At this stage harmful bacteria and chemical levels have been sufficiently reduced and the remaining inorganic compounds primarily (nitrogen, phosphorus, and potassium) are beneficial to the soil as an alternative to chemical fertilizers; replenishing nutrients that are lost during crop production. 

Our Programs Include Training on Market Gardening, Vegetable Production, and Small Animal Husbandry

Aquatic plants reproduce quickly requiring a third of them to be harvested twice a week. Harvesting the plants involves simply removing them from the water with a pitch fork. The harvested plants are utilized to produce the following products:  mulch, compost, silage serving as a high nutrient animal feed.  A team of six Mauritanian women were trained for one month in the operation and maintenance of the system, as well as health and socioeconomic impacts. The women continue to operate the system producing 1000 liters of treated water/day that is used to irrigate a 900 square meter plot of land producing vegetables, trees, ornamental plants, animal feed and a continuous source of income for their families. Women who once woke each day wondering what they would feed their families have now found value in waste water.