In the desert town of Ksar Terchane, in the northern Adrar region of Mauritania, West Africa, water is the most valuable resource. The villagers live on less than 2 liters (1/2 gallon) per day, which includes drinking, cooking, bathing, and washing dishes and clothes. Traditionally desert nomads, Mauritanians have become experts in water conservation; not a drop is wasted.

+ When you are thirsty you drink milk

+ Dishes are washed without soap so that the goats can drink the leftover water

+ The bath is done with (teapot), which allows a decent bath with only one liter of water.

However, in the late 1970s, drought and increased desertification began to alter their way of life, first requiring settlement in oasis villages to find water and grow food. Later, when the wells dried up, the fodder for the grazing goats ceased to exist, firewood became impossible to find, and when the hot desert winds became relentless, many began migrating to the cities in search of food. job.

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, the village families loaded all their belongings into the back of a taxi, tied their goats on top, and headed for Nouakchott with the promise of a better life in a place many of them had never known. visited. As I watched, I couldn’t help but think of “The Grapes of Wrath.”

Like many large cities in the developing world, population growth has not matched infrastructure growth. Therefore, the majority of the population lives in slums on the outskirts of Nouakchott. Although your environment has changed, the need to conserve water has not. For most of these families living on the outskirts of Nouakchott, access to running water does not exist and buying barreled water is 10 times more expensive than running water in the city center; which makes agricultural production almost impossible. Market gardeners previously tapped into the city’s main line that pumps water from an aquifer 60 km (37 mi) east of Nouakchott.

However, the increase in demand in the wealthy neighborhoods of Nouakchott forced the city to regulate and prohibit this activity. In addition to the problem of access to drinking water, the peripheral neighborhoods have become dumping grounds for wastewater (from septic tanks that have been pumped from the tributary neighborhoods). This wastewater was once dumped on the outskirts of the city, however as the city grew and the price of fuel rose, trucks began dumping in open lots in the slums. This area is also the solid waste dump, these areas have turned into waste swamps full of mosquitoes, odors and diseases, a dangerous health nightmare. The poorest of these neighborhoods is called ‘Kebbah’, which in the Hassaniya language means ‘garbage’. The anger is felt daily by these former villagers who once enjoyed the beauty and cleanliness of open spaces.

This problem is not specific to Nouakchott, it exists throughout the developing world in big cities that have an influx of people looking for ways to survive after their land has become uninhabitable due to desertification, deforestation, erosion, soil salinity and depletion of water resources.

In November 2003, prompted by an idea from former US Ambassador to Mauritania John Limbert, I started a local non-profit organization called Nature’s Voice Our Choice with the goal of developing a system that could treat wastewater using aquatic plants found in the vicinity of Senegal. River. The goal was to create a pilot project that could:

+ duplicate in peripheral neighborhoods

+ be built locally with minimal expense

+ function using only manual labor

+ be operated and maintained by local women

+ treat domestic wastewater according to the standards of the World Health Organization for the irrigation of vegetables for human consumption.

We partnered with a local apartment complex owner who agreed to let us use the lot adjacent to his complex as a “What’s Possible” experiment, in exchange for finding a solution to his wastewater problem.

The oldest method of wastewater treatment is aerobic decomposition through natural processes (water flow over rocks and plants, through sand, and into streams where bacteria break down the waste). The natural aerobic decomposition of wastewater is a long process, but it is possible to recreate nature. As? By building ponds 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 watersheds and cattails and cattails for the wetlands due to their proven effectiveness in other experimental projects and their availability in the nearby Senegal River. Water lettuce and water hyacinths float and grow on the surface of freshwater streams, rivers, and lakes. Plant roots provide an ideal environment for aerobic bacteria to grow. Contact of wastewater with large surfaces of aerobic (good) bacteria is the process of aerobic decomposition during secondary treatment. For irrigation purposes, recycled water can be used after secondary treatment. At this stage, the levels of harmful bacteria and chemicals have been sufficiently reduced and the remaining mainly inorganic compounds (nitrogen, phosphorous and potassium) are beneficial to the soil as an alternative to chemical fertilizers; replenish nutrients that are lost during crop production.

Aquatic plants reproduce rapidly, requiring a third of them to be harvested twice a week. Harvesting the plants involves simply lifting them out of the water with a pitchfork. Harvested plants are used to produce the following products: mulch, compost, silage that serves as nutrient-dense animal feed. A team of six Mauritanian women received training for a month in the operation and maintenance of the system, as well as in health and socioeconomic impacts. The women continue to operate the system producing 1000 liters of treated water/day which is used to irrigate a 900 square meter plot of land that produces vegetables, trees, ornamental plants, animal feed and a continuous source of income for their families. Women who once woke up each day wondering what they would feed their families have now found value in wastewater.