TC Cameroon: Pilot Study on Groundwater Quality and Health in Yaoundé

Country / Region: Cameroon, Yaoundé

Begin of project: August 1, 2011

End of project: December 31, 2013

Status of project: December 31, 2013

Student sampling groundwater Source: BGR

Background:
The German Federal Ministry of Economic Cooperation and Development (BMZ) funded a geo-studies specialists fund project (GeoSFF) which was carried out by the Federal Institute for Geosciences and Natural Resources (BGR), together with their partner, the National Institute of Statistics (INS) in Yaoundé, the capital of Cameroon. The Institute for Hygiene and Public Health (IHPH) of the University of Bonn and the Waste Water Research Unit (WWRU) of the University of Yaoundé 1 are also involved. The project idea was developed by INS during a 4-month GIS training period at BGR in 2010. INS wants to set up a pilot geographic information system (GIS) infrastructure within the "Cartographie et Statistiques de l‘Environnement" unit.

Following a joint excursion considering groundwater and sanitation issues in socially diverse neighborhoods of Yaoundé, a project opening workshop with stakeholders representing the city of Yaoundé, the Ministry of Health (MINSANTE), the Ministry of Energy and Water (MINEE) and the Ministry of the Economy, Planning and Regional Development (MINEPAT), the water supply company, the German Society for International Cooperation (GIZ) and the German Embassy took place in December 2012 in Yaoundé.

Microbiological sample analysis Source: BGR

Following this BGR started work on the development of the project infrastructure based on the concept of "Free and Open Source Software for Geographic Information Systems" (FOSSGIS). This consists of the desktop-GIS QGIS, the database server PostgreSQL, in conjunction with PostGIS, and the software R® for statistical analysis and graphical visualization. This environment is freely available, powerful, scalable, easily transferable and royalty-free for common system architectures. Personalized customizations or enhancements are possible at any time and remain with the user. One requirement of INS was to have open source software (OSS) installed and this is used productively by them at the server level.

Starting the questionnaire campaign Source: INS / BGR

At the same time, a water sampling campaign in the city of Yaoundé was conducted. This took place from 23.03 to 13.04.2012 as a combined (ground) water sampling campaign (led by BGR) and a parallel microbiological analysis campaign (led by IHPH). INS and WWRU arranged logistical support. WWRU at the Faculty of Science, University of Yaoundé 1, provided the necessary laboratory infrastructure. Students from the research laboratory supported the campaign as assistants. The fieldwork was preceded by two days of theoretical and practical training, followed by a joint field exercise, which was attended by students, stakeholders and the other partners. Thereafter, two field teams recorded 113 (ground) water supply points in the city and then took a total of 57 qualified samples of ground and surface water. Forty-eight microbial and inorganic parallel sample analysis was carried out under contracts awarded by two Cameroonian analytical laboratories. Comparison and control analysis (inorganic) of these samples was also performed at the water analysis laboratories of BGR, as was the determination of volatile organic constituents (VOC, BTEX).

Final workshop team Source: INS / BGR

The field campaign of BGR, IHPH and WWRU was followed by a project-specific health survey of 1,130 households in the project area and in a comparable area of the city that represented a different socio-economic structure and different hydrological conditions. In July 2012, GIS training of INS-staff took place at BGR on the basis of cooperatively collected geo-referenced data using Quantum GIS. The analysis of the research results followed. A technical report has been jointly authored. This report was presented to the Cameroonian stakeholders in Yaoundé (Ministries, City Council and scientific community) under the auspices of MINEPAT, in the presence of the German Ambassador in June 2013 in the Hilton Hotel. On this occasion the recommendations were discussed and amended. The results of the study are summarised below.

Results:
The pilot study on the pollution of ground and surface water in Yaoundé in relation to the health of the population (acronym: EPESS) is an effort to collect primary field data, carried out jointly between INS, BGR and IHPH. The primary objective of the EPESS study is to deliver reliable statistical indicators for a sustainable environmental management of the City of Yaoundé. These indicators shall serve to improve the living conditions of its population.

Location of sampling sites Source: INS / BGR

To meet this objective, the study combines different methodological approaches a) combined groundwater sampling campaign and laboratory analysis performed both at Yaoundé and Hanover, b) quantitative household survey on water and health related issues and c) a qualitative approach based on discussions with focus groups. In addition to a general view on the City of Yaoundé, the quantitative survey allows the comparison of five "spatial clusters" (fr: grappes). These spatial clusters can be differentiated by their hydrological environment, by their degree of town planning and their social structure.

Almost 90 % of the households in Yaoundé would consume treated potable water if the demand could be met. In the case of supply shortages of piped water, these households rely on stored reserves (54.7 %) or on bottled mineral water (10.2 %). Untreated water sources being used are production wells (5.7 %) but also springs (10.6 %) and shallow dug wells (12.8 %). The latter two are very unsafe from a hygienic perspective.

The shortages of piped water are due to frequent temporary cuts by the water supplier CAMWATER which have become common in the City of Yaoundé last two years. Almost 69.0 % of Yaoundé households stated that they suffer from piped water cuts at least four times a month. These temporary and frequent water cuts force households to resort to shallow dug wells (35.9 %) or springs (5.6 %). Less than half of these shallow wells/springs can be considered « amended » (46.6 %) in a perceptible sense. Using water from these dug wells/springs carries a major risk of infection.

Spatial distribution of electrical conductivity Source: INS / BGR

The quality of urban groundwater has been assessed based on 39 groundwater samples which were analyzed for a variety of microbiological and hydrochemical parameters. Samples were taken at the end of dry season 2012 in five spatial clusters. The results obtained for 21 shallow dug wells, 14 springs and 4 production wells showed a considerable presence of fecal bacteria in the water. This shows the considerable risk to which the population, forced to use groundwater due to water cuts, is being exposed. The analysis of nitrate (NO₃) as a chemical parameters showed that 51 % of all groundwater samples exceed the WHO concentration limit of 50 mg/l NO₃. From the chemical quality perspective, this groundwater is not suitable for human consumption. This applies in particular to babies and children under five years of age. It adds to the outlined microbiological risk and aggravates morbidity. The chemical analysis of groundwater has shown a strong, systematic and direct impact of waste water discharge procedures on groundwater quality. This is exemplified in the spatial distribution of nitrogen, chloride, potassium and sodium concentrations in groundwater. High and extreme concentrations are found next to the upstream limits of human settlement.

The location of the water tap is inside the household in 41.0 % of cases and with the neighbour in 39.5 % of cases, while it is located in the courtyard in 19.5 % of cases. This indicator is not only linked directly with the problems of water supply, but also with hygiene and the option to build and use modern flush toilets.

Spacial distribution of nitrate Source: INS / BGR

Local and disorganised waste water discharge is the consequence of the absence of a centralised sewage system in large parts of Yaoundé. Near to 58 % of households discharge their waste water into the next gutter. This situation affects the health of the local population. Excreta and toilet water are discharged into septic tanks by 52.0 % of households, while 34.2 % discharge into a pit latrine. It has to be noted that a non-negligible proportion of households (15.3 %) use the gutters for the discharge of excreta and toilet waste water, thereby creating immediate health risks.

Emptying septic tanks is not usually being practiced in Yaoundé, given that 73.6 % of all households declare to not having emptied their septic tanks within the past 10 years. The widespread use of unserviced septic tanks and pit latrines for waste water discharge constitutes a permanent load of nutrients and microorganism to the subsurface environment. Nitrogen and mineral salts find their way into the urban groundwater. The shared use of toilets by neighboring households (55.7 %) is frequent in Yaounde, indicating the situation how conditions of hygiene are shared amoung the neighbourhood. Badly cleaned and maintained toilets can be a source of contamination and disease. Moreover, with four to six households participating, the shared use of toilets is more pronounced.

Approximately 80 % of households use the services of the local waste utility HYSACAM to dispose of their household wastes on a regular basis. Although this is an elevated percentage of waste collection service coverage, more efforts remain for public administration to extend these services to households not currently being served. A large proportion (11.6 %) of those unserviced households dispose of their wastes into the scrubs or the courtyard.

Spatial distribution of E. coli Source: INS / BGR

The unhealthy state of the urban environment can be described by the presence of insects and objectionable animals in the lodgings. Vectors for deseases like cockroaches (92.6 %), mosquitoes (91.2 %) and mice/rats (87.1 %) are ubiquitary phenomena in households. With this widespread presence they have to be considered as important risk factors for the wellbeing of the population.

Within the reference period of the two weeks prior to the survey, the results show that 12.3 % of persons in households have been ill. Of those reported ill, 10.9 % suffered from one illness, while 1.4 % suffered from two or more deseases.

The percentage of morbidity during the reference period amounts to 5.9 %. With 5.3 % of prevalence, malaria is the most widespread disease. The other water-borne diseases, such as typhoid fever, amoebic and bacterial dysentery, diarrhea and skin diseases seem to be less widespread (< 1 %). Yet, their prevalence is elevated, compared with levels from other comparable scientific studies. The prevalence of non-water borne diseases such as asthma, caries, headaches, stroke, gastric infections, cough and measles is 5.9 %.

The mode of waste water discharge is more correlated with the prevalence of water-borne deseases (7.0 %) than with non-water bourne deseases (4.9 %). This prevalence of waterborne deseases can be attributed mainly to the widespread and rampant prevalence of malaria in the population of Yaounde. Nevertheless, frequent cases of water-borne diseases such as typhoid fever, amoebic and bacterial dysentery and diarrhea were reported at the end dry season. Therefore it is recommended that actions are taken to reduce the effects of water-borne diseases on the health of the population.

Literature:

Final Report

Final Report (reduced size)

Paper

FOUEPE, A., EYONG, G.T., KUITCHA, D., KRINGEL, R., YETOH, W.F., NDJAMA, J. & TEJIOBOU, A. (2020): Hydrogeochemistry and groundwater flow mechanisms in shallow aquifer in Yaounde, Cameroon. - Water Supply 20(4): 1334–1348; doi: 10.2166/ws.2020.050
KRINGEL, R., RECHENBURG, A., KUITCHA, D., FOUEPE, A., BELLENBERG, S., KENGNE, I.M. & FOMO, M.A. (2016): Mass balance of nitrogen and potassium in urban groundwater in Central Africa, Yaounde/Cameroon. - Science of the Total Environment 547: 382-395; doi: 10.1016/j.scitotenv.2015.12.090

Presentations / Posters

Partner:

National Institute of Statistics (INS), Yaoundé, Cameroon
Marie Antoinette Fomo
E-Mail: ma.fomo@yahoo.fr

Institute for Hygiene and Public Health (IHPH), University of Bonn, Germany
Dr. Andrea Rechenburg
E-Mail: andrea.rechenburg@ukb.uni-bonn.de

Wastewater Research Unit (WWRU), University of Yaoundé 1, Cameroon
Prof. Dr. Ives Magloire Kengne Noumsi (late 2020)

Contact 1:

Dr. Robert Kringel

Phone: +49-(0)511-643-2452

Fax: +49-(0)511-643-3664

E-Mail: Robert.Kringel@bgr.de

Contact 2:

Dr. Kristine Asch