The goal of this investigation was to identify the major causes and likely sources of the increased of physical and fluoride concentration in water resources of gamawa area with the aim of providing full details of fluoride mineralization if any. A total of 20 water samples were collected from various sources of groundwater tapping through boreholes and hand dug wells and from surface water of Bunga Jamaare river system passing through the study area. The field work comprise desk study where all previous literatures published was search to review the study area before field work and all field kits were collected such as sample bottle, Electrical conductivity meter, Thermometer, GPS, Pen, Field note book and sample bags. On the field twenty (20) water samples were collected which comprises of ten (10) from hand dug wells within the study area randomely selected, five (5) from surface water was collected at interval of one kilometer and five samples were (5) collected from boreholes selected within the research horizon Figure 5. The top film of the surface water and groundwater were removed, two litres of water samples was then collected in clean dry plastic bottles filled completely and cap tight to avoid excessive agitation or exposure to sunlight. Each sample was then labelled and preserved in the refrigerator until when they are ready for chemical analysis. The position of each sample location was taken using Global Positioning System (GPS) Garmin type. Physical parameters of the samples such us electrical conductivity, temperature, total dissolve solid and hydrogen exponent were measured directly on the field at spot. After the field work, samples were carried to the laboratory for chemical analyses at the University of Maiduguri Department of Geology Laboratory. The analytical method employed includes Atomic Absorption Spectrometry and Flame Photometry which was adopted for the analysis of Fluoride respectively.
The results obtained include TDS which ranges from 30 to 335mg/l, EC ranges from 70 to 660 µS/cm, pH ranges from 6.9 to7.8, and Temperature ranges from 36 to 42.1Oc while the Fluoride concentration ranges from 00.0 to 0.79mg/l. The concentration of fluoride in groundwater in Gamawa is very low may be as a result of the low rate of groundwater recharge sources such as rainfall in arid regions lead to prolonging water–rocks interaction which causes elevation of fluoride content became lower in groundwater or as a result of high evaporation causes precipitation of lower solubility minerals (CaCO3-) which reduce the availability of calcium ions in groundwater and promote dissolution of fluorite minerals. Therefore there is need for artificial addition of fluoride to the drinking water of the study area but, this have to be taken with precautions to avoid high fluoride concentration in the drinking water within the research area and further ascertain the groundwater quality of the study area so as to understand what actually causes dental fluorosis and dental carries to many inhabitant of the study area.
Keywords: Gamawa, Fluoride, Groundwater, Surface water, Hand dug wells and Boreholes