QUALITY EVALUATION OF EARTH DAM AND POND WATER IN GELLA, MUBI SOUTH LOCAL GOVERNMENT AREA Abstract

The present work was to evaluate the quality of ponds and earth dam water of Gella town in Mubi South Local Government Area of Adamawa State in order to examine its suitability for drinking and domestic purposes. Four ponds and an earth dam water samples were collected each during dry seasons between the months of November to April 2015/2016. The samples were analyzed using arithmetic mean and standard deviation which was then compared with the World Health Organization (WHO) and NAFDAC standard. Physicochemical parameters were studied using standard methods, concentrations of heavy metals determined using atomic absorption spectroscopy and bacteriological analysis conducted using standard methods. Result of the analyses revealed that the water samples were slightly acidic to slightly alkaline (pH 5.60 ± 0.17 – 7.20 ± 0.12).The calcium concentration in water studied were all below that of magnesium concentration which was between 0.94±0.01 to 2.17±0.01 mg/L and these magnesium concentrations were within permissible WHO and NAFDAC recommended standard limits. While the coliform count were above WHO and NAFDAC standards for drinking water, and the water samples were good for drinking and domestic purposes. Water treatment and regular monitoring of the water quality of the area and provision of industrial motorized borehole water for easy distribution to the community have been strongly recommended.

within the scope of present study.
In Nigeria today research indicates that, majority of the common water sources are polluted, resulting to serious outbreak of these and other diseases. The major issues of national and international interest are how these water pollution problems could be fully assessed and mitigated, proper knowledge and planning are thus essential. This paper aimed at evaluating the quality of ponds and earth dam water in Gella town, Mubi South Local Government Area of Adamawa state in order to provide data and information on the physical properties, chemical properties and heavy metals (such as iron, manganese and zinc), concentration of pond and dam water in this area. The data information that will be generated can serve as a guide in monitoring water contamination; it will also be useful in creating a baseline data of pond and dam water quality in the area under study.

STUDY AREA
The study was carried out in Gella, Mubi South Local Government Area of Adamawa state situated at the lower contour of Mandara Mountains, which separates Nigeria from Cameroon. Gella is the Headquarter Mubi South 98.34'' N and longitude 13 o 29' 97.65'' E [6]. Mubi is about 240 km from the State capital, Yola ( Figure 1).
According to the 2003 population projection of Mubi South is about 187.2 per square kilometers. The climate controls the amount of water that is available at the surface and subsurface at a given time. Virtually all rivers in Gella, Mubi South Local Government Area are dry, during the dry seasons. The people of Gella are predominantly farmers. Their major economic activity is crop production and livestock husbandry. Among the major crops cultivated include cereals such as maize, sorghum and legumes such as cowpea and ground nuts and potato tubers. Their subsidiary activity is extensive livestock production using range-land, crop residues and stored fodder. They keep large variety of animals among which are cattle, poultry, and sheep /goats.

SAMPLE COLLECTION
There are five ponds and one earth dam in Gella used by the community as a source of drinking water. The five ponds and one Bogga earth dam ( Figure 1) water samples were collected randomly in triplicate at Gella, Mubi South Local Government Area Adamawa State. Water samples were collected during the dry season between the months of November to April 2015-2016, using sterile 1000 cm 3 polyethene bottles. The water samples were preserved with HNO 3 .

TEMPERATURE AND pH
The temperature and pH of the water samples were measured at the point of collection according to the method described by Alexander [7]. The pH was measured using pocket sized pH meter while the temperature was measured with the help of mercury-in-glass thermometer graduated up 110 o C.

MEASUREMENT OF COLOR
The color of water samples was determined spectrophotometrically using the method of Gimba [8]. A DR 2000 (HACH) Spectrophotometer at wavelength of 450 nm was used.

MEASUREMENT OF TOTAL DISSOLVED SOLID (TDS) AND ELECTRICAL CONDUCTIVITY (EC)
The Total Dissolved Solids and Electrical conductivity was measured using a TDS/conductivity meter as described by Ishaku et al. [9]. 200 mls of distilled water and 200 mls of water sample was poured into two separate beakers. The TDS / conductivity meter switched on, and its sensor rod was dipped into the beaker containing distilled water which was given a reading 0.00 mg/L TDS. After that, the sensor rod was dipped into the second beaker containing water sample, the TDS/conductivity was then display the TDS value in mg/Liter.

MEASUREMENT OF TURBIDITY
Turbidity was measured using DR 2000 (HACH) spectrophotometer using the method of Mustafa et al. [10].

DEMAND (COD) AND DISSOLVED OXYGEN (DO)
Biochemical oxygen demand (BOD), Chemical oxygen demand (COD) and Dissolve oxygen (DO) were determined as describe by Onwughara et al. [11]. Five-day Biochemical Oxygen Demands (BOD5) was determined titrimetrically after incubation in tightly stoppered BOD bottles in the dark at 20 o C. Dissolve oxygen content of the sample water was determined using digital dissolved oxygen meter Calculation of COD: Where A= Total volume of KMnO 4 0.0125M added to the samples.

DETERMINATION OF HEAVY METALS
Magnesium, calcium and some selected heavy metals (iron, manganese and zinc) were determined using Atomic Absorption Spectrophotometer (Buck Scientific 210) as described by Babagana et al. [12]. In determination of magnesium, calcium and heavy metals concentration using Atomic Absorption Spectrophotometer (Buck scientific 210) was used. The water sample was aspirated into the instrument after all the necessary set up and standardization procedures. Atomic vapor was produced as the sample drop on the acetylene flame, a beam of monochromatic light with a wavelength at which only the element of interest was absorbed, passed through the flame. The atom of the element in flame absorbed some amount of light which was corresponding to its concentration. This was detected on the display unit read as the absorbance. A calibration curve of each element was plotted using the absorbance of the standard against their corresponding concentration and was used to determine the concentration of the elements in the samples.

BACTERIOLOGICAL ANALYSIS
The bacteriological analysis was carried out according to Uwama [13]. Five sterile test tube was placed on a test tube rack. 9 ml of sterile saline was prepared and added into each of the five sterile test tube. m1:10 serial dilution of E. coli broth up to 10 5 was made and 0.2 ml of 10 -5 dilutions was transferred into duplicate nutrient agar plate and the plate was labelled. A sterile glass spreader was used for sterilizing, by dipping it into alcohol and burn off alcohol over flame. The 0.2 ml of 10 5 dilution was spread evenly over the plate and allowed to dry.
The agar plate was incubated by inverting it at 37 o C for 24hours this was repeated for 10 -6 , 10 -7 dilutions. The total Coliform Unit (CFU) was examined and counted. The results were recorded. The number coliform unit was calculated using the formula Number of CFUs per ml =1/vol. plated × dilution factor × average no. of colonies.

STATISTICAL ANALYSIS
Mean and standard deviation were used for statistical analysis and the results were presented as mean ± standard deviation.

RESULTS
The result of physicochemical parameters of ponds and earth dam waters of Gella, compared with  The result of the total coliform count in earth dam and pond waters in Gella ranged from 510 to 6100 CFU/100 ml (Table 3).