3.2 Sample Collection
Fifty samples water used for domestic purposeswere collected from wells, dams, rivers, and municipal tap water supplies at different locations around Malete community. All samples were collected and kept in 1litre sterilized plastic bottles, and stored in insulated cooler containing ice and delivered on the same day to laboratory and all samples were kept at 4 °C until processing and analysis.
3.3 Physicochemical characteristics of the domestic water
The physicochemical parameters temperature (°C), pH and conductivity (μS/cm) were measured with portable devices immediately after sampling at each site (temperature: Delta Ohm HD8601P, Delta Ohm; Padua, Italy; pH: Eutech Cybernetics pHScanWP2, Eutech Instruments; Singapore and conductivity: HACH Model C0150 conductivity meter, HACH Company; Loveland, CO, USA).
The temperature was first measured with a thermometer by inserting into the samples collected and allowed to stand for one minute, then the result was immediately recorded. The pH was then measured by setting the pH meter to the pH mode and the temperature adjusted to 250C. The electrode of the already calibrated meter was then rinsed with deionized water and blotted using a piece of tissue. The electrode was placed into the sample to be tested and the pH of the water appeared on the display. The display was stabilized before the reading was taken. The electrode was then rinsed again with distilled water before taking another reading. The conductivity of the samples were measured using the conductivity meter, the temperature coefficient was first set to 250C. Its probe was rinsed with distilled water and the electrode was dipped in the test solution preventing air bubbles from being trapped in the slot of the probe. The sample was stirred gently in order to get a stable reading. After reading, the electrode was rinsed again with distilled water before capping it back over the probe.
Turbidity was measured in the laboratory for each thoroughly stirred sample on the day after sampling, using a EutechCyberScan WL Turbimeter TB1000 (Eutech).
3.3.1 Bacteriological and Mycological analysis of the domestic water
For the bacteriological analysis of water samples, Coliform test was performed by the most probable number (MPN) technique (Benson, 2008) and heterotrophic plate count (aerobic) by Pour Plate method (Sugita et al., 2013).
MPN test was performed in two stages: Presumptive test and confirmative test.
a. Presumptive Test
• Lactose broth was prepared and 15 ml of the sterilized media was distributed into each fermentation tube containing an inverted Durham tube.
• Five (5) fermentation tubes in three lines and mark 10 ml, 1ml, and 0.1 ml in each line were placed on a rack and the broth aseptically distributed accordingly.
• The effluent was well shaken and specific volume 10 ml, 1 ml, and 0.1 ml of the water sample was distributed into each tube under sterile conditions using sterilized pipettes.
• The tubes were placed in the incubator at 370C for 48 hours.
• After incubation, positive tubes were recorded indicated by the presence of trapped gas bubble inside Durham tubes and colour change of the media.
