**3.5 Turbidity**

Turbidity is the cloudiness of water caused by a variety of particles and is a key parameter in drinking water analysis. It is also related to the content of diseases causing organisms in water, which may come from surface runoff. The turbidity values obtained from the study sites range from 0.4–10.6. The standard recommended maximum turbidity limit, set by WHO for drinking water is 5 nephelometric turbidity units (NTU). The lowest turbidity values of 0.4 NTU and highest value of 10.6 NTU were found for samples from site TA1 and TB1, respectively (**Table 4**). The mean turbidity for sample locations revealed that KL and TB have values of 4.7 1.6 and 4.9 4.2. This may be as a result of the open nature of the water making it easy for impurities that could block light reception to flow into it. All sites in the study area except for sites KL2 and TB1 were below the WHO permissible levels of 5NTU.

### **3.6 Alkalinity**

Alkalinity is the measure of the acid – neutralizing capacity of water. In most natural waters, it is due to the presence of carbonate (CO3), carbonate (HCO-) and hydroxyl anions. The alkalinity levels recorded in this study range from 39 mg/l – 204 mg/l as shown in **Table 2** with a mean range of 109 65.19–167.7 27.61 as shown in **Table 3** during the dry season. The value of alkalinity obtained during the rainy season range from 31 mg/l –183 mg/l as shown in **Table 4** with a mean range of 96 57.89–131.33 14.50 shown in **Table 5**. These are higher than the range of 4.4 0.38 mg/c – 17.8 0.25 mg reported by Dimowo [22] in an assessment of some physicochemical Parameters of River Ogun (Abeokuta, Ogun State, South Western Nigeria).

This study revealed that all sites were above the WHO permissible levels of 1.0 – 100 mg.c except sites KL3 (39) and SD, (84) during the dry season and sites KL3 (31), MD, (87), SD, (56) SB2 (89) and TB3 (87). The high alkalinity levels could be

due to high concentration of basic cations such as calcium (Ca), magnesium (Mg), Sodium (Na) and Potassium (K).
