**3. Results and discussion**

The summarized results of the analyzed groundwater samples are shown in **Table 1**.

#### **3.1 General properties of groundwater**

With the exception of pH and TH, all the measured physical and chemical parameters (both cations and anions) of groundwater in the study area fell within their respective acceptable limits for drinking water for humans. The pH of


#### **Table 1.**

*Summary of water quality analysis results.*

twenty-three (23) samples, representing about 92% of groundwater in the area fell within the [7] acceptable range of 6.5–8.5 for potable water while two communities (Sabronum Camp and Amakrom) representing 8% had values within the range of 4–6.5 with respective values of 4.42 and 4.48.

Thus, according to [21], 92% of groundwater was neutral while only 8% were moderately acidic. Hardness varied from 48 to 348 mg/l with a mean of 186.22 mg/l, with the exception of two (2) samples from Adukrom and Ahwirewan representing 8% exceeding the recommended limit of 300 mg/l [7] for drinking water. Water with hardness exceeding 300 mg/l, according to [22] may cause encrustation. Furthermore, [23] classified groundwater based on hardness as soft when hardness is less than 75 mg/l, moderately soft if hardness lies between 76 and 150 mg/l, hard when values fall between 150 to 300 mg/l and very hard groundwater if values are greater than 300 mg/l. In this study, 4%, 32%, 56% and 8% of groundwater in the area could be described as being soft, moderately soft hard and very hard respectively. Thus, groundwater could be generally considered to be predominantly moderately soft to hard water. TDS fell below the [7] limit of 1000 with values ranging from 25 to 573 mg/l with an estimated mean value of 175.185 mg/l. This according to [24], indicate that groundwater in the study area is fresh and young since TDS and conductivity values were generally within acceptable limits.

### **3.2 Chemical quality of groundwater as drinking water**

The potability of sampled groundwaters in the Ahafo-Ano south District was evaluated using influential parameters (IPs). IPs is considered to be the drinking water quality parameters that have significant implications for the human health when ingested through water and food chain or by dermal contact [25]. By utilizing Eq. (1), the estimated relative weights (Wi) are presented in **Table 2**.

Eqs. (2)–(4) above, were utilized to estimate the respective WQI for each sampled groundwater was estimated and presented in **Table 2**. Based on the estimated WQI values, the potability of each sampled groundwater was appropriately classified by comparing to the scheme described in [20]. According to the scheme, groundwaters with WQI being less than 50 are 'Excellent' for drinking by humans, it 'Good water' when WQI range from 50 to 100; 'Poor water' if WQI range from 100 to 200; 'Very poor quality' if WQI range from 200 to 300 and 'Unsuitable as drinking water' when WQI exceeds 300 from **Table 2**,

The status of drinking water quality of sampled groundwater resources in the study area are shown in **Figure 4**.

Illegal artisanal gold mining is most intensive in Afrensini, Piniwutrim Amakrom with water quality described as unsuitable, unsuitable and very poor, respectively. It can be deduced that the anthropogenic activities in these three (3) communities might have rendered the groundwater qualities unsuitable for human consumption. Qualities of groundwater from ten (10) communities with lesser intensive


**Table 2.**

*Assigned and estimated relative weights.*

*Effects of Illegal Artisanal Gold Mining Operations on Groundwater Quality in Ghana… DOI: http://dx.doi.org/10.5772/intechopen.100242*

**Figure 4.** *Spatial distribution of drinking water quality of sampled groundwater.*

illegal artisanal gold mining activities were described as poor. Conversely, sampled groundwaters from five (5) and seven (7) communities (representing 20% and 28% respectively) where illegal gold mining operations were non-existent had excellent and good drinking water qualities respectively. Areas with excellent drinking quality include Attakrom, Meyeeden, Kokotuaso, Fedieya and Hwibaa while areas with good groundwater drinking quality include areas include Wioso, Nyamebekyire, Adukrom, Pokukrom, Kunsu camp, Datro and Dotiem (**Table 3**).
