Groundwater quality on dairy farms in central South Africa

Abstract

Dairy farms in central South Africa depend mostly on groundwater for domestic needs and dairy activities. Groundwater samples were collected from 37 dairy farms during 2009 and 2013. Sixteen water quality parameters were tested and compared to the standard. Four parameters in 2009 and six in 2013 exhibited 100% compliance with the standard. Nitrate, Escherichia coli and total coliforms showed relatively low compliance across farms and years. Almost all farms were noncompliant for hardness in both sampling years. T-tests revealed significant changes from 2009 to 2013 for pH (t = 2.580; p = 0.006), hardness (t = 2.197; p = 0.016) and potassium (K) (t = 1.699; p = 0.0468). For hardness, approximately 45% of the farms in 2009, and 57% in 2013, posed a health risk to sensitive consumers. More than 50% of the farms in both years demonstrated levels of nitrates that could pose a health risk, particularly for babies. High levels of coliforms and E. coli were found, indicating a health risk for clinical infections in consumers. The number of farms presenting 3 or more parameters with a health risk more than doubled from 13.5% in 2009 to 27.0% in 2013.

Surface Water and Groundwater Quality in South Africa and Mozambique—Analysis of the Most Critical Pollutants for Drinking Purposes and Challenges in Water Treatment Selection

“…In addition, microorganisms may be present in groundwater due to percolation/infiltration of untreated wastewater. This is the case reported by [19] for the groundwater below 37 dairy farms in the central Free State province of South Africa: E. coli was occasionally found up to 2.4 10 4 CFU/100 mL and its mean value in the monitoring campaign was equal to 84.5 CFU/100 mL in 2009 and 3.9 CFU/100 mL in 2013.…”

“…This practice leads to deterioration of the quality of the local surface water and also of the local groundwater resources due to percolation/infiltration. In addition, livestock farms, which represent an important activity for the rural communities, are not safely managed from an environmental view point and generally their household wastewaters, zootechnical effluents, and manure are directly released into surface water bodies or are directly spread on soil [19].…”

Variable water quality of domestic wells emphasizes the need for groundwater quality monitoring and protection: Stinkwater, Hammanskraal, Gauteng

“…Studies of groundwater quality across Africa are numerous, and include rural (Grimason et al, 2013), urban (Mangore andTaigbenu, 2004) and peri-urban (Mokuolu et al, 2017), as well as agricultural (Esterhuizen et al, 2014), industrial (Takem et al, 2015) and domestic (Vala et al, 2011) studies. Most of these studies reveal decreases in groundwater quality related to human activities at the surface.…”

Surface and Groundwater Quality in South African Area—Analysis of the Most Critical Pollutants for Drinking Purposes

“…The map in Figure 2 reports the indicative place where the investigations included in this study were carried out, with the corresponding reference. Table 1 reports the limits for the selected pollutants according to the Mozambique regulation (DM-180/2004 [10]) and South African law (SANS-241-1:2015 [11]). These values will be compared with the measured concentrations found in the two water sources (surface water and groundwater) in the area under study.…”