The performance of four wastewater treatment plants that serve the Buffalo City (Dimbaza, East London) and Nkokonbe (Alice, Fort Beaufort) Municipal areas in the Eastern Cape Province of South Africa was investigated for the removal of microbial and chemical contaminants. Statistical evidence showed a relationship between the quality of the final effluent and that of the receiving water body and the relationship was such that the better the quality of the final effluent, the better the quality of the receiving water body. The quality of both the effluents and the receiving water bodies was acceptable with respect to the temperature (mean range: 16.52 to 23.33°C), pH (mean range: 7.79 to 8.97), chemical oxygen demand (COD) (mean range: 7 to 20 mg/ℓ) and total suspended solids (TSS) (mean range: 161.43 to 215.67 mg/ℓ). However, in terms of the nutrients (orthophosphate-mean range: 3.70 to 11.58 mg/ℓ and total nitrogen-mean range: 2.90 to 6.90 mg/ℓ) the effluents and the receiving water bodies were eutrophic. The dissolved oxygen (DO) (mean range: 3.26 to 4.57 mg/ℓ) and the biological oxygen demand (BOD) (mean range: 14 to 24 mg/ℓ) did not comply with the EU guidelines for the protection of the aquatic ecosystems. The general microbiological quality of the effluents discharged from all the plants did not comply with the limits set by the South African authorities in respect of pathogens such as Salmonella, Shigella, Vibrio cholera and coliphages. The effluents discharged from the Dimbaza, East London, Alice and Fort Beaufort wastewater treatment plants were identified as pollution point sources into their respective receiving water bodies (Tembisa Dam, the Nahoon and Eastern Beach which are part of the Indian Ocean; the Tyume River and the Kat River).

Failures of sewage treatment systems, both within and outside South Africa, are most commonly ascribed to inadequate facilities and other factors resulting in the production of poor quality effluents with attendant negative consequences on the receiving watershed. The impact of the final effluent of a wastewater treatment facility in a suburban community of the Eastern Cape Province of South Africa on the physicochemical qualities of the receiving watershed was assessed between August 2007 and July 2008. Water quality parameters were analyzed according to the South African Department of Water Affairs and Forestry standards. The effluent quality was acceptable with respect to the pH (6.9–7.8), temperature (13.8–22.0°C), dissolved oxygen (DO) (4.9–7.8 mg/L), salinity (0.12–0.17 psu), total dissolved solids (TDS) (119–162 mg/L) and nitrite concentration (0.1–0.4 mg/L). The other physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1–4.0 mg/L), chemical oxygen demand (COD) (5–211 mg/L), electrical conductivity (EC) (237–325 μS/cm), and turbidity (7.7–62.7 NTU). The results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. The discharged final effluents had detrimental effects on the receiving body of water, thus suggesting the need for regular and consistent intervention by appropriate monitoring and compliance agencies to ensure adherence to acceptable standards for discharged effluents.

Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea in infants and in travelers from developed to underdeveloped countries, especially in regions of poor sanitation. The ETEC are acquired by the ingestion of contaminated food and water, and adults living in endemic areas develop immunity. The disease condition manifests as a minor discomfort to a severe cholera-like syndrome and requires colonization by the microorganism and the elaboration of one or more enterotoxins. The ETEC attach to the epithelial cells of the gastrointestinal tract and release substances that affect the normal functioning of the tract, thereby resulting in diarrhea, and subsequently millions of deaths everyday, particularly in children. The prevention of the spread of this strain of diarrheagenic E. coli depends on ensuring appropriate sanitary measures; hand-washing and proper preparation of food; chlorination of water supplies; and appropriate sewage treatment and disposal. Parenteral or oral fluid and electrolyte replacement is used to prevent dehydration, and broad-spectrum antibiotics are used in chronic or life-threatening cases, but in most cases, should be avoided because of severe side effects.

Wastewater treatment facilities have become sin quo non in ensuring the discharges of high quality wastewater effluents into receiving water bodies and consequence, a healthier environment. Due to massive worldwide increases in human population, water has been predicted to become one of the scarcest resources in the 21 st century, and despite large advances in water and wastewater treatments, waterborne diseases still pose a major threat to public health worldwide. Several questions have been raised on the capacity of current wastewater treatment regimes to remove pathogens from wastewater with many waterborne diseases linked to supposedly treated water supplies. One of the major gaps in the knowledge of pathogenic microorganisms in wastewater is the lack of a thorough understanding of the survival and persistence of the different microbial types in different conditions and environments. This therefore brings to the fore the need for a thorough research into the movement and behavior of these microorganisms in wastewaters. In this review paper we give an overview of wastewater treatment practices with particular emphasis on the removal of microbial pathogens.