Implementing a protocol for selection and prioritisation of organic contaminants in the drinking water value chain: Case study of Rand Water, South Africa

Abstract

Approaches that prioritise chemicals according to their importance as environmental contaminants have been developed by government agencies and private industries. However, it has been noticed that few approaches, such as one published by the United States Environmental Protection Agency (USEPA), address the needs of the drinking water industry. There is also no generic approach to the selection, prioritisation and monitoring of organic contaminants in the drinking water value chain. To safeguard drinking water industry customers, it was necessary to develop a generic protocol to assist with the identification of a list of organic contaminants for monitoring in the drinking water value chain. Once the protocol was developed, it was validated in a prototype drinking water value chain. This paper describes the implementation of such a generic protocol. The exercise comprised of testing each step of the protocol, from selection of the 'pool of organic contaminants' (Step I) to recommending the final priority list of organic contaminants (Step VII). Successful implementation of the protocol took place in the Rand Water (South Africa) drinking water value chain (from catchment to tap). Expert judgment was emphasized during the implementation as each step was validated and the opinion of key stakeholders used to shape the process. The tailor-made prioritisation criteria, reflecting the drinking water industry perspective, proved to be successful in selecting and prioritising organic contaminants for monitoring in the drinking water value chain. The organic contaminants were successfully prioritised in 3 classes: short-term priority for analysis, medium-term priority for analysis and long-term priority for analysis. This is a very important guide to assist water utilities in optimising their resources while not compromising the role of public health protection. Finally, a priority list of organic contaminants was identified for use by Rand Water and other water utilities.

Desalination and seawater quality at Green Point, Cape Town: A study on the effects of marine sewage outfalls (with corrigendum)

“…For example, the veterinary use of diclofenac, which is also a human pharmaceutical used as an anti-inflammatory treatment, was found to be responsible for the massive decline in populations of vulture species in certain areas of Asia 7 ; ethinylestradiol, one of the active ingredients in the contraceptive pill, has been associated with endocrine disruption and feminisation in fish 8 ; and there is concern that long-term exposure to antibiotic pharmaceuticals and disinfectant products may be contributing to the selection of resistant bacteria with significant impacts upon human health. 9 In South Africa, Ncube et al 10 suggested a protocol for the selection and prioritisation of contaminants in drinking water. Patterton 11 surveyed seven cities in South Africa and showed the presence of 32 compounds in drinking water, predominantly pharmaceuticals and pesticides, including carbamazepine (anticonvulsant), phenytoin (antiepileptic) and diclofenac.…”

Review: <i>Pharmaceutical and personal care products (PPCPs) as endocrine disrupting contaminants (EDCs) in South African surface waters</i>

“…However, it is increasingly becoming known that several types of PPCPs are also accumulating in water systems to the same extent as contraceptive medications. These compounds can serve as EDCs and are not completely removed during water treatment (Ncube et al, 2012). From these contaminants, pharmaceuticals stand out as one of the sources which might potentially cause endocrine-disrupting activities in non-target organisms.…”

Endocrine Disruptors and Health Effects in Africa: A Call for Action

“…There have been reports of DDT bioaccumulation in wildlife and humans since the late 1960s ( Van Dyk et al 1982 ; Wassermann et al 1970 ). Further monitoring has also revealed persistent organic pollutants (POPs), PAHs, PBDEs, polychlorinated biphenyls (PCBs), perfluorooctane sulfonate (PFOS), phenols, heavy metals such as cadmium and lead, phthalates, and bisphenol A (BPA) in African waters ( Ncube et al 2012 ; Olujimi et al 2010 ) and in animal tissues ( du Preez et al 2016 ; Nieuwoudt et al 2009 ; Nieuwoudt et al 2011 ; Polder et al 2008 ; van der Schyff et al 2016 ; Quinn et al 2009 ; Bornman et al 2010b ). The first report of endocrine disruption in a fish species in Africa involved intersex in the African catfish, Clarias gariepinus , inhabiting water sources contaminated with the estrogenic compound p -nonylphenol ( p -NP), possibly from upstream activites of industries, agriculture, informal settlements, and municipal treatment plants ( Barnhoorn et al 2004 ).…”