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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. [ABSTRACT FROM AUTHOR]

Eighty largemouth yellowfish, Labeobarhus kimherleyensis, were collected between April 2005 and February 2006 with gill nets close to the island (26° 52, 249‱ S, 28° 10, 249‱ E) in the Vaal Dam. The fish were killed, weighed and their length determined. Muscle, liver and spinal cord tissues were collected from each fish and the intestines removed and opened to expose Bothriocephalus acheilognathi. The tapeworms were collected in glass bottles and frozen. Water and sediment, as well as liver, muscle and tapeworm samples were digested and thereafter metal concentrations of 23 elements (lithium, beryllium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, antimony, tellurium, barium, mercury, thallium, lead and uranium) were determined with an ICP-MS. Bioconcentration of metals (selenium, mercury, and lead during autumn; copper, zinc, selenium, cadmium, antimony, thallium and mercury during winter; lithium, zinc, selenium, cadmium and antimony during spring; and zinc during summer) occurred in tapeworms. The highest mean value was recorded in sediment, followed by water, tapeworms and host tissue. A seasonal trend showed that a higher concentration of the metals had accumulated in tapeworms during winter when water levels were at their lowest. [ABSTRACT FROM AUTHOR]

Abstract: Twenty Largemouth yellowfish Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913) were collected in the Vaal Dam in the vicinity of RAU Island (Groot Eiland). Muscle-, spinal cord- and liver tissue were removed from each fish and the intestine opened to obtain Bothriocephalus acheilognathi. The tissues were then digested in a microwave digester and the metal concentrations were determined in each tissue with an ICP-MS. The results indicate that the worms have potential use as bioindicators, because in 8 elements (lithium, beryllium, manganese, selenium, mercury, thallium, lead and uranium) out of the 23 elements measured the cestodes have accumulated the highest metal concentrations, and in 7 elements (chromium, iron, zinc, molybdenum, cadmium, tin and barium) out of 23 elements the cestodes had the second highest metal accumulation recorded. [Copyright &y& Elsevier]