The Department of Biochemistry, Microbiology and Biotechnology on Monday, November 6, finished testing numerous samples of water which were taken at several points on campus each day last week (from Monday 30 October to Friday 3 November).
Samples of water taken from the Department of Ichthyology and Fisheries Science were found to contain levels of some silt and two compounds, ammonia and calcium carbonate, which were harmful to trout, but well within the safety limits for human consumption.
The levels of silt in the water made it unpleasant to drink, but the particles were not dangerous to human health.
The concentration of ammonia in the water was much lower than the safe limit for human drinking water, but higher than the limit for breeding fish.
The hardness of the water (i.e. whether it will scale your kettle), which is measured as the amount of calcium carbonate, was also too high for trout but safe for people. The water hardness was measured as 134 mg/L; trout can only tolerate 100 mg/L but humans can safely drink water with three times that amount.
Metal concentrations were measured in the water samples and it was found that there were some metals in the silt, but that the water itself contained no metal concentrations above the South African water quality safety guidelines.
In summary, the tap water on campus was safe (if unpleasant) to drink.
The cause of the colour and odour associated with the water over the weekend and this week is not known. While there have been no tests performed demonstrating that the tap water is currently unsafe for drinking, it has been advised that anyone concerned about the water quality continue to use the alternative water sources that are being provided.
Previous report (Thursday, November 2):
We have received warnings regarding potential pollution of the town’s water supply. The University sent out an official warning to students and staff today saying that the water is toxic to humans and that boiling it will not make any difference.
The email, from Guy White, director of the Rhodes University communications and development division said:
“According to Martin Davies of the Department of Ichthyology and Fisheries Science, over 35 000 fish at the University’s Experimental Fish Farm have died over the last few days as a result.
He says that trout fingerlings are seen as an accepted early warning system of polluted water. The deaths of these fish together with behavioural abnormalities which has been observed are indicative of the presence of heavy metal pollutants in the water.”
White went on to say “the particles are extremely toxic to human beings and cannot be removed through cooking or boiling water. Samples of water are currently being tested in the University’s Biotechnology Department but results of these tests will only be available by tomorrow.”
We would like to encourage all Grahamstown residents to be cautious until such a time as these reports are confirmed and the level of danger has been assessed.