A water pollution time bomb
Alarmed specialists say Durban’s water security is not so much threatened by scarcity as by upstream pollution – much of it emanating from Pietermartizburg’s Msundusi River. Fred Kocott and Siboniso Mngadi report
DURBAN might not face a Day Zero water crisis in the foreseeable future but a more insidious and pervasive threat: upstream pollution of the city’s major water source.
Already Inanda Dam, Durban’s primary water supply, is blooming with harmful blue-green algae (cyanobacteria).
If not addressed, this will lead to premature ageing and serious deterioration of this body of water through a phenomenon called eutrophication, says a leading aquatic scientist and Groundtruth director, Dr Mark Graham.
Graham said eutrophication can produce cyanotoxins. The World Health Organisation has warned that exposure to these toxins through drinking the polluted water can cause liver damage, skin irritation and rashes, stomach cramps, nausea and vomiting, diarrhoea, fever, muscle and joint pain, mouth blisters, drowsiness, slurred speech and increased salivation.
Graham said while the cyanotoxin levels in Inanda Dam were not yet considered unsafe to swim or canoe in, it was certainly not safe to drink, and would require additional and costly purification treatment before it enters Durban’s water supply.
“It requires an advanced treatment process which becomes hugely expensive. This will exponentially increase the costs of water to domestic and business consumers,” said Graham.
He said this could have major economic implications, particularly for a developing country like South Africa, where most people cannot afford to pay for water supply.
Graham has 30 years of experience in terrestrial and aquatic ecosystem management and has worked on numerous national and international projects investigating solutions to ecological problems.
He warned that if the levels of Inanda Dam become exceptionally low because of prolonged drought as in Cape Town, the toxic algal blooms could turn the water into a “great big biological soup”.
Ironically, Kwazulu-natal enjoys the cleanest and highest rainfall water catchment area in South Africa – the Drakensberg, from which flows crystal clear water into mountain streams and ultimately into rivers which supply most of the province’s water.
But as the rivers flow through agricultural, industrial and urban areas toward the sea, the once crystal clear water becomes increasingly polluted.
Graham said sewage-contaminated water flowing out of Pietermaritzburg and into the Msundusi and Umgeni rivers, along with nutrients from agricultural activity, were primary causes of algal blooms in Inanda Dam.
Many believe that problem lies in failure of the Pietermaritzburg municipality to rehabilitate the city’s ageing 1450km sewer network.
While Pietermaritzburg’s city manager, Sizwe Hadebe, argues that sufficient resources are allocated to maintaining the city’s sewer network, the latest river testing results from Umgeni Water tell a different story.
These results show that high levels of E. coli have increased dramatically over the last 10 years, with nearly 50% of sites now recording E. coli counts of 10000 units per 100ml of water. This is 10 times the permissible limit (1 000 units) determined by South Africa’s national water quality standards.
Graham said Pietermaritzburg’s original sewer network was built at the turn of the last century to cater for under 100000 people.
It has since been extended to serve up to between three million and four million people, but was not coping nor being properly maintained, said Graham.
This is despite the faecal pollution making headlines each year – always in the run-up to the iconic Duzi Canoe Marathon.
Two years ago a leading development consultant in Pietermaritzburg and acting CEO of Duzi Umngeni Conservation Trust, Richard Clacey, warned that not enough money was being allocated to rehabilitate the city’s sewer South Africa’s national water quality standards allow 1 000 units of E. coli per 100 ml of water in treated sewage water. An E. coli count below 300 is considered “good” quality for recreational sports in South Africa but drinking water should not contain any E. coli. network.
In an article in The Witness in early 2016 Clacey revealed that the municipality’s own studies had revealed that R94 million was required to urgently rehabilitate Pietermatizburg’s sewer network, but only R6 milion was allocated to address the crisis in the 2016/17 financial year.
How much has since been spent, Hadebe was unable to say this week.
Back in 2016, Clacey also cited river testing figures showing the dramatic escalation in E.coli levels in the Pietermaritzburg catchment area over a period of 10 years.
He said the continued decline in the river’s water quality posed a risk to the city’s reputation as a tourism destination and host of the Dusi Canoe Marathon, which brings R35 million annually into the local and regional economy.
Of greater concern, said Clacey at the time, was the eutrophication (toxic algal bloom) beginning to happen on Inanda Dam and the impact this would ultimately have on Durban.
“This threatens Durban’s water security and will lead to a sharp increase in the cost of water treatment, affecting the competitiveness and long-term sustainability of the region’s most important local economy,” wrote Clacey.
That was two years ago. This week Graham and other water specialists said the situation had since worsened, and echoed Clacey’s concerns that purification of water from Inanda Dam could become prohibitively costly.
If this happens, large industrial consumers of water will face increased production costs, as has happened with electricity.
This in turn will make final product costs uncompetitive or result in sharply lower profit margins.
“And the more we have to pay for water, the less is there to spend on maintenance, which is already not happening as it should,” said Graham.
Umgeni Water, the largest supplier of bulk potable water in KZN, was unable to disclose on Friday the amount it currently spends on water purification or advise whether it had budgeted for increased spending as a result of increased pollution in catchment areas.
In the meantime, pollution of Pietermaritzburg catchment continues to be monitored on a weekly basis.
In a recent e-mail accompanying the test results which get sent weekly to various stakeholders, including senior municipal staff and Department of Water and Sanitation officials, Umgeni Water pollution scientist Steve Terry said: “It is still nasty everywhere.”
Terry said that throughout 2017 the highest pollution levels were consistently recorded at Bayne’s Spruit, a small tributary of the Msundusi River that has historically served as a valuable resource to the nearby Sobantu community for fishing, swimming and irrigation purposes.
The latest Bayne’s Spruit sampling results reveal E coli counts in excess of 830 000 units per 100ml. This is practically slightly diluted raw sewage.
Several people have raised concerns that young children in Sobantu and other areas surrounding Pietermaritizburg continue to play in the city’s tributaries, including Bayne’s Spruit, particularly in the hot summer months.
“That is really dangerous. They are getting exposed to serious health risks,” said one stakeholder involved in the monitoring of water quality.
“People undertaking market gardening on banks of the river, using the water for irrigation, are also increasingly at risk. This undermines their livelihood opportunities,” added Graham.