"Not good for the season coming up, boating and fishing will be affected," read a comment on the Knysna-Plett Herald’s facebook page.
Another disgruntled resident complained: "We’ve noticed a very strong chlorine smell in the area. At high tides, the problem seems worse - almost as though a valve is opened somewhere to flush out the sludge with the tide? Can we get a follow-up on the test results too, and find out if chlorine or other chemical is being used to mask the smell, and kill germs? This could be even more damaging than the sewage. I think we should have regular updates on the E.coli (Escherichia coli) test results, and be kept informed in a transparent way."
The Acting Municipal manager, Lauren Waring was asked to comment on these allegations and she replied by assuring the public of the Knysna Municipality’s commitment to handling this matter in an open and transparent manner. She reiterated, "As previously stated, we will provide the public with relevant and accurate information as and when it is available."
Although warnings regarding the bacteria count in certain areas of the estuary had been placed on the municipal and the Knysna-Plett Herald’s websites, and, as custodians of the estuary, SANParks have committed to placing boards with these warnings at the relevant sites, the actual bacterial load figures were withheld by the Eden Municipality, although these results had been requested on several occasion.
Actual bacterial load
Fortunately, a concerned Leisure Island resident had taken it upon herself to have the lagoon water tested by Pathcare Laboratories to ensure the health of her family.
These tests were done on September 16. The results for a sample taken at the Ashmead outlet indicated a total Coliform content per 100ml of 24 196. The total faecal Coliform was also measured as 24 196 per 100ml, while E.coli type 1 per 100ml was tested as being 15 531.
Results for a sample taken at the Small Boat Harbour at Leisure Isle measured the total Coliform content per 100ml as 14 136, the total faecal Coliform per 100ml as 2 481 and E.coli type 1 per 100ml as 1 515.
According to the Department of Water Affairs (DWAF), faecal Coliform is one of the most commonly used bacterial indicators of faecal pollution and indicates the possible presence of pathogens responsible for the transmission of infectious diseases such as gastroenteritis, salmonellosis, dysentery, cholera and typhoid fever.
DWAF further warns that if the faecal Coliform count increases to above the 2 000 limit (which both samples were), the risk of contracting gastrointestinal illness increases. The volume of water that needs to be ingested to cause adverse effects decreases as the faecal Coliform density increases.
E.coli is used to evaluate the quality of wastewater effluents, river water, sea water at bathing beaches, raw water for drinking water supply, treated drinking water, water used for irrigation and aquaculture and recreational water. The presence of E.coli in the water has the same negative effects as that of faecal Cloriforms.
DWAF further states that should the E.coli count be greater than 400 (which both samples indicated), gastrointestinal illness could be expected to increase.
Although no figures of the bacterial load were provided by the municipality, Waring reassured residents, "We are still dealing with the sludge in the vicinity of the (Ashmead) culvert. Eden District Municipality Department of Municipal Health, is taking regular samples at various points in the estuary and as soon as they receive the results and communicate them to us, we update the water warnings on our website and forward them to the media." It must be noted that these warnings do not offer the actual bacterial load, but do indicate the possible risk to individuals as safe, medium, high or extreme.
Opening the valve
"We are most certainly not opening a valve somewhere to flush the sludge out with the tide, but operations are proceeding," explained Waring.
She further explained, "Chlorine is used in the process as a matter of course and we are not exceeding the allowed limits of chlorine usage."
Bio-augmentation process
As previously reported, Knysna Municipality implemented a bio-augmentation process at the oxidation ponds and bio-reactor of its wastewater treatment works, and, according to Acting Municipal Manager Lauren Waring, it is delivering positive results.
"We have definitely kick-started the biological processes within the plant," said Waring. "As we previously stated, it would have taken quite some time for the bacteria levels within the plant to reach the required levels naturally, but the bio-augmentation process has helped us along nicely and it is evident that the biological processes within the plant are getting back on track.
"While this is very good news in its own, we urge the public to adhere to the warning notices (on the municipal website), as well as the notice boards that SANParks has committed to placing at specific points along the estuary."
Zanemvula Gozongo, communication manager of Garden Route National Park, Knysna said, "Recent [water] samples show an improvement in water quality from the wastewater treatment plant. However, according to the latest sample results, high bacteriological counts are still measured at the outlet of this plant."
He further said that SANParks would keep its signage in place until the levels of bacteriological contamination reduced to an acceptable level.
Waring explained that in an effort to assist the municipality in removing the sludge in the vicinity of the culvert, the flow into the estuary was stopped at 10:30 on Thursday, September 15 and only reinstated around 20:00. This flow was redirected into the oxidation ponds and re-circulated through the plant. "This allowed us precious time to clear the culvert."
"A team of nine have been manually re-establishing the flow-channels along the walkway on Vigilance Drive and removing sludge with spades. We have also been using the vacuum tankers to pump out this sludge and we are expecting a visible improvement by the end of the week," said Waring. "The noxious smell in the area has in fact already subsided."
Executive Mayor Georlene Wolmarans was happy with the progress at the wastewater treatment works. "Unfortunately, that is only part of the bigger problem. In previous press releases we have acknowledged the fact that the estuary is polluted in certain areas and we realise that this problem requires long-term solutions.
"We continue to work with Eden District Municipality, SANParks and independent consultants to rectify this situation and to make sure that it is not repeated."
The public is urged to visit the Knysna Municipal website on www.knysna.gov.za for information about the safety of the Knysna Estuary water.
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The DWAF’s table showing the effects of E.coli on human health.
ARTICLE: FRAN KIRSTEN, KNYSNA-PLETT HERALD JOURNALIST
