Sewer spill in Sandriver canal

Update: 4 May 2018

CITY OF CAPE TOWN MEDIA RELEASE

Zandvlei water area re-opened to public

The City of Cape Town’s Environmental Management Department has advised that the Zandvlei water area is now open to the public following a short period of closure. As water quality testing results have shown a significant improvement, the City is re-opening the Zandvlei water area to the public for recreational activities, with the precautionary recommendation that water users stay about 50 m away from the inlet of the canal north of the marina. Read more below:

The City of Cape Town has undertaken ongoing water quality testing within the Zandvlei water body since last Friday, 27 April 2018, when the temporary closure of the vlei was effected. Test results made available today, 4 May 2018, has indicated a significant improvement of the water quality to levels that are acceptable as per the national recreational water use guidelines.

The precautionary closure of the water area has therefore been revoked as of today, Friday 4 May 2018. Recreational activities such as canoeing, windsurfing and sailing can therefore continue with the precautionary measure of staying about 50 m away from the inlet of the canal north of the marina (Sand and Landelvei River canal).

The City apologises for any inconvenience caused as a result of the temporary closure of the water area and thanks the public for their cooperation during this period.

End

Issued by: Media Office, City of Cape Town

Media enquiries: Julia Wood, Manager: Biodiversity Management Branch, Environmental Management Department, Tel: 084 464 9153, Email: Julia.Wood@capetown.gov.za.

27 APRIL 2018

CITY OF CAPE TOWN MEDIA RELEASE

Zandvlei water area closed to public until further notice

The City of Cape Town is temporarily closing the Zandvlei water area from today, Friday 27 April 2018, as a precautionary measure following water quality concerns. The closure only applies to recreational activities in the Zandvlei water area, including fishing. Access to the Zandvlei Estuary Nature Reserve and other visitor facilities in the area remain open to the public. Read more below:

The City of Cape Town has undertaken water quality testing at various points within the Zandvlei water body due to water quality concerns, and has concluded today that the water body should be closed to the public as a precautionary measure until further notice.

The closure only applies to recreational activities in the Zandvlei water area, including fishing, but does not prohibit access to the Zandvlei Nature Reserve and other visitor facilities in the area.

The test results showed high levels of faecal coliforms (Escherichia coli) within the water body, which indicates an elevated risk to human health.  The public is therefore advised to avoid all contact with the water at Zandvlei until these levels fall back within national recreational water use guidelines.

The high E. coli count is a result of a sewage spill earlier in the week due to a bulk sewer main collapse, which has subsequently been contained. The City has been monitoring the effect of the sewage spill into the water body and the additional pollutants entering the vlei from the catchment area. The additional pollutants are as a result of the flushing effect of the recent rain after an extended dry period. The results of these water quality tests dictated the decision to apply a precautionary approach for the safety of the residents of Cape Town.

The City will continue to monitor the water quality and expects to see an improvement in these levels soon. In the meantime, signage has been erected advising visitors to the vlei to exercise due caution. The public will be informed once the vlei is safe for recreational use. The City apologises for any inconvenience caused as a result of the closure of the water area and thanks the public for their cooperation during this period.

End

Issued by: Media Office, City of Cape Town

Media enquiries: Julia Wood, Manager: Biodiversity Management Branch, Environmental Management Department, City of Cape Town, Cell: 084 464 9153 or Email: Julia.Wood@capetown.gov.za

GroundUp article: Sewer pipe collapses and destroys homes (26 April 2018)

Update: Wednesday 25 April 18:00

Water quality
Preliminary results show EXTREMELY high counts of E coli. This is to be expected. We are waiting for an official call from Env Health. In the main vlei water is such that contact recreation should be avoided.

Volumes of spillage
We do not have exact figures but given the size of the pipe this is likely to be large volumes. The Zandvlei mouth was opened on Sunday in response to the spill; from the reserve side there is not much else that can be done.

Sand bank at the mouth / rubble weir
Due to the sand build up at the mouth – the rock weir has been totally buried by sand – there is likely to be minimal flushing with sea water, this will also depend on the rainfall we receive. At this point we estimate at least a week; but E coli levels will drop during this time.”

Update: Tuesday 24 April 10:00 am

The sewage have stopped and the water is looking clear.

As of yesterday at approximately 16h00 over pumping of the collapsed sewer commenced – this eliminates the need for the tankers that were apparently the source of the issue.
The spillage from the sewer was therefore almost completely eliminated from that time onwards, a recent check has confirmed that the overflow has stopped completely.
The contractor is currently sourcing at least one additional pump to act as a standby in case of a breakdown, also to assist with keeping the sewer flowing at peak times.

Whatever contamination found its way into the Sand River canal has long been washed downstream by the rain – it is therefore not feasible to pump out the canal.
We have however make plentiful use of bio-enzymes to attempt to minimise the environmental impact downstream.

The spill was pretty much confined to the Sand River canal – all of the stormwater drains in the area discharge there.

We are constantly monitoring the situation.

Further to this the structures that were over the area of the sewer that has collapsed are being moved, the appointed contractor is currently on site and is commencing repairs.
The primary aim is to make the sewer operational and reduce the dependence on temporary pumps to keep it so.

Also noting with gratitude that the new litter nets managed by residents of Marina de Gama seem to have done a good job of preventing the bulk of the oil slick relating to the spill from entering into the main waterbody.

Notice sent to stakeholders, Monday 23 April 2018.

Dear ZPAAC stakeholders

Brace yourself, this is very bad news.

As most of you know at this stage, there is a sewer spill into the Sandriver canal.

A main sewer pipe collapsed in the Vrygrond Area on Thursday. It is 3m underground. Above ground there is an informal settlement.

The situation was being maintained by pumping with trucks and so no sewage was entering the canals. However there has been violence at Vryground and the trucks which were pumping had to be withdrawn for safety. Sewage is now entering the canals. A contractor has been appointed to repair the canals but we have no details of how long the repairs will take.

This is a sectional pipe en route eastwards; it is a big pipe. It is basically the Southern Suburbs’ sewage.

All the people involved are currently trying to find ways to address this. For the moment the sewage will keep flowing. The mouth was opened on Sunday morning around 09:00. The sand plug at the mouth however means that there will be limited outflow to remove sewage.

Another option is to try dam the canal, but with the volumes involved the advice Dalton received is that it may not be possible.

Please advise all water users to be cautious, this is going to be a LOT of sewage.

Zandvlei in the drought

The drought is affecting the Zandvlei estuary in two major ways: the water quality and quantity as a potential source of water.

The important message here is that Zandvlei is under stress, like all other local wetlands, due to the low water levels from the drought. The nutrients that have accumulated in wetland systems over time can now be expected to be manifested in algae blooms , excessive plant growth and in this case a new weed species coming to the fore. Wetland systems can be expected to manifest water quality issues in response to the stress imposed upon them by years of city runoff, pollutants and the drought conditions. What we are seeing are symptoms of underlying stresses placed upon our wetlands.

Water quality

The condition of the Zandvlei estuary is currently a cause for closer monitoring. It is not as dire as some may suggest, considering what it has to accommodate:
1.         There is a larger than usual amount of stringy algae. This is due to the hot temperatures, and also a nutrient build up because there is not enough flow to flush the system, because of the extreme  drought.   Lower water levels concentrate nutrients already in the system – high temperatures spurn algal growth.
2.         The drought also means that there is a larger build-up of nutrients higher up in the catchment. When rain does come it washes large amounts of nutrients off the catchment into the estuary in one or two events, as opposed to continued rain with small amounts of nutrients over a long period.
3.         The biggest challenge the system currently faces is sediment build up which is impairing the functioning of the estuary as a nursery. The annual maintenance dredging has been redirected to drought emergency measures.
4.         The mouth opening depends on flow into the system to manage the salinity, and the flow has been low due to the extreme drought. The build-up of sand in the mouth of the estuary means that when there is tidal interchange the amount of water exchanged with the sea is limited. In addition, the budget for this is also constrained due to drought emergency measures. The sand bar, coupled with the long drought, means a decrease in sea water exchange and a decrease in flushing of the system. Thus the conditions seem to be set for poor water quality issues in the summer ahead.

The top priority of the ZPAAC currently is to dredge the estuary. While this will have a positive impact on the nutrient balance and hence pond weed growth, the pond weed management is not the main topic under scrutiny. Any help obtaining funds or assistance in getting any amount of dredging done will be welcomed.

Water extraction

There has been reports of water being extracted from the estuary. It is illegal (see below), but people removing water by hand from Zandvlei wouldn’t be a huge ecological disaster; there may be health consequences but this would probably be out of the ambit of the City to resolve.

In terms of the Marina; the first 2m of water is owned by the adjacent property and is not Council property. Thus Council permission is not needed as they are not the land owners. The person however still needs a water use licence from National Government and be registered as a water user.

The Zandvlei water has a high salt content (about half sea water) so it won’t be too good as drinking water.

Below is an extract of the present legislation – it is old and outdated but still in effect. If you witness water extraction, please call the reserve ranger staff (24/7) at 083 499 1717 (please note this is for ENVIRONMENTAL emergencies only).