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Sewage spills at Zandvlei Nature Reserve, chat with the reserve manager

David Rogers spent some time with Kyran Wright, Reserve Manager for Zandvlei Nature Reserve, to chat about the impact of sewage spills in the reserve.

DR: It seems that sewerage is a key threat to our system and so our fertilisers and probably pools being backwashed too.  As part of the ongoing message about awareness that can go to Zandvlei residents and also the broader community. Can you give me some thoughts about …

How to identify sewerage spills?

Sewage spills are identified by sight and smell (and even at times by sound!). Generally one will first notice a problem by the odour related to raw effluent. Our reticulation networks are well designed to limit the unpleasant odours of effluent, so when a sewage smell is apparent, there is often a problem (but importantly, not always). If one suspects a problem, it is best to do some cursory investigating to determine whether a spill is present, as knowing a location saves officials a great deal of time.

The smell, the look?

Whilst sewage is quite distinctive in its appearance, it can be easily confused.

In terms of smell- many people confuse the smell of Hydrogen sulphide (rotting eggs) and effluent. In a wetland environment, sulphurous smells are common and associated with decomposition, detritus and algal blooms. Raw effluent, whilst similar in smell, has a slightly earthier smell mixed with detergents. Remember that not only waste goes down sewage lines, but laundry and pool water too.

In terms of appearance, raw effluent almost always presents as grey to light brown, cloudy water. If it is clear, it is unlikely to be sewage. I have attached some pictures for reference. Usually, macerated pieces of toilet paper and human waste can be seen upon a closer inspection.

Sewage usually flows out of stormwater pipes as a pumpstation failure or blockage leads to an “overflow”, this overflow must go somewhere and usually that is into the stormwater network (which is an entirely separate pipe network). 

What to do in the event of a spill? Names to report?

If you detect a sewage spill, you should follow 3 methods of reporting, each with subtle strengths.

  1. Call the City’s emergency hotline and report the spill 107 (from a landline) or 021 480 7700 (from a cellphone).
    This gets immediate response and is sent straight to Reticulation (the number is 24 hours).
  2. Create a service request/C3 notification:
    This creates a record on the system of the sewage spill which aids in addressing problem areas/pump stations and can be used to hold officials to account. Hold on to your reference number.
  3. Contact the Zandvlei Reserve (021 444-1489) or Marina Da Gama (021 788-3311). Both Zandvlei Nature Reserve and the MDGA have the contact details of the relevant Reticulation Officials and can contact them directly to get action. This step allows the Reserve to follow up more directly with the reticulation officials and allows us to feedback to the residents.

What we can do as residents to keep the vlei well managed?

Reporting sewage spills is incredibly important – often these can go unnoticed or undetected. Time is critical when it comes to the impact from any spill so the sooner it is reported the better- we often have an incident reported to us days after it has been noticed and discussed ad nauseum in whatsapp groups, but no official report. We need residents to be eyes and ears for us and work together. Any illegal activities should also be reported to our Quemic rangers (and the reserve) on 083 499 1717

Other ways to assist is to get involved with volunteer organisations (such as ZVT) and participate in activities like litter clean ups.

What are the key issues being faced with regards to sewerage?

While most sewage spills are caused by mechanical or electrical failures in pump stations, often they are due to the cumulative impact of avoidable actions by residents and officials. Blockages are often the result of foreign, inappropriate items being dumped in reticulation manholes (e.g. old appliances, rags, tyres, etc) but can also be due to sand build up and root intrusion. Controlling Alien Invasive Plant species can assist in protecting sewage lines, as these ‘thirsty’ plants often crack and block pipes in search of water.

Another significant problem is poor building practices. Every resident should check where the downpipes from their property’s rain gutters go- sometimes, to save costs, builders will divert these straight into the reticulation lines leading to overloading of the system during storm events, and resulting in manholes bursting open and depositing significant amounts of effluent into the environment. Roof gutters should flow into the street drains and gutters for proper stormwater management.

Any other issues?

In terms of the City’s bylaws- pool backwashing must be diverted into reticulation lines, not stormwater drains. Pool water contains many chemicals specifically designed to kill biota (algae/phytoplankton) and these are incredibly damaging to the freshwater/estuarine ecosystems. Any pool water drained onto a street will eventually make its way into a river or vlei. Residents who own pools are requested to ensure that their backwash system is complaint.

Manholes are important pieces of infrastructure- they contain sewage as well as prevent safety hazards. These are often stolen and sold for scrap metal. Please report a missing manhole cover via a service request notification.

What do we do with our toxic materials — eg paint.

Household hazardous waste can be dropped off at City facilities- please see

The below types of waste are accepted. Items not accepted will have to be removed by a private, licensed service provider.

Types of HHW Accepted as household hazardous waste Not Accepted 
 • Asbestos waste material: 
• CFL (compact fluorescent lamps) and other discharge lamps
• Chemical waste products (air fresheners, all-purpose cleaners)
• Electronic waste 
• gutters or old cement heaters – no bulk waste will be accepted.
• limited to plant containers 
• Old paint and brushes 
• Pesticide waste and Used batteries
• Swimming pool chemicals 
• Used oils  
 • Any product contaminated by infectious bodily fluids
• Bulk household hazardous waste from residents’ homes, offices, businesses or schools
• Explosive and compressed waste: For instance, gas cylinders
• Medical waste: Blood-stained bandages and plasters, expired pharmaceuticals
• Sanitary waste: Soiled disposable nappies and adult diapers 
Household hazardous waste (HHW)

Where are we most likely to find sewerage and other issues entering the system?

Rivers! The majority of major pollution events do not occur in Zandvlei directly but emanate from upstream and are brought down the catchment to the Zandvlei waterbody via our rivers and stormwater network. Our three major rivers that enter Zandvlei are the Sand, Westlake and Keysers rivers. Sewage incidents entering the Marina are generally minor due to the relatively lesser amount of residences which are connected to any particular line. Compare that to a pumpstation failure in Retreat where multitudes more residences’ effluent can enter the system

What about Winelands and fertilisers and industrial users upstream. What is being done?

Abdulla Parker and Catchment Management can answer this. There are significant inputs but tracking and tracing is difficult. Pollsmoor however currently has a Directive issued against them to ensure good water quality. We need better practices in agricultural areas and to better understand the impact of golf courses.

Is there a larger map that we can use for this showing a larger area.