Minimising waste to landfill the beneficial usage of waste water sludge in agriculture

Vision Mission and Promise
Vision Mission and Promise

INTRODUCTION

The benefits of utilising the nutrients in waste water in agriculture have been recognised for well over 100 years. Waste water sludge has been used in the greater Cape Town area for more than 50 years but up until 2002, there were no clear guidelines applicable for agricultural or other purposes. In a joint effort with the City of Cape Town, EnviroServ played a part in the revitalisation of the beneficial use of waste water sludge in agriculture.



THE CHALLENGE

In consultation with the City of Cape Town, it was recognized that a means to improve generally poor-quality soils in the Cape Town area for agricultural purposes was needed. EnviroServ is contracted to the City of Cape Town for the removal and disposal of waste water sludge at the Vissershok Waste Management Facility.

THE SOLUTION

Instead of disposing of the waste water sludge, EnviroServ found a beneficial alternative in the form of land application, where the sludge is used to improve soil quality. The waste water sludge is collected, transported, stored and then spread at the required rate and finally ploughed into the ground. There is no doubt that the application of wastewater sludge to agricultural land is of major benefit. Due to the slow release of the nature of the nutrients, especially nitrogen, the potential for groundwater pollution is significantly reduced. In addition, the rate of emission of a nitrous oxide gas (a significant greenhouse effect contributor), is significantly lower than with synthetic fertilizers. There is a significant reduction in the quantity of synthetic fertilizer required to produce a reasonable crop.

 

THE OUTCOME

Diverting a very large quantity of wastewater sludge from landfill, the City of Cape Town benefits:
1. It has extended the life of the Vissershok Waste Management Facility by many years.
2. The quantity of leachate produced by the facility will be reduced since less water is being added now that quantity of sludge has been significantly reduced.
3. When the sludge is co-disposed in a waste management facility, a valuable source of nutrients is being lost. With land application, these valuable nutrients are used to assist in the production of food for an ever-increasing population.


IN CONCLUSION

EnviroServ is proud to have initiated the beneficial utilisation of waste water sludge by land application in the Western Cape. Today, we manage the largest operation of its kind in South Africa. This is in line with the company’s policy of developing sustainable waste handling technologies to the benefit of mankind.

Pledge & Values
Pledge & Values

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