The Wastewater infrastructure index provides an overall summary of the response towards waste water treatment in Greater Johannesburg.   Wastewater is collected from all domestic, commercial and industrial properties in the central city by making use of an extensive underground sewer systems.

• The Water Boards, governed by the Rand Water Act (RWB Statutes Act), sells water to local authorities and also reticulates to individual consumers outside of local authority areas. In the past the former Regional Services Councils (RSC) might have assumed the regional water supply / distribution function, but Rand Water will retain this responsibility. The Department of Water Affairs is involved in large water schemes for both urban and agricultural uses and also sells bulk water to Water Boards or municipalities (GJMC: Water and Sewage Investigation in the Metropolitan Area of Gauteng, 1996).

• In terms of the legislation Water Boards are able to own and operate Waste Water Treatment Works (WWTW). Previously, the Regional Services Councils had the option to assume a regional function of wastewater conveyance and treatment. Today local authorities are responsible for water and sewer reticulation and storage within their own boundaries. Water Boards may resist expanding their supply to regional boundaries since supply at the margin is more expensive than the average cost of supply.

• The existing supply infrastructure was designed and constructed to conform to the boundaries of the former local authorities. The current Metropolitan Local Council (MLC) boundaries may therefore fall under different reservoir supply zones and reticulation networks. The former Johannesburg Administration acted to a limited extent as a bulk supplier of water within the Central Witwatersrand area, providing bulk supplies of water through its storage and distribution system to Lenasia South-East, Soweto, Diepmeadow, Alexandra and Bedfordview. Rand Water is responsible for the abstraction and treatment of raw water, which is distributed in bulk to local authorities at a fixed tariff. Rand Water supplies 81 bulk supply meters to the GJMC (GJTMC: Water and Sewage Investigation in the Metropolitan Area of Gauteng, 1996).

• The water supply system consists of various elements including bulk conveyance from Rand Water supply points to local storage facilities (reservoirs, water towers, pump stations, bulk distribution mains and local reticulation mains) conveying water to the end user.

• The distribution of water is based on reservoir zones with reservoirs sited at predetermined levels within the local authority. This will ensure adequate minimum pressures and prevent excessively high pressures within the distribution system. The system is further broken down into water loss control zones within reservoir zones to monitor and control water losses. The planning, design and operation of the system are based on these zones. The boundaries of theses zones have been determined by existing or former political boundaries and to some extent by the incremental development of townships within former local authorities which have now been incorporated into the Metropolitan Council’s boundaries.

• The GJMC is also responsible for the bulk function of the provision and management of wastewater treatment and conveyance in bulk outfalls.

• Approximately 600 million liters of sewage is treated daily by different plant works in the Greater Johannesburg area:

1. The Northern Works in the north of Bushkoppies and

2. The Goudkoppies and Olifantsvlei Works in the south

• Wastewater emanates from the old administrative areas of Alexandra, Johannesburg, Randburg, Roodepoort, Sandton, Greater Soweto, Ennerdale and Lenasia. Approximately 95 % of the former Johannesburg area’s residents have access to waterborne sewerage systems, operated by the Council. The plants all operate on the so-called activated sludge system: a biological process specifically designed to remove major pollutants like carbon, nitrogen and phosphorous from the wastewater. By removing all the impurities it will be suitable for discharge into the river system.

• Approximately 10% of the recycled water is used as power station cooling water and 8% for irrigation of farms owned by the Council. The remainder is discharged into the Jukskei River in the north and the Klip River in the south (GJTMC: Water and Sewage Investigation, 1996).

• Wastewater can be purified either by using expensive chemical processes or by using less expensive biological processes. The latter processes are very similar to those occurring in natural water bodies and are nature’s method of disposing of waste matter. Today wastewater treatment plants are used to compact and accelerate natural processes using engineering and scientific knowledge. The aim of any biological water treatment process is to purify the wastewater by using the organic and inorganic nutrient components of the wastewater as a food source for micro-organisms.

As Greater Johannesburg is situated far from the major river systems, the purification of its wastewater to high standards is absolutely necessary.

• The various MLC’s are responsible for sewage treatment in their areas. This sewage is treated either in the Northern or the Southern treatment plants according to the location, which are both under the responsibility of the GJMC.
• A Wastewater Management Bill will be released during 1999 that will delegate certain powers to Local Authorities to make certain Regulations and By-laws.

Therefore faces major challenges regarding the provision of water and sewage.

REFERENCES

GJMC 1996: Water and Sewage Investigation in the Metropolitan Area of Gauteng.