|
|
|
|
|
|
|
The large cities such as Accra, Kumasi and Tema have relatively good roads, and electricity and water supplies. However, the development of adequate safe sanitation facilities has not followed the same pattern of development as other services, and consequently the current situation is inadequate. |
|
|
|
|
|
|
|
|
5.2
Current Operational Practices in Ghana |
|
|
|
|
|
|
|
|
A small survey was carried out on the sewerage system in Tema, a port city built about 30 years ago. It is under a poor state of repair, mainly due to a lack of programmed maintenance. Although it is approximately 30 years old, the problems are typical of a much older system. As Tema is a relatively new city, the Tema Development Corporation (TDC) was responsible for the sewerage system, although Tema Metropolitan Assembly (TMA) is expected to assume these duties in the near future. |
|
|
|
|
|
|
|
|
In practice about 95 per cent of the sewers suffer from sand deposition. Approximately 40 per cent of these pipes suffer a loss of cross-sectional area greater than 50 per cent. Thus at least half of the original flow capacity has been lost in these pipes, and consequently the so-called 'self-cleansing velocity' or 'minimum tractive tension' is not achieved and further deposition occurs. In addition to loss of capacity, the problem is further exacerbated by the addition of bulky materials, via the WC, into the sewer. Frequently the disposal of such materials leads to blockage formation. |
|
|
|
|
|
|
|
|
Blockages can take between 8 and 20 weeks to clear from the moment they are first identified. The loss of WC facilities or the emergence of sewage either into the surface water drain or from the inspection chamber is often the moment it is recorded. The householders then contact the direct labour department of TDC and the report is logged. Due to a large backlog of work, reports are not immediately attended to, although priority seemed to be given to persistent complaints. |
|
|
|
|
|
|
|
|
Three distinct catchments drain to pumping stations, which have emergency overflows from their wetwells into local water courses. Two of the pumping stations work sporadically due to pump maintenance difficulties, and there is evidence of frequent pollution incidents due to sewage flowing through the emergency overflows into local water courses. This is not perceived as a |
|
|
|
|
|