Agriculture Reference
In-Depth Information
6
An Analysis of the Quality of
Wastewater Used to Irrigate Vegetables
in Accra, Kumasi and Tamale, Ghana
Philip Amoah
1
I
NTRODUCTION
Cities in developing countries, including Ghana, are experiencing unparalleled
population growth. Rapidly increasing water supply and sanitation coverage
generates large volumes of wastewater, which is often released untreated into
the environment (streams, drains, etc.). In Ghana, most urban centres have no
means of treating wastewater and the sewerage network serves a small
percentage (4.5 per cent) of the total population (GSS, 2002). The need for
year-round production of vegetables in or near urban areas makes irrigation
necessary; hence, farmers in search of water for irrigation often rely on
wastewater. However, despite its importance for countless livelihoods, the use
of urban wastewater for irrigation is not without health risks. Wastewater
contains the full spectrum of pathogens found in the urban population, many
of which can survive for several weeks when discharged onto fields.
Effective wastewater treatment can reduce pathogen levels, but in most
developing countries it is not an option for the municipal authorities due to
the high costs involved (Keraita et al, 2002). Most new sewerage treatment
plants in Ghana are also operating below their design capacity. As wastewater
treatment does not appear to be a realistic option, banning the use of polluted
water by urban farmers has also been tried in Accra and other cities. This has
failed because such bans threaten the livelihoods of many individuals, which
run contrary to poverty-alleviation strategies. In these circumstances, urban
farmers express significant concerns because their livelihoods are at permanent
risk. Any solution to reduce health risks without forcing them to change their
(market-driven) cropping patterns or access to water would be appreciated.
In addition, Ghana's Tourism Board has started a campaign directed at
