Environmental Engineering Reference
In-Depth Information
availability of background pollution data, in addition to data regarding the quality and
quantity of point discharges, would allow the estimation of the contribution of the
combined diffuse pollution load from the area under consideration. Also, it would allow:
• Evaluating trends and variations in the status of the river water quality;
• Differentiating between the contributions of point and diffuse pollution sources and;
• Estimating the positive results of any water quality management program in the River's
catchment, with respect to point or diffuse pollution sources.
The data record and storage of such type of monitoring programs should include
meteorological data, related to the determined values of EMC, which would complement
and help the data analysis process and the results interpretation.
For specific stretches of urban rivers and streams flowing through low-income areas,
the application of bio-monitoring methods (Chapter 12) would contribute to the
evaluation of the environmental status of the water body, and could compliment the data
from monitoring programs reflecting the physical, chemical and microbiological status of
the stream.
3 WATER QUALITY ASSESSMENT OF AN URBAN STREAM
3.1
The study area
Part of the Kuwadzana high-density suburb was chosen as the study area for this
investigation because most of the home industries are located in a centralised, especially
designated plot. Thus, the area accessibility and the location of the residential areas and
the home industries plot close to a natural stream of water, made the study area enough
representative and easier for investigation and sample collection. The study was
performed during the wet season 2001-2002.
The Kuwadzana high-density suburb is located in the southwest part of the city of
Harare. The area comprises of about 13 km
2
. The high-density suburb, which was first
occupied in 1984, consists of housing density approximated to 11.2 dwelling units per
hectare, with a total of 110 persons per hectare. The residents include mostly a low-
income generating group, living in a moderately dense populated area. The people engage
themselves in informal sector activities such as the home industry establishments and it
was approximately estimated that about 30% of all residents rely on such activities as
their only source of income. The majority of the home industries enterprises were set up
in the late 1980's and especially in the 1990's when ESAP (Economic Structural
Adjustment Program) was introduced. Table 5.1 shows the general growth trend of the
home industries in Kuwadzana since the 1980's, based on Kuwadzana District Council
records, which were studied during 2002.
The major activities, which are incorporated into the home industry area are:
automotive service garages, furniture making, panel beating, painting, milling machine
operation (food processing), brick making and
