Environmental Engineering Reference
In-Depth Information
allow the implementation and enforcement of existing regulations, thus having an adverse
effect on the successful implementation of source control and abatement measures.
Low-cost sanitation technologies, as pit latrines, which are widely used as an option in
the region, both in rural and urban areas, often are the cause of diffuse pollution problems
(Chapter 6). Local by-laws and rural sanitation guidelines should consider this problem
and prescribe strict limits with respect to the application of appropriate on-site
technologies in cases of high ground water tables, such as dry pit latrines and bucket
latrines. The regulatory documents should provide for appropriate regular cleaning
methods and their implementation should be backed up by public education with respect
to operation and maintenance procedures. In cases, where water supply reticulation
exists, the provision of a basic sewer system might be feasible. However, there are two
possible problems, which might jeopardize the implementation of such measures:
• The first one is related to economic problems - the people, using the facilities might not
be able to payfor the installation and service required. Such cases require well-
regulated and administered system for subsidizing this practice by local authorities,
governmental or donor funds.
• The second problem is associated with the number of people served by each facility.
Even the best onsite technology could not operate properly and will fail to serve a
large number of people living in one place. In such circumstances, as well as in places,
where no sanitation exists at all, the local authorities might look for the provision of
ablution blocks, provided with clean water and sanitation facilities at convenient
locations, which could serve a relatively small portion of the settlements. The system
of ablution blocks could be supplied with clean water and a simple sewage system,
and could provide for a medium-term solution in such areas. The construction costs
could be funded by external sources, but the community should execute the operation
and maintenance, with limited technical services provided by the local authorities.
5.2
Storm water and solid waste management
A proper maintenance of road structures and drainage channels, together with a sound
solid waste management practice could lead to a considerable reduction of urban drainage
pollution. Irregular solid waste collection, and spreading refuse over the streets and
public places could be often seen in urban areas in the region, especially near market
places and transport terminals. This problem has been acknowledged by official
authorities and urban planners (Irurah et al. 2004). The corresponding pollution
implications with respect to the drain systems and natural watercourses, which would
collect the runoff and the washed litter, need no explanation or monitoring. The provision
of a proper solid waste collection, transport and disposal system should be viewed as a
priority measure of diffuse pollution source control, which should be provided by the
local authorities. Diffuse pollution with respect to existing or abandoned solid waste
disposal sites (Chapter 7), need special attention and the consideration of upgrading the
facilities or the special rehabilitation projects with respect to abandoned disposal sites.
In addition to the above-mentioned source control measures, pollution abatement
structures could be provided at the outlet of major storm water channels, such as
wetlands, ponds, detention basins, etc. In places where land is available, the provision of
natural treatment systems as wetlands before the discharge of drainage channels into
