PLANNING WATER SUPPLY AND SANITATION PROJECTS IN DEVELOPING NATIONS 1007
a remote area and should utilize anaerobic digesters whereby
the recovery and sale of methane gas, and digested sludge as
soil conditioner can be achieved. The central disposal facili-
ties should be equipped with running water, hose, and chemi-
cal solution for washing and cleaning the cans.
Experience has shown that such systems based on pay-
ments by the residents to private scavengers have been unsat-
isfactory. The service is poor, irregular and wastes may be
dumped uncontrolled upon land and in waters.
The box-and-can system should be used only as a tempo-
rary means of waste disposal with continued effort to replace
it by other more acceptable methods. Furthermore, it should
be carried out only under the supervision of trained person-
nel and under strict governmental control.
Urban Areas with Municipal Sewers The wastewater
collected through municipal sewers contains large volumes of
water. Therefore, treatment technology is much more complex
than discussed above. Treatment schemes to achieve second-
ary level of treatment (90% organics and total suspended solids
removal) include screening, grit removal, primary sedimenta-
tion, biological treatment (activated sludge or trickling filter),
final clarification, and disinfection. Other physical, chemical
and biological treatment processes may be added to remove
phosphorus, nitrogen, and additional organics and suspended
solids. The solids fraction (sludge) is digested aerobically or
anaerobically.
Although, such treatment technology may be desirable
for the developed nations, their use in developing nations
may not be appropriate. Such treatment processes are costly
to build, and complex to operate. Desirable treatment meth-
ods for developing nations may include the following:1) stabilization pond followed by effluent reuse on
farming lands,
2) Imhoff tanks followed by stabilization pond and
effluent reuse on farming land, and
3) upflow anaerobic sludge blanket process.Imhoff tanks provide primary sedimentation, and anaero-
bic digestion of settled sludge. The methane is collected for
energy source and digested sludge is used as compost. The
stabilization pond (oxidation pond or lagoon) is an earthen
basin that retains the wastewater for sufficient time to stabilize
the organic matter, and destroy large percentage of pathogens.
The effluent is used for irrigation, or discharged into natu-
ral waters. 40 – 43 The upflow anaerobic sludge blanket process
(UASB) was developed in Netherlands and is extensively
used and tested in the developing nations.^44 In this process the
wastewater enters the bottom of the reactor and percolates up
through the sludge blanket where organics are converted to
methane and carbon dioxide by anaerobic organisms. The gas
is collected, and treated effluent is drawn off from the top.^34COMMITMENTThe water supply and sanitation schemes in developing
countries cannot be successful without the willingness ofthe government to commit the resources to undertake water
supply and sanitation projects. Unfortunately, the govern-
mental priority in this area is quite low. Most of the develop-
ing countries set their priorities as follows: (1) agriculture,
(2) industries, (3) energy resource development, (4) educa-
tion, (5) commerce and transportation, (6) family planning,
(7) housing and urban development, and (8) water supply,
and sanitation, and environmental control.^45 Such priorities
have been set on account of necessities. It is necessary that
the developing countries give needed priority on water and
sanitation.FINANCIAL RESOURCESThe success of any program in any country depends upon
the financial commitments of the respective governments.
Developing nations (except for the oil exporting nations)
are poor and have very limited funds. A 1975 study indi-
cated that villagers if they have to pay more than 50 cents
per month for water supply, they would not participate in
the program.^45 Their ability to pay for water and sanitation
is very limited. Success of the program will depend upon
outside funds, and local labor.TRAINING AND MANPOWER DEVELOPMENTIt is well recognized that the success of any program
requires well trained people. Unfortunately, past experience
has shown that many internationally supported training pro-
grams were not successful because the emphasis was incor-
rectly placed. Engineers from developing nations when
trained in the western world generally learn the theory and
design of most sophisticated unit operations and processes
in water and wastewater treatment and environmental engi-
neering. When they return to their countries, they are gen-
erally eager to utilize such technologies, although in most
cases these may be quite inappropriate. Furthermore, for-
eign consultant’s unfamiliarity with the cultural and operat-
ing competence of the people in developing countries have
resulted in selection and design of technology that have not
functioned.
What is really needed is a program where training at all
levels may be effectively provided. The includes training of
central government officials and engineers; local govern-
ment officials, residents and technicians; on-the-job training
of operators; and users education. Government officials set
the priorities and make funding decisions. Engineers have
responsibility to evaluate, select and implement the appro-
priate technology. Local officials participate and support the
program. The technicians and operators have the responsibil-
ity for continued operation and maintenance of the system.
And finally, users education is essential as they are the ulti-
mate beneficiary.
In order to effectively provide such a complex training
opportunity, programs must be developed in the develop-
ing nations. Such training programs must be developed asC016_008_r03.indd 1007C016_008_r03.indd 1007 11/18/2005 11:01:58 AM11/18/2005 11:01:58 AM