Naz, Antonia Corinthia C and Mario Tuscan N. Naz. 2006. Modeling ...

egardless of the volume of waste. With more wastes, the cost per unit volume of waste
will decrease, although the total MOCs will increase. This is more pronounced when
capital costs are included. This demonstrates the economies of scale in ECOSWAM
services, especially in operating a sanitary landfill (SLF). On the other hand, disposing
only residual wastes in a SLF will entail lesser MOCs , although the cost per unit
volume of waste will increase. Disposing only residual wastes will lengthen the life of
the SLF and will result in savings in terms of avoided costs of the construction of
another SLF.
Numerous studies have demonstrated that solid waste disposal activities benefit
from large and significant economies of scale: the larger the capacity of a given site, the
lower the cost per ton of waste land filled. If these economies of scale exist, smaller
local government units may not be able to exploit them solely because their smaller size
would not justify the investment necessary to do so. However, a cluster of
municipalities may be able to do it. Municipalities should be encouraged to exploit these
scale economies (Laplante, 2003).
Table 14 shows the marginal costs that Tuba will incur in order to move from
the base case and to shift from one scenario to another. Since the base case is the
reference point, its costs shall be assumed to be zero. The lowest marginal cost will be
incurred when Tuba moves from the base case to scenario 1.
Table 14. Annual Marginal Costs Of ECOSWAM Services
To Move From Marginal Costs, PhP
Base Case to Scenario 1 3,456,212
Base Case to Scenario 2 5,221,780
Base Case to Scenario 3 5,781,798
Scenario 1 to Scenario 2 1,765,568
Scenario 2 to Scenario 3 560,018
Scenario 1 to Scenario 3 2,325,586
Table 15 shows the costs per stage of the ECOSWAM services. The costs of stage
2 or the collection and transport of wastes comprise an average of 62 percent of the total
costs. This is consistent with the findings of the DENR EMB and Cointreau (1994) that
collection costs account for about 40 to 80 percent of the total costs. Hence, should
LGUs want to reduce costs in ECOSWAM services, they need to reduce waste
collection and transport costs.
Table 15. Cost per Stage of the ECOSWAM Service as a Percentage of the MOCs
Stages Base Case Scenario Scenario Scenario Average
1
2
3
Stage 1 – Waste Segregation
& Reduction
4% 7% 9% 10% 8%
Stage 2 – Collection and
Transport
75% 54% 61% 59% 62%
Stage 3 – Disposal and
Sanitary Landfill
Management
21% 39% 30% 31% 30.%
Total 100% 100% 100% 100% 100%
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