Prepared by D. S. Harder*, A. U. Sajise** and E.M. Galing*** * Resources Environment and Economic Center for Studies (REECS), Quezon City, Philippines (E-mail: dieldre@yahoo.com) ** University of the Philippines at Los Banos (UPLB), Los Banos, Laguna Decentralized Wastewater Treatment Systems (DEWATS) for Urban Environments in Asia, 25-28 May 2011, Crowne Plaza Galleria, manila Philippines.

1. Willingness to Pay for Sanitation Services in Dagupan City,
Philippines1
D. S. Harder*, A. U. Sajise** and E.M. Galing***
* Resources Environment and Economic Center for Studies (REECS), Quezon City, Philippines
(E-mail: dieldre@yahoo.com)
** University of the Philippines at Los Banos (UPLB), Los Banos, Laguna
(E-mail: asajise@yahoo.com)
*** WB-WSP, Ortigas, Metro Manila, Philippines, UK
(E-mail: egaling@worldbank.org)
Abstract
Using the Contingent Valuation Method (CVM), the Study looks at the septage management and
sewerage2 services demand of households with latrines in Dagupan City, Philippines vis a vis the
cost of providing these services. The survey covers a total of 1200 respondents for the septage and
sewerage demand study. Under the Willingness to Pay (WTP) Study, certainty corrections and
protest vote screening were applied to WTP responses to control for hypothetical bias.
For the septage and sewerage studies, income was shown to significantly influence WTP. WTP
was also found to increase across income groups, indicating the plausibility of implementing a
socialized pricing scheme for the septage and sewerage fees. Another important implication of the
results is that increased demand for sanitation facilities would only take place as general income
levels of Dagupan City improves.
Under certain assumptions, the individually rational and financially viable Septage Fee is around
PhP 46.00/ mo with optimal desludging frequency of three years. This means that a self-financed
Septage Program is possible for the city. However, the case is different for the Sewerage program
since none of the proposed fees (including the average WTP of Php102/mo for the whole sample)
is sufficient to cover the huge investment costs associated with a self-financed Sewerage
infrastructure. Thus, the LGU has to source funds elsewhere.
Keywords
Septage; Sewerage; Willingness to Pay (WTP); Sanitation
1.0 BACKGROUND
This study on household sanitation behavior and demand for sanitation services in Dagupan City is
part of the continuing activity under the Program for Sustainable Sanitation for South Asia
(SuSEA). This is implemented in six pilot provinces nationwide that include the municipalities of
Bauco, Alabel, Guiuan and Polomolok as well as the cities of Dagupan and General Santos. The
overall objective of SuSEA is to increase the access of poor Filipinos to sustainable sanitation
services. It is composed of two national components: 1) Establishment of a national sustainable
sanitation program (NSSP); and 2) Formulation of a national sustainable sanitation communications
and hygiene promotion program (NSSCHPP).
Among the objectives of the NSSP is for all provinces and cities and half of the municipalities to
come up with a sustainable sanitation program, as well as a 100% increase in sustainable sanitation
investments by 2016. This links closely with the objectives of the study that aims to understand the
sanitation decisions households make and their willingness to pay for sanitation services.
In particular, using the contingent valuation method, the study looks at the septage management and
sewerage3 services demand of households with toilets in Dagupan City vis a vis the cost of
1
This study is an initiative of the SuSEA Program of the World Bank Water and Sanitation Program (WB-WSP) with Coffey International as the
resource agency/contractor of the Study
2 Sewerage demand covers only the Central Business District
3
Sewerage demand covers only the Central Business District

2. providing these services. It reveals what people say they would do given the hypothetical scenario
of providing sanitation services in their area.
2.0 THE CONTINGENT VALUATION METHOD (CVM)
2.1 The CV Design
Contingent valuation, a method used to study household preference and behavior, directly asks
people in a survey how much are they willing to pay (or willing to accept) for a good or service. It
is referred to as ‘contingent’ because people’s willingness to pay (WTP) responses is anchored on a
specific hypothetical scenario and description of the good/service to be provided. The hypothetical
market includes a statement of the proposed change (i.e. sanitation services) and an institutional
mechanism in which the proposed change is to be provided and financed (i.e. waterbill).
Since not all goods and services are traded in the market (i.e. reduction in water pollution),
information on market demand is usually unavailable, thus making Contingent Valuation a useful
and practical decision-making tool for valuing well-known goods. Initial applications of contingent
valuation studies in the Philippines have been on water and sanitation (Choe et. al. 1996; Lauria et.
al. 1999).
2.1.1 The Contingent Valuation scenario
The two hypothetical CV scenarios presented in the survey includes the septage and sewerage
management plans. This is compared to the existing practice or status quo (Table 1).
Table 1. CV Scenario for Septage and Sewerage Study
Status Quo Management Plan
Septage Only <5% of hh in 100% households w/ septic
Management Plan Dagupana have desludged tanks will be desludged
Coverage of their septic tanks
the Plan Sewerage Plan 0% sewerage connections 100% sewerage connections
for households & of hh and establishments in
establishments the Central Business District
Septage DENR composting Septage Treatment Facility @
Where sludge/ Management Plan facility (Sual Pangasinan) Dagupan City
wastewater is Sewerage Plan Canals that eventually Wastewater Treatment Plant
brought
discharges to the river (WwTP) @ Dagupan City
Septage Private desludgers LGU & Dagupan Water
Management Plan District or authorized
Management desludger
Sewerage Plan None LGU & Dagupan Water
District or private operator
Septage One time payment fixed fee per month added to
Payment Management Plan water bill
Scheme Sewerage Plan None Volumetric (based on water
consumption)
Frequency of Septage As needed Once every 3-5 yrs
desludging Management Plan (scheduled desludging by
area/zone)
2.1.2 Elicitation method

3. In framing the WTP question, the referendum dichotomous choice (DC) elicitation format was
used. This format uses bids that are randomly assigned to respondents and asking them whether
they would vote to pay the assigned amount that will be added to their monthly water bill. They
could either accept or reject the bid offer.
This type of elicitation format is realistic since individuals typically make purchase decisions based
on fixed market prices (‘take it or leave it’). This also minimizes if not totally eliminates the
incentive for respondents to lie or to engage in strategic behavior in order to influence the provision
of the good. The hypothetical scenario further includes a script that reminds respondents of their
budget constraint to get more valid WTP responses.
Certainty corrections were further applied to WTP responses. In particular, respondents who said
that they are willing to pay for the sanitation service but are unsure of their response are re-
classified as ‘no’ respondents. This is usually done in Contingent Valuation analysis to correct for
hypothetical bias. Overall, ‘no’ responses increased from 781 to 831 after the WTP responses to the
offered bid were adjusted for certainty. The data was also subjected to protest vote screening. The
study only considered valid ‘no’ responses if the reason for voting no is due to lack of preference
for the good or income constraint.
2.1.3 Setting of bid prices
One of the crucial decisions to make in any CVM study is the selection of bid prices. The research
team did an initial focus group discussion with households. The initial bids were then pre-tested to
151 randomly selected households from 4 barangays in Dagupan, namely: Barangays 2 & 4 (within
the Central Business District), Barangay Lomboy (island barangay) and Barangay Mangin
(interior/river barangay). The choice of pre-test sites took into account the income disparities
between zones or barangay classification. The final bids used for the survey are Php50, Php100,
Php150, Php200 and Php250.
2.2 General Empirical Strategy: CVM and the Random Utility Model (RUM)
The random utility model is the overall framework used to analyze the survey data. The model
posits that given two choices (i=1,2), a household chooses the first alternative over the other if the
utility gained from the first alternative is higher than the utility derived from the other. If we let Vi
be the indirect utility gained from choosing alternative i, then rationally choosing alternative 1
means that:
Note that the choice problem falls under the class of discrete or dichotomous choices. Since the
analyst only observes the actual choice and some but not all variables that affect the choice, a
random error term εi is included and Vi is considered as the deterministic component. The probability
of observing choosing alternative 1 can be written as:
Pr(y1 = 1) = Pr ( 1 (x1, m1 ) > V2 (x2 , m2 ))
V
An interesting application of this model is a hypothetical scenario used to analyze and explain the
stated preferences of households for the proposed Sanitation Programs in Dagupan City (i.e.
Septage and Sewerage Management Plans). These services will be available for a household in
exchange for a reduction in income. Suppose that the household is offered a price or bid (b) in
exchange for the hypothetical service. Agreeing to pay the bid or price implicitly implies that:

4. where:
v0 is the status quo utility
v1 is the utility after the proposed change
ti is the bid offered
zi is a vector of demographic variables (e.g. education, age, gender, etc.)
yi is respondent i’s income level
θi is a vector of other control variables (e.g. classification)
Assuming a linear utility function we can restate the earlier probability statements. Specifically, we
can rewrite the status quo indirect utility and decompose it to its’ deterministic and random
components (εij for j=0,1):
(2)
Similarly the indirect utility function for the proposed change is expressed as:
(3)
Notice that in the previous equation we are subtracting the bid from the income level. This is how
we capture the trade-off from reducing income but paying some amount ti. Using equations (2) and
(3), we can alternatively write equation (1) as:
(4)
or
Simplifying difference terms for the coefficients yields:
(5)
The next step would be to estimate the simplified β coefficients. This involves assuming a specific
functional form for the probability distribution Pr(•). A common assumption is the logistic function.
The log likelihood function is derived through taking the summation the log of the logistic function
for each observation or respondent. The usual estimation procedure for obtaining the estimated
coefficients is the Maximum Likelihood Estimation (Greene, 2002). Finally the
Mean WTP is calculated using the following formula:
(6)
2.2.1 Some Econometric Issues

5. There are two econometric issues associated with the nature of the data for the study. The first one
involves the nature of the CVM data for the Septage Management Plan. In particular, different
hypothetical scenarios were offered to households with and without water connections. Connected
households were offered the hypothetical scenario of whether they would be willing to pay some
bid amount for the SMP. Non-connected households, on the other hand, were offered a hypothetical
scenario of whether they would want to be connected or not. This was followed by the same
hypothetical scenario offered to connected households.
We conjecture that there is a potentially a larger hypothetical bias for non-connected households
because they essentially face two hypothetical scenarios. The likelihood of actually experiencing
the septage infrastructure is less real for this subgroup of respondents. A consequence of this is that
the probability of being offered a two-staged scenario is conditional on the household being
connected at the time of the interview. Since, the choice of being connected could be linked to
certain household characteristics, we expect that some will be more predisposed of having water
connections. This leads us to the potential problem of sample selection. Simply pooling connected
and non-connected households and following the specification outlined above for the septage
sample can lead to inconsistent estimates and hence biased WTP values. To address this issue we
first estimate an endogenous switching regression model where both the selection and outcome
variables are discrete or dichotomous.
Consider first the selection mechanism. A household chooses to connect to DCWD water system if:
Pr(connection = 1) = Pr(Vconnected (g + ε connected > Vnot connected (g + ε not connected )
) )
= Pr(ε ' > Vnot connected (g − Vconnected (g
) ))
where
ε ' = ε connected − ε not connected
The outcome variable on the other hand, pertains to the household’s answer to the CV scenario. The
household agrees to pay the offered bid if:
Pr(yes) = Pr(Vyes (g + η yes > Vstatus quo (g + η status quo )
) )
= Pr(η ' > Vstatus quo (g − Vyes (g
) ))
where
η ' = η yes − η status quo
Since, the error terms of the selection and outcome are hypothesized to be correlated we can
observe the conditional choice of agreeing to a bid as:
Pr  (η ' > Vstatus quo (g − Vyes (g ε ' > Vnot connected (g − Vconnected (g 
 ) )),( ) )) 
Pr(yes | connection = 1) =
Pr(ε ' > Vnot connected (g − Vconnected (g
) ))
Instead of estimating the conditional probability of observing an agreement to a bid, we can opt to
estimate the joint probability. To do this we can assume that both error terms are normally
distributed and estimate a bivariate probit expressed in equation terms as follows:
Pr  (η ' > Vstatus quo (g − Vyes (g ε ' > Vnot connected (g − Vconnected (g  =
 ) )),( ) )) ∫ ∫ φ (η, ε , ρ )dη d ε
η' ε '
where
φ is the bivariate normal density function
Looking at whether rho is significant or not at an assumed confidence level easily tests the presence
of sample selection. If rho is statistically different from zero then the decision to connect is

6. necessarily related to the decision of agreeing to a bid offer. A simple application of the
econometric model in the previous section to a pooled sample of connected and non-connected
households will lead to biased estimates of WTP.
2.2.2 Variables Used in the Various Analysis
The covariates used in the implementation of the empirical strategy are shown in Table 2:
Table 2. Variables Used in the Regression Model
Variables Description
bid Bid offered to respondent and assumes the following values: 50, 100, 150,200,
250
know Respondent’s score on sanitation issue test
age Age of respondent
civil Civil Status of respondent:
1 - Divorced/separated 3 - Married 5 - Widowed
2 - Live in 4 - Single
educ 1 has value of 1 if respondent finished some elementary; 0 otherwise
educ 2 has value of 1 if respondent has graduated from elementary; 0 otherwise
educ 3 has value of 1 if respondent finished some high school; 0 otherwise
educ 4 has value of 1 if respondent graduated from high school; 0 otherwise
educ 5 has value of 1 if respondent finished some years in College; 0 otherwise
educ 6 has value of 1 if respondent graduated from College; 0 otherwise
educ 7 has value of 1 if respondent have post-graduate schooling; 0 otherwise
educ 8 has value of 1 if respondent finished Vocational; 0 otherwise
hseown has value of 1 if respondent/ family of respondent fully owns the house; 0
otherwise
agehouse Age in years of respondent’s house
ageown Interaction term between age of house and house ownership: agehouse*hseown
yrslive Number of years household has lived in the house
yrslive2 Square of the yrslive
diarr has a value of 1 if any household member has had diarrhea in the past three
months; 0 otherwise
buss has a value of 1 if a business is being run in the house; 0 otherwise
Income 1 has value of 1 if household’s monthly income is <PhP 4,999; 0 otherwise
Income 2 has value of 1 if household’s monthly income is between PhP 5000 and PhP
9,999; 0 otherwise
Income 3 has value of 1 if household’s monthly income is between PhP 10,000 and PhP
20,000; 0 otherwise
Income 4 has value of 1 if household’s monthly income is between PhP 20,001 and PhP
35,000; 0 otherwise
Income 5 has value of 1 if household’s monthly income is >PhP 35,001; 0 otherwise
hh_all Total number of household members
age_septic Age of septic tank
Class 1 has a value of 1 if baranggay is classified as a Central Business District
baranggay; 0 otherwise
Class 2 has a value of 1 if baranggay is classified as a Coastal/ Inland baranggay; 0
otherwise
Class 3 has a value of 1 if baranggay is classified as a Island baranggay; 0 otherwise
Class 4 has a value of 1 if baranggay is classified as a River baranggay; 0 otherwise
2.3 Sampling Frame

7. For the septage and sewerage study, a total of 12004 respondents were sampled, distributed between
850 and 350 respondents, respectively. A 12% non-response rate was noted for the whole sample.
The allocation of the sample is based on the following formula:
 Niσ i 
ni = N  
ci


∑ Niσ i
ci


k
w h ere
N is th e total sam p le size
N i is th e total p op ulation in the ith inco m e strata
σ i is the in com e variance fo r the ith inco m e strata
c i is the cost of ob tain ing a sam p le from the ith inco m e strata
The above equation provides the least cost allocation for a fixed sample size given the variability in
income. We assume that cost differences are insignificant since Dagupan’s terrain is homogeneous
and its’ land area (4,446 has) is not that large. Thus, this variable can be ignored in the computation.
Variability in income5 is based on barangay clusters, which is the only available disaggregated
information from the baseline study6. However, for the sewerage study, a simple proportional
allocation was used because barangays under this scenario belong to the same type/cluster. Thus,
the ‘income variability’ cancels out in the equation.
For the septage study, sample allocation for each barangay was further categorized into households
connected and not connected to the Dagupan City Water District (DCWD). Considering all this, the
sample size allocation for the septage management and sewerage options are shown in Tables 3 and
4, respectively.
Table 3. Sample Size Allocation, Sewerage Respondents
No. of Type of Total survey
Name
Households Barangay Households
Herrero Perez 509 CBD 23
Lucao 1395 CBD 64
Pantal 3087 CBD 142
Poblacion Oeste 683 CBD 31
Barangay I (T. Bugallon) 124 CBD 6
Pogo Chico 903 CBD 42
Tapuac 913 CBD 42
TOTAL 7614 350
Table 4. Sample Size Allocation, Septage Respondents
4
The total sample takes into account cost and time considerations in doing the survey
5
Incorporating income variability is important since demand is basically determined by income and prices.
6
2007 Baseline Study Report: Dagupan City. Sustainable Sanitation in East Asia (SuSEA). It would have been ideal to use the income variability for
each barangay, but since the raw data from the baseline study was not available, further disaggregation is not possible.

8. Non- Total
No. of Connected
Name Type of Barangay connected Households
Households Households
Householdsa (survey)
Bacayao Norte 289 River 3 8 11
Bacayao Sur 307 River 3 9 12
Bolosan 660 River 6 19 25
Lasip Chico 166 River 2 5 7
Lasip Grande 267 River 3 8 11
Mamalingling 230 River 2 7 9
Mayombo 1222 River 12 36 48
Pogo Grande 380 River 4 11 15
Salisay 336 River 3 10 13
Tambac 424 River 4 12 16
Bonuan Binloc 1185 Coastal & inland 8 25 33
Bonuan Boquig 1978 Coastal & inland 14 42 56
Bonuan Gueset 3085 Coastal & inland 22 65 87
Caranglaan 1281 Coastal & inland 9 27 36
Maluedb 1567 Coastal & inland 11 33 44
Tebeng 463 Coastal & inland 3 10 13
Calmay 943 Island 7 21 28
Salapingao 418 Island 3 10 13
Herrero Perez 509 CBD 6 19 25
Lucao 1395 CBD 17 51 68
Pantal 3087 CBD 38 114 152
Poblacion Oeste 683 CBD 8 25 33
Barangay I 124 CBD 2 5 7
Pogo Chico 903 CBD 11 33 44
b
Tapuac 913 CBD 11 33 44
TOTAL 212 638 850
a
- 25% of total household covered
b
- In the actual survey, the sample size in Barangay Tapuac was adjusted from 86 to 69 since is was found out that 78% of the houses
in the area are apartments and excluded from the survey. The remaining respondents were transferred to Malued with sample size
increasing from 44 to 61 (all hh).

9. 3.0 SURVEY RESULTS
The discussion of survey results is divided into two parts. First is a qualitative description of the
data in terms of environmental and health hazards that relate to the design, construction and
maintenance of existing household sanitation facilities. The second part outlines the results of the
econometric strategy discussed in the methodology section.
3.1 Overview of Current Sanitation in Dagupan City7
3.1.1 Environmental problem/priorities
Base on household ranking, the more visible environmental threats that the local government should
give priority to include solid waste (36%) and flooding (30%). It is common knowledge that
majority of the barangays in Dagupan are vulnerable and susceptible to the disturbing effects of
inundation.
Poor sanitation (26%) only ranks third among the top environmental problems of Dagupan City
from the perspective of households respondents. This is not only in terns of lack of access to latrines
but also by the threat posed by badly designed sanitation facilities including the lack of proper
sludge and wastewater disposal systems. Receiving water bodies often absorb the pollution load
coming from households. Thus, it is not surprising that DENR-EMB included Dagupan River as
one of the rivers nationwide that pose contact risk to public health and the environment. It has
shown a very high total and fecal coliform level8, about 30 times higher than the DENR standard.
3.1.2 Current sanitation facilities & the environment
Survey results show that 43% of households have single vault septic tanks that do not conform to
the standard design prescribed under the Sanitation Code of Dagupan City. These vaults provide
only minimal treatment and limited sludge storage compared to two or three chambered septic
tanks. Although most of households reported that their septic tanks are water sealed (at least for one
chamber), 15% of the remaining septic tanks are bottomless or do not have concrete flooring. This
could lead to wastewater seepage.
In terms of location and access, the Sanitation Code of Dagupan City further stipulates that septic
tanks ‘should not be constructed under any building and shall be located such that desludging
equipment can have convenient access to the manhole’. Nonetheless, almost half of the respondents
interviewed had septic tanks located inside the house, with some directly under their toilets. A third
further reported that their septic tanks are more than 20 meters away from the nearest access road.
This concern however, can be addressed by using longer vacuum pumps (i.e. vacuum pumps of
Manila waters has a maximum length of 80 meters). The only constraint is the width of the access
road that should be able to accommodate the desludging truck. This could be a problem particularly
for the island barangays.
Another disturbing observation is the 13 meters average distance of the nearest water source to the
latrine, which is lower than the specified distance of 25 meters and above under the Clean Water
Act. However, the survey shows that only 6% of the respondents are familiar with this provision
under the Act. In general, the close proximity of toilets and water sources coupled with poorly
constructed septic tanks could lead to groundwater contamination that is hazardous to public health.
A faulty septic tank can also lead to hydraulic overloading9 particularly during flooding.
7
This section uses the original database (n=1200) as basis for discussion
9 Hydraulic overloading can force the waste out through the septic tank before it receives adequate treatment. It can lead to anaerobic
conditions in the drainfield and might not give solids time to settle out before being pushed through the system
(http://www.stormwatercenter.net/Assorted%20Fact%20Sheets/ Tool7-Non_Stormwater/SepticSystems.htm; accessed 4/28/2010).

10. Most respondents perceive that water from the septic tank goes underground (48%) or stays inside
the tank (38%)10. Only 9% believed that wastewater from septic tanks eventually finds its way into
the water bodies. More than three fourths of the respondents still had the misconception that septic
tanks can provide 100% treatment for sludge and wastewater, thus controlling for water pollution.
For the septic tanks to function as designed, it has to undergo regular maintenance through the
removal of built up solids. However, the survey shows that only 13% of households have desludged
their septic tanks for the past 10 years. This is despite majority of respondents agreeing to the
statement that septic tanks should be desludged once every three to five years as required under the
Sanitation Code of Dagupan City11. Desludging is done mainly as a response to emergency
situations such as septic tank overflow, clogging or damage caused by flooding, earthquakes, etc.
Poor maintenance reduces the effectiveness of septic tanks to treat waste before it is discharged to
the environment.
Also, there is no existing sludge treatment and disposal facility within Dagupan. The nearest DENR
approved composting facility is in Sual, Pangasinan. This resulted to indiscriminate disposal of
untreated or poorly treated sewage into the environment. The survey shows that of those that had
their septic tanks emptied, 40% do not know where the septage is brought while 30% buried their
waste in a pit (i.e. manual desludging). The rest disposed of the waste in nearby water bodies
(13%), in a farm (5%), or anywhere (7%). This practice is prohibited under the Sanitation Code of
Dagupan City, which stipulates that, ‘no discharge of septage or sludge shall be allowed in
manholes, drainage areas, canals, creeks, rivers or other receiving bodies of water or land’.
Unceremonious discharge of untreated sewage into vacant spaces and receiving water bodies
provides a vector for pathogens that could transmit disease to humans.
In terms of health impacts, 10% of the respondents reported incidences of diarrhea in the past three
months12. Meanwhile, occurrences of other waterborne diseases are negligible and no reported
outbreaks were observed during the duration of the study.
4.1 Econometric Results
This section covers the Willingness to Pay (WTP) of Dagupan City households for the Septage
Management Plan, and WTP of the Central Business District (CBD) households for the Sewerage
Plan. The final models used are corrected for both uncertainty and protest votes (CC/PC model).
In particular, the discussion includes characteristics of the respondents, results of the CV analysis
including simulation exercises that helped identify some important provisions of a potential Septage
Management Program and Sewerage Plan. For instance, we determine the most efficient desludging
frequency (only for the SMP) and pricing policy. Efficiency is referred to in the context of an
intertemporal decision wherein discounting or time preference plays an important role. Likewise it
also refers to that which is rational for the individual household as well as financially feasible to the
Local Government.
4.2.1 Implementing A Septage Management Program in Dagupan City
After screening for protest votes, 790 useable responses were used for the WTP analysis under the
Septage Management Plan (7% lower than the original sample). This includes both households
connected and not connected to the Dagupan City Water District (DCWD).
10 These respondents view septic tanks as simply a storage of sludge and urine rather than a primary treatment system
11 Apparently, this item, despite approval from respondents, gained the most comments. Those who got it wrong were respondents who
had larger septic tanks with only few household users.
12 Three percent of respondents also had diarrhea in the past week of the survey. On average, they spent Php604 for treatment,
including in patients.

11. Respondent Characteristics (pooled sample)
Based from the socio-economic profile of households, those that are willing to pay for the Septage
Management Plan are relatively younger. Also, nearly a third are married with an average of six
members per family. In addition, majority of these respondents are relatively well off in terms of
asset & income. Nearly a fourth earns monthly income greater than Php20,000 compared to 16% of
those who are not willing to pay. Households who support the Plan are likewise better educated. In
terms of location, a higher percentage of septage respondents from the Central Business District and
island barangays are willing to support the SMP while a greater number of refusals to pay were
observed from coastal/inland and river barangays.
Likewise, respondents who are willing to pay have older houses and septic tanks and have lived
longer in their current residence. In general, septic tanks have a mean age of 16 years for both
subgroups. Respondents from the island barangays used to have hanging latrines, some access
public or shared toilets within their neighborhood while others had to reconstruct their toilets and
septic tanks after the damages brought by typhoons Ondoy and Pepeng, including the 1990
earthquake.
Bid Distribution
Cursory evidence shows that in general, percent of respondents saying ‘yes’ on willingness to pay
for the Septage Management Plan decreases with the offered bid (Fig 1), thus conforming to
theoretical expectations.
59.28
60
50
36.42
40
% yes response
26.92
30
18.00
20
10.32
10
0
50 100 150 200 250
Bids (Php)
Fig 1. Bid Distribution of ‘Yes’ Responses, the Septage Plan
Similarly, percentage of those saying yes to the offered bid increases with income (Table 5).
Table 5. Distribution of WTP Responses by Income Bracket, Septage Respondents
Income Willingness to Pay
bracket
No % no Yes % yes All
Income 1 74 69.81 32 30.19 106
Income 2 191 73.75 68 26.25 259
Income 3 194 69.53 85 30.47 279
Income 4 62 63.27 36 36.73 98
Income 5 25 53.19 22 46.81 47
Total 546 100 243 100 789a
a
– excludes one don’t know response for income

12. Willingness to Pay for a Septage Program
As elaborated earlier, a bivariate probit model was used to test whether the error terms in the
selection mechanism and the outcome decision (i.e probability of agreeing to the offered bid) are
correlated. A simple likelihood ratio test shows that the correlation parameter (ρ) is not significantly
different from zero. Thus, we can run a logit regression on the pooled sample of connected and non-
connected households.
The results of the logit regression for the Septage study are shown in Table 6. The negative and
significant coefficient for the bid offer indicates that respondents are less likely to pay for higher
bids. Younger respondents are also more likely to pay for the sanitation service. Besides this, ones’
knowledge on sanitation issues increases the probability of saying yes to the bid offer. In particular,
knowledge regarding the provisions of the Sanitation Code of Dagupan City as well as general
knowledge on wastewater hazards and sanitation can increase the probability of agreeing to a bid
offer by 13 percentage points. The probability of agreeing to a bid is also positively related to the
level of education. This implies that well-informed households tend to agree more to the offered
bid, perhaps, because these households can comprehend the scenario better. We can see this because
all the categorical variables for education (educ 2 to educ 8) are significant and exhibit positive
signs. Another determinant of the probability of agreeing to an offered bid is the age of the house.
The variable is negatively related with the probability of paying the bid offer. That is, households
with older houses have a lower probability of supporting the Septage Management Plan. This is not
surprising since old houses are prone to abandonment.
The information obtained from the logit analysis is used to compute for the amount that households
on average are willing to pay (WTP) for septage service improvements (Table 7). Calculations
show that the mean WTP of Dagupan City residents is around PhP 73. Note that WTP increases
with income. For instance, households with monthly income in excess of 35,000 would be willing
to add PhP 121 to their monthly water bill to avail of the improved septage services. While
households in the lowest monthly income bracket (below PhP 4,999) are willing to pay an
additional PhP 67 per month. Furthermore, the WTP for each income bracket are significantly
different from each other at 5% level of confidence. The variability in the WTP across income
brackets is suggestive that a “socialized” pricing scheme can be implemented.
However, not all of the WTP amounts shown in Table 8 would pass a referendum. Estimates show
that for the whole sample and across income brackets, only 50% on average would vote for a
referendum that will add the septage fee to the existing water bill. The calculated bid or proposed
price and the probability of a yes vote are shown in Table 8. From the table, inorder to have at least
60% of households across income brackets agreeing to a new septage ordinance, the proposed
septage fee should only be around PhP 46. The discussions to follow will revolve only on the bids
that would pass a referendum, i.e. bids PhP 0.50 to PhP 73.00

13. Table 6. Results of Logit Regression for the Septage Program
Variables Coefficients
bid -0.0134***
Know (score) 0.6555*
age -0.0196***
civil 0.0492
educ 2 1.4595*
educ 3 1.8127**
educ 4 1.5965**
educ 5 2.0786**
educ 6 1.9787**
educ 8 2.2788**
hseown -0.0014
agehouse -0.5830*
ageown 0.0021
yrslive 0.0022
yrslive2 0.0093
diarr 0.0001
buss 0.3662
Income 2 0.2794
Income 3 -0.3054
Income 4 -0.0790
Income 5 0.2850
hh_all 0.4004
age_septic -0.0078
Class 2 -0.2574
Class 3 0.0269
Class 4 -0.3794
constant 0.1418
*** significant at 1%; ** significant at 5%, * significant at 10%

14. Table 7. Calculated Willingness To Pay for the Septage Program, by Income Bracket and for the
Whole Sample
Income bracket WTP/mo
(N=790)
Income 1 67
Income 2 55
Income 3 73
Income 4 102
Income 5 121
Whole Sample 73
Table 8. Probability of Paying/Voting for Different Proposed Fees
Probability of Paying Proposed Fee (PhP/
(%) mo)
30 133.80
40 101.60
50 73.00
60 46.00
70 23.00
80 7.00
90 0.50
99 0.00
The Efficient Price and Desludging Frequency
We are now left with the question on the relevant price to charge households and the optimal
desludging frequency. To answer this, we will use the Benefit Cost Analysis approach. BCA
assumptions are outlined in Appendix Table 1.
The welfare gains households derive from different fees and desludging frequencies are shown in
Table 9. The figures are welfare gains in present value terms of different pricing schemes and
household desludging frequency. The Status quo represents the present value of paying the average
commercial desludging price of PhP 2,500.
The first thing to notice is that the range of septage fees widens as the desludging frequency is
shortened. For example, if the Dagupan LGU imposes that households desludge their septic tanks
once in every 10 years, then households will only rationally participate in that scheme if Septage
fees are between Php 0.50 and PhP 7.00. This is because they will be better off with the status quo
of hiring a commercial desludger and paying him the average of PhP 2,500 (or PhP 1,060 in PV
terms) every 10 years. On the other hand, if the mandated desludging is every three years, then the
Septage Program will be more appealing to households. We expect, given the current cost
assumptions that households will participate if the Septage fees are between PhP 0.50 to PhP 46.00.
Fees falling between these ranges are shown to be superior to the status quo.
What drives the results of the BCA analysis is the discounting or assumptions on households’ time
preferences. Increasing the interval between desludging (i.e. reducing desludging frequency) favors
the status quo because they are smaller in present value terms.

15. Table 9. Welfare Gains of Households from Various Proposed Fee and Desludging Frequencies
Bid/ 3 Year Desludging 5 Year Desludging 10 Year Desludging
Price
(PhP/ Difference Difference Difference
mo) PV PV PV PV PV PV
(Proposed (Status (Proposed (Status (Proposed (Status
Septage) Quo) Septage) Quo) Septage) Quo)
73 2,636 2,066 -570 3,653 1,708 -1,945 5,921 1,060 -4,861
46 1,661 2,066 405 2,302 1,708 -594 3,731 1,060 -2,671
23 831 2,066 1,236 1,151 1,708 557 1,865 1,060 -805
7 253 2,066 1,813 350 1,708 1,357 568 1,060 492
0.5 18 2,066 2,048 25 1,708 1,683 41 1,060 1,020
An attendant question is which of these proposed septage fees would be feasible to implement?
Earlier, we have answered the question on which fees and desludging frequency is rational for the
household. We found out that the three-year interval will yield the largest gains for the
households. Given this, we will analyze which of these Septage fees would be financially viable to
implement along with the three-year desludging plan. Another BCA was conducted using the same
assumptions in Appendix Table 1.
Given the assumptions, results show that the financially viable Septage Fees are PhP 46/mo. and
PhP 73/mo. By financial viability, we mean that the initial investment costs are recovered (fully
paid) within 10 years and that yearly operation and maintenance (O&M) expenses are also
recovered within the lifetime of the project, which is set at 25 years. These are the only Septage
Fees that will result to a positive Net Present Value (NPV). Given this, the only rational and
financially viable Septage Fee is PhP 46. Thus, with the current information at hand, a Septage
Fee of PhP 46/ mo. is recommended. Households in turn will receive regular scheduled desludging
of their septic tanks every three years.
Table 10. Financial Viability of Different Proposed Septage Fees
Bid/ Price NPV
(PhP/mo) (3 year Desludging)
73 103,152,095.48
46 28,591,923
23 -34,922,297.86
7 -79,106,103.73
0.5 -97,055,775
Comparison of the Proposed Septage Program with Other Existing Programs
The recommended Septage Program would charge PhP 46/ mo. or approximately Php 2/ cu. m. if
the average household water consumption were 24 cu. m. per month. These charges are similar with
the computed price by the LINAW project in Dumaguete CIty. In terms of monthly water bill, the
proposed fee is close to the partial charges of Manila Water. It roughly constitutes 11% of the
average household water bill of PhP 416.20 (Table 11).

16. Table 11. Charges for Septage and Sewerage Programs in the Philippines
Manila Water Sewerage and sanitation programs are funded partly by 10%
environmental fee charged to all MWSS customers on the water bill.
Households covered by sewerage are also assessed 50% of household
water bill. This is not enough to cover O&M of sewerage (perhaps
only 60-70%). There is also some cross- subsidization from water
supply income
Dumaguete City Dumaguete will cover its O&M costs for its septage treatment facility
through a user fee of PhP 2/m3 on the water bill. This user fee will
cover both capital and operating costs, as well as funding an
environmental fee
Zamboanga City Metro Zamboanga Water District sets its sewerage charges at 50% of
the water bill, and has a 99% collection rate, allowing it to fully
recover its O&M costs.
Others Other cities charge a flat rate (or zero) tariffs, collect revenues lower
than their O&M costs and, are dependent on subsidies from the LGU
or, where managed by a Water District, on cross-subsidies from
water supply income.
Source: USAID (2007)
All in all, the proposed Septage Management Plan is not far from existing and planned Septage
Programs in the country. The innovation is that the numbers obtained came from a more rigorous
methodology. Furthermore, we are sure that the recommendations are based on household stated
behavior or preferences.
4.2.2 Implementing the Sewerage Plan13 in Dagupan City
For the Sewerage Plan, the useable sample for the analysis is 322 after protest screening (8% lower
than the original sample).
Respondent Characteristics
Households who are willing to pay are relatively more mature in age, have older houses and septic
tanks and have lived longer in their current residences relative to respondents who are not willing to
support the Sewerage Plan. Both, however, have almost the same number of household members
per family, number of families living in the house and number of houses owned within Dagupan
City.
For both subgroups, nearly three fourths are female and married. Respondents who are willing to
pay are also more educated as two thirds have reached college. Thus, they may be more familiar
with sanitation issues and can better appreciate the Sewerage Plan presented to them.
A higher percentage of WTP respondents also had income under brackets 4 & 5 or income greater
than Php20,000/month (28%) vis a vis those who are not willing to pay (16%).
Bid Distribution
Similar with the Septage Plan, the figure below exhibits a negative relationship between the offered
bid and the percentage of respondents who said ‘yes’ to the Sewerage Plan. This observed trend
13The CBD area is estimated to generate 2,772 cubic meters of wastewater per day, necessitating the need for a maximum design
capacity of 6,00 cubic meters/day for the wastewater treatment plant. This takes into account population growth and the corresponding
increase in wastewater generation. The projected cost of the STF would be around PhP 250-300 million. Nonetheless with additional
construction of sewer lines/pipe networks, total investment could increase up to Php500-600 Million to fully address the sanitation
problems of Dagupan City (SuSEA 2008)

17. conforms to economic theory.
80
71.64
70
60 51.61
% yes response
50
40
29.23
30 22.73
19.35
20
10
0
50 100 150 200 250
Bids (Php)
Fig 2. Bid Distribution of ‘Yes’ Responses, Sewerage Plan
Table 12 also shows a positive relationship between income and willingness to pay.
Table 12. Willingness to Pay for the Sewerage Plan by Income Brackets
Income Willingness to Pay
bracket
No % no Yes % yes All
Income 1 24 77.42 7 22.58 31
Income 2 57 65.52 30 34.48 87
Income 3 83 61.03 53 38.97 136
Income 4 23 52.27 21 47.73 44
Income 5 9 39.13 14 60.87 23
Total 196 61.06 125 38.94 321
Willingness to Pay for the Sewerage Plan
Results of the logit regression for the Sewerage Program are shown in Table 13. For the final model
used, only the bid, knowledge, and Income 4 estimates were found to significantly differ from zero.
The bid variable shows a theoretically predicted sign. Specifically, the probability of a ‘yes vote’
decreases with the increasing bid offer. Income 4 is the only significant income bracket. This means
that compared to the relatively poorest households in the CBD, households with income between
Php20,000 to Php35,000 have higher probability of agreeing to the bid offer. All other income
brackets have the same probability of agreeing to an offered bid relative to income 1. The
knowledge variable is also significant but it does not have the predicted sign. This counterintuitive
result indicates that households with more knowledge on sanitation issues are less likely to pay. One
explanation would be that these households might have already been doing actions to improve their
level of sanitation. Hence, they may be reluctant to pay more for a new program. Since, we have no
information on the specific sanitation decisions of households other than what is associated with
decisions affecting their septic tanks, we were not able to control for this in the regression model.
In terms of the marginal effects of these variables, income bracket 4 has the largest effect.
Households in this income bracket are 33 percentage points more likely to vote for an offered bid
than those in other income brackets. On the other hand, increases in the offered bid by PhP 50
reduce the probability of saying yes by only 0.03 percentage points. The marginal effect of the

18. knowledge variable is around 28 percentage points. Thus, the probability of agreeing to a bid for
more knowledgeable households are lower by 28 percentage points compared to less knowledgeable
households. The caveat in the previous discussion however, still holds in the analysis of the
marginal effects for this variable.
The computed WTP for the Sewerage Program for the whole sample and for each income bracket is
shown in Table 14. Computed WTP per income bracket are significantly different from each other
at 5% level. The mean WTP for the whole sample using the certainty and protest corrected model is
PhP 102. What is interesting to note, is that unlike the trend observed for the WTP for Septage, the
WTP for Sewerage increases with income for the first four brackets and then declines with further
rise in income (bracket 5).
Table 13. Results of Logit Regression for the Septage Program
Variables Coefficient
bid -0.013***
know -1.261**
age 0.010
civil -0.187
educ 2 1.222
educ 3 0.442
educ 4 1.464
educ 5 1.504
educ 6 1.704
educ 8 1.883
hh_all -0.073
hseown -1.101
agehouse 0.106
ageown -0.111
yrslive 0.026
yrslive2 -0.000
diarr 0.499
buss -0.288
Income 2 0.492
Income 3 0.801
Income 4 1.391**
Income 5 0.970
age_septic -0.001
class 2 0.223
constant 1.254
*** significant at 1%; ** significant at 5%, * significant at 10%

19. Table 14. Calculated Willingness To Pay for the Sewerage Program, by Income Bracket and for the
Whole Sample, in Php
Income WTP/mo (Php)
Income 1 48
Income 2 83
Income 3 103
Income 4 157
Income 5 137
Whole Sample 102
Going back to Table 14, the mean WTP for the whole sample has a 50% chance of being voted and
is therefore expected to pass the referendum. Table 15 shows the proposed fee and the
corresponding probability of payment. If 60% of households will vote for the Sewerage program,
then the proposed legislation should charge a sewerage fee of PhP 73.00. The sewerage fees
households would be willing to pay range from PhP2 to PhP102 per month. Note that these values
are higher than the fees for the Septage Management Program.
Table 15. Probability of Paying for Different Proposed Fees, Sewerage Program
Probability of Proposed
Paying (%) Fee(PhP)
30 164
40 129
50 102
60 73
70 45
80 18
90 2
Which of these referendum-passing fees would be financially viable? Given assumptions in
Appendix Table 2, BCA results show that the prospects for an LGU financed Sewerage Program for
Dagupan is less optimistic. Given the huge investment outlay14, none of the proposed fees are
financially viable (Table 16).
Table 16. NPV of Different Referendum Passing Fees, Sewerage Program
Additional Price/ cu. NPV
Fee/ month m.
102 4.3 -151,422,433
73 3 -187,779,355
45 1.9 -222,882,591
18 0.8 -256,732,139
2 0.1 -276,791,131
14 Note that we have conservative cost and slightly exaggerated revenue assumptions

20. Comparison of WTP Estimates With Other Studies
The bleak scenario for a self-financed Sewerage Program begs the question of whether the estimates
are indeed far off from other studies. The only other study on household’s willingness to pay was
conducted in 199315. Table 17 shows that in general, the WTP for Sewerage is in the range of the
values obtained by the study. However, even if we use the estimates for Dagupan from this 1993
study, it would not still be sufficient to cover the huge investment requirements for the proposed
self-financed Sewerage Program.
Table 17. Other WTP Estimates, Philippines
Location Sewer Sewer Connection
Connection + Treatment
(PhP/mo/hh) (PhP/mo/hh)
Calamba 124 103
Davao 62 92
Dagupan 169 207
Source: Philippine Environment Monitor (2003)
4.2.3 Household Perceptions on the Hypothetical Scenario for the Septage and Sewerage Plans
Payment Vehicle
Respondents were asked of their opinion regarding the hypothetical elements contained in the CV
scenario, particularly the payment vehicle. Waterbill was chosen due to its wider coverage,
mandatory nature (i.e. disconnection as effective sanction against non payment), credibility, and
close link with sanitation services16. The Dagupan City Water District is also supportive of the Plan
and is willing to collect sanitation charges to its customers. Overall, respondents from the two
subgroups agree with the idea that they will pay for the septage and sewerage fees through their
monthly waterbill. The major reason why some households did not agree to the current payment
vehicle is the continuous increase in the water rates. We learned that the DCWD increased its rate
per cubic meter months before the survey thereby creating a negative impact to respondents’
decision making.
An alternative payment vehicle considered by some respondents includes a separate bill for septage
and sewerage fees that will be handled by a private collector, so that the computations of the
charges will be clear to them. Another suggestion would be to add these charges to the garbage fee
(Php30/mo) collected by each barangay. Respondents find the barangay solid waste management
program successful and the collection of fees efficient. The idea of collecting the sewerage and
septage fees through community tax certificates was also forwarded (Table 18).
Belief in the success of the Program/Plan
Majority of the respondents believe that the Septage and Sewerage Management Plans, once
implemented, will succeed in attaining the goal of reducing environmental pollution and health
hazards associated with poor sanitation. In fact, some are already curious as to the design, location
and actual start of the Project. Those that remained skeptic on the plausibility of the Plans gave
three major reasons: a) distrust on the LGU due to possible corruption of funds; b) impact to others
who may not be able to afford the fees and; c) failure of other people to cooperate (Table 19).
15 The date of the original study was cited in the Philippine Environment Monitor, 2003. However, there were no citations of the exact
study in the publication.
16 However, the disadvantage of using this payment mechanism is the timing of increase in water rates before the survey period.

21. Table 18. Respondent’s Perception to the Payment Vehicle & Alternative Schemes
Septage Sewerage All
N % N % N %
Agreement of using waterbill as
payment vehicle
No 242 30.63 82 25.47 324 29.14
Yes 548 69.37 240 74.53 788 70.86
Reasons for not agreeing
Water bill is continuously increasing 140 57.85 58 70.73 198 61.11
Not all have water connection 29 11.98 4 4.88 33 10.19
Don’t like mandatory payment 39 16.12 15 18.29 54 16.67
Prefers annual rather than monthly 10 4.13 1 1.22 11 3.40
collection
Don’t like DCWD service 1 0.41 - - 1 0.31
Other people will not understand how 6 2.48 4 4.88 10 3.09
the fee will be computed
All fees should be shouldered by the 6 2.48 - - 6 1.85
gov't
Will migrate soon 2 0.83 - - 2 0.62
Separate bill instead of adding to water 9 3.72 - - 9 2.78
bill
Alternative payment proposed
Don't know 14 5.79 3 3.66 17 5.25
Monthly electric bill 5 2.07 2 2.44 7 2.16
Community tax 8 3.31 11 13.41 19 5.86
Land tax 1 0.41 3 3.66 4 1.23
Barangay collection 35 14.46 15 18.29 50 15.43
Garbage fee 20 8.26 11 13.41 31 9.57
Government fund 2 0.83 4 4.88 6 1.85
None 116 47.93 15 18.29 131 40.43
Own separate bill 41 16.94 18 21.95 59 18.21
Table 19. Respondent’s Belief in the Success of the Septage & Sewerage Plans

22. Septage Sewerage ALL
N % N % N %
Belief in the success of the program
No 166 21.01 63 19.57 229 20.59
Yes 624 78.99 259 80.43 883 79.41
Reasons for no response 1112
Money will be used for other purposes 1 18 7 11.11 8 3.85
Lack of trust in the LGU due to corruption 70 42.17 22 34.92 92 44.23
LGU lask technical skill to operate STF 4 2.41 2 3.17 6 2.88
Water district may not agree to collect 8 4.82 2 3.17 10 4.81
payment
Project difficult to implement 10 6.02 8 12.7 18 8.65
Other people may not cooperate 19 11.45 12 19.05 31 14.90
Others cannot afford addt'l fee 32 19.28 11 17.46 43 20.67
Effect on Water Connection to DCWD
Table 20 shows that 95% and 88% of sewerage and septage respondents respectively would retain
their DCWD connection even if majority will vote for the septage/sewerage fee to be added to the
waterbill. One of the main reasons for keeping their pipe water connection is the difficulty of
finding alternative water sources in their area. On aggregate, 5% of those who choose to disconnect
to the DCWD opt to get water from handpumps, neighbors with pipe connection and from water
vendors.
4.0 CONCLUSIONS AND POLICY DIRECTIONS
This study has looked at the stated preference for two hypothetical programs namely: a) Septage
Management Plan that would affect households in Dagupan City; and b) Sewerage Program for
households in the CBD area of Dagupan City. Several quantitative methodologies were employed to
formulate policy recommendation that would be helpful in crafting a Sanitation Management Plan
for the City. The empirical evidence provided in this study serves as a relevant input into the
regulatory process of establishing fees for septage management and sewerage services based on
consumer demand.
Specifically, the results point to the following:
1. Income plays an important role on respondents’ willingness to pay. For the septage and sewerage
studies, the variability of WTP across income groups indicates the plausibility of implementing a
socialized pricing scheme for the fees. However, actual implementation of these fees would
require a strong public consultation for the target to be met. Another important implication of the
results is that increased demand for sanitation facilities would only take place as the general
income levels of Dagupan City improves. Similar with the findings in General Santos City, the
success of any sanitation initiative goes hand in hand with improvements in income levels and
distribution.

23. Table 20. Decision to Stay Connected to DCWD & Alternative Water Sources
Septage Sewerage All
N % N % N %
Connection decision if waterbill will
increase
Don't know 38 6.42 8 2.48 46 5.03
Keep connected 521 88.01 305 94.72 826 90.37
Disconnect 33 5.57 9 2.8 42 4.60
Sure of keeping connection to DCWD
Very unsure 3 0.54 - - 3 0.35
Unsure 60 10.83 41 13.06 101 11.64
Sure 373 67.33 189 60.19 562 64.75
Very sure 118 21.3 84 26.75 202 23.27
If disconnected where to obtain water?
Neighbor with pipe connection 7 21.21 1 11.11 8 19.05
Public tap 1 3.03 1 11.11 2 4.76
Water vendor - - 7 77.78 7 16.67
Handpump 23 69.7 - - 23 54.76
River 1 3.03 - - 1 2.38
Deep well 1 3.03 - - 1 2.38
2. The individually rational and financially viable Septage Service Fee, given the assumptions
outlined in Appendix Table 1, is around PhP 46.00/ mo. This corresponds to the optimal
desludging frequency of three years. The septage fees are found to be similar to existing
arrangements elsewhere in the country. This Septage fee further allows recovery of investment
costs within 10 years as well as cover operating and maintenance (O & M) expenses of the
Septage Program within a project lifetime of 25 years. This means that a self-financed Septage
Program is possible for the city.
3. The story for the Sewerage Program, however, is not as optimistic. There is a range of bids or
prices that households would agree to pay (with average of Php102/month for the whole
sample). These bids are slightly higher than that of the WTP for the Septage Program. However,
none of these can cover the huge investment costs associated with a self-financed Sewerage
infrastructure based on BCA assumptions outlined in Appendix Table 2. Thus, it would be
prudent for the LGU to look for other funds.
4. To implement the septage management and sewerage plan, waterbill can be used as a payment
vehicle since its mandatory nature allows more efficient collection of fees unlike voluntary
payment schemes such as community tax certificate and garbage fees. However, the computation
of fees must be made transparent on the bill to allay the fear of customers of any hidden charges.
If a private contractor will make a separate collection of septage and sewerage fees from the
water bill, this needs to be studied carefully for cost implications.

24. References
ADB. 2007. Asian Water Development Outlook: Country Paper- Philippines. Manila: Philippines.
Choe, K., D. Whittington and D. T. Lauria. 1996. “The Economic Benefits of Surface Water
Quality Improvements in Developing Countries: A Case Study of Davao, Philippines.” Land
Economics 72(4):519–37. Cochran, W. G. 1977. Sampling Techniques. 3rd ed. New York: John
Wiley.
Lauria, D. T., D. Whittington, K. A. Choe, C. Turingan, and V. Abiad. 1999. “Household Demand
for Improved Sanitation Services: A Case Study of Calamba, the Philippines.” In Bateman, I. and
K. Willies, eds., Valuing Environmental Preferences: Theory and Practice of the Contingent
Valuation Method in the US, EU, and Developing Countries. Oxford: Oxford University Press.
SUSEA. 2008. Draft Report of the Local Sustainable Plan of Dagupan City.
USAID. 2007. Septage Management in the Philippines: Current Practices and Lessons Learned.
World Bank. 2003. Philippine Environment Monitor: Water Quality

25. Appendix Table 1. BCA Assumptions for Septage Management Plan
Assumed Value Source Remarks
Initial Investment PhP 60 M SUSEA Baseline
Study Report for
Dagupan City, 2008
Financing Costs 10 years to pay with 3
year grace period; Interest
rate set at 10% per year
Desludging and Php 350/ cu. m. ADB, 2007 These figures are based on
Treatment Costs desludging costs; PhP 55/ calculation of Manila Water
cu. m. treatment costs operations. Note that we have
excluded the Bioapplication
Costs which amounts to PhP
644/ cu. m.
Annual Operating Salaries 960,000 USAID 2007 These estimates were based
and Maintenance Repairs 300,000 on the LINAW project in
(O and M) Supplies 300,000 Dumaguete. The project is
Expenses Analysis 30,000 expected to serve 22,000
households and 2,500
Monitoring 120,000 business establishments in
Dumaguete City. Since
Dagupan is much larger these
figures were increased by
39% for the analysis
Revenue Base 75% of households have SUSEA Baseline
water connection; This Study Report for
comprises the paying Dagupan City, 2008
population
Serviceable 97% of households have SUSEA Baseline
Households septic tanks will be Study Report for
eligible for the program Dagupan City, 2008
Frequency of 1/3 of eligible
Service households will be
serviced every year
within the three year
interval
Average Size of 10.8 cu. m. SUSEA Baseline Corresponds to a septic tank
Septic Tank Study Report for with a 2x3x1.8 dimension;
Dagupan City, 2008 Only 1/3 of this amount (i.e.
3.2 cu. m.) will be left
undesludged as per Sanitation
Code of the Philippines
Other assumptions:
1. Planning Horizon of 25 years
2. Discount rate of 10%
3. Annual Household Growth rate of 1.2%

26. Appendix Table 2. BCA Assumptions for Sewerage Plan
Assumed Value Source
Initial Investment Php 500 M SUSEA Baseline Study Report for
Dagupan City, 2008
Financing Costs 10 years to pay with 3 year
grace period; Interest rate set
at 10% per year
Other assumptions:
1 Planning Horizon of 25 years
2 Discount rate of 10%
3 Annual Household Growth rate of 1.2%