GCOE Discussion Paper Series
Global COE Program

Human Behavior and Socioeconomic Dynamics
Discussion Paper No.180

Welfare Effects of Access to Water Service in Cambodia

Theara Horn

February 2011

GCOE Secretariat
Graduate School of Economics

OSAKA UNIVERSITY

1-7 Machikaneyama, Toyonaka, Osaka, 560-0043, JapanWelfare Effects of Access to Water Service in Cambodia
Theara Horn†

Abstract
From data collected by questionnaire survey of three communes in the Kandal province ofCambodia, where public water supply remains inaccessible, this study estimates the demand
function for drinking water and finds that the price elasticity is between -0.26 and -0.29. Basedon this, and given the price set by the Phnom Penh Water Supply Authority, expansion of service
would increase per capita water consumption by 9.8 liters per day, increase consumer surplus by
4.6 percent of total expenditure and decrease the number of households surviving on less than 30
liters of water per day by 5.3 percent. A simulation is used to calculate the water price such thatthe benefit of water connection exceeds the cost.

Keywords: Water Service Access Expansion, Infrastructure Development, Welfare, Cambodia
JEL: H44, H54, L95

I thank Professor Nobuo Akai, Professor David Flath, Professor Miki Kohara, and Mr. Phyrum Kov for
their useful comments and suggestions. I am also grateful to Mr. Huot Sokheng, officer of Phnom Penh
Water Supply Authority for his kind support during the hearing. Thanks also to some students at theRoyal University of Law and Economics for their assistance during the survey. Financial aid from JSPS
Research Fellowships for Young Scientists is gratefully acknowledged.
†

Osaka University, Graduate School of Economics, 1-7 Machikaneyama, Toyonaka, Osaka, 560-0043,
Japan; Email: hge016ht@mail2.econ.osaka-u.ac.jp

0Welfare Effects of Access to Water Service in Cambodia
1- Introduction
Several previous studies find a positive effect of piped water access on welfare metrics suchas childhood mortality in India (Guillot and Gupta, 2004) and Egypt (Abou-Ali, 2003), and Gini
coefficient and poverty head-count ratio in Cambodia (Basani, Isham and Reilly, 2004).
In
Cambodia, the proportion of the population served with improved water has expanded in recent
years but remains low. In 2008, only 55% of the urban population and 5% of the rural
population had access to piped water (WHO/UNICEF, 2010). The households that cannot obtainpiped water must make do with surface water, wells, rain water, and the like. Piped water
service is supplied by both public and private providers. Small private water supply networks
serve some areas where public piped water is not available. Surface water is a main water source
for small private networks. These private suppliers do not always comply with physical,
chemical and biological standards for treating water before distribution (Baker, 2009). They
supply water by truck, rickshaw or small-scale supplying infrastructure. Nevertheless, the water
tariff of private suppliers is usually several times higher than public water utilities (Garn et al.,2002). This can be a burden for people living in inaccessible areas, who are typically poorer thanthose living in accessible areas.
Because of the political instability in the past decades, there are so far only a few
development case studies that focus on Cambodia. Among them, Garn et al (2002) conducted asurvey of the performance of public and private water utilities, in seven towns and one district in2002. They found that private utilities provided better service quality than did public utilities,
but that private utilities also set higher prices. Basani, Isham and Reilly (2008) use the datacollected by Garn et al (2002) to study factors that influence access to water and estimated priceand expenditure elasticities of the demand for water consumption.
They find that highconnection fee is an obstacle for poor people to get access to clean water and that the elasticity ofwater demand ranges between -0.5 and -0.4.
Furthermore, they calculate that, if directconnection were to become available for all households in their sample, the Gini coefficient
would decrease by three percent and the poverty head-count ratio would improve by six percent.
This paper estimates the welfare gain using similar methods as in Basani, Isham and Reilly(2004). However, there are three differences. First, this paper estimates the welfare effect ofaccess to pipe water based on consumer surplus gains, increase of water volume consumption
and improvements for people living on less than 30 liters per day. In contrast, Basani, Isham andReilly (2004) focused on changes in Gini coefficient and alleviation of poverty. Second, I also
analyze the cost and benefit of the project, based on estimates of consumer surplus, and find a
range in which PPWSA can increase its water price and still achieve improved overall welfare.
Third, the questionnaire is done in the area around Phnom Penh city which is different from thelocations targeted by previous studies.

12- Phnom Penh Water Supply Authority (PPWSA)
Recently, with assistance from the international community and good management, PPWSA
has developed its capacity for supplying water services. There have been remarkable
improvements in water supply coverage, continuity of service, and revenue collection withacknowledged good management.1 In 1993, there were 26,881 water connections (a mere 20%
coverage), supply duration was 10 hours a day and operation costs were heavily dependent on
government subsidies. In 2008, there were 178,150 connections (85% coverage), supply
duration was 24 hours a day and operating costs were covered by tariff revenues (Chea, 2009).
PPWSA has undertaken to revise its tariffs in three steps. The first step in June 1997
replaced the previous flat rate with a rate schedule, and the second step in January 2001 raised
the rates in each block (See Table 1). The tariff schedule is one in which customers who use
more water pay a higher rate. This is one element of the government’s Poverty Reduction
Policy. In general the industrial customers and higher income households that use more water
pay more than do others. And those who use little water, which tend to be low-income
households, pay less. The tariff rate in the two lowest blocks is actually below the average costof supplying water which is 900Riels/m3. The aim has been for PPWAS to extend its service
coverage without overlooking the poor and still maintain financial viability. In addition to thegraduated tariff schedule, low-income households have also been given discounts on connection
fees and on monthly-installment payments. As of 2008, these discounts have been proffered tomore than 17,000 new customers. Water supply capacity in provinces surrounding Phnom Penh
is still limited, but there is a new project underway to expand PPWSA service to these areas(Chea, 2006). My goal is to predict the economic benefit of this project based on data gleaned
from a questionnaire distributed in three communes targeted for extension of water service.
3- The survey
The targets of the survey are three communes in Kandal province, Cambodia: Baekchan,
Bakkhaeng, and Praekkompus. The three communes are all in the expansion area but differ inways relevant to the demand for water services.
The survey was done by face-to-face interviews in the native language (Khmer) in August
2009. The questionnaire consists of three main groups of questions. The first group of questions
pertain to the respondents’ socio-economic data such as age, number of family members,
occupation etc. The second group of questions is about current water usage such as water
source and monthly volume of water consumption2. The third group of questions is about thehousehold’s monthly income and expenditures and on what assets the household such as1

Some awards have been given for the good management and performance of PPWSA, such as ADB
Water Prize 2004, Ramon Magsaysay Award 2006, French Medal 2010 (Légion d’Honneur) and theStockholm Industry Water Award 2010. The reasons of success and some developments of PPWSA canbe found in Araral (2008) and Das et al. (2010).
2
For some households which buy water from private vendor through rickshaw or truck delivery, we ask
number of barrels they buy monthly and calculate with total volume of water purchase by multiplying
with storage volume of barrel.
2

motorbike, television, electric fan, cow etc. In all, 180 households (90% of the planned sample
size of 200 households) agreed to be interviewed. The detailed results of the first group of
survey questions for each of the three communes are summarized in Table 2.
4- Methodology and Descriptive Statistics
4-1-Demand Function and Elasticity
A demand function is estimated to calculate the price and income elasticity of water
consumption. The water demand function is Q = Q (income, waterprice, Z), where Q is volume
of water consumption per capita, income is monthly income per capita, waterprice is the flat-rate
price of water paid by a household to buy 1m3 of water volume from a private vendor, and Z is avector of household characteristics used as control variables. The demand function in log-linear
form can be written as:(1)
ln Qi     ln(income) i   ln( waterprice ) i   i Z i   iwhere  is income elasticity,  is water price elasticity and  i is error term.
4-2-Consumer surplus based on price change
In this paper, the price paid by not-yet-connected households is collected through interview
and it is higher than the water price of PPWSA. The Consumer surplus is calculated following
the same method as Strand and Walker (2003).
First, the non-stochastic part of equation (1) can be rewritten asln Qi     ln(income)i   ln( waterprice )i  i Z i
Rewriting it in this form,ln Qi  A(i)   ln Pi(2)where Pi = waterpricei ; A(i)     ln(income) i   i Z i

A(i) is assumed to be independent among household.
The consumer surplus is obtained as in equation (3), (the calculation is available in Appendix).
1
Pi Qi   P0  
1    CS (3)1     Pi  

4-3-Cost and Benefit
From equation (3), the total benefit of the project is calculated using average consumer
surplus, discount rate and life-span of transmission mains. Suppose that ρ is the discount rate
which is equal to long-term interest rate, 0<ρ <1, and t is life-span of water supply main,commonly 50 years.
The present value of connection benefit to each household (PVB) is3  1 CS 1  T
 1  CS
PVB  t1
t 0 (1   )
1
1 

T 1







CS
1 
 CS
1

1
1 

(4)

The project should be implemented if the cost of connection is less than total present value of
project. The current connection fee of PPWSA is around 400,000 Riels (approximate 100USD).
4-4-Descriptive Statistics
The sample size is 180, which is 90% of our target number 200, as some households refused
to be interviewed. After removing outliers and incomplete responses from the sample, thesample size is 147. Some households use their own water sources such as wells, for which there
is no data on water price and these observations are excluded from the estimation. So, in thisstudy, the data used for estimating the price elasticity in equation (1) is that of the households
who buy water from private vendors.
Watervolume is monthly volume consumed per capita. It is the total amount of water
consumption by the household divided by the number of household members. Waterprice is theamount of money spent to buy 1m3 of water volume from a private seller. The price differs
among the three communes depending on the characteristics of the water source, location orwater delivery methods. Income is estimated to be equal to total expense per capita, defined as
the ratio of household’s monthly expenditure to the number of household member. In this paper,
expenditure is used instead of income as most of respondents tend to understate their income
relative to their expenses3. In the estimation, household assets are also used as control variables.
These include televisions, electric fans, and the like which may represent the household’s wealth(similar method as Basani, Isham and Reilly, 2008). The summary statistics for the variables are
in Table3.
5- Estimation Results
The price and income elasticity of water consumption are estimated with two models. In thefirst model, the only independent variables are water price and estimated income. In the second
model, in addition to price and estimated income, other control variables such as household
assets and characteristics are also included. Concerning the multi-collinearity problem, the meanvif value is estimated for both models. For both models, the mean vif value is not more than 1.3,
indicating that multi-collinearity is not a problem (See Table4). The Breuch-Pagan test ofheteroskedasticity is also conducted and the results validate the assumption of constant variancefor both models. The result of OLS regression demonstrates that price elasticity is between -0.29
and -0.26 and income elasticity is between 0.59 and 0.65 (See Table 4).
3During the interview, the expenditure is asked before the income. Surprisingly, several households givea lower income than expenditure. Therefore, expenditure and family asset are used instead of income.
This is similar to the method used in Basani et al (2004, 2008).

4

My results may be compared with the estimates of Basani, Isham and Reilly (2008) for seventowns and one district. They found that price elasticity was between -0.5 and -0.4 and theexpenditure elasticity was around 0.2. My results show that for the households living in thethree communes, the price elasticity of demand for piped water is relatively low, possiblyreflecting the higher living standard of households in the three communes compared to those in
the provincial areas used in the study of Basani, Isham and Reilly (2008).
From the result of both estimation models, the average price elasticity estimated in this paper
is -0.275. From this, let us predict the improvement of water consumption conditions andincrease in consumer surplus which can be gained if the water is supplied at the current price of
PPWSA. With the relatively lower price of PPWSA, the water consumer can save some money
and improve water consumption (Table5). From the result, approximately 4.6% of total expense
can be saved from the cheaper water price. Moreover, according to the guidelines of WHO(2005), to meet health standards, the minimum level of water volume needed for each person for
drinking, cooking and personal washing is 30 liters per day. Of the 76 households in the sample
who bought water from private providers, 23.7% of them live on water less than the standard
level. This can reflect the low living standard, high water price or difficulty of access to water.
Using the estimnated price elasticity, if the water is supplied at the current water price of
PPWSA, the percentage of households living under this standard would decrease from 23.7% to18.4%. Similarly, average water volume per capita would increase from 70.1 liters per day to
79.9 liters per day, a 13.9% increase in water consumption compared with current water
consumption bought from private vendors. The percentage improvement can actually be higher
than the above results if we take into account improvements in the convenience of water accessand improvement in quality in addition to price effects.
Consumer surplus is calculated using equation (3) with average estimated price elasticity inthe two models equal to -0.275 and Po equal to the current water price of PPWSA. The resultshows that the consumer surplus can increase by 4.6% of household total expenditures withcurrent water price of PPWSA.
The present value of connection benefit is calculated using equation (4) with the average
consumer surplus discount rate equal to interest rate. The interest rate in Cambodia is fairly highon average, 7.65% per annum in 2008 (ADB 2009) and it slightly fluctuates yearly. As theinterest rate is not exactly determined, in the simulation, discount rate evolves from 5% to 20%
to calculate the total benefit of connection. Figure 2 presents value of benefit that eachhousehold may gain from connection. For example, if the interest rate is 7%, the total present
value of benefit from PPWSA service connection with current price is about 3.4 million Riels(approximately 870 USD). Comparing to connection cost of 400,000 Riels (approximately
100USD) for a water meter and 10-meter-long pipe, the total household benefit is several times
higher than the cost. That can be even higher if considering the improvement in health whenusing the well-treated water.
According to population census done by National Institute of Statistics of Cambodia in 2008,
population density in Kandal province (i.e. targeted location) is 12.8 times lower than that of5

Phnom Penh city. As densely populated area may serve with a cheaper water price as cost on
network infrastructure can be lower (Estache and Rossi, 2002), we can consider possible pricedisparity between Phnom Penh city and survey area that may be implemented to cover the cost of
infrastructure. Figure 2 presents some results of present value of consumer surplus for various
assumed water prices. The simulation is done with some alternative prices: current block-rate
PPWSA price, 1.5 times current block-rate PPWSA price, 2 times current block-rate PPWSA
price, 2.5 times current block-rate PPWSA price. As the interest rate is fairly high in Cambodia,
the discount rate is set to evolve from 5% to 20%.
From the result, we find that, the benefit gain is much higher than the connection cost. With
the simulation, the consumer surplus curve shifts down toward the connection cost, just equaling
it when the price is approximately 2.5 times current PPWSA. This is one indication of the net
social benefit that the current water price bestows on each household. The result can intuitively
mean that there is a social benefit if more households were to connect to PPWSA rather thanusing their own wells. So, the expansion of water supply to surrounding area of Phnom Penh by
PPWSA is important to economic development.

6- Conclusion
The paper investigated the benefit of future water service expansion using survey data ofwater usage in three communes in the area surrounding Phnom Penh city, Cambodia. From theestimation, this study finds that the expansion would increase dwellers’ well-being. If Phnom
Penh Water Supply Authority were to supply water in those areas at its current block-rate price,
it would improve the water consumption and consumer surplus. From this study sample, theexpansion of water by PPWSA would decrease the population living below standard water
consumption level of 30 liters per day by 5.3 percent, increase average per-capita water
consumption by 9.8 liters per day, and increase the purchasing power of household’s total
expenditures through consumer surplus gain of 4.6 percent.
Further, from the result of simulation of water prices, average benefit to each household of
the current PPWSA price is higher than the water connection fee. The benefit becomes similar
to connection fee when the price becomes 2.5 times higher than the current price. So, the current
PPWSA water price would imply high average benefit per household. Therefore, households
would tend to make water connection when there is service expansion to their area at the current
price. Further research on willingness-to-pay for water tariff and connection fee at targeted
location may be helpful for setting future policy on water price, to make the service accessible
until the poorest households.

6

References
Abou-Ali, H. (2003). “The effect of water and sanitation on child mortality in Egypt,”
Working Paper No. 112, Department of Economics, Goteborg University,
Araral, E. (2008). "Public Provision for Urban Water: Getting Prices and Governance
Right", Governance, Vol. 21, No.4, p.527-549
Asian Development Bank (2009), Key Indicators for Asia and the Pacific, Cambodia
Baker J. L.(2009). “Opportunities and Challenges for Small Scale Private Service
Providers in Electricity and Water Supply: Evidence from Bangladesh, Cambodia, Kenya and thePhilippines,” Working Paper, World Bank and PPIAF
Basani, M., J. Isham and B. Reilly (2004) “Water Demand and the Welfare Effects ofConnection: Empirical Evidence from Cambodia,” Working Paper Series, No. 0429, Middlebury
College
Basani, M., J. Isham and B. Reilly (2008) “The determinants of water connection andwater consumption: Empirical Evidence from a Cambodian Household Survey,” World
Development, Vol. 36, No.5, p.953-968
Chea, Visoth (2006). “Performances Improvement, Phnom Penh Experience,”
presentation slide at Capacity Building Workshop on Partnerships for Improving the Performanceof Water Utilities in the Asia and Pacific Region, 25-27 July 2006, Bangkok, Thailand.
http://www.un.org/esa/sustdev/sdissues/water/workshop_asia/presentations/chea.pdf
Chea, Visoth (2009). “HR Practices: PPWSA’s case,” presentation slide at Twinning
Regional Forum, Daejeon, Korea, February 2009http://www.adb.org/Water/WOP/PDFS/HR-Practices-PPWSA-CAM.pdf
Das B., Ek Sonn Chan, Chea Visoth, G. Pangare and R. Simpson(2010) “Sharing theReform Process: Learning from the Phnom Penh Water Supply Authority (PPWSA)”
http://data.iucn.org/dbtw-wpd/edocs/2010-046.pdf
Ek Sonn Chan (2007). “PPWSA: Getting the Fundamentals Right,” Cambodia paper, 5th
World
Water
Forum,
16-22
March
2009,
Istanbul,
Turkey.
www.idrc.ca/uploads/user-S/12388606151Cambodia_paper_WWF5.pdf
Estache A. and MA. Rossi (2002) “How different is the efficiency of public and private
water companies in Asia?” World Bank Economic Review 16(1): 139–148.
Garn M., J. Isham and S. Kahkonen (2002) “Should We Bet On Private or Public Water
Utilities in Cambodia? Evidence on Incentives and Performance from Seven Provincial Towns”
Middlebury College Economics Discussion Paper No. 02-19.
Guillot, M. and S. Gupta (2004) “Water access, household sanitation and childsurvival in India” Department of Economics, University of Wisconsin-Madison.
Strand, J. and I. Walker (2003) “The value of water connections in Central American
cities: A revealed preference study,” Working Paper, Department of Economics,
University of Oslo, http://folk.uio.no/jostrand/watervaluepaper.pdf
WHO (2005) “Minimum water quantity needed for domestic use in emergencies,”
www.searo.who.int/LinkFiles/List_of_Guidelines_for_Health_Emergency_Minimum_water_qua
ntity.pdf (Retrieved in 2010)
WHO / UNICEF 2010 “Joint Monitoring Programme (JMP) for Water Supply andSanitation,” http://www.wssinfo.org/datamining/tables.html# (Retrieved in 2010)7

Appendix: Consumer Surplus
The calculation follows the same method as Strand and Walker (2003). However, this paper
assumes price of PPWSA is lower than current price of private suppliers, (i.e. Po < Pi).
We have, ln Qi     ln(income) i   ln( waterprice ) i   i Z i(1)

ln Qi  A(i)   ln Pi

Rewriting it in this form,(2)

where Pi = waterpricei ; A(i)     ln(income) i   i Z iA(i ) is assumed to be independent among household.

From (2), we obtain Qi  e A(i ) Pi
A( i )Pi  e



1

Qi 

1

 a(i ) Qi or Pi   e A(i ) Qi  e A(i )Qi 1
A( i )(3)1

where a(i)  e   Pi Qi 

(4)Because A(i ) is assumed to be independent among households, e A(i ) and a(i) are also
independent. From Figure 1, the consumer surplus (CS) can be calculated by
Q0

CS   Pi dQ  Pi Qi  P0Q0

(5)

Qi

where Pi denotes current water price paid to a private vendor and Qi is volume of current water
consumption. P0 is water price determined by PPWSA, which is expected to be lower than theprivate vendor’s price Pi. And Q0 is water consumption when price is equal to P0
Figure1: Consumer Surplus
P

AVC

MC
Pi
P0

1

Pi  a(i) Qi 

MR
Qi

Q0

Q

Q0

8

Replacing Pi of equation (4) into (5), we obtain,
1

Q0



CS   a(i )Qi dQ  Pi Qi  P0Q0
QiQ0

 11 Q  a(i )  1   Pi Qi  P0Q0
1  
Q1
 a(i) 1
   1
   Pi Qi  P0Q0
Q

Q
 0
i

 1 



 1
 1
 1
1   1
 a(i )  Q0   Qi    a(i)
 Q0   Qi    Pi Qi  P0Q0
 1 




(6)

 1

1

From (4) Pi  a(i) Qi  , then Pi Qi  a(i) Qi 

 1

Similarly, when price equals P0 , P0 Q0  a(i) Q0 
Substitute these into (6), we obtain CS .

 1a(i)   1

 Q0   Qi  
 1


.

(7)

1

From (4), a(i)  Pi Qi  . Substituting this into (7), we get
1

1
 1

Pi Qi   1
Pi    1
CS 
Qi Q0   Qi 
 Q0   Qi    1 
  1 





 1

Pi Qi  Q0 

=

1

  1  QiPi  eFrom (3)As

A( i )

Qi

1

 1
Pi Qi  Q0  =11    Qi 



(8)



, e

A( i )P i 1Qie A(i ) is independent from household, we have e A(i )  e A(0) .




Pi
P
 0 1
Then,
1
Qi
Q0

or

Q0  P0  
Qi  Pi 



(9)

9

Replace (9) into (8), the consumer surplus of household is:1
Pi Qi   P0  
1    CS 
1     Pi  Table1: Water tariff of PPWSA
Category

BeforeJune 1997

Domestic
250
Riels/m3
Administrative
Commercials
Industrials

700
Riels/m3

June 1997
Block
Tariff3( m /month)(Riels/ m3)
 15
300
16-30
620
31-100
940
 100
1260
Flat rate
940
 100
940
101-200
1260
201-500
1580
 500
1900

January 2001-Present
Block
Tariff3( m /month)(Riels/ m3)
7
550
8-15
770
16-50
1010
 50
1270
Flat rate
1030
0-100
950
101-200
1150
201-500
1350
 500
1450

Source: Ek Sonn Chan (2007)

Table2: Some characteristics of access to water of three communes.

Percentage of water expense to total
expenditure (%)
Average monthly water volume perhousehold (m3/month)
Current water price ( Riel/m3)
Buy water from private operator
Observation Number
Main water source

Baek Chan

Bakkhaeng

Praek Kompus

Total

6.2%

3.2%

6.6%

5.7%

10.84

11.48

17.88

14.65

2915
46
54

1796
22
37

4500
13
89

2770
81
180

Pond

River

Well

10

Table3: Data Statistics
Variables
Watervolume
Waterprice
IncomeTV
Motorbike
Telephoned_toiletd_commercial

Definition

Mean

Std.Dev

Min

Max

Monthly water consumption per capita (m3)
Water tariff paid for 1 of water(Riel/m3)
Estimated to be equal to monthly total
expenditure per capita (10 thousand Riels)
Number of television that households owns
Number of motorbike that households owns
Number of telephone that households owns
1 if water is used for toilet
0, otherwise
1 if household owns business for whichwater is used as intermediate good.
0, otherwise.

2.10
2771
10.7

1.83
1374
5.81

0.16
380
0.93

10
6250
31

1.10
1.05
1.68
0.64

0.57
0.81
1.26
0.48

0
0
0
0

3
4
6
1

0.25

0.43

0

1

Table 4: Estimation of Water Demand Function
Dependent Variable: ln(water volume)ln(waterprice)ln(income)Model1-0.29**(0.145)0.59***(0.147)TV
Motorbike
Telephoned_commercial
d_toilet
Constant-4.10**(2.076)1
76
0.20

Mean vif
Observation
Adjusted R2

Model2-0.26*(0.155)0.65***(0.145)0.20(0.166)-0.13(0.128)0.10*(0.086)
0.48**(0.200)-0.09(0.188)-5.29**(2.144)
1.3
76
0.29

Note: In parentheses is standard errors. (***), (**), (*) present p-value at significance level of 1%, 5%,
10% respectively.

11

Table 5: The benefit to be gained from PPWSA price comparing with private vendor’s. Percentage of household consuming
less than 30 liters per day (%). Mean water volume per capita(liters/day). Percentage of increased water
consumption volume (%). Ratio of consumer surplus gain tototal expense (%)

Flat water price rate ofprivate vendor
23.7

Current block rate
price of PPWSA
18.4

70.1

79.9

-

13.9

-

4.6

Figure2: Simulation of water price and consumer surplus gain
Present Value of Consumer Surplus ( unit : million riels ; 4000 Riel = 1USD )6

Current PPWSA Price*2.5 times
5

Current PPWSA Price* 2 times
Current PPWSA Price*1.5 times

4

Current PPWSA Price
Connection fee

3
2
1
0

0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.2

discount rate

12ρ