1
Toolkit for Urban Water Supply Projects
Module 2
Water Consumption Patterns and
Minimum Water Requirements
Table of Contents
1 Water Consumption Patterns in Low Income Urban Areas 2
2 Meeting the Health Objectives of Urban Water Supply 3
3 Quantity, Quality or Both? 5
4 Domestic Water Treatment Practices and the use of Spring Water 6
5 What are Safe Sources of Drinking Water? 6
6 Standards and Consumption Patterns 7
List of Abbreviations 9
Bibliography 9
1 Water Consumption Patterns in Low Income Urban Areas
In many low income urban areas a large majority of all fetch their water at one of the water kiosks of their Water Service Provider (WSP). All their water? The answer is no. In most low income areas, households, in addition to the water kiosk, have access to alternative sources of water. Many households continue to fetch water from protected yard wells, shallow wells, hand pumps, springs and streams. Why would a household continue to fetch water from an unsafe source if there is a kiosk where safe treated water can be fetched at an affordable price?
The answers to this question were provided by local residents during a large number of studies carried out in various African countries.[1] The following reasons were mentioned:
· It is more convenient to fetch water within the yard.
· It is cheaper to fetch water used for doing the laundry from a protected or unprotected yard well, a shallow well or a spring.
· Spring water, well water and even water fetched from the stream can be made safe and drinkable by adding WaterGuard or by boiling it.
· Kiosk water is too expensive (this answer is usually given by a small minority of residents).
The fact that most households also fetch water at the kiosk means that households use a variety of water sources. The same studies also show that households mainly go to the kiosk to fetch the water they use for drinking and preparing meals. Water for other usages such bathing, laundry, and cleaning (kitchen utensils, etc.) is often fetched from unsafe sources. This is because residents share the view that the quality requirements of, for example, bathing water are less.
These consumption patterns explain why daily per capita kiosk water consumption levels are relatively low. In Solwezi and Monze (two Zambia towns), for example, per capita consumption of kiosk water ranges between 1.1 and 10.3 litres/day (see also Table 1).
Table 1: Per capita consumption levels in the main Peri-Urban areas of Monze and Solwezi (Zambia)
Month(Year: 2006) / Monze / Solwezi
Kiosks water consumption / Kiosk customers / Kiosk customers (2)
Per capita consumption / Per capita consumption
M3 / M3 / M3
Zambia/Freedom / Zambia/Freedom / Kyawama (1) / Zambia
June / 1,657 / 3.2 / 1.1 / -
July / 1,870 / 3.5 / 1.0 / 7.6
August / 2,447 / 4.6 / 1.0 / 8.2
September / 2,613 / 5.1 / 1.6 / 10.3
October / 3,341 / 6.3 / 2.4 / 9.8
November / 2,985 / 5.9 / 2.6 / 9.9
1): Due to irregular meter reading at kiosk 2 and 3, only 4 of the 6 Kyawama kiosks were considered
2): Solwezi; 78% of all households in Kyawama use kiosks, 63% of all households in Zambia use kiosks
Only in low income urban areas where residents do not have easy access to alternative sources of water which are nearer and maybe cheaper, per capita consumption levels are significantly higher. In Kanyama Compound in Lusaka (Zambia), for example, per capita consumption levels range between 19 and 24 litres/day. In Kware, a large low income area in Ongata Rongai, average daily consumption of piped water is 17.1 litres.
2 Meeting the Health Objectives of Urban Water Supply
Experience shows that residents, who use water from a yard well or water from a nearby spring for laundry or bathing, continue to use these sources after the introduction of kiosks. Sensitisation efforts aimed at convincing residents to abandon their sources of free, but unsafe water tend to be not very effective.
In many cases the WSP also simply lacks sound scientific health arguments needed to warn residents against the risks of using water from “unsafe” sources.[2] In this context, it is important to mention that yard wells, springs and protected yard wells are usually reasonably well maintained and kept clean.
Can the WSP conclude, considering these consumption patterns and low per capita consumption levels, that it has achieved its important health objectives? If persons only consume 1 litre of kiosk water very day, is that enough? Do residents of the low income urban areas make the right decisions when it comes to the choosing water sources and the use of the water of these sources?
These questions raise an important issue; how much water an individual needs on a daily basis? How many litres of water each day and how many litres of safe water each day? During workshops and meetings, many participants emphasise the figure of 20 litres/person/day. When being asked where this figure comes from, many mention the World Health Organisation (WHO) or the Ministry of Health as their source. Twenty litres per person per day! But does it have be safe and treated water?
To find answers to these questions, it is important to consult some of the publications prepared by the WHO (All WHO publications discussed in this document are included in this Section).
The WHO publication “Minimum Water Quantity Needed, for Domestic Uses” presents the following guidelines:
Table 2: Minimum water requirements
Medium term allocationDrinking / 3 – 4 litres/person/day
Food preparation and cleanup / 2 – 3 litres/person/day
Personal hygiene / 6 – 7 litres/person/day
Laundry / 4 – 6 litres/person/day
Total: / 15 – 20 litres/person/day
Source: WHO
Twenty litres per person per day can therefore be seen as a minimum water requirement. There are, in most cases, no (public) health reasons why water which is used for personal hygiene and for laundry cannot be fetched from unsafe sources such as springs, wells and even streams. It is important to note that bathing water is usually heated before use.
This leaves us with the daily requirements for drinking and preparing meals (including cleanup). According to the WHO, a person needs 5 to 7 litres per day. If water from unsafe sources is used to clean kitchen utensils the daily requirement range drops to 4.5 - 6 litres. A minimum of 3 to 4 litres of water are required to meet the minimum drinking (hydration) requirements.[3]
We can, therefore, conclude that all urban residents residing in low income areas need to consume a minimum of 5 to 7 litres of safe water per person per day and if they use this water only for drinking and food preparation, the service provider has met minimum health objectives.
3 Quantity, Quality.....or Both?
Howard and Bartram argue that:
“The evidence from the literature consistently points to use of water as being important to controlling disease and the fact that lack of access to water may impede its use and thereby adversely affect health. The evidence indicates that the benefit from increased quantity of water would only be felt in relation to the gross differences of service level and that hygiene behaviour is more important within populations using communal water sources (including kiosks, H.S). This suggests that incremental benefits, among households with a communal water source of water, from increased quantities of water used are limited.
Review of the data regarding hygiene practices and disease, therefore, does not enable the definition of a minimum quantity of water recommended for use to ensure effective hygiene is practiced. The evidence suggests that while benefits are accrued from increased availability of water, this is not solely related to quantities of water used, although increased availability is likely to increase quantities used. The evidence further suggests that it is the effective use of both water and cleansing agents (such as bathing soap, H.S.) and the timing of hygiene practices that are more important than volumes of water used.” (Howard, G and Bartram, J. 2003: 16).
Howard and Bartram continue by stating that:
“The importance of water availability has been show to influence health… Most of the studies cited in the above-mentioned reviews as providing evidence of the greater importance of quantity actually provided measures of accessibility, with the assumption that increased accessibility equates to increased volumes of water used. “(Esrey et al 1991).
A study carried out in Jinja, Uganda shows clearly that average daily per capita consumption figures are higher.
Type of supply / Average consumption (l/c/d) / Service levelSprings/hand pumps / 15.8 / Communal
Public stand post / 15.5 / Communal
Yard tap / 50 / In compound
House connection / 155 / Within house
Source: WELL (1998)
What do these statements and findings mean for the low income urban areas in Kenya, Zambia, Rwanda (etc.), where residents fetch water for drinking and preparing meals at the kiosk and water for usages such as bathing and laundry from yard wells? Residents mentioned the accessibility of the yard well as being one of the main reasons for the continued use of the well. If availability of water has a positive impact upon health, the presence of a (protected) yard well should be seen as an asset and not as a health risk, provided the quality of well water is such that it can be used for the above-mentioned usages. To our knowledge, no studies have been carried out in Kenya, which focus specifically on the (potential) risks of using well water for bathing and laundry.
4 Domestic Water Treatment Practices and the use of Spring Water
What if, as is the case in Solwezi (Zambia), residents consume less? Does it mean that residents do not act responsibly? Not necessarily. The study carried out in Solwezi shows that a minority of peri-urban residents practice domestic treatment of unsafe water. Water fetched from wells is treated by adding Clorin.[4] Only a few residents stated that they boil the water before drinking. Also in Solwezi, a number of residents residing in the western part of Kyawama (a large urban slum), fetch water from a spring which is located in the nearby marshland. The spring is well maintained and clean and is users claim that the water is pure and safe. Most users of this spring drink its water without treating it. As long as we do not know anything on the quality of the water fetched at this spring, we cannot conclude that residents are taking a health risk by drinking spring water. After all, many respondents claimed that the spring has been there for years and that they had always drank its water without suffering any negative consequences.
5 What are Safe Sources of Drinking Water?
According to the WHO (see WHO, Health through Safe Drinking Water and Basic Sanitation, This article can be obtained at the Website of the WHO: http://www.who.int/water_sanitation_health/mdg1/en/print.html):
“Access to safe drinking water is the proportion of people using improved drinking water sources: household connection; public standpipe; borehole; protected dug well; protected spring; rainwater.” (page 1)
In Zambia the Central Statistical Office (CSO) has adopted a similar list of sources of safe drinking water. The CSO publication which presents the results and analysis of the Living Conditions Monitoring Survey Report 2002 – 2003 states:
“The sources considered (in the survey report, H.S) were lake/stream, unprotected well, pumped water, protected well, borehole, public tap and own tap. Among these water sources, protected wells, boreholes, pumped water and taps are regarded as clean and safe sources of water supply, whereas, unprotected wells, rivers and lakes/streams are considered to be unclean and unsafe sources of water supply.” (CSO, November 2004: 133).
It remains to be seen, however, whether all these sources can be considered safe. In Kampala (Uganda) a study was carried out which showed clearly that the water quality of the water fetched at most protected springs found on the slopes of the informal settlements is not good. According to a Feasibility Study carried out by a consultant in 2003:
“Practically all protected springs are contaminated and that water from these sources should not be used for drinking purposes. At the same time one has to conclude that many residents share the perception that it is safer to drink water from a spring than treated water from a tap.” (NWSC/KfW 2003)
Water of many springs is, in fact, not considered to be fit for drinking. Many residents, however, continue to consume spring water. [5] Using data from a water usage study, it was calculated that 33% of low-income population used protected springs as their first choice water source, however, overall use of protected springs was in the region of 63%.(Guy Howard, et al 2002)
Residents of Matisi area in Kitale no longer trust the quality of their protected wells and rely on the services of donkey cart water resellers. .
Recent water tests (January 2006), carried out by Lusaka Water and Sewerage Company (LWSC), show that the water of some of the boreholes, which supply peri-urban areas managed by the Lusaka Water Trusts, is not of good quality.
During a study carried out for the Ministry of Local Government and Housing in Central Province,[6] Zambia, residents of Zambia Compound in Serenje complained bitterly about the quality of the water they fetched at the 2 hand pumps. According to the residents, the taste of the water had changed as a result of higher population densities and the fact that many households have pit latrines in their yards.