Graywater Reuse in Other Countries and its Applicability to Jordan -- continued --

1.0   Introduction

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Jordan does not have enough water. The kingdom has a scarce enough resource to begin with – no major rivers and minimal rainfall – but the abnormally sharp rise in population (from about 400,000 in the 1920s to 5.2 million in 2001, to a projected 9.2 million in 2020) (Hashemite Kingdom of Jordan 2002) has left Jordan with an increasing gap between requirements and available supply.  

The projected figures for water requirements and supply, developed jointly between the Ministry of Water and Irrigation (MoWI) and the World Bank (WB) (World Bank 2001) are summarized in the bar chart shown in figure 1.1.

Jordan’s water requirements will continue to rise from a figure of 1,205 MCM (million cubic meters) in 1998 to 1,647 MCM in 2020. This is due to increasing population, rising living standards (target per capita municipal requirement of 130 liters/day (l/d) in 1998 rising to 155 l/d by 2020), and an expected increase in industrial requirements. On the other hand, the available water supply will rise only slightly from 898 MCM in 1998 to 1,287 MCM in 2020, assuming that the MoWI’s capital investment program goes ahead as scheduled. Among other things, this investment program includes tapping the non-renewable Disi aquifer in southern Jordan to boost the supply to Amman, making available additional water from the Wihdeh and Wadi Mujib dams, and reducing losses by network rehabilitation and other system improvements. Additional water also will be made available as a result of increasing reuse of treated wastewater.

As indicated by the bar chart, there is an annual shortfall between water requirements and water supplies. The shortfall is currently made up by constraining water available to the irrigation sector, by overdrawing the kingdom’s increasingly vulnerable groundwater reserves (essentially borrowing water from our children), and by shortfalls in the amounts supplied for municipal use. The gap between requirements and demand should decrease slightly during the next decade (due to the implementation of a number of capital programs by MoWI), but will increase thereafter. There is no immediate solution to this increasing gap.

Aside from improving and consolidating the available water supplies at the macro scale, Jordan also needs to improve the efficiency of water use by customers. Examples of such ‘demand side management’ improvements include the use of low-water-use fittings (faucets, showers, toilets etc), improvement of plumbing codes to ensure better quality plumbing, and the reuse of graywater. Any means of reducing the domestic demand, without impacting quality of life or health, will contribute to the long term water balance. Since the people of Jordan already make do with only a proportion of the per capita water usage in other countries, there is limited scope for demand reduction in the municipal sector. However, there are ways in which households can either reduce their water demand at no real cost to their standard of living, or obtain slightly more benefit from their existing water supply. Reusing household graywater is one of these ways.

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Graywater is the output from bathtubs, showers, sinks, floor drains and washing machines, which although no longer clean, is not as contaminated as toilet water. This water can be relatively easily treated on-site for reuse in non-potable contexts such as toilet flushing and garden irrigation. Studies in other countries have estimated that the usable domestic graywater resource easily could amount to 35% of the total domestic demand. Relatively clean graywater is also produced by non-domestic establishments such as restaurants, hotels, schools, and other public buildings.

By intercepting graywater before it goes to the septic tank or the municipal wastewater system, and providing some treatment (in certain cases, no treatment may be required) the water may be reused to irrigate plants. With a little additional treatment, the water also may be used for toilet flushing. Of course, some safeguards are required – these will be discussed later in the report - but provided care is taken as to what enters the graywater in the first place, and the risks to human and plant health are minimized, such reuse is simpler than many people assume.

Graywater reuse is being increasingly widely practiced in other countries, where water is scarce, and often occurs whether legal or not. The technical means of providing safe ways to reuse graywater, and the issues associated with health and environment have been examined in detail by a number of authorities in other countries. Jordan’s wastewater policy (Hashemite Kingdom of Jordan 1997) requires that all wastewater be regarded as a resource rather than waste. It is likely that practical, safe ways to reuse graywater can be developed and promoted in Jordan.

This report will examine how graywater is used in other countries, and will discuss some of the issues which may affect the transfer of such technology and practices to Jordan.