Introduction

Water Freedom System

Survive Global Water Shortages

Get Instant Access

Israel is a developed, water-scarce country, with mostly arid or semi-arid climate. Unlike many developed countries, Israel's population is rapidly growing, causing an increase in the domestic demand for water. Additionally, Israel's economy has continued to expand in the past few years, even in the face of a global recession, thereby creating an additional source of demand for the local water resources. Domestic demand places the greatest pressure on water resources, constituting about half of the total national demand for water (Table 7.1). This is followed by agriculture water use, and finally by industrial water use, which is about 6% of the total.

To meet to the needs of the rapidly growing population and local expansion, Israel has increased its exploitation of groundwater resources; this causes an increase in the salinity level of local aquifers, leading to some severe issues of local aquifer contaminations. Additionally, local trends of urban development, as well as increased adoption of water desalination and irrigation with wastewater, have combined to further accelerate the buildup of groundwater salinity. Recurring droughts, attributable to the global climate changes, will exacerbate these problems of overexploitation and contamination of groundwater resources.

To address these problems, Israel has adopted to use of several alternative water sources, including treated wastewater for agricultural use and desalinated seawater for domestic water use. Treated wastewater constitutes about 16% of the total water supply (Table 7.2), and its share is growing as the freshwater supply decreases. Wastewater and brackish water together account for more than half of the total agricultural water use (Table 7.3), with wastewater alone supplying 36% of the total water use in agriculture.

Desalinated water supply is 300 mcm (22% of the total water supply), and expected to increase to 750 mcm/year by 2020. However, desalination is relatively expensive and energy-intensive, using up scarce fossil fuels and increasing greenhouse gas emissions that contribute to global climate change. If all the domestic water supply was based on desalinated seawater, the process would require an energy supply equivalent of 5% of the total electricity consumption in Israel [1].

Table 7.1 Water consumption by sector (mcm) [2]

Change

Sector_2008 2009 2008/2009 (%)

Agriculture 673 599 -11

Industry 82 75 -8

Households 731 663 -9

Total 1,485 1,337 -10

Table 7.2 Water supply by source (mcm) [2]

Change

Source_2008 2009 2008/2009 (%)

Freshwater 1,125 995 -12

Wastewater 231 219 -5

Brackish water 130 124 -5 Total 1,485 1,337 -10

Table 7.3 Water supply for agriculture by source (mcm) [2]

Freshwater Wastewater Brackish water Total

Source

259 44

218 36

122 20

599 100

2009 Percent of total (%)

A commonly advocated alternative of renewable energy supply from bio-fuels is problematic in Israel's case, because as an agricultural crop these fuels require land and large quantities of water for production [3]. Other methods of decreasing energy use in desalination processes may become available by increasing capital investment in production technologies.

Irrigation with treated wastewater makes it possible to delay desalination. Wastewater is treated to secondary or tertiary treatment level to decrease organic and inorganic hazards. However, as its salinity is higher than source water, it is major cause of groundwater salinity.

Advantages of wastewater treatment

• A reliable supply of water at a low cost.

• A partial solution for effluent disposal.

• Reduces the need for fertilizer use.

Disadvantages

• Damage to crops and soils.

• Increases the risk of groundwater contamination.

Treatment

• Higher level treatment reduces the potential damage, but is more expensive.

Was this article helpful?

0 0

Post a comment