came to view wastewater treatment as a necessary and viable environmental infrastructure investment.

During and following the completion of the World Bank-supported project, the Chilean water and sanitation sector was phasing in major reforms so that the private sector could finance the huge investments needed to achieve universal water and sewerage services including wastewater treatment. The reforms were completed in 1998 and a 30-year concession was awarded to the private consortium AguasAndinas in 1999 to provide water and sewage services to the Santiago metropolitan area, which has now resulted in universal treatment for the city (see Box 2.7).

The completion of the Sanitation Plan guarantees that 130,000 hectares of agricultural land will be irrigated with clean water, so that the authorities can lift restrictions on growing vegetables. Also, health risks to farm workers who currently are in direct contact with polluted water will be fully controlled.

_Sources:_ Bartone, 1994; Ferreccio, 1995; Laval and Ferreccio, 2007; Bitrán and Arellano, 2005; Larrain, 2009; Yayur, 2009.

**Box  5.4: Israel’s experience with wastewater reclamation and use for irrigation as part of integrated water resources management**

Since the early 1970s, Israel has carried out significant efforts to achieve massive use of wastewater for agricultural purposes, and is presently using almost 72% of all the sewage produced in the country for irrigation – amounting to half of all irrigation water (Mekorot, 2007). As a result, in 2000 agriculture used less than 40% of the freshwater resources, down from almost 70% in 1985. During drought years, freshwater supply to agriculture is severely cut off, while farmers connected to reclaimed wastewater systems continue to receive a full quota (Juanicó, 2008).

Wastewater irrigation emerged as an unavoidable response to severe water scarcity, a concentrated population with high levels of water consumption and sewage production, and the pollution of limited water resources. In 1959, parliament passed a Water Law which defined sewage as a “water resource.” However, wastewater irrigation was only practiced in isolated uncontrolled projects, and it was not until the 1970 cholera outbreak in Jerusalem that strict wastewater irrigation regulations were introduced, and the Ministry of Health was assigned regulatory responsibility.

An early stimulus for wastewater treatment and use was the World Bank Israel Sewerage Project, the first sewerage loan to be financed by the Bank. Approved in 1972, the Sewerage Project provided support to Israel’s National Sewerage Program designed to improve and modernize the country’s sewerage facilities, in order to protect and preserve water resources and to improve public health (Streit, 1986; Bartone, 1991). An ex post evaluation concluded that it was a successful project incorporating appropriate least-cost technology, and that the provision of sewage treatment and reuse facilities constituted a major environmental improvement and a significant supplementary source of water for irrigation. The project also pioneered the use of long-detention storage reservoirs for treatment. Other important features of this project were the provisions for cost-sharing and division of responsibility between municipalities wanting to dispose of wastewater and farmers wanting to use it.

Over the intervening decades, a regulatory structure evolved to protect public health and promote sustainable agriculture (Juanicó, 2008). In 1977, the Shelef Commission set different water quality standards for the irrigation of different crops, including unrestricted irrigation (Shelef, 1991). The Public Health Law of 1981 restricted wastewater irrigation to a list of allowed crops, and all reuse projects required a permit; and the Public Health Law of 1995 imposed treatment requirements for all towns with population greater than 10,000 (BOD < 20 mg/l and SS < 30 mg/l). The Halprin Commission in 1999 set public health requirements for wastewater irrigation following the California school. Finally, the Inbar Commission recommendations of 2003, approved in April 2010, set stricter environmental requirements for wastewater irrigation including nutrients, salts, metals and other pollutants.

While the initial effluent quality requirements were aimed at the protection of public health, the Inbar Commission requirements address the protection of the environment through sustainable reuse. A particular threat to sustainability linked to effluent irrigation is the salination of soils and aquifers, since salts are added during domestic and industrial use and are recycled together with the wastewater. There has been a steady 55