dewatering, and a permit was being sought for land application in agriculture.

Each WWTP was built under a DBO arrangement with a three year operating requirement, by a separate consortia made up of design firm, a supplier firm, and a construction firm. The total cost of the project was $325 million. Financing came from an OECF loan ($110 million), a Federal grant ($110.), and selffinancing by the Monterrey water and sewerage utility ($115 million). In 2000, the average cost of treatment was 13¢/ m<sup>3</sup> including debt repayment.

Cost recovery for sewerage and treatment is achieved through a 25% surcharge on metered domestic and industrial water consumption. Industry pays an additional ‘decontamination charge’ when effluent BOD5 exceeds 450 mg/l, at a rate of 13¢/kg of BOD5. With these tariffs, the Monterrey Water and Sewerage Service (SADM) covers costs and generates reserve funds for future expansions. By the year 2000, through a combination of 50% self-financing and 50% federal subsidy, and with the experience gained by managing the DBO contracts and taking over the operations of the three existing WWTPs after three years, SADM was able to build a 250 lps WWTP and was preparing to double the capacity of the Norte WWTP.

As a result of this project, in 1995 Monterrey became the first major city in Latin America to achieve universal sewerage and wastewater treatment, and safeguarded the downstream utilization of its wastewater for irrigation.

## _Source:_ Bartone, 2000.

**Jordan – planned indirect wastewater irrigation:** The original As Samra plant was built in 1985 and consisted of 32 ponds occupying 200 ha.  It was designed to treat 0.8 m<sup>3</sup> /s of wastewater, but almost from the beginning of operations it was severely overloaded, eventually handling almost 2.2 m<sup>3</sup> /s, leading to concerns about the quality of treated effluents and raising concerns about the safety of wastewater use. In response, the As Samra plant was replaced in 2008 by a new conventional treatment plant with capacity to treat 3 m<sup>3</sup> /s of wastewater from Amman and Zarqa (with a combined population of approximately 2.3 million people) with eventual expansion in 2015 to 6 m<sup>3</sup> /s. This has been accomplished under a 25-year Build-Own-Operate-Transfer (BOOT) agreement signed in 2000 with a private consortium, and a total investment of $169 million. (See Box 2.8 for a broader description of the Jordan wastewater irrigation project.)

_Source:_ <u>http://www.miga.org/projects/index_sv.cfm?pid=656</u>

**Greater Tehran Southern WWTP – planned indirect wastewater irrigation:** The Southern Wastewater Treatment Plant, inaugurated in 2009, reclaims 5.2 m<sup>3</sup> /s of Tehran’s wastewater for use in irrigation. It is an activated sludge plant with tertiary nitrification, chlorine disinfection, sludge digestion, energy recovery and utilization, and sufficient area to store sludge for one year. The plant was financed by the World Bank and tendered by the Tehran Sewerage Company as a DBO project with a two-year operating requirement, and built at a cost of US$121million. The plant – designed to meet the 1989 WHO guidelines – produces an effluent suitable for unrestricted irrigation and digested sludge suitable for land application.

The effluent is discharged to a nearby irrigation channel where it is mixed with other water sources, and goes to irrigate an additional 15,000 ha in the Varamin Plains irrigation scheme bringing the total to 50,000 ha and increasing the size of the irrigation project by 43%, making it one of the largest in the world. Digested sludge, after one year of storage, is applied to agricultural parcels at a rate of once every four years. Crops grown include wheat, cotton, cantaloupes, sunflowers and alfalfa. During the non-irrigation season the effluent is used for groundwater recharge.

_Source:_ World Bank, 2000; 2009.

# _5.2.5 Using economic instruments_

Since the international acceptance of the 1992 Dublin Principles, water has been viewed as an economic good (Principle 4). The commonly accepted application of this principle for financing 71