Use Of Treated Wastewater In Agriculture Research Articles

Challenges and Prospects of Using Treated Wastewater to Manage Water Scarcity Crises in the Gulf Cooperation Council (GCC) Countries

The Gulf Cooperation Council (GCC) countries are located in the driest part of the world with an annual per capita water availability of 500 m3 compared to the world average of 6000 m3. Agricultural water demand, which is more than 80% of the total water consumption, is primarily met through the massive exploitation of groundwater. The enormous imbalance between groundwater discharge (27.8 billion m3) and recharge (5.3 billion m3) is causing the excessive lowering of groundwater levels. Therefore, GCC countries are investing heavily in the production of nonconventional water resources such as desalination of seawater and treated wastewater. Currently, 439 desalination plants are annually producing 5.75 billion m3 of desalinated water in the GCC countries. The annual wastewater collection is about 4.0 billion m3, of which 73% is treated with the help of 300 wastewater treatment plants. Despite extreme water poverty, only 39% of the treated wastewater is reused, and the remaining is discharged into the sea. The treated wastewater (TWW) is used for the landscape, forestry, and construction industries. However, its reuse to irrigate food and forage crops is restricted due to health, social, religious, and environmental concerns. Substantial research evidence exists that treated wastewater can safely be used to grow food and forage crops under the agroclimatic conditions of the GCC countries by adopting appropriate management measures. Therefore, GCC countries should work on increasing the use of TWW in the agriculture sector. Increased use of TWW in agriculture can significantly reduce the pressure on freshwater resources. For this purpose, a comprehensive awareness campaign needs to be initiated to address the social and religious concerns of farming communities and consumers. Several internal and external risks can jeopardize the sustainable use of treated wastewater in the GCC countries. These include climate change, increasing costs, technological and market-driven changes, and regional security issues. Therefore, effective response mechanisms should be developed to mitigate future risks and threats. For this purpose, an integrated approach involving all concerned local and regional stakeholders needs to be adopted.

Water management with wastewater treatment and reuse, desalination, and conveyance to counteract future water shortages in the Gaza Strip

Groundwater is the only freshwater source available for the Gaza Strip of Palestine, but Gaza groundwater is heavily polluted from agricultural activities and seawater intrusion. Water resource planners therefore have to find innovative alternate sources of water to minimize existing and future deficits. Possible management options include the use of treated wastewater (TWW), desalination, and conveyance of water between locations based on the demand. However, these options require significant funding and therefore, economic evaluation. Sophisticated economic and mathematical tools are now available that allow such analyses. A water allocation system model was used to economically evaluate various options for the projected water demands in 2010, 2020, and 2030. Results show that the use of TWW in agriculture can significantly increase net benefits and reduce water prices. However, any reduction in groundwater pumping can impact net benefits and increase water prices if additional supply is not found. Similar observations were made with the shadow value of water. However, water deficits cannot be accommodated with the existing supply including the use of TWW in agriculture. A combination of TWW use and desalination can increase the supply in an economically competitive manner while reducing groundwater pumping to minimize seawater intrusion. The increased net benefits and profits derived from such supply enhancements surpass the costs to rebuild and maintain the required infrastructure for the Gaza Strip. Key words: Water allocation, wastewater reuse, desalination, conveyance, sustainable water management, economic benefits, the Gaza Strip.

Multi‐Criteria Decision Analysis of Treated Wastewater Use for Agriculture in Water Deficit Regions1

Al‐Juaidi, Ahmed E., Jagath J. Kaluarachchi, and Ungtae Kim, 2010. Multi‐Criteria Decision Analysis of Treated Wastewater Use for Agriculture in Water Deficit Regions. Journal of the American Water Resources Association (JAWRA) 46(2):395‐411. DOI: 10.1111/j.1752‐1688.2009.00409.xAbstract: Coastal regions such as the Gaza Strip of Palestine with limited freshwater supply suffer significantly due to the rapid depletion of water levels, seawater intrusion, and increased water demands. In such regions, use of treated wastewater (TWW) is a viable option if public health issues are addressed. The goal of this paper is to address the use of TWW in agriculture while considering net benefit, economic efficiency of water use (EEWU), environmental goals, and public health risks. The proposed methodology considers public health risk assessment and multi‐criteria decision analysis to assess the beneficial use of TWW in agriculture. The methodology was demonstrated for the Gaza Strip. The health risk assessment suggests that increasing the elapsed time between irrigation and consumption and switching from surface to sprinkler and drip irrigation are practical measures to reduce public health risks. The optimization and decision analyses show that proper allocation of freshwater and TWW and distribution of land area by crop type can significantly increase the net benefit and EEWU. In most cases, net benefit increased by 44%, groundwater use reduced 29% while increasing the EEWU by threefold compared with the existing conditions. The multi‐criteria decision analysis with weighted goal programming can develop flexible management options that considers a given decision‐maker preference. When groundwater abstraction for agriculture reduced from 57 to 36 Mm3 as per decision analysis, the corresponding area below mean sea level decreased by 58% indicating significant aquifer recovery.