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

Abstract

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.x Abstract: 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.

Zero Risk Does Not Exist: Lessons Learned from Microbial Risk Assessment Related to Use of Water and Safety of Fresh Produce

“…B. fragilis phage B40‐8 was chosen because it is considered as a conservative model for human enteric viruses and may be expected to be inactivated at a slower rate than the human viruses (Petterson and others ). The resulting first‐order decay constant ( k = 1.07 per day, σ = 0.07) has been used in several other studies (Al‐Juaidi and others ), including some that used this model to represent survival of enteric viruses on other types of produce (Hamilton and others , ). Decay or the loss of viability/infectivity of pathogenic microorganisms is traditionally modeled, assuming a simple first‐order kinetic model where the decay constant is affected by various environmental factors (temperature, solar radiation, relative humidity, and presence of inhibiting/inactivating substances).…”

“…Use of nondisinfected secondary treated reclaimed water for fresh produce irrigation leads to an unacceptable high annual risk of infections (Tanaka and others ; Hamilton and others ). Increasing the microbial removal efficiency of wastewater treatment is associated with a reduction in public health risk associated with fresh produce consumption (Al‐Juaidi and others ; Pavione and others ). Therefore, the use of a tertiary treatment step with disinfection was judged necessary to adequately contain infection risks of, for example, enteroviruses when eating fruits and vegetables (Munoz and others ).…”

“…First, the selection of an appropriate type of irrigation method must be considered. Several QMRA studies modeled the impact of different irrigation practices (van Ginneken and Oron ; Stine and others ; Al‐Juaidi and others ). Only a minority were actually based on experimental studies (Stine and others ).…”

Risk Control in Recycled Water Schemes

“…exposure to pathogens Al-Juaidi et al (2010). demonstrated that, given the same treatment and irrigation conditions on agricultural land areas, tertiary treated effluent drip irrigation at 25 days elapsed time between last irrigation and consumption led to the lowest annual risk of 10 -12 compared with 10 -9 and 10 -8 annual risk for sprinkler and surface irrigation respectively.…”

Prioritization of water management under climate change and urbanization using multi-criteria decision making methods

“…There have been many studies on water resources planning and management using various MCDM methods (Pavlikakis and Tsihrintzis, 2003;Chen and Hou, 2004;Levy et al, 2007;Meyer et al, 2009;Chung and Lee, 2009;Al-Juaidi et al, 2010;Zardari et al, 2010;Chung et al, 2011a). In decision making, the weights assigned to the decision criteria attempt to represent the genuine importance of the criteria.…”