Overall Methodology

The conceptual framework for planning and management of MAR is illustrated in Figure 3.1. The principle guidelines for the conceptualisation of MAR planning and management are briefly summarized below:

1. The MAR planning process starts with basin characterization followed by an analysis of the water resources system (WRS) and the existing water resources problem. After identifying the real problem facing the WRS, the first MAR planning task is to identify whether MAR is a potential response. The Driver, Pressure, State, Impact and Response (DPSIR) concept, proposed by the Organization of Economic Co-operation and Development (OECD, 1993) can assist to structure the pertinent problems and to evaluate potential response(s).

2. If MAR is a potential response, then a preliminary feasibility study is required to determine the possibility of MAR in the region. The feasibility study mainly includes the determination of the existing water budget and possible reliable water sources as well as the analysis of the hydrogeological system in order to make decisions concerning the MAR technology to implement and where the best location for MAR infrastructure may be. The feasibility study helps to prepare a conceptual plan, detailed guidelines, and a draft of regulatory aspects of the project. The detailed activities of the feasibility study will vary with the geographical location and extension of the project area, as well as with the existing information and technology (ASCE, 2001).

Figure 3.1: Managed aquifer recharge project planning flowchart (modified after Rusteberg et al., 2008)

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Section 3.3 illustrates an outline of research efforts for MAR pre-feasibility analysis.

3. After the confirmation of potentiality for a MAR system within a regional and or local WRS, the principle MAR project planning steps in a region include:

 Clearly determining the water quantity and quality of an area is necessary for an analysis of potential water resources for MAR. Water resources include surface water, storm water, treated effluent, water from flash floods, brackish water, desalinated water, or imported water (see chapter 2, section 2.1.2 for details). The available quantity of non-committed water needs to be verified against the water demand. In order to fulfil the water demand, different water resources can be considered and used simultaneously in the MAR planning.

 In addition to water quantity, water quality is quite important to avoid further groundwater pollution and the exposing of humans to public health hazards. The water quality parameters should be verified against the WHO standard (WHO, 2006a; WHO, 2006b) or to local guidelines. If the source of water does not meet the water quality standard, then there are two possibilities: (1) discard the water source, or (2) suggest for further pre-treatment. In this case, the cost of further pre-treatment plays an important role in MAR implementation and must be studied in detail.

 After available water resources are verified, selecting proper technology and finding a suitable place for MAR is the next step. Due to limited appropriate space and conflicts of interest concerning land use, finding a location for MAR is a challenging task. A number of surface and subsurface characteristics need to be considered for selecting suitable sites for MAR. Each MAR technology is suited to its own type of surface and subsurface conditions. A number of MAR techniques, such as infiltration, injection, bank infiltration, etc., are now widely practiced around the world (see chapter 2, section 2.1.2 for details) and these techniques are designed for specific types of land. An investigation therefore requires comprehensive Spatial Multi Criteria Decision Analysis (SMCDA), supported by a hydrogeological study and mathematical modeling. Detailed methodology of the SMCDA and hydrogeological analysis used in this study is given in section 3.4. After selecting the proper location and technology for MAR, a system design is prepared and supplementary hydro-infrastructure is planned.

 Project options are then prepared for further comprehensive analysis. Different sources of water (with varying quantity and quality), possible uses of recovered water, possible MAR locations, and possible technologies are considered. The MAR options are all created to fulfil the WRS problem solution, which is set in the beginning. The planners are therefore obliged to review alternatives regarding WRS development in their region.

 Project options are ranked and the best project option is determined for implementation. An analysis of socio-economic and environmental impacts as well as an evaluation of MAR options‘ performance toward the main water resources management objectives is integral to project ranking. Multi-criteria analysis (MCA) techniques support the decision makers (DMs) in

making the best possible decision by ranking the options. A number of decision criteria, which mostly represent the possible environmental, social, health, and economic factors are considered. The selection of representative decision criteria is a participative process, involving relevant stakeholders, since their opinions, mostly reflected in criteria and options‘ importance, affects the evaluation of alternative MAR options/strategies (Rusteberg et al., 2011). Project alternative ranking is considered to be the most critical step in the whole planning process.

Detailed methodology developed and used in this study for MAR strategy formulation, criteria selection and quantification, and strategy ranking is given in section 3.5.

 For groundwater quality management, risk control, and MAR regulation formulation, the information regarding water quality changes and the fate of emerging pollutants in the underground after recharge is quite important. Emerging pollutants may persist during MAR implementation within the recharged water even after wastewater treatment. The aquifer system can improve the water quality by acting as underground reactor, which is called ‗Soil- Aquifer- Treatment (SAT)‘. A good and properly designed monitoring network supplies adequate information related to groundwater quality changes, both spatial and temporal. Hence, Mathematical modeling to quantify possible groundwater flow and transport processes and to determine the possible results of the mixing of native water with recharged water is considered by the MAR practitioners. The outline of the local scale integrated approach for simulating SAT operation is given in section 3.6.

4. MAR project alternatives may be determined to be non-feasible long after a project alternative has been implemented and monitoring and environmental analysis have begun. In this case groundwater quality may not have in fact met standards of quality set by environmental regulations. In order to ensure the achievement of regulatory standards, a decision support system (DSS) may be invaluable in this respect. A DSS user may try to improve project performance by slightly changing decision variables related to MAR management (system operation), water recovery, location, and other options before a project is decided upon and the infrastructure is built. After analysis of all the project options with the DSS, determining the contribution of the most preferred project to the overall IWRM goal is performed. With this final step the WRS system analysis with respect to MAR is complete.

For comprehensive support of MAR project planning under water scarce conditions, an innovative geospatial decision support system (G-DSS) was developed within the scope of the European Research Project GABARDINE. The following G-DSS modules were developed and integrated into the GIS platform: (a) Geo DATA-base management module, (b) DPSIR module, (c) MAR PLANNING module (d) a spatial MCA module for MAR site selection, and (e) a MCA module for MAR option comparison and ranking (Rusteberg et al., 2011). For comprehensive support to the planning of MAR-systems in water scarce areas, the above-mentioned planning framework,

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developed within this dissertation, served as a basis for the complete development of the G-DSS. The modules c, d, and e from the above paragraph were developed and introduced into the G-DSS. Once again, these modules are: (c) MAR PLANNING module, (d) Spatial MCA module for MAR site selection, and (e) MCA module for MAR option comparison and ranking. A further significant contribution was made concerning the development of the DPSIR module (b) of the G-DSS. Chapter 4 gives a detailed description of G-DSS and its interface.

Based on the detailed flow chart, the following four important MAR planning tasks were selected and were subjected of practical and detailed investigation on case study level: (1) MAR pre-feasibility analysis, (2) Site selection and ranking, (3) Analysis, comparison and ranking of MAR planning and management options, and (4) Soil-Aquifer-Treatment (SAT) system operation and impact assessment.

A total four detail individual methodology, one for each MAR planning task mentioned above, were developed in this dissertation, which are described in the following sections. To make each methodology independent of other methodologies, water resources problem analysis, can be performed by DPSIR analysis, was maintained as the first step in each analysis.