Constraints of Application of Wastewater Treatment and Reuse in Mediterranean Partner Countries

Abstract

The scarcity of water and the need for protecting the environment and natural resources are the main factors leading countries in the Mediterranean region to introduce the reuse of treated wastewater as an additional water resource in their national plans of water resource management. In Mediterranean Partner Countries (MPCs), treatment and reuse of wastewater have already been applied to a certain extent, but there is still great scope for extending these practices.

This chapter aims to identify and discuss factors, which act as constraints to the broader application of treatment and reuse practices and technologies in MPCs. The report largely concentrates on the reuse of wastewater for the purpose of irrigation, which is the most common reuse activity in MPCs.

The key types of constraints reviewed in the report are the following: Financial constraints; Health impacts and environmental safety; Standards and regulations; Monitoring and evaluation; Technical constraints; Institutional set-up; Political commitment; and Public acceptance and awareness.

This chapter also illustrates how certain types of constraints have been recognized and dealt with in practice, by means of specific good practice examples from Tunisia (on national political commitment and farmer involvement), Jordan (on standards development and national political commitment) and Egypt (on grey water treatment in rural areas using low-cost systems).

Despite progress in some cases, further action and research is needed to address the factors currently limiting the application of these technologies in MPCs. The chapter thus puts forward a set of recommendations on priority actions and research needed. Priority recommendations concentrate on the aspects of financing and cost recovery, political commitment for treatment and reuse in the context of national water policies and ways of mitigating risks on public health and the environment.

1 Introduction

Countries in the Middle East and North Africa are characterized by more repetitive periods of drought and irregularity of rainfall. It is predicted that chronic scarcity of water will be reached by 2025 along with further degradation of the water resources quality. The scarcity of water resources and the need for protecting the environment and natural resources are the main factors leading countries in the Middle East and North Africa to introduce the reuse of treated wastewater as an additional water resource in their national plans of water resource management [1].

On the one hand, in Mediterranean Partner Countries (MPCs),¹ treatment and reuse of wastewater have already been applied to a certain extent, particularly, Tunisia and Jordan are the MPCs with the highest wastewater reuse rates. On the other hand, it should be mentioned that even though planned reuse of treated wastewater is not a common practice in several MPCs yet, the unofficial use of raw wastewater is quite common, e.g., in Morocco or as indirect use of drainage water in Egypt.

Several factors still act as constraints to the broader application of treatment and reuse practices and technologies in the region of Mediterranean basin. Against this background and the arising need to review current constraints on treatment and reuse, this chapter aims to:

• Review and summarize key factors that act as constraints to the application of wastewater treatment technologies and practices of reuse in MPCs.

• Illustrate ways to deal with and possibly overcome key constraints by presenting some good practice examples from different regions and projects in the Mediterranean.

• Highlight key further action and research needed to support further treatment and reuse in MPCs.

This chapter mainly concentrates on the reuse of wastewater for the purpose of irrigation, which is the most common activity in MPCs. However, it should be kept in mind that wastewater can also be used for other purposes, e.g., industrial reuse, environmental reuse, potable reuse and others.

The sources of information used include reports from national projects, especially from countries participating in the INNOVA-MED project. Also reports from European-funded projects in the MPC region provided valuable information, especially EmWATER (Efficient Management of Wastewater treatment and reuse, financed by the MEDA Program) and the MEDAWARE Program (Euro-Mediterranean Regional Water Program for Local Water Management) under the MEDA Regional Indicative Programming. In addition, literature from internationally funded projects was taken into consideration, such as information from the WaDImena collaborative project on water demand management (funded by the International Development Research Centre, Canadian International Development Agency and International Fund for Agricultural Development) and the comparative study of the FEMIP Trust Fund – through the European Investment Bank – examining the current reuse of wastewater in selected countries of southern Mediterranean.

2 Key Constraints to Treatment and Reuse

Table 1 provides an overview of the most relevant constraints to the treatment and reuse of wastewater in MPCs. The overview of constraints, which is further elaborated in the sections that follow, is based on existing literature (e.g., [2–4]) as well as expert discussions within the INNOVAMED project.

Table 1 Key types of constraints to treatment technologies of wastewater (WW) and reuse of WW

As made obvious in the following, some types of constraints are closely interrelated, for example concerns about health and environmental impacts are linked to the issue of standard formulation and enforcement as well as effective monitoring.

2.1 Financial Constraints

In several cases in the Mediterranean basin, wastewater is not treated properly because the construction cost of efficient treatment systems is very high, especially for small- and medium-sized communities [3]. Advanced wastewater treatment technologies are even more expensive than conventional ones.

In addition, the initiation of treatment plants depends first on the establishment of a sewerage network. In Morocco, for instance, the cost of financing sewerage networks makes future treatment plants seem illusory [5]. Similarly, in Palestine, lack of funds for sewage collection systems is reported as a key problem [6].

Furthermore, in Morocco 60% of activated sludge treatment plants are out of order, due to the expensive cost of electricity, the absence of equipment maintenance and the lack of coordination between different contributors in the management of these plants [4].

In this context, it should be noted that involving the private sector as a financier in wastewater reuse projects is not common in the region, which can be attributed to unattractive economic prospects linked to (1) high capital requirements, (2) stringency of quality standards, (3) weak regulatory and enforcement systems, (4) low cost recovery and (5) price setting for reclaimed wastewater and freshwater by governmental decree, with a strong tendency to keep tariffs low [2].

The high investment and operational costs related to the collection and treatment of the influents, as well the conveyance and distribution of the treated effluents lead to the fact that reclaimed wastewater itself is often a financially expensive water source [2]. For instance, in Morocco, freshwater is still favoured over reclaimed wastewater as it is very cheap, thus giving no financial incentives to reuse wastewater [7]. In Tunisia, incentives were introduced to encourage farmers to utilize reclaimed water through cost reductions. The cost of one cubic meter of reclaimed water was approximately US$ 0.015 per cubic meter compared with US$ 0.0818 per cubic meter charged for freshwater supplies (in 1998). However, farmers still preferred to use freshwater to avoid restrictions imposed by reclaimed water reuse [8].

Also investment costs for the conception of irrigated areas with treated wastewater can be high, for example in Tunisia it is estimated at 10,000 TD/ha [5]. Thus, subsidizing reuse systems may be necessary at the early stages of system implementation, particularly when the associated costs are very large.

A general socio-economic constraint in MPCs is that the population does not pay high enough fees for wastewater treatment and drinking water services to cover the operation and maintenance costs of total expenses. For instance, residential users in Egypt (who account for ca. 80% of average system use) pay currently only ca. 35% of operation and maintenance costs of sewage treatment plants, and nothing towards the capital costs. The capital costs of wastewater treatment plants (WWTPs) in Egypt are presently financed mainly through donor grants and loans [5].

Also, in Jordan and Tunisia, the water price that farmers are willing to pay for reclaimed wastewater hardly covers the operation and maintenance costs for its conveyance and distribution. However, ambitious attempts to recover the full cost of treatment, conveyance and distribution might not succeed according to [29]. Among major factors that reduce farmers’ willingness to pay for reclaimed wastewater are “worries about health impacts,” “crop marketing,” “and distrusted water quality,” and the “availability/accessibility to fresh water at low price.” On the issue of crop marketing, treated wastewater is usually not suitable for crops that are most economically profitable such as vegetables. Indeed, the list of crops where reused water can be applied is restricted (usually to hay). Cropping restriction/freedom is thus one of the most important factors that influence the decision of farmers to irrigate with reclaimed wastewater [2].

2.2 Health Impacts and Environmental Safety

According to Fatta et al. [3], concerns for human health and the environment are the most important constraints in the reuse of wastewater.

It is frequently the case that sewage treatment plants in MPCs do not operate satisfactorily and, in most cases, wastewater discharges exceed legal and/or hygienically acceptable maxima. The reason for this does not necessarily lie in the treatment plants themselves, but in the frequent lack of adequately trained technicians capable of technically operating such treatment plants.

Irrigating with untreated wastewater poses serious public health risks, as wastewater is a major source of excreted pathogens – bacteria, viruses, protozoa and helminths (worms) that cause gastro-intestinal infections in human beings [9]. Inappropriate wastewater use poses direct and indirect risks to human health caused by the consumption of polluted crops and fish. Farmers in direct contact to wastewater and contaminated soil are also at risk [10]. Reuse of wastewater in agriculture may also lead to livestock infections.

Increasingly, wastewater in the Mediterranean region is also loaded with other substances, such as heavy metals, which must be removed for the reuse of wastewater as well as different trace pollutants, including organic and inorganic compounds and emerging contaminants, such as pharmaceutical substances. Also dissolved inorganic constituents, such as calcium, sodium and sulfate, may have to be removed for wastewater reuse [11, 30].

In environmental safety terms, unregulated and continuous irrigation with sewage water may lead to problems such as soil structure deterioration (soil clogging) resulting in poor infiltration, soil salinization and phytotoxicity [12]. For instance, in Jordan salt levels in the soil tended to increase in some areas irrigated with wastewater, which was related to the salinity of wastewater as well as to on-farm management. Salinity implies that a certain number of less resistant crops cannot be irrigated by wastewater [3].

In Tunisia, the main environmental quality constraint to the reuse of wastewater is the excess of nitrogen.²

Potential environment impacts from the reuse of wastewater in agriculture also include groundwater and surface water contamination as well as natural habitat and ecosystem deterioration.

In Morocco, in some plants wastewater undergoes only secondary treatment and hence treated wastewater does not comply with the standards for wastewater reuse in agriculture [3]. Furthermore, although the irrigation of vegetable crops with raw wastewaters is forbidden, the ban on this is not respected which makes the consumer of agricultural products and the farmer face risks of bacteria or parasite contaminations.

A pilot project in Morocco examines the issue of industrial discharges into the sewerage network, which constitutes a constraint on the quality of treated wastewater (ultimately to be reused in agriculture). Industrial discharges should be pre-treated to reduce the industrial pollution load reaching the WWTPs.

2.3 Standards and Regulations

An important element in the sustainable treatment and reuse of wastewater is the formulation of realistic standards and regulations. “Realistic” implies that standards must be achievable and the regulations enforceable. Unrealistic standards and non-enforceable regulations may do more harm than having no standards and regulations, because they create an attitude of indifference towards rules and regulations in general, both among polluters and administrators. For instance, the cost of treating wastewater to high microbiological standards can be so prohibitive that in some cases the use of untreated wastewater is allowed to take place unregulated [3].

Without question, the enforcement of microbiological guidelines or crop restrictions remains important, but a better balance between safeguarding consumers’ (and farmers’) health and safeguarding farmers’ livelihoods should be made, especially in situations where the required water treatment or agronomic changes are unrealistic [12].

Usually, the makeup of standards and regulations is based on other international practices. Particularly, most of the wastewater reuse standards in the Middle East and North Africa region are based either on United States Environmental Protection Agency (USEPA) or on World Health Organization (WHO) guidelines [10] (see Box 1). Zimmo et al. [31] provide a detailed discussion of available wastewater reuse standards for Egypt, Jordan, Lebanon, Palestine, Greece, Turkey, Tunisia, Cyprus, Spain and Morocco.

In general, there is need for establishing milder standards and guidelines that take into consideration the scheme- and country-specific conditions. A set of inclusive guidelines should be established that enable establishing site-specific standards for each irrigation scheme [2]. Also, additional treatment (up to tertiary level) in certain cases to remove crop restrictions would help change farmers’ attitude, because it would allow them to grow cash crops (vegetables) [12].

Attention should, however, also be paid to cases where existing regulations are not adequate to deal with the reuse activities taking place. For instance in Egypt, strict direct reuse standards are set in the Code of Use and the types of crops that can be irrigated with treated wastewater are very limited. However, none of these strict regulations are applicable for the indirect reuse of wastewater via agricultural drainage canals, which is a common practice in Egypt. Here, relevant laws only regulate the standards for discharge into agricultural drainage canals. In practice, the effluent quality of many treatment plants and direct dischargers does not comply with these standards. In addition, no restrictions of the crops irrigated with drainage canal water are stipulated [13].

Box 1 WHO Guidelines for Wastewater Reuse

The WHO started to develop guidelines for the sound use of wastewater already in 1973. These guidelines were updated in 1989 and most recently in 2006 (third edition of guidelines for the safe use of wastewater, excreta and grey water in agriculture and aquaculture).

The WHO guidelines are based on the so-called Stockholm framework, which emphasizes the assessment of health risks before the elaboration of risk management, namely, the setting of health-based targets and the creation of guidelines. The WHO guidelines include insights on policy, legislation, institutional frameworks and regulations. This comprehensive approach allows setting priorities, involving different stakeholders and facilitating communication of information between groups.

The 2006 WHO guidelines outline key criteria for the sustainability of projects in wastewater reuse. These are:

(1) health, (2) economic feasibility, (3) social impact and public perception, (4) financial feasibility, (5) environmental impact, (6) market feasibility, (7) institutional feasibility and (8) technical feasibility.

All in all, these criteria ensure that projects are adjusted to different communities and contexts and remain therefore sustainable.

The 2006 guidelines also set standards and reduction goals for pathogens and chemical contaminants and give recommendations for reduction measures to achieve human health and environmental health. In fact, the third edition of the WHO guidelines (of 2006) has been extensively updated to take account of new scientific evidence and contemporary approaches for risk management. The revised guidelines reflect a strong focus on disease prevention and public health principles.

Source: [15].

3.1 Monitoring and Evaluation

In several cases, the outflow of wastewater treatment systems does not meet standard quality either because standard operating procedures are not followed or because there is no qualified personnel to control and monitor the whole treatment procedure. The competent authorities in most of the countries in the Middle-East and North Africa region are currently not capable of being aware at all times of all data and information concerning the treatment plants. A prerequisite for the control and monitoring of all the activities taking place in relation to treatment and reuse, which is currently absent, is trained personnel of the authorities and the operators [3].

Also in the case of wastewater reuse systems, in many Mediterranean countries, the aspects related to monitoring and evaluation programs are irregular and not well developed. This is mainly due to weak institutions, the shortage of trained personnel, the lack of monitoring equipment and the relatively high cost required for monitoring processes. However, ignoring monitoring evaluation parameters and/or performing monitoring irregularly and incorrectly could result in serious negative impacts on health, water quality and environmental and ecological sustainability. In addition, it is important to introduce appropriate technical and organizational measures to systematically warn managers of wastewater reuse of breakdowns that may occur in the WWTPs, to avoid the flow of untreated wastewater into the distribution network [12].

3.2 Technical Constraints

A key technical constraint to wastewater treatment and reuse technologies in MPCs is the insufficient infrastructure for the treatment of wastewater [4] to produce safe treated wastewater. In Morocco, for instance, insufficient wastewater collection and treatment lead to a low percentage of wastewater suitable for reuse (only 13% of wastewater is considered as treated). In general, sanitation coverage in the Mediterranean region remains inadequate, particularly in rural areas [8].

In addition, engineers and decision-makers in this region tend to stick to the few technologies that they know – activated sludge, trickling filter and lagoon systems – and do not have exposure to wide varieties of technologies. In other words, authorities responsible for wastewater treatment may lack information on appropriate treatment technologies. Moreover, it should be considered that activated sludge technologies are expensive, which often means that countries barely recover operation and maintenance costs of wastewater treatment for these technologies [2]. In general, a large part of the technology transferred to MPCs for wastewater treatment does not actually work in practice due to high costs for proper operation and the lack of qualified technical personnel.

As far as the design of existing WWTPs is concerned, it can be an obstacle for the agricultural reuse of wastewater. Most of the existing WWTPs in the Middle-East and North Africa region were designed for environmental protection, and reuse was rarely considered in their planning and implementation. Even when reuse has been considered, assessment of the actual needs of the reclaimed wastewater users is often limited. Moreover, the nutrient content in the reclaimed wastewater has rarely been considered in the design criteria for WWTPs as well as in setting up the quality standards and regulations for wastewater reuse [2].

An additional constraint to waste water reuse is the limited availability of infrastructure for the conveyance and distribution of the treated effluent, especially, where the infrastructural requirements are high and the financial resources are limited. For instance in Tunisia, the treatment plants are generally far from the irrigated areas and this fact is one of the constraints to higher reuse rates [5]. Using the reclaimed wastewater in the vicinity of the WWTPs as far as possible overturns this disincentive and makes wastewater irrigation more attractive [2].

Some additional technical constraints to the reuse of wastewater reported in Tunisia include the great variability of wastewater quality provided by different treatment plants, the lack of storage basins for inter-seasonal storage of wastewater to be reused as well as the high content of suspended solids in treated wastewater, which cause many clogging problems [5].

3.3 Institutional Set-Up and Personnel Capacity

Weaknesses of the institutional set-up and poor coordination at intra- and inter-sectoral levels are another factor limiting the spread of wastewater treatment and reuse in the Mediterranean region. Planning, design, implementation, operation and maintenance of wastewater treatment and reuse facilities are usually distributed among many governmental departments, while coordination and cooperation between these bodies is lacking [2]. For instance in Morocco, the administrative structure concerning the reuse of wastewater is complex and includes no less than eight different offices or departments that are involved directly or indirectly [4].

Also, conflicts between different institutional actors involved in the process of treating and reusing wastewater may act as a constraint. In Tunisia, for instance, the main obstacle to further improvements in the rate of wastewater reuse is an institutional conflict over standards of wastewater treatment between the Ministry of the Environment, which is in charge of treatment standards, and the Ministry of Agriculture, which is in charge of wastewater reuse. According to the Ministry of Agriculture, the quality of treated wastewater must be improved, because current quality standards are not suitable for micro-irrigation and drip irrigation systems; to apply these irrigation techniques, it is necessary to reduce suspended solids in the treated irrigation water. However, the Ministry of the Environment supports the current standards of quality related to the existing secondary treatment [14].

In Palestine, the efficient financial and technical management of treatment plants and associated facilities requires strong institutional support. At present, the institutional responsibilities for wastewater management in the West Bank are not well defined, generally due to the overall absence of significant wastewater infrastructure. In addition, there is a weak networking system for the exchange of information and available data [6].

To plan, design, construct, operate and maintain treatment plants, appropriate technical and managerial expertise must be present. This requires the availability of an adequate number of engineers, access to a local network of research for scientific support and problem solving, access to good quality laboratories and monitoring system and experience in management and cost recovery. In addition, all technologies, including the simple ones, require devoted and experienced operators and technicians, with extensive education and training [12].

However, in the Mediterranean countries, few governmental agencies are adequately equipped for the tasks of wastewater management. Unfortunately, a considerable number of WWTPs in MPCs but also Mediterranean EU countries are not being operated due to lack of appropriate expertise and/or high costs of operation.

Ultimately, the lack of knowledge of plant operators on efficient operation, control and monitoring has an impact on the quality of treated effluents and subsequently poses risks to human health and the environment.

At the same time, public utilities, which are frequently in charge of wastewater treatment and reuse, are often expected to contribute to the alleviation of unemployment by hiring and keeping a large number of low-qualified staff. In addition, public utilities are subject to civil service salary rules, which restricts their ability to attract and maintain highly qualified personnel that is essential to the successful performance of key technical and managerial functions [2].

3.4 Policy and Political Constraints

The lack of political commitment and of a national policy and/or strategy to support wastewater treatment and reuse also acts as a constraint in certain MPCs.

For instance in Morocco, next to financial constraints and the missing awareness of public authorities, there is lack of a national policy in the field of wastewater management with the aim to protect water resources. In fact, with assistance from international organizations, Morocco launched several projects and experiments on wastewater treatment and reuse with significant results. However, in spite of the acquired experience, wastewater treatment and reuse projects have achieved only little progress in practice, due to the above-mentioned constraints [5].

In Palestine, wastewater reuse projects in the West Bank are also associated with political obstacles, next to financial, social, institutional and technical ones. First, the wastewater reuse concept is still tied to the political issues regarding the Palestinian water rights, because Israel considers reused wastewater as part of the total Palestinian freshwater rights. Second, an integrated vision for wastewater reuse issues is missing, which should include among others political and institutional aspects, water policy, awareness, marketing and tariffs [6].

3.5 Public Acceptance and Awareness

Limited involvement of local farmers, civil society and the private sector is also amongst the major factors that limits the growth of wastewater reuse [2].

There is a strong argument that farmers’ involvement in all phases of a reuse project increases the opportunities for sustainability, reduces the managerial and financial burden on government institutions and, most importantly, improves the willingness of farmers to use and pay for reclaimed wastewater [2].

Farmers need to be informed about the health risks related to the use of wastewater and about the appropriate management procedures. In addition, farmers need to be convinced that treated wastewater can provide an attractive resource and that they can save money through reducing the application of fertilizers.

The involvement of crop consumers is at least as important as they are the ultimate financiers for the treatment and reclamation of wastewater and they are the potential consumers of irrigated crops [2]. Linked to that is the need to understand how the crop marketing system operates. The study by Abu-Madi [2] revealed that consumers often cannot distinguish between crops irrigated with freshwater and reclaimed wastewater. The existing system for crop marketing in which reclaimed-water crops are on offer together with freshwater crops is a good incentive to farmers to use reclaimed wastewater. Unfortunately, however, such marketing systems might tempt farmers to irrigate with raw untreated wastewater. Therefore, the crop marketing system has to be monitored to safeguard public health. The effects of the presence on the market of crops irrigated with reclaimed wastewater needs further study.

Responsible agencies have an important role to play in providing the concerned public with a clear understanding of the quality of the treated wastewater and how it is to be used, with confidence in the local management of the public utilities and the application of locally accepted technology, and with assurance that wastewater reuse involves minimal health risks and detrimental effects on the environment. In this regard, the continuous exchange of information between authorities and public representatives ensures that the adoption of specific water reuse program fulfils real user needs and generally recognized community goals for health, safety, ecological concerns program, cost, etc. In this way, initial reservations are likely to be overcome over a short period [12].

4 Dealing with Constraints: Lessons from Practical Examples in MPC

This section illustrates how certain types of constraints have been recognized and dealt with in practice, by means of specific examples from the Mediterranean region. The examples draw both on contributions of the INNOVAMED partners and current literature, and they reflect lessons learned from past and ongoing projects and activities.

4.1 Tunisia: National Reuse Strategy and Public Participation Efforts

Tunisia is one of the developing countries, which has developed the use of treated wastewater in irrigated agriculture for more than 30 years. The treatment sector has undergone continuous development that permitted the setting up of a planned infrastructure of facilities [14]. Approximately 24% of treated wastewater effluent is used for irrigated agriculture. Tunisia has also taken action to mitigate environmental and health risks associated with untreated wastewater use more than elsewhere in the world [10].

The following sections indicate that the practice of wastewater reuse in Tunisia has enjoyed political support for its nation-wide establishment. In addition, attempts have been made (and succeeded), at least in one irrigation scheme, to involve farmers from the early stages of project planning and implementation. However, experience from other regions of Tunisia show that further efforts still need to be made in terms of education and participation of local communities and end-users of wastewater.

4.1.1 Strategy and Policy to Promote Reuse

The relative success of reusing wastewater in Tunisia is related to political interest to support this activity. Since 1998, treated wastewater reuse was the subject of increasing political interest expressed within large subsidies provided within the water pricing policy (20% of the full price) to promote treated water reuse. Besides, a presidential decision was established in December 1999, aiming to coordinate all sectors for treated water reuse. The agricultural sector remains the most important field of reuse and an ambitious program was prepared within the forward development plans to reach 14,000 ha irrigated with treated wastewater [5].

Given the mobilization of almost all conventional water resources by 2010, the exploitation of non-conventional water resources, such as treated wastewater, is one of the main focal points of the Tunisian national strategy for water resources mobilization [5].

ONAS (National Sanitation Utility) has been in charge of preparing a national strategy for the improvement of treated wastewater. The study for this national strategy was completed in 2002 and aimed at identifying different treated water demands, reducing losses, protecting conventional water resources, maximizing socio-economic advantages from non-conventional water (e.g., by removing restrictions imposed in the case of irrigation) and minimizing environmental risk (especially the risk reduction in pollution and eutrophication due to excessive nitrogen) [5].

The strategy of treated wastewater reuse proposed some suitable answers to the national context of water resources and notably to regional specificities. The main objective is the increase in the rate of reuse from just above 20% to 40–60% according to the use sector [5]. In the following, there are some key proposals of the national strategy for the sector of agricultural irrigation, which remains the key sector of application of wastewater reuse in Tunisia.

Crop restriction is the most important issue that often leads to farmers’ reticence. In Tunisia, wastewater is mainly processed up to a secondary treatment stage and is used for restrictive irrigation. Farmers are in search of safety and favourable conditions to ensure better valorization and higher incomes. The improvement of treated wastewater quality and removal of restrictions could lead to large-scale acceptance by farmers. Thus, complementary treatment or disinfection has to be developed.

Also, the lack of information on potential health risks, related to wastewater reuse and impacts on crops and soils, discourages farmers. Treated wastewater salinity and the high cost of hydraulic facilities are other constraints, which also obstruct the development of the sector and limit projects profitability [5].

Information campaigns for farmers have to be extended and advice needs to be provided on the nitrogen content of treated wastewater, which can largely substitute mineral fertilizer supply.

In addition, generalization of the treated wastewater use in arboriculture, associated with micro-irrigation systems and the use of subsurface irrigation techniques should increase the number of crops, which can be irrigated with treated wastewater.

Lessons Learned

The case of Tunisia shows how political commitment and the inclusion of wastewater treatment and reuse in the national strategy for water resources can promote treatment and reuse in an MPC. Political commitment has been expressed in form of subsidies for treated wastewater within the water pricing policy, the passing of relevant presidential decisions to support this activity as well as the preparation of a national strategy for the improvement of treated wastewater use to propose answers suitable to the national context of water resources as well as regional specificities.

4.1.3 Participation of Farmers in Wardanine Reuse Irrigation Scheme

The participatory approach with regard to wastewater reuse projects is likely to support safer and more efficient use of reclaimed wastewater as well as to maximize the reuse rate. This approach was successively applied in the Wardanine reuse scheme of Tunisia. In this scheme, farmers were involved from the early stages of the project planning and implementation in 1996. A water user association was formed representing 25 farmers that irrigate with reclaimed wastewater. This association was headed by a committee of seven elected members. The main tasks of the committee at the implementation phase were to [2]:

• Contribute to the construction of the project by solving design and operational difficulties between the contractor and the local population.

• Contribute to the opening of new agricultural roads.

• Help in selecting the sites for reservoir and pumping station.

• Coordinate between the equipment providers and the farmers.

After 5 years of project implementation, the main tasks of the farmers’ committee were to [2]:

• Supervise the distribution of the reclaimed wastewater: The irrigation scheme utilizes 800–1,000 m³/day, which is the entire treated effluent from the Wardanine WWTP that is 3 km away. There is a reservoir that has a capacity of 500 m³ and a pumping station adjacent to the WWTP. Approximately 95% of the reclaimed wastewater is used to irrigate fruit trees (mainly peaches and apricots) and only 5% irrigates fodders. However, due to the small capacity of the WWTP and reservoir, water is mainly supplied between 7 am and 7 pm, which is not practical and insufficient for irrigation that often occurs at night. Therefore, this is an unresolved point of conflict between the water users association and the Tunisian National Sewerage Agency.

• Collect water revenues from the farmers: The committee can use the collected revenues for operation & maintenance (O&M) purposes.

• Carry out certain O&M works, such as the cleaning of the reservoir.

• Represent the farmers with the Agricultural Bank for loans and subsidies.

Lessons Learned

The participatory approach facilitated the implementation and management of the reuse project but it also increased the willingness of farmers to use and pay for reclaimed wastewater. It has to be mentioned that the Wardanine reuse scheme is the only scheme out of the schemes surveyed by Abu-Madi [2] in Tunisia and Jordan, where an attempt was made (and succeeded) to involve farmers. Therefore, this example supports the argument that farmers’ involvement in all project phases increases the opportunities for sustainability and reduces the managerial and financial burden on government institutions.

4.2 Jordan: Reuse as Integral Component of Long-Term Water Resource Management

Wastewater treatment has been given priority in Jordan for many years. Currently, more than 60% of the Jordanian population is connected to sewage systems. In addition, Jordan’s desperate need for water has necessitated the reuse of treated wastewater in agriculture for many years [16].

All of the treated wastewater collected from the As-Samra WWTP, the country’s largest plant treating the domestic wastewater of the capital Amman and of Jordan’s second largest city Zarqa, is mixed with freshwater and used for unrestricted irrigation in the Jordan Valley. Thus, wastewater represents 10% of the current total water supply [10]. Jordan is reusing up to 85% of its treated wastewater [17].

The Jordan Valley is an area of low annual rainfalls (average of 100 mm to 300 mm per year) and agricultural irrigation consumes approx. 70% of available fresh water resources [18]. The effluent of the treatment plant As-Samra is first discharged into two consecutive wadis and temporarily stored in the King Talal Reservoir, being diluted with surface and precipitation water on its way, to irrigate approx. 11,300 ha of agricultural land [19].

The WWTP at As-Samra has been operational since 1985. In practice, diluted reclaimed water has been used for irrigation in the Jordan Valley since the mid-1980s. However, there had not been any binding guidelines or standards governing the agricultural reuse in the past, while there was increasing concern with regard to possible health hazards and environmental risks [20].

Growing public discussions and concerns regarding health and environmental aspects of reclaimed water use in the Jordan Valley led to the launching of action on behalf of the Jordanian authorities and international organizations.

4.2.1 Developing Standards and Guidelines for Health and Environmental Impacts of Reuse

To address the adverse affects of reclaimed water on soils and crops, the Jordan Institution for Standards and Metrology published the Technical Regulation Jordanian Standard 893/2002 on the use of wastewater for irrigation in agriculture [21]. Jordan was one of the earliest countries to adopt WHO and FAO effluent reuse guidelines for irrigation, which served as the basis for the Jordanian Standard. Its current version is the Jordanian Standard 893/2006 dealing with “Water-Reclaimed Wastewater” and “Domestic Wastewater.” This Standard specifies the conditions that effluents from WWTPs should meet in order to be discharged into streams, wadis or water bodies or to be used for artificial groundwater recharge and for irrigation purposes [16].

However, the Standard 893/2002 did not cover the water quality of the receiving water once the reclaimed water had been discharged and blended with other water sources. In this context, the Reclaimed Water Project (RWP) was implemented in 2003–2006 jointly by the Jordan Valley Authority (JVA) and Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) with the support of the Jordanian and German Governments.

When the project commenced in 2003, the legal and institutional framework for the agricultural use of reclaimed water, especially of diluted reclaimed water applied for unrestricted agricultural irrigation in the central and southern Jordan Valley was not clear. There were no guidelines for blended reclaimed water or the quality of irrigation water in general. With regard to crop production, there were no safety guidelines for the occupational health of the irrigators, and there was no monitoring of the safety of fresh fruit and vegetables. Furthermore, there was no regular monitoring of the impact of the use of reclaimed water for irrigation on soils and groundwater [20].

As a first step, a baseline survey regarding the legal situation and the mandates of the involved organizations and stakeholders was carried out. With the help of national and international expertise, guidelines for irrigation water quality, crop quality and for monitoring and information systems were proposed. Interdisciplinary working groups adjusted the proposed guidelines to the conditions in Jordan and proposed applicable concepts [18].

Particularly, the proposed irrigation water quality guidelines were based mainly on the guidelines of the FAO [22] and WHO [32]. The proposal was approved by all relevant national authorities in 2004 and distributed and implemented during 2005. In 2006, the irrigation water quality guidelines were modified and revised by an interdisciplinary working group consisting of Jordanian authorities and universities. The modified guidelines were released in 2006 and take into consideration all water sources other than those mentioned in the Jordanian Standard 893. Furthermore, the guidelines cover all unrestricted agricultural crops. The modified guidelines also take into consideration regional and international regulations and standards. Furthermore, several international references were reviewed and adapted to develop guidelines appropriate to Jordanian conditions that can serve as the foremost guidelines dealing with irrigation water quality in Jordan [23].

The RWP also developed agronomic guidelines for the safe use of reclaimed water in the Jordan Valley [19]. Based on the intensive monitoring of nutrient contents of soils, reclaimed water and of the prevalent farming practices on more than 20 farms, one conclusion drawn was that reclaimed water provides plants with 20–40% of their total macro nutrient requirements. The agronomic guidelines were tested and implemented on-farm in cooperation with innovative farmers on 15 demonstration sites between 2004 and 2006. The project drew up fertigation sheets in Arabic language to be used directly by farmers. Previous surveys revealed that farmers in the Jordan Valley spend approximately 10.7 US$ million per season on buying commercial fertilizers. Considering the results of the monitored areas, it was shown that the reduction in commercial fertilizers according to the guidelines did not affect the yields. Particularly, P and K fertilizers could be reduced by up to 60% for some crops. Hence, farmers could save up to 60% of the fertilization costs, which is equivalent to US$ 770 per hectare [19].

In the area of public health, a state monitoring system for the quality of fresh fruit and vegetables under reclaimed water irrigation has been developed. As a first step, a national multidisciplinary working group was initiated in 2003 and elaborated a proposal for the monitoring program, including crop safety guidelines for Salmonella, E. coli, nitrate, lead and cadmium. In August 2005, a memorandum of understanding was signed by the JVA, Ministry of Health, Ministry of Agriculture, Jordan Food and Drug Administration, and the National Centre for Agricultural Research and Technology Transfer. The memorandum defines the responsibilities and the frame of commitments and implementation started in December 2005. In the harvesting period, random sampling of crops eaten uncooked from farms in the Jordan Valley irrigated with reclaimed water as well as from local markets in the Jordan Valley and Greater Amman is carried out. The samples are analyzed for Salmonella and E. coli as well as for nitrate, lead and cadmium [20].

With regard to environmental impacts, the first activity of the RWP was designing concepts for a groundwater monitoring program and a soil monitoring program. Based on the two concepts and results of sampling campaigns during the project, a combined long-term soil and groundwater monitoring concept was elaborated, introduced and discussed with Jordanian authorities and academics. The concept was accepted and implementation started in April 2006 [20].

4.2.2 Wastewater Reuse in Jordan’s National Water Strategy

Due to Jordan’s limited water resources, the Government of Jordan decided in 1997, as part of its Water Strategy, that “wastewater should not be managed as ‘waste.’ It should be collected and treated to standards that allow its reuse in unrestricted agriculture and other non-domestic purposes, including groundwater recharge” [20]. Thus, high priority was placed on the resource value of reclaimed water and Jordan was committed to a policy of complete reuse of treated wastewater effluents.

In 2009, the new National Water Strategy was published, formulating a number of goals which shall be achieved by 2022.

Agricultural irrigation and wastewater reuse will increasingly grow in importance, due to growing population, overexploitation of groundwater resources, and a reduction in precipitation. Hence, important goals for irrigation water are, inter alia, that all treated wastewater designated for irrigation shall be used for activities that demonstrate the highest financial and social return including irrigation and other non-potable uses. Wastewater reuse shall be used where the turnover is the most profitable. For the reuse of wastewater, a risk management system shall be introduced with treated wastewater standards accordingly [21].

In fact, wastewater reuse is also mentioned in the set of core principles of the Strategy:

“… Jordanians must use water more effectively and efficiently and will use and reuse water wisely and responsibly …”

Among others, the Strategy puts forward the following approaches to further support wastewater reuse in irrigation [21]:

• Introduction of appropriate water tariffs and incentives to promote water efficiency in irrigation and higher economic returns for irrigated agricultural products managing treated wastewater as a perennial water source, which shall be an integral part of the national water budget.

• Ensuring that health standards for farm workers as well as consumers are reinforced and that all wastewater from municipal or industrial treatment plants will be treated in such a way that the effluent meets the relevant national standard.

• Periodical analysis and monitoring of all crops irrigated with treated wastewater or mixed waters.

• Designing and conducting programs on public and farmer’s awareness to promote the reuse of treated wastewater, methods of irrigation, handling of produce.

Lessons Learned

In Jordan, wastewater reuse has become already an integral effective component of long-term water resources management.

An important step towards gaining political support was the inclusion of wastewater reuse in Jordan’s National Water Strategy since 1997. This was a signal of placing high priority on the value of reclaimed water.

Jordan developed national standards on the use of wastewater for irrigation in agriculture to adverse public concerns regarding health and environmental aspects of reclaimed water use. Because water quality regulations and effluent standards are in place, water-borne diseases have been reduced in Jordan [24].

In addition, with the support of the Reclaimed Water Project (RWP), additional guidelines were developed and proposed for irrigation water quality, crop quality and for monitoring and information systems. This experience showed that it is vital to create the necessary awareness among the involved agencies, such as the key ministries and other stakeholders. It has proven efficient and successful to initiate national interdisciplinary working groups with specialists of the involved authorities for the elaboration of guidelines and monitoring programs [20].

Meanwhile, the prerequisites for a sound legal framework in Jordan for safe and environmentally harmless agricultural use of reclaimed water are in place. The implementation of monitoring activities has started and contributes to more transparency regarding health and the environmental impacts of irrigation with reclaimed water. What still needs to be done is to transform the guidelines effectively into standards and to ensure the subsequent implementation of the proposed monitoring programs and the enforcement of the recommended threshold values [20].

Furthermore, experience in Jordan revealed that it is not sufficient to intervene only in terms of the legal framework. Such action needs to be complemented by awareness campaigns. Certain studies carried out on farmers and their families’ health and safety condition in the context of the RWP showed a necessity for awareness raising amongst those that will first be in contact with reclaimed wastewater.

4.3 Egypt: Grey Water Treatment at Village Level

Sanitation services in Egypt are less developed than those for water supply. Although urban coverage with improved sanitation gradually increased from 45% in 1993 to 56% in 2004, rural sanitation coverage remains very low at 4%. The low coverage, in combination with a sub-optimal treatment, results in serious problems of water pollution and degradation of health conditions because the majority of villages and rural areas discharge their raw domestic wastewater directly into the waterways. The discharges are increasing year after year due to the population growth as well as the rapid implementation of water supply networks in many villages without the parallel construction of sewage systems [25].

The main limiting factors for WWTPs at small community level are land availability, cost constraints including also costs for operation and maintenance and compliance issues with Egyptian standards [26].

In addition to the problem of sewage, villagers in Egypt also face the urgent problem of disposal of grey water (wash water, kitchen water, laundry water, and bath water) as illustrated in the following sections. This problem is the focus of the following two village case studies, where projects have been set up to treat grey water using gravel bed hydroponic systems.

4.3.1 El Nassria Grey Water Treatment Unit: A Case Study on Village Wastewater Collection

4.3.1.1 Background

The village El Nassria has a population of approximately 25,000 (mainly farmers); most of them are tenants of small pieces of land. The vast majority of the population is poor, with very limited income and education. The village is supplied with fresh water and electricity. It also has a health care unit, two primary schools, one preparatory school and an agricultural cooperative.

The village is deprived of some of the basic services, with special reference to wastewater treatment and solid waste management facilities. Such deprivation is manifested in the dirty narrow streets and alleys, where people dispose their wastewater and solid waste.

4.3.1.2 The Pre-Intervention Context

There is no wastewater treatment facility at the village, and houses are provided by some type of preliminary septic tanks for the collection of municipal wastewater. People are not willing to dispose their grey water into their municipal tanks, so as not to fill the tanks too soon and to have the trouble and cost of emptying them more frequently.

As a result, women tend to dispose grey water in the streets and in the fields. Street disposal of grey water poses a potential threat to people’s health, especially for children spending long hours in the streets, as grey wastewater is a major source of diseases. Houseflies and mosquitoes swarm the areas where such water is disposed of, creating more problems and posing more threats to the community.

4.3.1.3 Technical Aspects of the Grey Water Treatment System

To deal with this problem, a grey water treatment system has been developed, which is made of seven water collection units, each of 70 cm height, covered with a screen that prevents solid waste to enter the collection tank. The collection tanks are located around the village streets, covering an equal area of the village.

Collected grey water is directed to a settling tank with a volume of 24 m³ through a network of pipes and inspection chambers. The water in the settling tank is retained for 2–8 h before it moves to the gravel filter through a force main line. Finally, the treated wastewater is discharged into the village drain and ends up as an additional supply for irrigation.

4.3.1.4 Treatment Unit (Gravel Bed Hydroponic)

The gravel filter is 28 m long and 2 m wide, with a slope of 1:100 to allow water movement. The concrete structure is topped with layers of sand and gravel, 35 cm deep lined with a plastic sheet, 500 micron thickness.

Dense reeds are grown on the gravel. Reed roots are rhizomes that tend to expand and ramify within and beneath the gravel layer. The rhizomes provide a good support for a variety of microorganisms that enrich the gravel bed. The roots also provide the oxygen needed for the growth of these microorganisms to survive.

The biofilm formed by the combination of the microorganisms and the gravel system is the elemental factor that degrades pollutants and converts them into simple organic compounds, hence bringing the pollution load (biological oxygen demand) of the wastewater to acceptable levels. The system is provided with a weir to generate oxygen, a vital component for the microorganisms to thrive.

4.3.1.5 Financing the Facility

The main constraint in the planning phase of this grey water treatment unit on village level was lack of initial funding for the in-situ installed facilities. This was overcome by start-up financing by the Global Environmental Facility (GEF) to establish the facility. However, the operation of the facility is the responsibility of the inhabitants, thus an evaluation should be made if operation and maintenance costs can be adequately covered in practice.

4.3.1.6 Institutional Manageability and Administrative Capacity

The Women Society of Nassria (WSN) is a local association in charge of constructing and operating the grey water treatment unit. One of the main objectives of WSN is to make the connection between the Village Council and the treatment facility, whereby, the Council is sharing the supervision and management of the facility during operation. Meanwhile, the WSN is planning to hire two workers and one supervisor for troubleshooting and for ensuring the smooth running of the facility.

4.3.1.7 Raising Awareness

Once the idea of the project and the technique to be used was approved, a community-wide campaign was launched to introduce the project to the entire community and to mobilize them for the work to come. A number of meetings were held, in which some of the specialists and key officials have addressed the community. A number of senior governmental officers attended some of the meetings held at the village to answer the questions raised by the community members. Representatives of the Ministry of Water Resources and Irrigation, mosques, churches and members of the Village Council also attended the meetings. Most of the meetings concentrated on the impact of grey water on health, environment and economics. In addition, the need and potential to reuse this water and consider it a resource, as opposed to considering it as waste, was discussed. Some leaflets that sum up some of the advantages of the project and the need to implement it were produced and distributed. The campaign was well received by the community because grey water management is a need-driven demand. The awareness raising campaign was able to reach all sectors of the community.

WSN is also planning to hire four to five female environment specialists to help further mobilize the community, raise awareness and communicate with the community, giving guidance for the proper handling and management of grey water.

4.3.2 Gaafar Village Grey Water Treatment Facility: A Community-Based Approach

4.3.2.1 Sanitation and Grey Water at Gaafar

Gaafar village is deprived of wastewater treatment facilities. For some time, the vast majority of the houses were not provided with toilets. People had to defecate in the open, causing some serious health problems, especially for women who tended to refrain from defecation until late at night. In the meantime, community development organizations have provided many of the houses with toilets, and currently most of the houses have toilets. Most of the houses are provided with some type of septic tanks for municipal waste collection. However, these septic tanks are mostly bottomless allowing waste to infiltrate to groundwater, causing some serious pollution to groundwater resources.

In addition, grey water is one of the pressing problems in the village, next to municipal solid waste and excessive use of pesticides. The Gaafar women community considers grey water as their most important problem, because women often have to carry it for long distances to dispose it either in the drain or in the fields.

The Mahaba Society for Development and Environment (MSDE), a well-established non-governmental organization involved in a variety of activities on family care and helping out needy families, has organized a number of meetings that encompassed the whole spectrum of stakeholders to set the priority of the problems they face at Gaafar. The meeting had a good participation from community members, who rated grey water and solid waste as the most important problems that need an urgent intervention.

4.3.2.2 The Project of a Grey Water Treatment Facility

As answer to the grey water problem of Gaafar, a grey water treatment facility is being constructed which is based on a gravel bed filter grown with succulent reeds. As in the case of Nassria, grey water is collected in collection tanks, 70 m high, located at different parts of the village to cover various streets.

Grey water is then collected in a settling tank, 12 m³, where water settles for 2–8 h. After the elimination of much of the suspended solids at the settling tank, water is driven through a force main line to the gravel bed filter, through a line of 500 m. The gravel bed filter is a concrete construction with two beds, each with a diameter of 2 × 50 m. Each bed is covered with a 25 cm layer of gravel, lined with a 5 cm layer of sand, with a plastic membrane of 500 micron thickness envelopes the gravel and sand layers. Reed roots are rhizomes that tend to expand and ramify underneath and beneath the gravel layer. The rhizomic roots provide a good support for a variety of microorganisms that enrich the gravel bed.

The system would be provided with a weir that would help generate oxygen, an essential component for the good performance of the gravel bed filter.

4.3.2.3 Institutionalization, Capacity Building and Awareness-Raising

The MSDE is planning to train one or two community members to supervise the facility and provide necessary troubleshooting measures when needed.

A program to raise awareness and to build capacity in the field of grey water treatment and the use of the gravel bed hydroponic system is being delivered to a number of villagers. The program would also include factors that affect the quality of the performance and efficiency of the gravel bed hydroponic system.

4.3.2.4 Stakeholder Involvement

One of the community members has donated a piece of land of approximately 350 m², on which the gravel bed filter would be built. The area is close to the drain that would receive the treated effluent, Shiekh Yehia drain. However, the cost of bed constructions, reeds and others is covered through the GEF. The construction of the system is carried out by a private contractor under the supervision of the Mahaba Society.

The contribution of other community members will be restricted to monthly fees, after the completion of the project. The fees will be used to pay the limited staff, which will look after the facility, including guarding, and troubleshooting measures.

Other stakeholders involved in the project include the Department of Public Health, Department of Water Resources and Irrigation, Department of Agriculture and Governorate Council.

Lessons Learned

Effectiveness of gravel bed hydroponic systems

Although both examples of gravel bed hydroponic system installation above have not delivered yet insights on the effectiveness of the system, the following lists some of the main system advantages [26]:

• Easy operation and reasonable capital cost.

• Excellent efficiency of removing pathogens at a level almost similar to WHO standards.

• High efficiency of removing nutrients, many organics.

• Effluent compliance with Egyptian regulations.

• Land requirements not ideal but could be afforded at village level.

• Effluent can be used straight for agriculture.

The efficacy of such biologically based system in treating wastewater is well established. Good performance of the unit depends on a number of factors that include:

• The dense and succulent growth of the reeds and their expanding root system.

• The diversity and richness of the microorganisms.

• The retention time of the wastewater in the structure.

• Bed length and gravel size.

It should also be kept in mind that microorganisms, the driving power for the system, are very sensitive to particular contaminants that could find their way to wastewater, such as phenols and cyanide. Nevertheless, in view of the domestic nature of the grey water, the possibility of such toxicants presence is rather low. However, such information should be passed on to community members for information purposes.

Need for monitoring

Early running of the gravel bed should be accompanied by a regular monitoring of the quality of treated wastewater. Samples of wastewater entering the system and samples of water discharged into the drain should have their COD, BOD, total suspended solids TSS, measured. Monitoring programs should be performed on regular basis to make sure that the system is performing satisfactorily. If poor performance is recorded, reasons should be ascertained to take necessary steps.

Factors that might contribute to inferior performance may include:

• Disposal of farm animal’s excreta, due to its high organic load.

• Short retention time.

• Inefficient microorganisms.

• Poor root growth.

• Toxins in wastewater.

Financing, stakeholder involvement and awareness

The examples show that the funds for establishing these grey water treatment systems could be raised due to the relatively reasonable capital cost of the system. Costs for operation and maintenance are to be covered through community member fees, thus an evaluation should be made in due time whether these costs can be adequately covered in practice.

In both cases, the involvement of local association and non-governmental organizations was very important for initiating and organizing the construction of the system. In addition, awareness campaigns helped in mobilizing and informing the community about the advantages from correct operation of such a grey water treatment system.

Box 2 Highlights of the Gravel Bed Hydroponic System

• Gravel Bed Hydroponic (GBH) reed bed systems consist of channels sealed with geomembrane.

• The channels are filled with gravel and wastewater is percolated horizontally below the surface of the gravel. This subsurface flow reduces the potential for breeding sites of insects, especially mosquitoes and aquatic snails.

• Reeds, predominantly Phragmites australis, are planted in the gravel and grow hydroponically using nutrients in the sewage.

• The reeds maintain the hydraulic pathways and their rhizospheres support intense microbial activity which ensures sewage treatment.

5 Recommendations for Future Actions and Research

The Mediterranean population becomes increasingly urban; therefore, it becomes more important to ensure that urban wastewater receives proper treatment and is reused to permit additional uses. The current Mediterranean water deficits could be, in part, alleviated by the adoption of safe wastewater reuse programs. Therefore, further action and research is needed to address the factors currently limiting affordability, robustness and user acceptance of these technologies in Mediterranean environments.

This section formulates recommendations of the INNOVA-MED project for priority actions and research proposed, to overcome key constraints to treatment and reuse of wastewater and sludge in MPCs. The recommendations are structured along key types of constraints as identified and described in the section “Key constraints to treatment and reuse” of this chapter.

• 1. Financing, cost recovery and marketability

  • Funding needs to be secured for further facilities of wastewater treatment in MPC, also to produce treated wastewater, which is safe for reuse. New funding opportunities should be explored, e.g., future EU funding earmarked for the Mediterranean region with emphasis on sanitation and wastewater treatment improvement.

  • Efforts need to be made towards reducing the burden of heavy operation costs of treatment facilities. Considering that, in some cases, 75% of WWTP operation costs are due to electricity consumption, research results on possibilities to achieve electricity savings in operating conditions should be used in practice. Research shows that with certain changes in operating parameters, e.g., in terms of time of aeration periods, large savings in electricity can be achieved. Preconditions are knowledge of the operating system and of the appropriate modeling techniques; in this context, collaboration between the wastewater treatment industry and the academia is needed [27].

  • Operation electricity costs can also be reduced via State reductions in the cost of electricity supplied to treatment plants. For instance, in Turkey, the new Environment Act (under revision) foresees that the establishments (local authorities and industrial plants), which run a WWTP will be entitled to get 50% reduction in the cost of electricity that they use (Berber R. personal communication 2008).

  • Other ways to significantly reduce the operational electricity costs of wastewater treatment in MPC include the broader use of solar energy, due to the suitability of climate and weather conditions in these countries.

  • Next to costs for treating wastewater, also costs for the reuse of treated wastewater need to be recovered. It is argued that a fundamental element for sustainable reuse is the payment of a fee to cover costs of mobilization. This fee, however, would be substantial and regularly paid, only if the practiced agriculture is able to generate products of sufficient added value. Thus, it needs to be ensured that wastewater reuse is profitable to farmers for gaining acceptance as a practice. Specific research should be carried out on ways to extend the list of crops, which can be irrigated with wastewater (especially for well-marketable vegetable crops), e.g., by upgrading treatment technologies and the quality of wastewater and/or by applying irrigation systems with absence of contact between water and the product to guarantee hygienic quality.

• 2. Political commitment

  • The reuse of treated wastewater in MPC needs clear political support and the development of appropriate strategies in the context of a country’s overall water resources policy to promote this practice. Commitment to reuse should be part of the proclaimed water policy and strategy in all countries of the Mediterranean region, particularly those suffering from water scarcity.

• 3. Mitigating health and environmental risks (including standard development and monitoring)

  • Carry out adequate treatment of wastewater – well accepted treatment processes need to be listed, in combination with their removal potentials.

  • For accepted treatment processes, easy to measure parameters should be developed e.g., temperature measurement for thermal treatment, oxidation-reduction potential (ORP) for anaerobic or aerobic processes or pH for lime treatment.

  • The relevant process parameters shall be monitored at least daily, and preferably continuously if practicable. Records shall be kept and made available upon request to the competent authority for inspection purposes and/or for customers.

  • The processes shall be initially validated by log10 reduction with test organisms.

  • Control wastewater outlets in the network.

  • Industrial wastewater should be pretreated to domestic wastewater quality levels prior to discharge into public sewers. This should help avoid many complications in the treatment and reuse of wastewater.

  • Common guidelines (ISO standards) should be developed on the operation of wastewater treatment facilities in MPC.

  • Promote the use of streamline life cycle analysis in the field of wastewater in MPC.

  • Monitor the contamination level in soil and crops irrigated with treated wastewater.

  • Monitor quality of groundwater where treated wastewater is used.

  • For an affordable monitoring system of the quality of water for reuse, it is proposed to limit the number of parameters to be monitored (e.g., to coliforms, helminths, salinity, pH, nitrogen).

  • As it is hard to keep the consumers’ confidence and to cope with emerging contaminants, effect measurements should be considered besides chemical and pathogen monitoring data.

  • Use drip irrigation in water reuse, because it reduces considerably health risks.

  • Further research should be carried out on corrective measures for soil salinity and alkalinity, soil health protection and human health risk management. From the macro-scale analysis point of view, it is recommended for Mediterranean countries setting up demonstration and extension of the Best Management Practices for saline and treated wastewater under different cropping systems.

  • Common norms and standards for the reuse of treated wastewater in MPC should be established. So far, different MPC have taken different regulatory approaches with varying standards to manage the reuse of treated wastewater and sludge. In this context, it is important to comply with the framework criteria given in the WHO guidelines for the safe use of wastewater (latest version of 2006). The guidelines, however, also need to be adapted to local conditions for each Mediterranean country, to satisfy its own set of conditions. See also [31] for further recommendations on the development of water reuse guidelines for Mediterranean countries.

  • Different levels of accepted quality (e.g., class I excellent quality, class II good quality, class III satisfying) will give incentives for an improvement in wastewater quality over time. Viable options based on different treatment levels for different uses of wastewater (including food and non-food crops, landscaping and groundwater recharge) but also of sludge should be assessed accounting for the parameters of the Mediterranean region and social acceptance.

  • Quality standards need to be developed also for sludge, for its safe reuse and the safeguarding of soil quality, e.g., in terms of heavy metal concentration and pathogens. Especially, the effluent of industries needs to be monitored for heavy metals and Best Available Technologies (BAT) should be applied in industrial processes.

  • Code of good practice of reuse

    • Beside obligatory requirements, it could be envisaged to set up codes of good practice for the use of wastewater and sludge in the different countries and for various applications. The codes should contain certain provisions for not impairing the quality of groundwater, the prevention of leaching from storage; selection of application periods in terms of weather conditions. In agriculture, the sludge shall be used when there is need for growing of crops, taking into account all the other fertilizers applied.

    • It needs detailed plans for reducing the amount of potentially hazardous substances, materials, elements or compounds that end up in the sewer, and therefore in wastewater or sewage sludge because of their presence in cleaning products, detergents, personal care products, medicines, pipes, or others.

    • Therefore, consumers should be informed of the composition of the products, substances or materials that could end up in the sewer and how to dispose of them in a way which does not pollute wastewaters.

  • Nitrogen pollution risk mitigation

    • It is important to establish with high precision the water balance in the soil plant system, by quantifying the inputs (rainfall, irrigation volume) and the outputs (crop uptakes and evaporation).

    • Nutrient contents should be analyzed, in particular, treated wastewater nitrogen. This will allow quantifying the amount of added nitrogen in the applied irrigation, considering the yield level to be achieved, to evaluate the nutrient uptake.

    • Based on the soil analysis, the balance of mineral nitrogen remaining in the soil should be considered.

    • The irrigation dose is an important factor that conditions nitrate leaching. Therefore, in light sandy soils, it is recommended to reduce the amount of water applied and increase the frequency. At this level, it is recommended to consider the importance of optimizing the rate of nitrogen and the irrigation water depth on the basis of crop water and nitrogen requirements for the different stages.

    • Crops with high nitrogen uptake should be chosen and/or maximum soil crop cover should be assured.

    • It is recommended to mix rich nitrogen waters and low nitrogen waters or alternate these two types of waters.

    • It is also strongly recommended to establish a nitrogen mass balance, coupled with a water balance, to protect the aquifer against nitrate contamination. The objectives are to keep nitrate concentration in the water below 50 mg/l or to assure 0% annual increment rate in case the nitrate concentrations exceed 50 mg/l.

• 4. Improving the technical setting

  • It is recommended to select the most suitable treatment technology on case-by-case basis, based on the type of possible reuse of the treated wastewater. In a first step, it is proposed to select the appropriate irrigation system for a specific crop, keeping in mind that drip irrigation allows to reduce health risks from reused wastewater. As a second step, the appropriate wastewater treatment system should be selected.

  • Future research should focus on the development of affordable technologies, emphasizing biotechnologies for wastewater treatment and safe agricultural reuse in the Mediterranean. In addition, we should focus on innovative, appropriate and cost-effective technologies (and biotechnologies) for sludge treatment.

  • In the INNOVA-MED project, the following newly emerging technologies were identified and considered as innovative proposals to be used in wastewater treatment and reuse in MPC: Tertiary treatments such as advanced oxidation processes, biological treatments (advanced anaerobic treatment, membrane bioreactors, alternating anaerobic and anoxic treatments, etc.), chemical and biological integrated systems to reduce the operational costs of the treatment plant as well as wastewater reuse treatments (reverse osmosis systems, ultrafiltration and nanofiltration). However, it should be kept in mind that wastewater treatment systems are capital-intensive and require expensive and specialized operators. Therefore, before selecting a wastewater treatment technology in an MPC (including new techniques mentioned above), an analysis of cost-effectiveness needs to be made and compared with all conceivable alternatives [28].

  • A strategy for the inter-seasonal storage of treated wastewater should be developed in each country.

• 5. Raising awareness and acceptance of reuse

  • The participation of end users of treated wastewater should be systematic already at the inception phase of a reuse project.

  • Capacity building and training should be organized for farmers on how to use wastewater as well as on sanitary protection and health protection aspects.

  • Awareness campaigns should be carried out educating on the danger of reusing raw wastewater and on the advantages of using treated wastewater. It is also necessary to communicate up-to-date information on appropriate processing and crop protection technologies to authorities responsible for wastewater treatment and reuse as well as the end users.

  • To achieve positive perception of treated wastewater reuse and high level of compliance among users, demonstration activities are needed. Users and the public need to be well informed about the scientific facts of wastewater reuse and evidence of benefits in simple comprehensible ways; by means of demonstration, they should also be able to see the tangible results.

  • For the consumer, it should be clear that the applied wastewater was treated appropriately, this needs to be ensured by monitoring programs which are accessible for the general public and supervised by special (trusted) authorities or independent experts.

  • There should be a provision on producer responsibility and certification. Producers are to be responsible for and guarantee the quality of wastewater and sludge supplied. Producers should implement a quality assurance system for the whole process, i.e., control of pollutants at source, wastewater and sludge treatment, including the communication of information to the receiver. The quality assurance system shall be independently audited. The origin and the quality of the wastewater and sludge applied need to be known and shall be able to be traced back.

  • A quality competition or benchmark system between suppliers could give further incentives to achieve excellent quality.

• 6. Institutional coordination and strengthening personnel capacity

  • There is need for more qualified technical personnel and need for personnel training to achieve efficient operation of WWTPs. For instance, a new Environment Act in Turkey (currently being revised) foresees that WWTPs must maintain necessary technical staff and develop expertise for their operation. The new Act will also provide measures for training technical personnel, and creating an Environmental Management Unit in each of the respective establishments (Berber personal communication 2008).

  • A close dialogue between institutions in the water treatment and reuse chain is necessary to co-ordinate and complete their respective efforts. This can be supported by encouraging cooperation benefits between different institutions.