Assessment of On-Site Wastewater Treatment Systems in Unsewered Communities in Jordan

DEGREE PROJECT IN THE ENVIRONMENTAL ENGINEERING AND SUSTAINABLE INFRASTRUCTURE, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2020

Assessment of on-site wastewater treatment systems in unsewered communities in Jordan

HANI SHUBAIL

KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT

TRITA-ABE-MBT-20728

www.kth.s e

Assessment of on-site wastewater treatment systems in unsewered communities in Jordan

Hani Shubail [email protected]

Supervisor Sahar Dalahmeh, PhD Department of Energy and Technology, Swedish University of Agricultural Sciences Email [email protected]

Elzbieta Plaza, (Prof.) Water and Environmental Engineering, Department of Sustainable Development, Environmental science, and Engineering (SEED), School of Architecture and the Built Environment (ABE) KTH Royal Institute of Technology Stockholm, Sweden

Examiner Elzbieta Plaza, (Prof.)

KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT Department of Sustainable Development, Environmental Science, and Engineering

SE-100 44 Stockholm, Sweden

Summary in Swedish

För att täcka centraliserade avloppsreningssystems drift och underhåll är det kapitalinsättningen av stor betydelse, förutom högkostnadsprogram, något som anses vara olämpligt för låginkomstländer. In-situ avloppsreningssystem verkar vara en lovande lösning till detta. För att dock säkerställa att dessa ej belastar den omgivande miljö och fungerar som det skall i förbehåll att dessa ständigt övervakas. Konstruerade våtmarker är en typ av in-situ vattenreningsteknik. Dessa system är lämpliga för småstäder, bergiga och tätortsområden. Dessa system är kostnadseffektiva och flexibla vad dess implementering och hantering anbelangar. Två dylika system är i fokus av denna studie, nämligen två konstruerade våtmarker i Sakib - Jerash i Jordanien och i synnerhet utforskas dess prestanda, social acceptans i och dessutom utfördes en nyttokostnadsanalys. Båda våtmarkerna i denna rapport har konstruerats med ett vertikalt markflöde och är i drift sedan januari 2020 och juli 2015 respektive.

Dessa två system ger goda reduktioner med avseende på biokemiskt syrebehov och kemiskt syrebehov (BOD, COD), totalt suspenderat material (TSS), och effektivitet rörande patogen borttagning (TC och E. coli). Även om patogen borttagningseffektivitet i sig var hög förblev patogenhalt hög i det lokala direktivs avseende; de lokala förutsättningarna, nämligen designparameter och belastningsförhållanden, tillåter dock uppbyggande och drift av dessa två systemen som i fokus i detta studium. Beträffande borttagning av näringsämnen visade det sig att båda systemen har låg kväve- och fosforborttagningseffektivitet. Vissa förslag och rekommendationer föreslogs för att förbättra näringsämnen samt systemens effektivitet vad gäller patogenborttagning; i synnerhet dessa förslag beträffar pumpa ut slammet ur septiktanken, utbyte och backspolning av vattenfiltermedia, vattenväxterinförande eller tillägg av en extern kolkälla samt användning av en ytterligare aerobfiltreringsenhet vid utlopp. Det visade sig att det jordanska samhälle sätter käppar i hjulet vad gäller implementering av dessa våtmarker emedan dess förfarande är oacceptabelt. Dylika problem kan överbryggas genom full insyn, föredrag och workshops samt allmänhetens deltagande. Det sistnämnda gav upphov till en ökad känsla av äganderätt robust, något som ledde till ökat intresse för ansvar i drifts- och underhållsfrågor. Vad nyttokostnadsanalysen anbelangar visade det sig att implementering av ett dylikt system skulle vara fördelaktigt och värdefullt som alternativ för kluster på tätorts- och landsbygdsområden.

Avloppsvattenbehandlingen med lermineraler verkar hittills vara en lovande metod vid betraktande av tidigare studier. Det behöver dock göras ytterligare undersökningar för avloppsvattenbehandlingen med lermineraler vid bestämmande av den optimala lermineral

koncentration och dess exponeringstid.

Abstract Centralized wastewater treatment systems need substantial funds besides high-cost operation and maintenance programs, which could be considered unsuitable for low-income developing countries. As a solution, it becomes the trend towards on-site wastewater treatment systems (OWTs) due to its cost-effectiveness and flexibility of implementation and management. However, the keenness to implement these systems appropriately and monitor them continually is crucial to ensure that they do not impact the surrounding environment and human health. Constructed wetland is one of the on-site wastewater treatment systems. These systems are comparatively affordable alternative technology, and adequate systems for small communities, rural, and hilly areas. In the present study, two constructed wetlands as on-site wastewater treatment systems in Sakib - Jerash Governorate, Jordan, were investigated regarding systems performance, social acceptance, and cost-benefit analysis. The first system is a vertical flow constructed wetland (VCW) that has been operating since January 2020. The second system is a recirculation vertical flow constructed wetland (RVCW) that has been in operation since July 2015. The checking of the theoretical design parameter and the actual loading conditions of the septic tanks and wetlands in both systems showed that both implemented septic tanks and the wetlands are adequate and appropriate for the design goals. The wetlands’ treatment performance showed sufficient capability in organic matter removal efficiencies: Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS) removal efficiency. For pathogens: Total Coliform (TC) and Escherichia coli (E.coli), even though the removal efficiency was high, the effluents' values exceeded the local directive. Concerning nutrients removal, both systems showed low nitrogen and phosphorus removal efficiencies. Some suggestions and recommendations were proposed for improving nutrients removal and pathogen removal efficiencies. These recommendations were in desludging the septic tanks, replacing the filtering media, introduce plantation or add other carbon sources to the system, and using an additional aerobic filtration unit in the wetlands’ outlets. The study showed that the Jordanian society's nonacceptance of the on-site wastewater treatment systems could be handled through full transparency, educational workshops, and public participation. The latter contributed an increased sense of ownership robustly and increased concern of responsibilities on the operational and maintenance matters. Regarding the cost-benefit analysis, the study results demonstrated that the implementation of a constructed wetland as an on-site wastewater treatment system could be a beneficial and valuable alternative for clusters in rural areas and even in newly urbanized plans. The promising method for the treated wastewater's disinfection using clay minerals needs further investigation to determine the optimum clay mineral concentration on treatment and the needed time for exposure. Keywords

Constructed wetland — Decentralized wastewater treatment — Jordan — On-site wastewater treatment system.

Acknowledgments The author has to thank God Almighty, the Most Gracious, the Most Merciful, who deserves the praise for successfully and peacefully giving the author the ability to complete this dissertation. First and foremost, the author has to express the sincerest gratitude to the supervisor, Dr. Sahar Dalahmeh, from the Swedish University of Agricultural Sciences (SLU), Department of Energy and Technology. Without Dr. Sahar's instructions and guidance throughout the entire thesis period, the author would not improve the research capability to get the outcomes of this dissertation. The continuous follow-up to all novelties during the study and endeavor to overcome all difficulties and obstacles faced by the author was real support and encouragement. Likewise, the author expresses the gratefulness thanks to Prof. Elzbieta Plaza, Department of sustainable development, environmental science, and engineering (SEED), KTH, for granting the author the trust and the acceptance to examine this thesis. The author presents appreciation for Dr. Moayied Assayed, Head of Division of Water Studies, Royal Scientific Society (RSS) for the helpful discussion, and insightful suggestions. Besides, for giving the author the chance to use the RSS physical and chemical laboratory to conduct the thesis's required tests. Special thanks to Eng. Mohammed Mashatleh, member of water studies division, RSS, for the continuous readiness to provide the author with the needed tools and instruments for sampling and carrying out laboratory testing. The tremendous support from Dr. Moayied and Eng. Mohammed during experimentation, analysis, and characterizations was indescribable. The sincere appreciation is given to Dr. Jwan H. Ibbini, Assistant Professor, Department of Land Management and Environment, Faculty of Natural Resources and Environment, Hashemite University (HU), and Dr. Jwan's assistant, Eng. Mais Thaher for, the real support and cooperation, to secure the author's access to the HU's biological laboratory to conduct the dissertation's biological tests. From Dr. Jwan and Eng. Mais, the author got continuous inspiration, care, and support. Special thanks to the author's collage Spyridon Xenos for the contribution in translating summary into Swedish. Finally, the author gives gratitude to beloved parents for continuous prayer throughout the study. Finally, the author wants to admit that without the sincere support and sacrifices made by the lovely wife, Sarah Al-Serri, the author would not be the person the author is today.

III

Table of contents

Table of contents IV List of figures VI List of tables VI List of abbreviations and symbols VII 1. Introduction 1 2. Aim and objectives 2 3. Study borders and delimitations 3 4. Theoretical background 3 5. Study area 7 5-1. Jerash. 8 5-1-1. The vertical flow constructed wetland (VFCW) - Sakib 1. 9 5-1-2. The recirculating vertical flow constructed wetland (RVFCW) - Sakib 2. 10 6. Methodology 12 6-1. Assessment of design parameters and actual loading conditions of the septic tanks and wetlands. 12 6-2. Treatment performance of the wetlands. 13 6-2-1. Wastewater sampling and analyses. 13 6-2-2. Laboratory tests and analysis. 13 6-3. Group discussion/interviews. 15 6-4. Cost benefits analyses. 15 6-4-1. Significant cost components. 16 6-4-2. Significant monetary benefits. 17 6-5. Literature review. 17 7. Results and discussion 17 7-1. the theoretical design parameter and actual loading conditions of the septic tanks and wetlands. 17 7-2. The treatment performance of the septic tank. 19 7-3. The treatment performance of the wetlands. 19 7-3-1. Solids and organic matter. 21 7-3-2. Nutrients. 23 7-3-3. Microbial tests. 27 7-4. Social acceptance. 29 7-5. Cost-benefit analysis (CBA). 30 8. Conclusion 32 9. Uncertainties 33 10. Future scope 33

11. References 35

12. Appendix – A (Instruments, detailed test procedures and theoretical information regarding Ph; EC, DO, BOD5, COD, Nutrients and bacteria) 41 13. Appendix – B (Calculation tables) 52 14. Appendix – C (Groups discussion) 55 15. Appendix – D (Laboratory tests photos) 61

List of figures

Figure (1) Location of study cases of wastewater treatment systems of septic tank 9 followed by wetland wastewater (Sakib 1 and Sakib 2) in Sakib village – Jerash- Jordan

Figure (2) Illustration of wastewater treatment components in Sakib 1, which included the 10 wetland (A), the septic tank (The modified septic tank previously) (B).

Figure (3) The schematic diagram for the septic tank followed by CW in Sakib 1. 10

Figure (4) Illustration of wastewater treatment components in Sakib 2, which included the 11 wetland (A), the septic tank (B) the splitter (C) and the storage tank (D).

Figure (5) The schematic diagram for the septic tank followed by RCW in Sakib 2. 12

Figure (6) The average concentration of (A) biochemical oxygen demand BOD5, (B) 22 chemical oxygen demand COD, and (C) total suspended solids TSS in the influent and effluent of wetlands in Sakib 1 and Sakib 2.

Figure (7) The average concentration of (A) nitrate NO3, (B) total nitrogen TN, and (C) 26 - 27 phosphorous PO4 in the influent and effluent of wetlands in Sakib 1 and Sakib 2.

Figure (8) The E.coli average measurements for both systems' influent and effluent. 28

Figure (9) The HQ40D Portable multimeter. 41

Figure (10) The DR1900 Portable VIS Spectrophotometer. 42

Figure (11) The Digital Reactor Block 200 (DRB 200). 42

Figure (12) The BD 600 apparatus. 43

Figure (13) The Masterclave 528. 43

Figure (14) Sampling for laboratory tests. 61

Figure (15) A side of laboratory output. 62

List of tables

Table (1) The standard values for both reclaimed water for discharge into torrents, 8 valleys, or bodies and water reuse for irrigation.

Table (2) The laboratory measured parameters, test methods, kits names, standards 14 methods, control solutions, and apparatus.

Table (3) The calculated theoretical design parameter and actual loading conditions of 19 the septic tanks and wetlands.

Table (4) Summary of the measured laboratory tests for the system in Sakib 1. 20

Table (5) Summary of the measured laboratory tests for the system in Sakib 2. 20

Table (6) Calculations of significant cost components. 30

Table (7) Calculations of significant monetary benefits. 31

Table (8) The operational characteristics of the HQ40D Portable multimeter. 41

Table (9) Test sample volumes and nitrification inhibitor dosage according to BOD5 44 range value.

Table (10) The Idexx tables for quantifying bacteria indicators (TC, E. coli, and 52 Pseudomonas aeruginosa).

Table (11) The Microbial test calculations' and results' tables on 04/03/2020. 53

Table (12) The Microbial test calculations' and results' tables on 08/03/2020. 53

Table (13) The Microbial test calculations' and results' tables on 16/03/2020. 54

Table (14) The contractor pricing on the systems' tendering. 54

List of abbreviations and symbols

BOD5 Biochemical oxygen demand

COD chemical oxygen demand

CWs Constructed wetlands

EC Electric conductivity

E. coli Escherichia coli

DO Dissolved oxygen

HFCW Horizontal flow constructed wetland

HLR Hydraulic loading rate

HRT Hydraulic retention time

HU Hashemite University

KM Kilometer

KTH Royal Institute for technology

MPN Most probable number

- NO3 Nitrate

OLR Organic loading rate

OWTs On-site wastewater treatment systems

PE People Equivalent

VII

- PO4 Phosphorous

RSS Royal Scientific Society

RVFCW Recirculation vertical flow constructed wetland

SLU Swedish University of Agricultural Sciences

SEED Department of sustainable development, environmental science, and engineering

TSS Total suspended solids

UHR Ultimate high range

ULR Ultimate low range

USEPA United States Environmental Protection Agency

VFCW Vertical flow constructed wetland

TC Total coliform

TN Total nitrogen

TP Total phosphorus

VIII

1. Introduction Lack of sanitation services leads to many diseases that affect public health. Nearly 40% of the world's population lacks basic sanitation (Ritchie & Roser, 2019), and usually, the rural areas have a potential shortage in such services compared to urban areas (Massoud et al., 2009). About 82% of the rural population in developing countries are affected by this issue (WHO, 2015). According to Van Afferden et al. (2010), any area or settlement has less than 5000 population considers as rural (Van Afferden et al., 2010). The conventional centralized wastewater treatment systems need adequate funding and appropriate local expertise, making them challenge to be provided in rural areas due to the low population density and dispersion of housing. Consequently, the trend towards decentralized wastewater treatment systems or on-site wastewater treatment systems (OWTs) grows and develops due to its cost-effectiveness and flexibility of implementation and management (Massoud et al., 2009). Furthermore, decentralized wastewater treatment systems are an attractive option in arid countries suffering from drought and limited water resources. According to different perspectives, several studies provide different definitions for decentralized wastewater treatments or on-site wastewater treatment systems. Van Afferden et al. (2015) defined the decentralized wastewater treatment as a system that collects, treats, and reuses/disposes the treated effluent at its point of generation vicinity (Van Afferden et al., 2015). The OWTs could be defined as systems that collect the wastewater and do the treatment then discharge the treated wastewater for a property or facility inhabited by 20 persons (Oakley et al., 2010). Another definition by Massoud et al. (2009) that the on-site wastewater treatment system as that decentralized systems which is less resource-intensive. Moreover, it has a more ecologically sustainable form of sanitation that receives wastewater from a house, a cluster, a small commercial facility, and whose wastewater output limits are unknown. These systems are usually simple and low-cost systems that require less maintenance and monitoring. Such simple and cost-effective systems are suitable for small and isolated settlements or villages with low population densities (Massoud et al., 2009). The OWTs serve to meet the needs of wastewater treatment and facilitate the on-site reuse such as irrigation and work to prevent environmental pollution and related health problems as a result of direct discharge of untreated wastewater to the surrounding environment (Lienhoop et al., 2014). Van Afferden et al. (2015) added that decentralized wastewater treatment systems allow high flexibility in dealing with growing urban sprawl situations and are considered suitable solutions for challenging topographical conditions (Van Afferden et al., 2015). However, the reliance on OWTs is often needed in areas that depend on domestic drinking water wells, making these treatment systems linked to the spread of several diseases that threaten human life like infection and diarrheal disease. Moreover, the effect on aquatic systems (Schaider et al., 2017), where OWTS is one of the most commonly doubtful sources of fecal pollution of water resources (Carroll et al., 2005). In this sense, the keenness to implement these systems appropriately and under constant monitoring is crucial to ensure that they are persistent and not impacting the surrounding environment and human health (Bradley et al., 2002). As aforementioned, due to the earnest water scarcity experienced by many countries in the world, water management experts and specialists' concern shifted towards the reuse of treated wastewater

for irrigation purposes. More accurately, this shifting has to be at its maximum levels to become a

valuable alternative than using other water resources and a priority to adapt to the current global situation (Nelson et al., 2008). Thus, this contributes not only to minimize the impacts on the environment and public health instead maximize the farthest reuse of the water as well (Massoud et al., 2009). It is crucial to ensure the quality of the treated wastewater particularly, in countries that suffer from water scarcity, have limited water resources, and consequently use treated wastewater for irrigation (Iasur-Kruh et al., 2010). Redder et al. (2010) believe that the tendency to reuse the treated wastewater for irrigation is essential wherever there is a shortage of water like in arid subtropical areas of the world. However, these applications could comprise epidemiological risks, particularly in developing countries that lack the needed financial ability to implement them properly (Redder et al., 2010). Risks from reliance on the OWTs were associated with either the design's, operating's, or maintenance's programs for these systems, i.e., failing to choose the appropriate technology for the specific wastewater characteristics or the failure of these systems in some processes of treatment (e.g., removal of nutrients or pathogens). Furthermore, the 2002 report of the United States environmental protection agency explained one of the essential reasons for the OWTs performance variance. The responsibility for operating and maintaining the system is often assigned to inexperienced and uninformed owners. Consequently, it could lead to most system failures. Such examples of system failures due to the lack of experience are the accumulation of sludge in the tanks and hydraulic overloading (USEPA, 2002). Regarding Sweden in this context, Wallin et al. (2013) illustrate that Sweden relies on on-site wastewater treatment systems for around 700,000 permanent rustic residential buildings. Today, half of these on-site wastewater treatment systems are poorly performing compared to environmental and health current legislation. The aging of OWTs in Sweden is one of the significant sources of nutrient loads and water pollution sources where those systems were constructed from the 70s decade and earlier. It is considered that 15% of phosphorus loads to the environment are the result of OWTs. Furthermore, the total emissions of nutrients from OWTs are equal to those from urban wastewater treatment plants, although the number of Swedes who are still dependent on OWTs represents only a seventh of Sweden's total population. In other words, despite the continuous decrease in the Swedish rural population every year, these loads steadily increase from these systems (Wallin et al., 2013). 2. Aim and objectives

The inductive research question for this thesis was, " Could the on-site wastewater treatment systems be an effective alternative to centralized wastewater treatments in low-income countries with limited resources?". For this question to be investigated, the thesis aimed to assess two on-site wastewater treatment systems consist of septic tanks followed with a vertical flow constructed wetlands (CWs). The systems under investigation located in Sakib village in the city of Jerash - Jordan. The first system (Sakib 1) is a vertical flow constructed wetland (VCW) operating since January 2020 as a new system, and its operating's results represent the time- limited performance assessment. The second system (Sakib 2) is a recirculation vertical flow constructed wetland (RVCW) in operation since July 2015. The results achieved from this system

represent long-term performance assessment.

Aspects of assessment in this thesis included the systems performance and operation aspect, the social aspect, and the economic aspect. Accordingly, the objectives of the study were determined as follows: 1. To assess the design adequacy of the septic tanks built in Sakib - Jerash, Jordan, in terms of volumes, sludge storage capacities, and loading rates of the treatment systems. 2. To assess the treatment performance of the two constructed wetlands built in Sakib - Jerash, Jordan. 3. To study the social acceptance of the two constructed wetlands in Sakib - Jerash, Jordan. 4. To analyze the cost-benefit of the two constructed wetlands in Sakib - Jerash, Jordan. 3. Study borders and delimitations The targeted geographic areas in this thesis were small-scale communities with dispersed dwelling housing systems in Sakib village in the city of Jerash – Jordan. The community is representative of community that are directly dependent on the OWTs due to the financial and technical difficulties related to linking them with the centralized wastewater treatment plants. Due to the limited time of the study period and to ensure having representative samples of the treated wastewater to investigate the treatment quality, the analysis had been intensified and done on a daily basis. Furthermore, the assessment's results will be within the present, and for the near- future time horizon. The main three delimitations in this thesis will be: - The assessment is considered a short-term assessment during the spring season. The seasonal variations, temperature differences, and effects of precipitation were not included. - This study was limited to the assessment of the quality of wastewater treated in the wetland, which effluent was used for irrigation. However, the effects of reusing the treated water on quality of soil, and effects on irrigated crops were not analyzed within the study. - The parameters included in the wastewater quality analysis were limited to these types which had available reagents, test kits and apparatus. - The change in the stability of the assessed system's performance under various seasonal conditions and operational modes (hydraulic and organic loads) were not included in the current study. 4. Theoretical background People living in rural, semi-urban areas, and new dispersed settlements rely on the conventional system (cesspools or cesspits) to discharge wastewater from their properties. Reliance on cesspools/cesspits causes many environmental and health problems besides its impact on the quality of life as a result of: - When the cesspit is not adequately sealed, wastewater leaks through soil and rock layers and contaminates the groundwater. - The cesspool needs continuous discharge when constructed on an impermeable rock layer. Moreover, when there is no financial ability to do this, the cesspool is left to

overflow, causing odors and spreading of diseases.

- When tankers draw the cesspool, it is impossible to ensure that this wastewater will be discharged to the places designated for it, as some tankers illegally empty it into the valleys (Lienhoop et al., 2014). OWTs, as an alternative, have proven effective by providing the necessary service and efficiency, which emulates the efficiency of centralized wastewater treatment systems. Consequently, it becomes indisputably, reliable technology all over the world. Several treatment technologies could be considered as OWTs. Primary technology, secondary technology, treatment/disposal technology, and dry sanitation systems classify those technologies. Simple septic tank and Imhoff tank systems are counted as examples of primary on-site wastewater treatment technology. The secondary on-site wastewater treatment technologies like facultative lagoons, anaerobic or aerobic lagoons, sequencing batch reactors, and constructed wetlands (CWs). Subsurface infiltration, trenches, and beds, seepage pits, mounds, and fills are systems that represent the treatment/disposal technology. The composting toilet is an application of a dry sanitation system (Massoud et al., 2009). Constructed wetlands (CWs) are one of the on-site wastewater treatment systems. These systems are comparatively new and affordable alternative technology in the wastewater treatment field. CWs are adequate systems for small communities, rural or hilly areas, where centralized wastewater treatment systems are not financially and technically feasible. CWs provide several advantages such as they often use renewable energy sources, usually the mechanical parts not needed, and could be run out with minimum construction, operation, and maintenance costs (Stefanakis et al., 2009; Hang et al., 2016). The CW system primarily consists of a septic tank and the wetland. The septic tank is used to collect the wastewater and works as a primary treatment unit where it acts as an anaerobic bioreactor or digester for the retained organic matter. Besides, it removes most of the settleable (sludge) and floatable materials (scum) before the influent redirects to the constructed wetland (USEPA, 2002; Leverenz et al., 2010). The partial digestion of the organic solids in the septic tank reduces the sludge and scum volume up to 40% and adjusts the wastewater by hydrolyzing organic molecules for subsequent treatments (USEPA, 2002). For achieving good sedimentation in the septic tank, it is needed to provide a convenient wastewater residence time with quiescent conditions in the tank known as the hydraulic retention time. The septic tank volume, geometry, and compartmentalization are the design considerations to obtain these conditions (Ibid). During the passage and treatment of the wastewater in the septic tank over the years, the layers of sludge thicken and gradually reduce the amount of space available for sewage. Septic tanks should be pumped every 3 to 5 years, depending on the size of the tank and the number of people served to ensure proper system performance and reduce the risk of hydraulic failure (Ibid). Furthermore, for ensuring efficient performance of pretreatment in the septic tank, regular maintenance has to be made. Cleaning of floatable materials and pumping of the sludge is the only septic tank maintenance requirements. The wetland is the primary unit for treatment, consisting of a specific land area (according to the type of the constructed wetland and proposed objectives of the treatment) containing the filter media. The filter media is divided into layers (mostly three to four layers) of different gravel sizes. The effluent comes out from the wetland through the installed outlet pipe within the last layer in the filtration media. Two or four vertical pipes installed from the base of the filter media to the top

of the wetland known as ventilation risers, which work to facilitate the air penetration into the

drainage system and the filter media (Nivala et al., 2013). For higher nutrient removal, wetlands could be constructed as a planted system on the filter media's top surface. The effluent from the septic tank, which is the influent to the wetland, is distributed into the wetland through perforated surface or subsurface pipes. By gravity, the water is transported in the system to filter and complete the treatment steps by exposing it to the oxygen and media's bacteria (Leverenz et al., 2010). If the treated effluent is to be used for irrigation, the system's outlet is connected directly to the irrigation distribution pipes or stored in storage tanks for future use. Otherwise, discharged to the nearest surface water source or valleys. According to their hydrology, there are two central systems of CWs: the free water surface or subsurface. Similarly, according to the water flow direction, the subsurface constructed wetlands could be classified as horizontal (HFCW), vertical (VFCW), or hybrid. Hybrid systems consist of several types of CWs associated respectively to reach higher treatment results and more intricate treatment efficiency, especially for nitrogen and phosphorus removal. The most common hybrid systems comprise VFCW and HFCW systems arranged in a staged path (Vymazal, 2010). CWs of the same types could vary in their features, e.g., planted roots density, hydraulic conductivity, and influent wastewater characteristics according to the constructed wetlands' designated objectives and the prediction of the removal processes (Wu et al., 2016). The CW's depend on a series of several mechanisms to execute the treatment processes, including sedimentation, filtration, precipitation, adsorption, volatilization, and plant uptake. However, the bacterial/microbial activity is the primary mechanism for the most contaminant removal due to its ability to work under aerobic and anaerobic circumstances (Meng et al., 2014). The bacteria stick with the surface of the CW's media particles and the roots of the plants (if planted constructed wetland), forming a biofilm that works on the essential decomposition and disintegration of contaminants in the wastewater (Iasur-Kruh et al., 2010). The wetlands' effectiveness in treating the domestic wastewater for the reduction of biochemical oxygen demand, suspended solids has been proven in several studies and could be compared to the conventional centralized treatment (Redder et al., 2010). The limited dissolved oxygen (DO) concentration in the CW's filtration beds represents anaerobic conditions that enhance organic compounds' degradation through microbial degradation. Wetlands have a better rate of biological activity than most ecosystems. This feature is attained by the advantage of the wetland's land area, with the sun's underlying natural environmental energies, media/soil, wind, animals, and plants. These factors help these systems require minimal energy and chemicals to be operated and meet treatment objectives (Vymazal, 2010). An efficient wetland system’s design is required to ensure producing high-quality effluent water. The gravel material used for the filtration media besides the hydraulic flow rate are two significant parameters in CW's design (Iasur-Kruh et al., 2010). Meng P. et al. (2014) illustrated in their study that the media used as filtration beds in the constructed wetland is a vital component not only because of its adsorption capacity for contaminants but also it provides the ideal conditions for microbial growth and plants settlement (if available). The gravel properties, including particle size, surface area, porosity, hydraulic conductivity, pH, and organic matter content, contribute to the microbial mediated processes. Gravel with a bigger grain size in the upper layer in constructed wetland beds is the significant parameter affecting the performance in suspended solids retention and the mass transformation

rate of the oxygen. However, depending on extremely large-sized media should be avoided as the

top coarse layer's surface area becomes insufficient for the biofilm's growth. Similarly, using too small grains of gravel, e.g., organic soil, can provide a higher specific surface area for biofilm formation. Thus, the exceedingly narrow pore diameters may result in the joining of surface aggregations and pore blocking. The porous media may offer a larger surface area for biofilm growth and increase the interaction area with contaminants in wastewater. Furthermore, using materials rich in organic matter in the filtration beds can supply the needed carbon source to enhance the constructed wetland's microbial processes (Meng et al., 2014). Zeolitic volcanic tuff is one of the most used media in the constructed wetlands in Jordan. The solidification of ash and other sediments coming out of volcanic vents is what creates the volcanic tuff. Tuff comparatively is a porous rock whose mineral composition is predominantly glass (Geology Science, 2020). The zeolitic volcanic tuff is a soft, lightweight aggregate with a specific gravity of 1.89 kg/m3. The zeolitic volcanic tuff has a good porosity with a value of 60.5%, and the water absorption of 8.7% (Al Dwairi et al., 2018). Volcanic tuff is available widely in the Jordanian land. However, it varies on its mineral content and quantity associated with zeolites based on the weathering rate and zeolitization processes from one location to another (Ibid). Although CW systems prove their effectiveness in achieving the required treatment, however, they have some secondary cons, such as the need for a relatively large surface area (3–5m2 / population equivalent) to be constructed, which makes them not suitable for all conditions (Moelants et al., 2008). Tanner et al. (2012) estimate an area of (4–8 m2 per person equivalent) to construct a horizontal constructed wetland (Tanner et al., 2012). Furthermore, the limited aeration and the need for intermittent alternating through media beds to prevent the surface's blocking limit the ingrained usage of these systems (Sklarz et al., 2009). HFCWs are predominantly anaerobic systems as oxygen transportation through the saturated media is limited where transportation is occurring through the planted macrophyte roots in relatively small amounts (Tanner et al., 2012; Nivala et al., 2013). As a result, the efficiency in eliminating nitrogenous compounds in HFCWs is relatively low (García-Pérez et al., 2009). The trend to the VFCWs enhances the oxygen transfer rate and consequently increases the effectiveness of removing the organic matter and nitrification (García-Pérez et al., 2009; Sklarz et al., 2009). VFCWs have high redox chances to support aerobic microbial processes. On the one hand, a notable higher BOD removal and nitrification results could be gained from VFCWs. On the other hand, lower denitrification has been noticed in VFCWs compared with HFCWs (Meng et al., 2014). Depending on area topography to use gravity instead of pumping in CWs considering the proper design of the wetland's sidewalls to avoid the overflow is called a passive CW system. Using extensive/passive and natural CW systems, perform better and more robust options than compact/active CW systems. As they require fewer or non-mechanical parts, less energy will be used, and little maintenance will be needed (Moelants et al., 2008; Nelson et al., 2008; Oakley et al., 2010).

For constructed wetlands' performance enhancement, the recirculation had been introduced to the systems to increase both nitrification (via multiple infiltration through the unsaturated beds) and

denitrification (via added dosage with carbon-rich influent) (Tanner et al., 2012).

5. Study area

Jordan is a developing country suffering from severe water scarcity (Van Afferden et al., 2010; Mayrhauser, 2012). The country ranks as the fifth nation to have the highest water shortage, where rainfall is less than 5 centimeters each year (Whitman, 2019). Climate change (Ibid) and the steady influx of refugees from Syria since 2011 are factors that elevate this problem (Alshoubaki & Harris, 2017; Whitman, 2019). Jordan had a high population growth rate until recently. Jordan's population growth rate between 2000 and 2019 was within the range of 1.37% and 5.00%. However, 1.00% is the current population growth rate (World Population Review, 2020). Van Afferden et al. (2010) epitomize in their study the wastewater situation in Jordan in several fundamental points as follows: - The yearly available water consumption in Jordan is less than (200 m3/capita), one of the lowest worldwide. - Some studies estimated daily water consumption between 77L to 83L/capita in the Jordanian northern urban areas. Where for the rural areas, it was between 20L to 28L/capita. - Approximately 0.52 million people living in Jordanian rural areas principally depend on cesspools or planted ditches to discharge their wastewater as they do not have sewer systems or are not connected to central wastewater treatment systems. Mostly improperly sealed cesspools infiltrate through fractured rock and cause considerable groundwater pollution. Furthermore, some sewage tankers which suck those cesspools dump wastewater illegally into valleys. As a result, the robust need to establish decentralized wastewater treatment systems and reuse treated wastewater is essential. - According to the Jordan National Water Master Plan, the planned amount of treated wastewater for reuse starting from 2020 has to be (101×106 m3/year). This quantity represents 15% of the available total renewable water resources. - In the new water strategy (2009–2022) prepared by the “Royal Commission on Water”, the decentralized treatment systems should serve the semi-urban, rural communities, and even new urban settlements (Van Afferden et al., 2010). Lienhoop et al. (2014) believe that Jordan has a lot of entirely unexploited water sources from the wastewater. 38% of the population (mostly in rural areas) is not connected to sewer systems, and accordingly, their wastewater does not treat in the centralized wastewater treatment plants for reuse purposes (Lienhoop et al., 2014). Attention to OWTs is a crucial issue that must be taken to protect the surface and groundwater besides protecting agricultural production in this country (Lienhoop et al., 2012; Lienhoop et al., 2014). Consequently, the reuse of the treated water is crucial to extenuating the physical, social, and economic stresses generated from this water scarcity (Van Afferden et al., 2015). The on-site wastewater treatment Jordanian standards number 863/2006 approved by the Board of Directors of the Standards and Metrology Institution at its session No. 6/2006, held on 13/06/2006, is the Jordanian directive in use for on-site wastewater treatment systems evaluation. The directive contains several sections that clarify general requirements, standard requirements, quality control, and evaluation mechanisms for reclaimed domestic wastewater. Table (1)

summarizes the maximum standard values for the reclaimed water for discharge into torrents,

valleys, or bodies of water and the maximum standard values for the reclaimed water reuse for irrigation. Table (1): The standard values for both reclaimed water for discharge into torrents, valleys, or bodies and water reuse for irrigation.

Max. directive value for

Standards Reclaimed water for Reclaimed water reuse for discharge into torrents, irrigation valleys, or bodies of water

Biochemical oxygen demand (BOD5) 60 200 chemical oxygen demand (COD) 150 500

Dissolved oxygen (DO) > 1 -

Total suspended solids (TSS) 60 200

Power of hydrogen (pH) 6 - 9 6 - 9

Nitrate (NO3) 80 45

Total nitrogen (TN) 70 70 phosphorus (PO4) 15 30

Escherichia coli (E. coli) < 1000 < 1000

5-1. Jerash. The two systems under assessment lie in the Sakib area in Jerash governorate, as can be seen in figure (1). Jerash governorate locates 53 km north of the Jordanian capital, Amman. The city lies at an altitude of 648 meters above sea level. According to the Köppen-Geiger system, Jerash's local climate is classified as Csa (Mediterranean hot summer climates) with occasional short and light freezing conditions in winters. Jerash has moderate to warm weather with an average temperature of 17.5 °C. The warmest month is August, with 25.2 °C. The coldest month is January, with 8.5 °C. Average annual precipitation is estimated at 393 mm, and more precipitation in the winter than the summer season. The driest month is June, with an average of 0 precipitations. The most rained month is January, with 92 mm precipitation (climate-data.org,

ND).

Figure 1. Location of study cases of wastewater treatment systems of septic tank followed by wetland wastewater (Sakib 1 and Sakib 2) in Sakib village – Jerash- Jordan

5-1-1. The vertical flow constructed wetland (VFCW) - Sakib 1. This system was executed in July 2015 to treat the wastewater from a cluster consisting of five dwellings with an average flow rate of 290 L/day/house by a modified septic tank system. The modified septic tank system failed to comply with the designed targeted treatment purposes due to the lack of operational experience and shortage in the necessary maintenance. The septic tank system was upgraded lately to include a non-planted VFCW, which was put in service in January 2020. The upgraded system (modified septic tank and VFCW) currently serves a cluster of seven dwellings and thirty-six persons with an average flow rate of approximately 1.5 m3/day. The wastewater collects from each house to the built sewer chambers then directed to the septic tank (the modified septic tank previously). The septic tank was used as a pretreatment stage before pumping the wastewater to the wetland with a designed detention time of 3-4 days. The septic tank has a net inner dimension of 7.3 m length, 1.2 m width, and 1.20 m depth and divided into four chambers (three sedimentation chambers and a pumping chamber). The wetland has a dimension of 10.0 m length, 4.0 m width, and 0.95 m depth. The wetland's walls were built with 20 cm concrete blocks and painted from outside by bituminous paint. From inside (for all walls and the wetland's base), covered and lined by a geotextile waterproofing membrane. The treatment media used was the zeolitic volcanic tuff and divided into three layers. The top layer of the media (filter layer) was 65 cm and used an 8-16 mm gravel size, the second layer (transit layer) was 10 cm and used a 4-8 mm sand, and the base layer (drainage layer) used a 16-20 mm gravel size. The wastewater is fed to the wetland via a distribution network (perforated pipes) lies on the surface of the upper wetland's bed and covered with a shed, which is a halfpipe for aesthetic purposes. For aeration condition enhancement, two ventilators rise on the wetland surface where the first ventilator is connected to a 4-inch perforated pipe within the top layer and the other connected with the outlet drainage pipe in the bottom layer. The treated water flows from the wetland to the outlet concrete chamber. A submersible pump with an automatic float was placed in the feeding (pumping) chamber in the septic tank and based on the water height at the septic tank, the water to be pumped to the constructed wetland. The effluent from the system currently discharges to the valley. However, the landlord where the

constructed wetland was built is planning to store the treated water in a storage tank to be used

soon to irrigate his farm. Figure (2) shows the different parts of the constructed wetland in Sakib 1, and figure (3) shows the schematic diagram for the septic tank followed by CW in Sakib 1.

(A) (B) Figure (2): Illustration of wastewater treatment components in Sakib 1, which included the wetland (A), the septic tank (The modified septic tank previously) (B) .

Figure (3): The schematic diagram for the septic tank followed by CW in Sakib 1.

5-1-2. The recirculating vertical flow constructed wetland (RVFCW) - Sakib 2. This system serves a cluster consisting of four dwellings and a total of twenty-four persons and an average flow rate of 1 m3/day. The recirculating constructed wetland's design parameters are based on EPA guidelines (1993). The wastewater is collected from each house to the built sewer chambers then directed to the septic tank. The septic tank was designed as a pretreatment to hold the wastewater with a designed detention time of 3-4 days, before pumping the wastewater to the wetland. The septic tank has a net inner dimension of 3.6 m length, 1.2 m width, and 1.6 m depth and divided into three chambers (two sedimentation chambers and dosing chamber). The wetland has dimensions of 7.5 m length, 5.5 m width, and 1 m depth. The wetland's walls were plastered and lined using polyethylene lining sheets with 6-8 µm diameters. The treatment media used was the zeolitic volcanic tuff and divided evenly to two layers 50 cm each. The top layer of the media (treatment layer) used a 4-8 mm gravel size, where the second layer (discharge layer) used a 16-20 mm gravel size. The wastewater feeds the wetland via a distribution manifold (perforated pipes) lies on the surface of the wetland's upper bed and covered with a shed, which is

a halfpipe for aesthetic purposes. For nitrification and denitrification enhancement purposes, the

treated water discharges from the wetland to a splitter chamber for recirculation. The splitter concrete chamber was built with a dimension of 1.40 × 0.6 × 0.35 m. The splitter was constructed to split the water from the constructed wetland into two volumes, i.e., 1/3 directed to the irrigation tank and 2/3 redirected to the septic tank. A submersible pump with an automatic float was placed in the septic tank and based on the water height at the septic tank, the water to be pumped to the constructed wetland. The landlord of the land where the constructed wetland was built stores the treated water in a storage tank—the storage tank connected to an irrigation network extending over his farm's surface. Figure (4) shows the different parts of the constructed wetland in Sakib 2, and figure (5) shows the schematic diagram for the septic tank followed by recirculating constructed wetland in Sakib 2.

(A) (B)

septic tank (B) the splitter (C) and the storage tank (D).

Figure (5): The schematic diagram for the septic tank followed by RCW in Sakib 2.

6. Methodology 6-1. Assessment of design parameters and actual loading conditions of the septic tanks and wetlands. For assessing the design adequacy of the septic tanks and the wetlands, the actual operating parameters and loading conditions of the system were calculated. Specifically, actual People Equivalent (PE) of the systems, wastewater liquid volumes, hydraulic retention time (HRT), sludge volume, the required septic tanks volumes had been done. The PE is the used term to describe the size of the wastewater treatment system. In practice, at average water consumption of (150 to 180) l/capita/day, it was assumed that this capita produces 54 grams of Biochemical oxygen demand (BOD) per 24 hours. The Actual People Equivalent (PE) was calculated according to equation (1).

Actual People Equivalent (PE) = BOD5 concentration × volume of wastewater / number of the people ………. Eq.(1) The mean HRT was defined as the average time the wastewater stays inside the septic tank. HRT is a very crucial parameter for hydrogen and methane production within this time. The fermented hydrogen may shift to methanogenic one when HRT is prolonged (David et al., 2019). HRT was calculated according to equation (2). Hydraulic retention time = volume of the tank / flow rate………. Eq.(2) The sludge volume is the amount of the sludge accumulation per day in the tank and was calculated according to equation (3). Sludge volume = sludge accumulation rate × number of people connected ………. Eq.(3) Where, the sludge accumulation rate is 0.234 l/capita/d (Gray, 1995). The required septic tank volume for the system is the adequate volume for both daily wastewater liquid volume and the stored sludge until desludging. According to Franceys et al. (1992), the required sludge storage capacity was calculated according to equation (4). B = P × N × F × S………. Eq.(4) Where, B = Required sludge storage capacity in liters. P = Number of people connected to the tank.

N = Number of years between desludging.

F = A factor which relates the sludge digestion rate to temperature and the desludging interval, (For N = 5 and Temperature between 10 – 20 oC, F = 1). S = Rate of sludge accumulation that may be taken as 25 liters per person per year for tanks receiving WC waste only, and 40 liters per person per year for tanks receiving WC waste and sullage (Franceys et al.,1992). For the wetlands, the hydraulic loading rate (HLR) and organic loading rate (OLR) had been calculated. The HLR of the wetland is the volume of wastewater applied to one m2 of the wetland per time. The hydraulic loading rate was calculated according to equation (5). Hydraulic loading rate = flow rate / area of wetland………. Eq.(5) The OLR of the wetland is the amount of organic material per one m2 of the wetland per time. The Organic loading rate was calculated according to equation (6).

Organic loading rate = concentration of BOD5 × Hydraulic loading rate………. Eq.(6)

6-2. Treatment performance of the wetlands. 6-2-1. Wastewater sampling and analyses. For evaluating the treatment performance of the wetlands, grab samples of wastewaters were collected at the wetland’s entry points and the wetland’s outlet. For Sakib 1, the inflow collection point to the wetland was located at the effluent of the septic tank (Figure 2b). For Sakib 2, the inflow to the wetland was located at the pumping compartment in the septic tank, and it included wastewater coming from the septic tank and recirculated effluent from the RVFW (Figure 4b). Within two weeks, three samples were collected for Sakib 1 influent and effluent (Table 4). For Sakib 2, were two samples under the same period (Table 5). The inflow of the septic tank was not included in the sampling plan as the targeted treatment performance evaluation is for the wetlands. However, the results of previous measurements by RSS at the construction period were used for the wastewater BOD5 and TSS concentrations. The septic tanks will be evaluated regarding design parameters (volumes, sludge storage capacities, and hydraulic loading rates).

6-2-2. Laboratory tests and analysis. For assessing the treatment performance of the two wetlands, several physical and chemical measurements and laboratory tests were conducted and analyzed for the wetlands' influents and effluents. The physical and chemical measures included pH, dissolved oxygen (DO), electric conductivity (EC), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total - - suspended solids (TSS), and nutrients values expressed by phosphorous (PO4 ), nitrate (NO3 ) and total nitrogen (N). Furthermore, some of the biological tests carried out to measure influents' and effluents' total coliform (TC), Escherichia coli (E.coli), and Pseudomonas Aeruginosa (P. Aeruginosa). The measured parameters were determined using chemical kits and according to methods shown in Table 2. The procedures for the determination of each of the test parameters were described in the manuals provided by the supplier and are briefly described in Appendix A. The analytical quality was ensured by using control solutions with known concentrations of

the substance for every measurement series (specified in Table 2).

Apparatus

HQ40DPortable multimeter HQ40DPortable multimeter 600 BD apparatus DR1900 PortableVIS and Spectrophotometer Digital 200 BlockReactor oven, Filtrationand apparatus, desiccator DR1900 PortableVIS and Spectrophotometer Digital 200 BlockReactor DR1900 PortableVIS and Spectrophotometer Digital 200 BlockReactor DR1900 PortableVIS and Spectrophotometer Digital 200 BlockReactor IDEXX IDEXX IDEXX

ATCC ATCC

–

d Voluette

mg/L NO3 mg/L

aeruginosa

mL an mL

Solution, pH 7.00 pHSolution,

ControlSolution name/value

Buffer Conductivity NaCl, Standard 1000Solution, µS/cm 2418328) kit test A no. (Art. from Lovibond Standard COD 300 Solution, mg/L Distilled water NitrogenNitrate Standard 10.0 Solution, Nitrogen, Standard Ammonia 10Solution, Ampules, 50 mg/L 50 Solution, PhosphateStandard mg/LPO43 as Escherichiacoli ATCC 0001325922/WDCM from IDEXX Escherichiacoli ATCC 0001325922/WDCM from IDEXX Pseudomonas 00025)27853 (WDCMfrom IDEXX

N.C)

- (F P

s, control s, solutions, and apparatus

Standard Method

Standard Method 52102011 B Standard Method 5220 D Standard Methods 2540 EPA and D Method 160.2 USEPApart 40 CFR 136 Standard methods (4500 Standard Methods 4500 Standard Method 9223 A Standard Method 9223 A Standard Method 9223 A

2 2

Unit

µS/cm, mS/cm mg/l O mg/l O mg/l mg/l NO mg/l N mg/l PO MPN MPN MPN

13.5 and and 13.5

200

range

–

1500 100

4000

2419.6 2419.6 2419.6

- - -

- – – –

Measurement Measurement

0 0.01 40 20 0.45˃ µm 0.23 5 20 Jun 1 with (Increases dilution) 1 with (Increases dilution) 1 with (Increases dilution)

TNTplus

Kit Name Kit

pHprobe EC probe HighCOD, Range Digestion Reagent LR Nitrate TNTplus HR Reagent and Nitrate TNTplusReagent Nitrogen, UHR Total, TNTplusReagent Phosphorus, and Reactive Total UHR Reagent Colisure Reagent Colisure Reagent Pseudalert reagent

substrate substrate substrate

- - -

Test method Test

Respirometric bottles DigestionReactor Method Residue, non filterable Dimethylphenol method Persulfate digestion method Ascorbicacid method Enzyme Test Enzyme Test Enzyme Test

)

(Nitrate)

(Escherichia

(Biochemical (Biochemical

(Chemical (Chemical

N N 5 5

(Total suspended suspended (Total

(Phosphorus)

(Electrical (Electrical nitrogen)(Total (Total coliform)

Test parameter Test 3

4 4

aeruginosa

Table 2: 2: Table laboratory The measured parameters, test methods,kits names, standards method pH EC conductivity) BOD oxygendemand) COD oxygendemand) TSS solids) NO TN PO TC E.coli coli) P. (Pseudomonas aeruginosa

6-3. Group discussion/interviews. For the social assessment and the cost-benefit analysis for the on-site wastewater treatment using constructed wetland, some meeting discussions and group discussions were conducted. The meeting discussions were conducted with the Royal Scientific Society (RSS) representatives as the authority who executed the project (Dr. Almoayied Assayed, Head of Division of Water Studies and Eng. Mohammed Mashatleh, member of water studies division). The meetings provided information about the hydrology situation in the study area, the systems' design criteria and the followed directive, a full insight about the operation and maintenance procedure for the systems under investigation, and the most severe mistakes in the construction stage that could affect on the performance of the systems. Two group discussions were carried out with the households of each system. The group discussions provided much information about the study area, the study area's social and economic situation, the health condition in the study area, and a clear view of previous and current situations before and after executing the on-site treating systems. Furthermore, the group discussions provided information about avoided expenditure by implementing the on-site treatment system. Details of the minutes of the group discussions could be found in Appendix (C). 6-4. Cost benefits analyses. To achieve the third aim of this study, which is the economic aspect of implementing a constructed wetland for on-site wastewater treatment, an analysis of a constructed wetlands cost- benefit has been conducted. It was supposed to conduct a full-scale cost-benefit analysis for the systems under evaluation; however, due to the Covid-19 pandemic, which led to the full lockdown for all Jordan activities within the study period, this was not feasible. Instead, and due to not much time available to conduct the site-specific survey, a direct cost-benefit analysis for implementing the constructed wetlands was done using a benefit transfer method. The benefit transfer method could be done using the ready-made data and information from other studies that had been carried out previously in other places relevant to Jordan and the context of the study regarding site topography, area, size, and population (Shamyan, 2011). In the cost-benefit analysis, the focus will be on the direct technical costs and direct monetary benefits of the systems under investigation. Even though some direct costs and benefits have no monetary value (e.g., avoiding odors and insects) and external costs and benefits (e.g., environmental and health improvements) will not be included in this analysis. The on-site wastewater treatment by a constructed wetland technology could be designed for a limited lifetime depending on the quantities of wastewater loading and the constructed wetland's contaminants' removal capacity. However, as long as a suitable design, proper monitoring, reasonable loading, and continuous maintenance are applied, a long-term service could be gained. Many observed long-term constructed wetlands show that these systems have the capability not too much loss of performance effectiveness for broken down pollutants such as BOD5, TSS, and nitrogen as long as the above parameters are applied. The performance might decrease over time for retained pollutants within the constructed wetlands such as phosphorus and metals. In this regard, periodically removing the sediments and replacing the media are solutions to achieve a longer-term service (Davis L., 1995). Therefore, 30 years of on-site wastewater treatment lifetime

was assumed for the systems under evaluation to analyze the cost-benefit.

Lienhoop et al. (2014) believe in their study that there is not enough data and records in Jordan about the illness incidents associated with wastewater borne (Lienhoop et al., 2014). The conducted group discussions confirmed this. The households stated that they do not have any history of a disease for the area, which is directly linked to the cesspool's problems. However, the households stated that they suffered the fall incidents of livestock in one of the cesspools at least once every two years. An incident like this has cost them a lot of money and effort renting a loader to get this livestock out beside the cost due to losing the cattle's life. According to all mentioned above, the cost components and monetary benefits were calculated as follows: 6-4-1. Significant cost components. Construction cost Both systems' tendering was in the same period. Sakib 1 system designed as a modified septic tank works with the attached growth technology. The construction cost for the system was 13400 JRD (1 JRD = 1.41 USD). Later on, the system was updated to a vertical flow constructed wetland besides using the modified septic tank as a pretreatment anaerobic septic tank with a cost of 7000 JRD. Regarding Sakib 2, the system is a recirculation vertical constructed wetland with construction's cost reaching 11900 JRD. A network/collection system constructed for both clusters with construction costs 9735 JRD for Sakib 1 and 6490 JRD for Sakib 2. Besides, the electrical and mechanical installation for each system was 1000 JRD. The contractor pricing table is shown in figure 14 in Appendix B. Administrative/consultancy cost Included the tendering, topographical survey, design, management, document printing, laboratory tests, arranging workshops, and transportation. The estimated administrative/consultancy cost for each system was 500 JRD. Operation cost The operating cost of both systems is represented solely by the amount of the monthly increase in electricity bills used by the pump to feed the wetland with the wastewater from the septic tank for the system's whole lifetime (30 years). For Sakib 1, the increment in electricity bills was 25 JRD monthly while the increment in electricity bills was around 7 JRD monthly in Sakib 2. Maintenance cost Included septic tank desludging and the replacement of the wetlands beds media to ensure the longer-term service. As aforementioned, the Sakib 1 system was updated to a vertical flow constructed wetland. The updating cost was 7000 JRD. The yearly laboratory tests cost 330 JRD. The septic tank desludging needs to be done every three years interval, and its cost 285 JRD per time and will be done for nine times in the remaining lifespan. The replacement of filtration media is estimated to be once every five years. The cost of 1 m3 of zeolitic volcanic tuff with transportation is 16 JRD. Therefore, Sakib 1 (38 m3)'s media replacement cost is 608 JRD, where it is 656 JRD for Sakib 2 (41 m3).

6-4-2. Significant monetary benefits. Avoided expenditure on cesspit pumping The households in each cluster paid monthly 60 JRD for cesspool pumping. This monthly expenditure is avoided for the whole lifetime of the system (30 years). Avoiding buying freshwater for irrigation The households in Sakib 2 depend on rainfall for irrigation, and they did not buy any additional freshwater. However, in Sakib 1, the households bought the irrigation freshwater in the summer season (five months/yearly), which costs them 50 JRD/time. This expenditure is avoided for the whole lifetime of the system (30 years). Avoided expenditure on cesspit incidents As mentioned before, the households stated in the groups' discussions that they were suffering from the fall incidents of livestock or passing animals in one of the cesspools at least once every two years. One incident cost them at least 300 JRD/time renting a loader from Sakib city to drive to their area to get this livestock out from the cesspool and the cost of the required maintenance to the cesspool. Avoided expenditure on building the replacement cesspits The continuous pumping of wastewater from the cesspool leaving the sedimented residuals makes the cesspool with less capacity over time, and a new cesspool construction will be needed. In such a rocky area, the excavation has to be done by a compressor that costs 100 JRD daily, and each cesspool needs 20 days to be excavated. An additional cost of 400 JRD/cesspool for the civil work. By this summation, each cesspool cost around 2400 JRD. The seven cesspools in Sakib 1 and the five cesspools in Sakib 2 will need to be replaced after around 15 years of operation. 6-5. Literature review. For finding the literature and references related to the subject of the study, some criteria were specified to search for it and get the most relevant reports and articles. The endeavor was to obtain literature dealing with on-site wastewater treatment and constructed wetlands from all over the world and not only in regions with the same conditions or are similar to the conditions of the study area. The keenness was to obtain the latest literature and scientific articles related to the field of study as far as possible by determining the tool in the research machine to be within the period from 2010 to 2020. Several keywords were relied upon during the search for literature and references such as on-site wastewater treatment, decentralized treatment, constructed wetland, nitrogen removal, phosphorus removal, and Jordan's wastewater. The search database used was Google Scholar and Springer Link. Websites with databases of scientific reports, academic journals, and e-books such as ScienceDirect, National Center for Biotechnology Information (NCBI), ResearchGate, and Academia were also used.

7. Results and discussion 7-1. the theoretical design parameter and actual loading conditions of the septic tanks and wetlands.

According to RSS’s previous measurements at construction period, the reported BOD5

concentrations for the collected wastewater in both Sakib 1 and Sakib 2 were 1207 and 1004 mg/l,

respectively. The TSS concentrations in septic tanks influent were 378 mg/l in Sakib 1 and 341 mg/l in Sakib 2. The volume of wastewater inflow to Sakib 1 system is 1500 l/day while it is 1008 l/day in Sakib 2. By using equation (1), the calculated actual PE were 50.3 mg/ capita day -1 in Sakib 1 and 41.8 mg/ capita day -1 in Sakib 2. Although the low water consumption by the householders in both clusters (42 l/person), the calculated actual PE was around the assumed practical value of PE (54 mg/capita). The calculated PEs prove the high organic matter in the wastewater. For assessing the septic tanks' adequacy, the sludge volume must be calculated to be added to the liquid inflow wastewater volume to the tank and compare them with the septic tank volume. By using equation (3), the daily produced sludge volume for both tanks was calculated to be 8.4 l/day in Sakib 1 and 5.6 l/day in Sakib 2 (Table 3). However, the septic tank acts as an anaerobic digester, and the sludge digestion rate depends on the ambient temperature and the desludging interval. Thus, equation (4) had been used to calculate the required sludge storage capacity in the septic tank by assuming five years desludging interval and the temperature between 10 – 20 oC (as it is the case in the study area). The estimated sludge volume for Sakib 1's tank was 7200 l, and for Sakib 2, it was 4800 l (Table 3). With adding the daily liquid inflow wastewater volume for each cluster to the calculated estimated sludge volume, the needed septic tanks' volumes will be 8700 l and 5808 l for Sakib 1 and Sakib 2, respectively. Sakib 1's septic tank total volume is 10.5 m3, and Sakib 2's septic tank total volume is 6.5 m3. By comparing the existing septic tanks' volumes with the required to occupy the daily inflow wastewater and the sludge with five years desludging interval, the implemented septic tanks in both systems are adequate for the design purposes. The HRTs were calculated for both tanks using equation (2) to be 7 days for Sakib 1 and 6.5 days for Sakib 2. The designed retention time for both tanks was three to four days, which is less than the calculated HRTs and no risk for shifting of the fermented hydrogen to methanogenic one. However, the short hydraulic retention times reducing the treatment processes in the septic tank due to the empty of the active microorganisms from the tank (David et al., 2019). Both septic tanks had been in service for five years. Thus, the actual HRTs need to be calculated considering the real available volume in each tank, which contains the accumulated sludge within these five years. The available volume in Sakib 1's tank is 3300 l, where it is 1700 l in Sakib 2's tank. Thus, and by using equation (2) again, the actual HRTs for the septic tanks in Sakib 1 and Sakib 2 are 2.2 days and 1.7 days, respectively, which are less than the designed HRTs in both systems (3 - 4 days). Regarding the wetlands, Sakib 1's wetland area is 40 m2, and Sakib 2's wetland area is 41.25 m2. By using equation (5), the calculated HLR for Sakib 1's and Sakib 2's wetlands were 37.50 l/day/m2 and 24.44 l/day/m2, respectively. These values are less than the maximum value of the HLR in wetland's design criteria (40-80 l/day/m2) (Ridderstolpe, 2004). The OLRs were calculated using equation (6) to be 19.3 g/day/m2 for Sakib 1's wetland and 2.08 g/day/m2 for Sakib 2's wetland. The maximum value of the OLR in wetland's design criteria (4-6 g/m2/day) (Ridderstolpe, 2004). The organic overloading rate in Sakib 1 could be handled with the intermittent dosing that will distribute this organic overload to several time intervals. Thus, the wetlands' area in both systems could be considered convenient and sufficient for the design goals. The continuous wastewater feeding operation in the constructed wetland is limiting the redox

conditions. While the intermittent feed operation with periodic flood and drain leads to the

subsurface aeration and enhances redox conditions (Meng et al., 2014). Nivala et al. (2013) see that by depending on smaller and more frequent doses in vertical constructed wetlands, improves the oxygen transfer through avoiding interim saturation of the bed medium and encourages the capillary flow in the media (Nivala et al., 2013). Furthermore, giving a chance to the wetland to percolate the whole water within its beds every once in a while, will enable the propagation of oxygen from the ambient air into the wetland's beds (Vymazal, 2010).

Table (3): The calculated theoretical design parameter and actual loading conditions of the septic tanks and wetlands people Sludge volume The required Hydraulic Actual hydraulic Wetland Wetland organic equivalents (l/day) sludge storage retention time retention time hydraulic loading rate (PE)* capacity for 5 (day) (day) loading rate (g/m2/day)*** mg/ capita day-1 years (l) (l/day/m2)**

Sakib 1 50.3 8.4 7200 7 2.2 37.5 19.3

Sakib 2 41.8 5.6 4800 6.5 1.7 24.44 2.08

* The assumed practical value of PE is 54 mg/capita. ** The maximum value of the hydraulic loading rate in wetland's design criteria is 40-80 l/day/m2 *** The maximum value of the organic loading rate in wetland's design criteria is 4-6 g/m2/day

7-2. The treatment performance of the septic tank.

The measured BOD5 concentrations in septic tanks effluent (wetland influents) were 515.5 mg/l in Sakib 1 and 85 mg/l in Sakib 2. While the measured TSS concentrations in septic tanks effluent (wetland influents) were 147 mg/l and 10 mg/l in Sakib 1 and Sakib 2, respectively. The low

measured BOD5 and TSS concentrations in Sakib 2's septic tank effluents were due to the recirculation in this system as the recirculated treated effluents mix with the influents in the dosing compartment in the septic tank. The pretreatment in the septic tank reached a removal

efficiency of 57% BOD5 and 61% TSS in Sakib 1. It was reported that in this pretreatment

process, a reduction in 5-day carbonaceous biochemical oxygen demand (CBOD5) by 49% and total suspended solids (TSS) by 74% could be achieved (Diaz-Elsayed et al., 2017). 7-3. The treatment performance of the wetlands. The pH of the wastewater in Sakib 1 wetland system was within 7.11-8.44 for influent and effluent. The EC was within 720-4200 µs/cm, and DO of 0.3 mg/L in the influent and 3.1-3.8 mg/L in the effluent (Table 4). Influent and effluent measurement in Sakib 2 wetland system showed a pH of 6.63-7.73, EC of 750-4900 µs/cm and DO of 5.31-6.78 mg/L (Table 5). The laboratory analyses and calculations are illustrated in the tables in Appendix (B). The results of the treatment performance of the wetlands will be presented by the solids and organic matter removal efficiency, the nutrient removal efficiency, and microbial removal efficiency. The laboratory test results in both Sakib 1 and Sakib 2 wetlands for all parameters under investigation are summarized in Table (4) and Table (5).

Table (4): Summary of the measured laboratory tests for the system in Sakib 1.

Wetland influent Wetland effluent

4/3/2020 5/3/2020 8/3/2020 12/3/2020 16/3/2020 17/3/2020 4/3/2020 5/3/2020 8/3/2020 12/3/2020 16/3/2020 17/3/2020 Temp. (C) 12 14.7 17 17.1 16.9 13.4 12 15.5 17 17.8 16 12.5 pH 7.3 7.34 7.24 7.11 7.3 8.44 8.36 7.06 7.09 7.53

EC (µs/cm) 1173 2240 4200 722 1503 3320

DO (mg/l) 0.3 0.29 3.12 3.82

TSS (mg/l) 0 130 164 0 20 2

COD (mg/l-O) 1239 1394 917 211 208 179

BOD (mg/l-O) 594 437 22 2

PO4 (mg/l-PO4) 59.58 92.66 62.02 37.96 40.34 59.3

NO3 (mg/l-NO3) < .23* 7.304 1.24 48.36 436.04 92.35

T-N (mg/l-N) > 100** 446 > 1000** > 100** 348 243 Total Coliform (MPN) > > > > 13566500 1073200 241960** 241960** 241960** 241960** E.coli (MPN) > > > > 11199000 54800 241960** 241960** 241960** 241960** Pseudomonas > 154670 238200 3100 aeruginosa (MPN) 241960** * Reading was under range. The lower limit of the test kit was taken as the maximum value. ** Reading was over range. The higher limit of the test kit was taken as the minimum value.

Table (5): Summary of the measured laboratory tests for the system in Sakib 2.

Wetland influent Wetland effluent

4/3/2020 8/3/2020 10/3/2020 16/3/2020 17/3/2020 4/3/2020 8/3/2020 10/3/2020 16/3/2020 17/3/2020 Temp. (C) 12 17 15 16.9 13.6 12 17 15.4 17.3 13.6

pH 7.21 7.73 7.27 6.78 6.63 6.79

EC (µs/cm) 869 4440 750 4910

DO (mg/l) 5.31 6.78

TSS (mg/l) 0 10 0 4

COD (mg/l-O) 422 330 209 < 100*

BOD (mg/l-O) 85 < 4*

PO4 (mg/l-PO4) > 60** 85.76 > 60** 69.62

NO3 (mg/l-NO3) > 155** 340.12 > 155** 558.14

T-N (mg/l-N) > 100** 290 > 100* < 200** Total Coliform (MPN) > > 1119900 < 1* 9800 7240 241960** 241960** E.coli (MPN) > 770100 < 1* 1613 6300 1700 241960** Pseudomonas 17550 1000 185 < 1* aeruginosa (MPN) * Reading was under range. The lower limit of the test kit was taken as the maximum value.

** Reading was over range. The higher limit of the test kit was taken as the minimum value.

7-3-1. Solids and organic matter.

The laboratory test results show that the percentage removal efficiency for BOD5 was 98% and

99% for the wetlands in Sakib 1 and Sakib 2, respectively. The average BOD5 in both wetlands' effluents' BOD5 (Table 4 and Table 5) complied with the Jordanian directive value of reclaimed water for both discharges into torrents, valleys, or bodies of water (60 mg/l-O) and reuse for irrigation (200 mg/l-O). For COD, the calculated percentage removal efficiency was 83% for Sakib 1 and 60% for Sakib 2. The effluents' COD values in both wetlands are under the Jordanian directive value of reclaimed water reuse for irrigation (500 mg/l-O). Both systems have effluents' COD values, which are slightly over the Jordanian directive value of reclaimed water discharges into torrents, valleys, or bodies of water (150 mg/l-O).

Much lower values for influent's BOD5 and COD concentrations were measured in Sakeb 2’s wetland than in Sakib 1’s wetland, as shown in (figures 6 A and B). The average value of influent's BOD5 was 515.5 mg/l O in Sakib 1, and 85 mg/l O in Sakib 2. The influent's COD measurements showed an average value of 1183 mg/l O in Sakib 1 and 376 mg/l O in Sakib 2. The influent's samples were taken from the pumping chamber in septic tanks for both systems. The pumping chamber in Sakib 2 is the chamber that receives effluent from the septic tank and effluent from the wetland that is recirculated (recirculation ratio 2:3). So, the recirculation in

Sakib 2 wetland contributes to shows lower values of influents' BOD5, COD, and TSS than the measured in Sakib 1. The TSS removal was 92.5% and 60% TSS in Sakib 1 and Sakib 2, respectively (figure 6 C). The recirculation in Sakib 2 might result in resuspension of solids from the pumping chamber and thus TSS removal efficiency is low. The EC removal was 14% in the Sakib 2 wetland, where the efficiency is double in the Sakib 1 wetland with 27% EC removal efficiency. It was supposed to measure the influent flow velocity within the wetlands' media. However, the lack of primary data of the flow within the bed media before the start of systems' operation and the lockdown in Jordan because of the Covid-19 pandemic made it impossible.

Removal of BOD5 (98%), COD (83%), and TSS (92.5%) achieved in Sakib 1 were comparable to

93% for BOD5 and COD removal efficiency reported by Nelson et al. (2008), 95% for BOD5,

84% for COD, and 90% for TSS reported by Sklarz et al. (2009) and 99% for BOD5, and 98% for TSS removal efficiency besides increasing DO concentration from 1.8 to 4.3 mg/L reported by

García-Pérez et al. (2009).

Figure (6): The average concentration of (A) biochemical oxygen demand BOD5, (B) chemical oxygen demand

COD, and (C) total suspended solids TSS in the influent and effluent of wetlands in Sakib 1 and Sakib 2.

7-3-2. Nutrients. The results showed an increase in the effluent's nitrate concentration compared to the influent's nitrate concentration which indicates an effective nitrification process (Figure 7A). The average nitrate concentration in Sakib 1 increased from 0.74 mg/l-NO3 in influent to 70 mg/l-NO3 in the effluent. Similarly, the average nitrate concentration in Sakib 2 increased from 340 mg/l-NO3 in influent to 558 mg/l-NO3 in the effluent. Regardless of the high nitrate concentrations in Sakib 2, both systems show an apparent potential for nitrification processes. However, the Jordanian directive values of reclaimed water regarding the allowed nitrate concentration for discharges into torrents, valleys, or water bodies and reuse for irrigation are limited to 80 and 45 mg/l-NO3, respectively. The high nitrate concentration in Sakib 2's influent was due to the system's recirculation, i.e., the influent contains the treated effluent which already had exposed to nitrification processes. The pH values in both systems influent and effluent during the assessment were between 6.5-8.5. This pH value could be considered ideal for both nitrification and denitrification. In constructed wetlands, the temperature range of 28–36 °C is the most favorable for nitrification activity, and this activity will be restrained when the temperature drops to 10 °C. The increase in temperature up to 60 °C enhances the denitrification activity. No detection for denitrification if the temperature is less than 5 °C (Meng et al., 2014) due to the decreasing of bacterial activity at the lower temperatures (Leverenz et al., 2010). Regarding total nitrogen removal efficiency (Figure 7B), unfortunately, the effluent's TN concentration in Sakib 2 was not quantified due to using a high range test reagent in the laboratory test and the opportunity to redo the test with dilution was not available due to the lockdown in Jordan because of the Covid-19. However, using the lower range of the test reagent as the effluent TN concentration, a minimum total nitrogen removal efficiency of 31% will be achieved, and most likely could be more. The TN removal efficiency calculated for the Sakib 1 system was less than in Sakib 2, 22%. The recirculation of the effluent in Sakib 2 caused better denitrification processes as what reported by Leverenz et al. (2010) that the recirculation of the effluent to the septic tanks improves the denitrification nevertheless a maximum nitrogen removal rates of 50- 60% could be achieved (Leverenz et al., 2010). It is worth noting that if the recirculation in the Sakib 2's wetland was to the collection chamber in the septic tank instead of the pumping chamber may lead to more anaerobic conditions and thus higher total nitrogen removal efficiency. It has been reported that vertical constructed wetlands have high nitrification activities but not denitrification (Ye & Li, 2009; Vymazal, 2010). The reported TN removal efficiencies were 43% (Nelson et al. 2008; Vymazal, 2010), and 54.74% (Xiong et al., 2011). Moreover, it was reported by Hang et al. (2016) that the average nitrate removal of VFCW is 31% (Hang et al., 2016). For improving the denitrification processes in both systems, an additional carbon source will be required (Ye F. & Li Y., 2009; Xiong et al., 2011). The regeneration/regrowth of nitrifying bacteria can be encouraged by increasing the organic concentration and nutrients in the systems (Wu et al., 2016). Sufficient denitrification processes require a ratio of 4:5 nitrate to carbon (Baker, 1998). The systems in Sakib 1 and 2 had a low capacity of denitrification. One factor could be that the zeolite contains no extra carbon to be used by the denitrifying bacteria. To enhance the system's performance in nitrogen removal a source of carbon can be added. An enhanced nitrate and nitrite removal efficiency was observed with a higher C/N ratio in the media of the constructed wetland.

When the influent's COD/N ratio is low, or the present COD in the influent has been consumed

during the nitrification processes, an additional external carbon source is needed to comply with denitrification steps (Fernández-Nava et al., 2010). Hang et al. (2016) show in their study that the nitrate removal efficiency of VFCW under investigation was 31% while with adding an external carbon source, the nitrate removal efficiency increased to 84% (Hang et al., 2016). Leverenz et al. (2010) believe that woodchips are an efficacious source for carbon to be added to the media of constructed wetlands. Its availability with a much cheaper cost than the gravel makes it an economically applicable substitutional media in subsurface flow constructed wetlands (Leverenz et al., 2010). The observed improvement in effluent's nitrate concentrations in the woodchip wetlands reached 99.7% (Ibid) and 99% (Saliling et al., 2007) nitrate removal efficiency. However, a loss of woodchips mass could be noticed within time. Saliling et al. (2007) show that a loss of 16.2% of woodchips masses recorded after an operation period of 140 days. Thus, when it is determined to add woodchips to the constructed wetland's media for biological denitrification, the lifetime limitation of woodchips must be considered (Saliling et al., 2007). The phosphorus removal efficiency was 36% and 19% for Sakib 1 and Sakib 2, respectively

(Figure 7C). The average phosphorus concentration in Sakib 1 effluent was 46 (mg/l-PO4), while the value in Sakib 2 was 70 (mg/l-PO4). Both systems do not comply with the Jordanian directive values of reclaimed water for both discharges into torrents, valleys, or water bodies (15 mg/l-PO4) and reuse for irrigation (30 mg/l-PO4) concerning phosphorus removal efficiency. Notable to mention that the carried-out tests were in March at temperatures between 12 and 18 °C. The removal efficiency of phosphorus by microbial uptake and biomass accumulation in the constructed wetlands is improving in the summer and autumn seasons with increased temperatures (Wen et al., 2011; Dzakpasu et al., 2015). Recirculation in wetlands enhances the phosphorus removal as it exposes the effluent to more adsorption in the wetland media. Sakib 2 system is a recirculation system, and so, it is supposed to provide a better phosphorus removal efficiency than the non-recirculation system in Sakib 1. However, the long-term operation (more than four years) could be the reason for the lower phosphorus removal as the media might already satiate with returned phosphorus, causing a sharp decline in phosphorus removal efficiency (Dzakpasu et al., 2015). Previous studies reported that the vertical constructed wetlands usually have a relatively low phosphorus removal efficiency, and it is rare that a wetland is designed and implemented with a phosphorus removal as a primary target (Vymazal, 2010; Stefanakis & Tsihrintzis, 2012). The reported phosphorus removal efficiencies were 56% (Vymazal, 2010), 50% (Nelson et al. 2008), 33% (García-Pérez et al., 2009), and 33.3% (Stefanakis and Tsihrintzis, 2012). García-Pérez et al. (2009) believe that the low phosphorus removal efficiency in vertical constructed wetlands is due to the short flowing distance and retention time (García-Pérez et al., 2009). Lan et al. (2018) show that the wetland media could contribute phosphorus removal to 87.5% of influent's phosphorus input while the contribution from the plants' uptake and the microbial activities reaches about 26.4% (Lan et al., 2018). According to that, using special porous media or high sorption capacity media for the wetland is a proposed solution to enhance phosphorus retention. Adding a filter unit for further effluent treatment is another proposal (Vymazal, 2010; Stefanakis and Tsihrintzis, 2012). Besides, use plants that need phosphorus in significant amounts

for average growth, and harvesting them is an option as well (García-Pérez et al., 2009).

Planting in constructed wetlands is a way to improve treatment efficiency. The presence of plants in the constructed wetlands enhance the microbial density, activity, and diversity (Meng et al., 2014) as the region of soil in the vicinity of plant roots provides a larger surface area and medium for attached microbial growth (Xiong et al., 2011). Besides, the plantation in constructed wetlands works on producing the O2 and reserving the carbon through the increase in plant biomass (Xiong et al., 2011). In the long term, a possibility that plants give a share in a supplementary carbon source to the system as a result of plant decay (Leverenz et al., 2010). Attention must take place about planted wetlands that, if the plantation is not harvested, a return for the nutrients to the water from plant tissues will occur due to the decomposition processes (Ye F. & Li Y., 2009). About the average removal rates of total phosphorus (TP), Wen et al. (2011) show in their study a comparison between planted and unplanted hybrid constructed wetlands. The results were that the planted constructed wetlands reached a TP removal rate between 93.4% and 98.3% during the year. On the other hand, the TP removal rates for the unplanted hybrid constructed wetlands were between 91.6% and 96.6%. Thus, the planted constructed wetlands may produce better effluent regarding phosphorus removal (Wen et al., 2011). Ye F. & Li Y. (2009) clarified in their study that the planted constructed wetlands have potential better nitrification processes by reducing the bed medium's anaerobic condition. Plants transport

O2 to the continuously water-saturated bed medium and create aerobic microsites that work in nitrification processes (Ye F. & Li Y., 2009). However, in the long term, a reduction in nitrogen removal in planted constructed wetlands has been reported probably as a result of plant aging, causing the nitrogen release to the system (Stefanakis et al., 2009). Adding an extra aerobic filter behind the secondary treatment processes (constructed wetland) improves the removal of many organic wastewater contaminants (Conn et al., 2006). Zeolite is a hydrated aluminum-silicate mineral where the aluminum and silicon polyhedra are joined by the involvement of oxygen atoms (Vohla et al., 2011). Zeolites count as a microporous material. The zeolites have microporous voids smaller than 2 nm, super microporous between 0.7–2 nm, and ultra-microporous, which is smaller than 0.7 nm. By this feature, natural zeolites are adequate for gathering microorganisms, taking off ammonia nitrogen from liquids, and purifying gases (Stefanakis and Tsihrintzis, 2012). The narrow pore-size distributions in the crystalline zeolites are what distinguish zeolites. In addition to its low cost, cation exchange capacity, high strength in high temperatures, and its neutral chemical structure. All mentioned, makes zeolites applicable for adsorption of gases, odor control, water filtering, and more applications (Stefanakis et al., 2009; Stefanakis and Tsihrintzis, 2012). Noteworthy, Jordan has an estimated 2% of the zeolite in the world (Woodford C., 2019). The use of zeolite as substrates within constructed wetland systems does not significantly improve nitrogen and phosphorus removal rates. Even though one promising alternative has been presented in some studies, zeolite is used in a filtration unit with one-day retention as a final treatment stage to improve the quality of wetland's effluent (Stefanakis and Tsihrintzis, 2012). Stefanakis et al. (2009) stated that by adding the zeolite-filters to the wetland outlet, a better effluent quality would be gained. The results achieved were higher removal rates of effluents'

BOD5 (60.6% - 63.2%), COD (52.5% -62.0%), TKN (75.1% -83.2%), NH4+ -N (78.3% -85.8%), and total phosphorus (40.5% - 56.8%) when compared with wetland's effluent without attached the zeolite-filters to the outlet (Stefanakis et al., 2009). At higher temperatures, the higher removal

rates were observed (Stefanakis et al., 2009; Stefanakis and Tsihrintzis, 2012). Stefanakis et al.

(2009) result also illustrates that fine-grained zeolite showed better functional than coarse-grained zeolite for organic matter and nitrogen removal. Conversely, the coarse-grained zeolite has a higher ability to retain phosphorus (Stefanakis et al., 2009). The results achieved in Stefanakis and Tsihrintzis (2012) came to confirm the previous study. The overall performance of the system VFCW in addition to the zeolite-filters attached to the wetland's outlet achieved BOD5 removal (95.1% - 96.3%), COD removal (93.3% - 95.0%), and NH4+ -N removal (78.0% - 83.3%) (Stefanakis and Tsihrintzis, 2012).

Figure (7): The average concentration of (A) nitrate NO3, (B) total nitrogen TN, and (C) phosphorous PO4 in the influent and effluent of wetlands in Sakib 1 and Sakib 2.

7-3-3. Microbial tests. The quantification of bacterial pathogens for the two systems under assessment was a kind of challenge during the study. The continuous rainfall with variable rain intensities during the study period was an obstacle as it causes fluctuations in the quantities of TC, E.coli, and Pseudomonas aeruginosa for both systems. Carroll et al. (2005) report that the rainfall causes an increase in FC and E. coli (Carroll et al., 2005). The microbial laboratory tests showed a low pathogen removal efficiency in the Sakib 1 system. Although the TC and E. coli removal efficiencies for Sakib 1 not been precisely quantified, considering the upper MPN value of IDEXX reagent as the amount of E.coli in the influent, a result of minimum 0.5 log10 removal efficiency for E.coli for this system will be calculated. The bacterial contamination for Sakib 1 effluent were around 1.0×106 MPN/100mL for TC and around 5.5×104 MPN/100mL for E. coli. The Jordanian directive values of reclaimed water for discharges or reuse for irrigation state an allowed value of 1000 MPN/100mL E.coli. That could be due to the installing of uncleaned zeolitic volcanic tuff in the wetland filter bed besides installing the bed layers on a rainy day (Mashatleh M., 2020). Regarding Pseudomonas aeruginosa, Sakib 1 system has a 2 log10 removal as the Pseudomonas aeruginosa for Sakib 1 effluent reduced to around 3 ×103 from 24×104 MPN/100mL in the influent. Likewise, the results of the microbial laboratory tests for pathogen removal efficiency in the Sakib 2 system were 3 log10, 2 log10, and 1 log10 for TC, E.coli, and Pseudomonas aeruginosa, respectively. The effluent of Sakib 2 measured 9,8×102 MPN/100mL for TC, 6,3×102 MPN/100mL for E.coli, and 1,85×102 MPN/100mL for Pseudomonas aeruginosa. Even if this system is a recirculation wetland, this did not influence the removal of the indicator bacteria (Wu et al., 2016). The Pseudomonas aeruginosa bacteria contribute to the removal of nitrates and nitrites at the on-site wastewater treatment systems as the Pseudomonas aeruginosa bacteria are facultative anaerobe which uses oxygen from nitrates and nitrites for surviving, in the absence of free oxygen (O2) (Xu et al., 2017). The low quantity of Pseudomonas aeruginosa in the Sakib 2 system could indicate the anaerobic condition in the system. The TSS removal efficiency is also

an essential factor as the particulate matter could protect fecal indicator bacteria from disinfection

(Wu et al., 2016). Noteworthy, the TSS removal efficiency for Sakib 2 was just 60%. Figure (8) shows the average E.coli measurements for both systems' influent and effluent. During the microbial tests, significant fluctuation in quantifying the bacterial indicators in both systems. This fluctuation could be due to the might regrowth pathogens within the wetlands' media. The temperature, solar intensity, and water composition are factoring that regrowth of pathogens in the constructed wetlands immensely depend on (Wu et al., 2016). Adding an extra aerobic filter behind the secondary treatment processes (constructed wetland) could act as a disinfection media for pathogens in the treated effluent (Al-Turk E., 2016). Using rock clay minerals (Natural Nanoparticles) in the wetland outlet as a final filter for the treated effluent has potential benefits for pathogen disinfection. The results achieved by Al-Turk E. (2016) study of using solar radiation and clay minerals for wastewater disinfection were that a concentration of 0.1% clay minerals (weight: volume) gained the best results for wastewater disinfection with and without solar radiations. The TC disinfection efficiency without solar radiation was 19.3% after 3 hours. With solar radiation, the TC disinfection efficiency was 99.9% under the same period. For E.coli, the disinfection efficiency after 3 hours of exposure was 47.9% and 100% without and with solar radiation, respectively. Notable is the 100% E.coli disinfection efficiency with solar radiation achieved after just 2 hours. Finally, and regarding P. aeruginosa, the disinfection efficiency after 2-4 hours of exposure was 63.8% and 99.9% without and with solar radiation, respectively (Al- Turk E., 2016). It is needed to mention that the percent of 0.1% rock clay mineral concentration was the largest value used throughout the study. The plan was to carry out one experiment as a continuity for the study mentioned above. The plan was to measure the effects of adding more clay concentrations (0.2%, 0.5%, and 1.0%) on time required for wastewater disinfection. However, the full lockdown in Jordan due to the Covid-19 pandemic made no opportunity for this to be done.

Figure (8): The E.coli average measurements for both systems' influent and effluent.

7-4. Social acceptance. Implementing shared system like constructed wetlands for on-site wastewater treatment faces a challenge with regard to societal acceptance due a number of issues related to (i) land tenure and ownership, especially when the wetlands users are not relatives. The land designated for constructing the on-site treatment system is usually privately owned, and hence societal nonacceptance for sharing the systems creates among the residents (Mashatleh M.,2020). (ii) Effects of land value, i.e., landowner and the adjacent landowners incorrectly believed that such systems affect the future value of the lands in the region due to the problems of odors emitted from operating the systems. (iii) Environmental disturbance, i.e., the people believe these systems might attract insects and rodents that may, in turn, attract some reptiles such as snakes, some predatory such as hyenas, and vandalized animals such as wild boars that are widely available in the Jordanian countryside. Before implementing the two systems under study, landowners reported that they were reluctant about the system's implementation on their land. This resistance lasted for a short time. Afterward, RSS hold keen and constant awareness workshops targeting landowners and beneficiary families. The awareness aimed at explaining the operating mechanism and benefits they would gain to their health and community. Besides, arranging some visits to the sites of on-site wastewater treatment systems that were implemented previously to demonstrate such systems' success achieved the desired goals. As a result, they agreed to implement these systems. Ensuring the arrangement of workshops for all stakeholders that transparently clarify all operational aspects and illustrate societal, health, and economic gains from such projects is a fundamental criterion for any project not just to obtain the beneficiaries' acceptance. But also, the stakeholders' quest for its success. The educational workshops for beneficiaries of on-site wastewater treatment systems contribute significantly and effectively to developing public awareness and knowledge and help them to carry out simple operation and maintenance tasks directly by them. Public education considered the first step in the path of proper operation and maintenance (Moelants et al., 2008). According to (Assayed M., 2020), one of the essential criteria for the successful implementation of such systems is the continuous presence and understanding of the represented and responsible person for operating and maintaining the system. The ease of access to the person who benefits from the system constantly besides his interest in implementing the operational instructions, and doing the needed maintenance prevents the system failure. RSS had a few failed experiences in the operation of on-site treatment systems that were implemented previously. The main reason for that was the inability to reach the benefiting person from the system or his lack of interest in reporting to RSS's management about any problems or malfunctions (Assayed M., 2020). Despite the increment in the monthly cost in electricity bills and the individuals' effort to operate and maintain the on-site treatment systems, all families in both clusters agreed that the current situation was much better than the previous situation. The getting rid of thinking about the necessity of pumping-out the cesspool at least once a month and avoiding the unpleasant odors they were suffering when cesspool overflow. Moreover, the day the cesspool was sucked out, they had a definite impact on their health and economics as that saved them a great effort, cost, and time they were spending in finding the suction truck. Households acknowledge their increased sense of safety, and they no longer need to fear

cesspools whose presence previously posed a threat to their children and their livestock. Besides,

they avoided the presence and spread of insects and reptiles in the area around and inside their homes, where they currently gather mainly on the wetland's surface, which has become a suitable environment for them to live. Currently, reptiles feed on insects. Likewise, birds feed on reptiles. Otherwise, killing and getting rid of them by households becomes easier. Furthermore, the existence of birds around the wetland to feed on insects and reptiles and drink water adds to the place a beautiful view and makes it a place of more excellent value to the population psychologically. The landowners expressed remorse for the time lost during their reluctance to implement these systems in the beginning due to their incorrect belief in some of the cons that may come as a result of implementing the systems. It became clear to them later that the reality is precisely the opposite.

7-5. Cost-benefit analysis (CBA). The obtained results from the conducted CBA showed a total cost for implementing an on-site wastewater treatment consists of septic tank followed by a constructed wetland of 46240 JRD for Sakib 1 (1280 JRD/person) and 28255 JDR for Sakib 2 (1180 JRD/person). The most costly component in the cost analysis was the construction cost. Sakib 1 system had an additional cost due to the upgrading of the system from the modified septic tank to septic tank followed by a constructed wetland which was 7000 JRD. The benefit analysis showed a total benefit of 50400 in Sakib 1 system (1400 JRD/person) where it was 38100 JRD in Sakib 2 (1590 JRD/person). The most benefits gained as avoided expenditure were the expenditure on cesspit pumping and the expenditure on building the replacement cesspits. Tables (6) and (7) summarizes all the significant cost components, all the significant monetary benefits and related calculations. Table (6): Calculations of significant cost components.

Sakib 1 Sakib 2 Cost measure Cost per unit Total cost Cost per unit Total cost (JRD) (JRD) (JRD) (JRD)

System construction 13400 + 13400 + 11900 11900 including upgrading 7000 7000

Construction Network/collection 9735 9735 6490 6490 cost system

Electrical/mechanical 1000 1000 1000 1000 installation

Administrative/consultancy cost 500 500 500 500

Operation cost (12months.30years) 25 9000 7 2520

Septic tank desludging 285 2565 285 2565 (every three years) Maintenance cost Media replacement 608 3040 656 3280 (once/5 years)

Total cost 46240 28255

Table (7): Calculations of significant monetary benefits.

Sakib 1 Sakib 2 Benefit measure Cost per Total cost Cost per Total cost unit (JRD) (JRD) unit (JRD) (JRD)

Avoided expenditure on cesspit pumping (12 months/30years) 60 21600 60 21600

Avoiding buying fresh water for irrigation (5 months/30years) 50 7500 0 0

Avoided expenditure on cesspit incidents (Every two years) 300 4500 300 4500

Avoided expenditure on building the replacement cesspits (once after 15 years) 2400 16800 2400 12000

Total cost 50400 38100

It should be pointed out that other costs such environmental cost and aesthetic benefits were not included in this cost-benefit analysis despite that these benefits were acknowledged by the families. Such benefits include ● The avoided odors from cesspools: The odors generated from the constructed wetland operation are neglectable compared to the situation before implementing it. ● Avoided infiltration to the groundwater: The water infiltrates from the cesspools, causing the contamination to the groundwater and nearby surface water. ● Avoiding the costs of mosquitoes, insects: The system's implementation helped to significantly reduce the spread of mosquitoes and insects in the cluster and even restricted their presence to the surface of wetlands. ● Avoiding the property damage: The continuous overflow of the cesspool could cause potential damages around the property. For example, destroying the cultivated areas and affecting the foundations of the house. ● The added value from additional agricultural production: The treated water provides an additional water source for irrigation, especially in (Sakib 2)'s cluster as they were previously dependent on the rainfall to irrigate their trees. ● Expanding the area under cultivation: Group discussion in Sakib 1 revealed that if useful and adequate treated water becomes available, they desire to expand the cultivated areas and use this water in the best way. Moreover, if the amount of this water increases, they are ready to transfer this water to irrigate other farms that belong to them. ● Better landscape aesthetics and more recreational benefits for society: By expanding the cultivated areas and increasing green spaces, more recreation areas will be created with better landscape aesthetics. ● The increase in property value: The amended sewer situation in the village could potentially increase property value. However, this feature depends on if the whole village

benefits from the improved sewer situation (Lienhoop et al., 2014).

● Increase the public participation and trust: Sharing the households in decision-making, construction, operation, and maintenance of the systems develops a sense of responsibility and concern and increases public trust in public services. By just considering the direct monetary benefits in the cost-benefit analysis, the analysis does not clearly illustrate how the households in both Sakib 1 and Sakib 2 clusters benefited from the implementation of the on-site wastewater treatment systems. However, the other monetary and non-monetary benefits will add value to the system strategy. The Sakib 1 system upgrade raised the cost of this system. However, and by considering all benefits, the system remains beneficial and valuable.

8. Conclusion The study provided an assessment of design, technical performance, social acceptance, and cost- benefit analysis for two constructed wetlands as on-site wastewater treatment systems implemented in the Sakib area - Jerash Governorate, Jordan. Benefits represented in reducing the environmental burdens caused by the presence of cesspools and providing a new source of water for reuse in irrigation that will improve agricultural production. The theoretical design parameter and actual loading conditions of the septic tanks and wetlands in both systems were checked. The calculated values showed that both the septic tanks and the wetlands implemented in the two systems are adequate and appropriate for the design goals. However, as both septic tanks were in service for five years, the immediate septic tanks' desludging is recommended. Furthermore, for enhancing the pretreatment in the septic tanks, it is preferred to prolong the short hydraulic retention time in both tanks to prevent empty of the active microorganisms from the tanks. The carried-out laboratory tests showed an acceptable removal efficiency for both systems regarding organic matters and suspended solids. Similar to previous studies about the constructed wetlands, the two systems under assessment have low nutrient removal efficiency. Although the recirculation system in Sakib 2 showed better results in denitrification processes, this system still, in general, has a lower nutrients' removal efficiency than the new system in Sakib 1. Regarding the microbial tests, the two constructed wetlands could have a potential capacity for pathogen removal. However, the values of indicator bacteria's MPN for the treated wastewater in both systems was very high in particular TC and E.coli. The wetland overfeeding during operation, low water consumption in both clusters, and the massive regrowth of the microbial community within the wetland's bed contribute substantially to this increment. For the treatment performance enhancement of the two constructed wetlands on Sakib, the following were suggested: - The septic tanks in both systems need to be desludging immediately with keeping the desludging interval to be three years maximum in the future. Furthermore, the pump in the septic tanks dosing compartment needs to readjust to elongate the dosing interval and increase the hydraulic retention times in the septic tanks. - The expected semi-full saturation of retained phosphorus associated with the long-term operation makes the media in Sakib 2 need to be replaced with new zeolitic tuff media to be more porous and have higher sorption for better phosphorus removal efficiency. - The plantation or adding woodchips to Sakib 1's media as an additional carbon source to

the wetland to enhance the nitrification and denitrification processes.

- An additional filtration unit of clay minerals or zeolite to each wetland outlet to improve pathogen removal and nutrient removal efficiencies. Concerning the aspect of social assessment, the results of this study demonstrated that misconceptions and lack of understanding about the on-site wastewater treatment systems could be contained, and concepts could be corrected through educational workshops. The educational workshops provide clear information about the systems and increase awareness about their operating and maintenance instructions. The cost-benefit analysis's results showed that the implementation of a constructed wetland as an on-site wastewater treatment system is a beneficial and valuable alternative for clusters in rural areas and even in newly urbanized plans. This outcome would be reinforced by considering the direct monetary benefits and both the indirect monetary and non-monetary benefits. A further full- scale cost-benefit analysis for a constructed wetland as an on-site wastewater treatment system needs to be done to add a robust base to convince the donors and authorities to support and expand the project in Jordan. 9. Uncertainties During the laboratory tests, it is unattainable to eliminate errors and uncertainties. Instead, the reduction through a careful selection of parameters and ensuring the experimental settings. According to each test procedure, the required temperature and pH parameters limits ranges were determined and achieved to obtain the most accurate and comparable values. It was planned to carry out several tests for each measurement for both systems within six weeks to avoid errors and inconsistencies in the results. Moreover, to study the effects of gradual temperature increasing on the efficiency and performance of the systems. However, the situation with the Covid-19 prevented that. The lack of time was the reason to force the author to do several samplings and tests within a brief period. Moreover, during the spring semester, the timing of this period, with very high fluctuation in temperature, could lead to unrepresentative results for system performance. Furthermore, the lack of data and laboratory tests history for the systems' performance led to the late realization of the required dilution factors for tested samples to become measurable within the test reagents range. Bias while conducting the group discussion may be present. It was supposed to do each group discussion with all households of the cluster. However, in Sakib 1, only the landlord and two households were in the group discussion. While in Sakib 2, only the landlord and one of the households were in the group discussion. Furthermore, most answers were just from the landlords in both group discussions. 10. Future scope The subject of this thesis is of value to all developing countries, whose population represents approximately 82% of the world population (World Population Review, 2019). These countries lack the financial capacity to finance centralized wastewater treatment systems. Therefore, most parts of these countries rely on decentralized wastewater treatment systems. Likewise, other countries in the world still depend on on-site wastewater treatment systems in parts of it, mainly

rural areas and areas that do not have a high population density or sporadic dwelling houses.

For full coverage achievement of all the topics mentioned in this study, further investigations are required to be done regarding the capacity of the clay minerals for wastewater disinfection and the optimum concentration for this usage. Furthermore, determining the best type from the several Jordanian volcanic tuffs available, which have the better capability and the higher porosity to be

used in constructed wetlands, need to carry out more investigations and laboratory tests.

11. References

9223 Enzyme substrate coliform test. (2017). Standard Methods For the Examination of Water and Wastewater, 23rd. Published [online], Accessed 17 March 2020 .

Al Dwairi, R., Saqarat, B., Shaqour, F., and Sarireh, M., 2018. Characterization of Jordanian Volcanic Tuff and its Potential Use as Lightweight Aggregate. Jordan Journal of Earth and Environmental Sciences, 9(2), pp. 127 – 133.

Alshoubaki, W.E. and Harris, M., 2017. The impact of Syrian refugees on Jordan: A framework for analysis. Journal of International Studies, 11(2), pp. 154-179.

Al-Turk, E. A. H., 2016. Water Disinfection by Solar Energy, Degree of Master in Climate Change and Arid Land Sustainability. Deanship of Scientific Research and Graduate Studies, Hashemite University. Zarqa - Jordan.

Assayed Moayied, 2020. Head of Division of Water Studies, Royal Scientific Society. Personal meeting discussion conducted on 2nd March 2020.

Baker, L.A., 1998. Design considerations and applications for wetland treatment of high-nitrate waters. Water Science and Technology, 38(1), pp.389-395.

Bradley, B.R., Daigger, G.T., Rubin, R. and Tchobanoglous, G., 2002. Evaluation of onsite wastewater treatment technologies using sustainable development criteria. Clean Technologies and Environmental Policy, 4(2), pp.87-99.

Brake, P., 1998. Biochemical Oxygen Demand (BOD) and Carbonaceous BOD (CBOD) in Water and Wastewater. WA State Department of Ecology, Publication, (98-307), pp.28.

Carroll, S., Hargreaves, M. and Goonetilleke, A., 2005. Sourcing faecal pollution from onsite wastewater treatment systems in surface waters using antibiotic resistance analysis. Journal of Applied Microbiology, 99(3), pp.471-482.

Centers for Disease Control and Prevention (CDC), 2018. Pseudomonas aeruginosa in healthcare settings. HAI/CDC [online] accessed 22 March 2020 .

Climate-data.org, ND. Jerash Climate (Jordan). [online] Accessed 23 April 2020 .

Conn, K.E., Barber, L.B., Brown, G.K. and Siegrist, R.L., 2006. Occurrence and fate of organic contaminants during onsite wastewater treatment. Environmental science & technology, 40(23), pp.7358-7366.

David, B., Federico, B., Cristina, C., Marco, G., Federico, M. and Paolo, P., 2019. Biohythane Production from Food Wastes. In Biohydrogen (pp. 347-368). Elsevier.

Davis, L., 1995. A handbook of constructed wetlands: A guide to creating wetlands for: agricultural wastewater, domestic wastewater, coal mine drainage, stormwater. In the Mid-Atlantic Region.

Volume 1: General considerations. USDA-Natural Resources Conservation Service.

Diaz-Elsayed, N., Xu, X., Balaguer-Barbosa, M. and Zhang, Q., 2017. An evaluation of the sustainability of onsite wastewater treatment systems for nutrient management. Water research, 121, pp.186-196.

Dzakpasu, M., Scholz, M., McCarthy, V. and Jordan, S.N., 2015. Assessment of long-term phosphorus retention in an integrated constructed wetland treating domestic wastewater. Environmental Science and Pollution Research, 22(1), pp.305-313.

Environmental, F., 2014. Conductivity, salinity and total dissolved solids: fundamentals of environmental measurements. [online] accessed 22 March 2020 .

Extension, (ND). Water quality. Nutrients in Water, Utah State University, [online] Accessed 18 March 2020 .

Fernández-Nava, Y., Marañón, E., Soons, J. and Castrillón, L., 2010. Denitrification of high nitrate concentration wastewater using alternative carbon sources. Journal of Hazardous Materials, 173(1-3), pp.682-688.

Franceys, R., Pickford, J., Reed, R. and World Health Organization, 1992. A guide to the development of on-site sanitation. World Health Organization, pp.66.

Garcia-Perez, A., Harrison, M. and Grant, B., 2009. Recirculating vertical flow constructed wetland: green alternative to treating both human and animal sewage. Journal of Environmental Health, 72(4), pp.17-21.

Geology Science, 2020. Tuff. Geology Science [online] Accessed 7 April 2020 .

Gray, N.F., 1995. The influence of sludge accumulation rate on septic tank design. Environmental technology, 16(8), pp.795-800.

Hach, 2014. Oxygen Demand. Chemical-Reactor Digestion COD Method 8000 ULR, LR, HR, HR plus+. [online] Accessed 12 March 2020 .

Hach, 2016. Phosphorus. Reactive (Orthophosphate) Method 10209 and Total Phosphorus Method 10210, UHR Ascorbic Acid Method using TNTplus™ 845. [online] Accessed 12 March 2020 .

Hach, 2018. Nitrogen, Total, Persulfate Digestion UHR Method 10208, Spectrophotometer, TNTplus™ 828. [online] Accessed 12 March 2020 .

Hach, 2020. Nitrate, Dimethylphenol HR Method 10206, Spectrophotometer, TNTplus™ 836. [online] Accessed 12 March 2020 .

Hang, Q., Wang, H., Chu, Z., Ye, B., Li, C. and Hou, Z., 2016. Application of plant carbon source for denitrification by constructed wetland and bioreactor: review of recent

development. Environmental Science and Pollution Research, 23(9), pp.8260-8274.

Iasur-Kruh, L., Hadar, Y., Milstein, D., Gasith, A. and Minz, D., 2010. Microbial population and activity in wetland microcosms constructed for improving treated municipal wastewater. Microbial ecology, 59(4), pp.700-709.

IDEXX, 2017. Pseudalert. 24-hour detection of Pseudomonas aeruginosa. [online] Accessed 16 March 2020 .

Khan, S. and Ali, J., 2018. Chemical analysis of air and water. In Bioassays (pp. 21-39). Elsevier.

Lan, W., Zhang, J., Hu, Z., Ji, M., Zhang, X., Zhang, J., Li, F. and Yao, G., 2018. Phosphorus removal enhancement of magnesium modified constructed wetland microcosm and its mechanism study. Chemical Engineering Journal, 335, pp.209-214.

Leverenz, H.L., Haunschild, K., Hopes, G., Tchobanoglous, G. and Darby, J.L., 2010. Anoxic treatment wetlands for denitrification. Ecological Engineering, 36(11), pp.1544-1551.

Lienhoop, N., Cardona, J., Salman, A. and Karablieh, E., 2012. Cost Benefit Analysis of decentralised wastewater treatment and re-use in Jordan: An application in Maghareeb and Ma’addi. Work package 7, Deliverables D701 and D704, The German Federal Ministry of Education and Research (BMBF).

Lienhoop, N., Al-Karablieh, E.K., Salman, A.Z. and Cardona, J.A., 2014. Environmental cost– benefit analysis of decentralised wastewater treatment and re-use: a case study of rural Jordan. Water Policy, 16(2), pp.323-339.

Liu, W., 2016. Nutrient Pollution in Wastewater: An Emerging Global Problem - Analyte Guru - Post. [online] Analyte Guru. Accessed 13 March 2020 .

Lovibond, 2019. BD 600. Tintometer GmbH, [online] Accessed 16 March 2020 .

Mashatleh Mohammed, 2020. Department of water studies, Royal Scientific Society. Personal meeting discussion conducted on 27th February 2020.

Massoud, M.A., Tarhini, A. and Nasr, J.A., 2009. Decentralized approaches to wastewater treatment and management: applicability in developing countries. Journal of environmental management, 90(1), pp.652-659.

Mayrhauser M., 2012. Water Shortages in Jordan. State of the planet, [online] Accessed 11 May 2020 .

Meng, P., Pei, H., Hu, W., Shao, Y. and Li, Z., 2014. How to increase microbial degradation in constructed wetlands: influencing factors and improvement measures. Bioresource technology, 157, pp.316-326.

Moelants, N., Janssen, G., Smets, I. and Van Impe, J., 2008. Field performance assessment of onsite individual wastewater treatment systems. Water Science and Technology, 58(1), pp.1-6.

Nelson, M., Cattin, F., Rajendran, M. and Hafouda, L., 2008, November. Value-adding through creation of high diversity gardens and ecoscapes in subsurface flow constructed wetlands: Case

studies in Algeria and Australia of Wastewater Gardens® systems. In Proceedings of 11th

International Conference on Wetland Systems for Water Pollution Control (Vol. 1, pp. 344-356). Ujjain: Institute of Environmental Management and Plant Sciences, Vikram University.

Nivala, J., Headley, T., Wallace, S., Bernhard, K., Brix, H., van Afferden, M. and Müller, R.A., 2013. Comparative analysis of constructed wetlands: The design and construction of the ecotechnology research facility in Langenreichenbach, Germany. Ecological Engineering, 61, pp.527-543.

Oakley, S.M., Gold, A.J. and Oczkowski, A.J., 2010. Nitrogen control through decentralized wastewater treatment: Process performance and alternative management strategies. Ecological Engineering, 36(11), pp.1520-1531.

Oram Brian, 2014. The pH of Water. Water Research Watershed Center, [online] Accessed 19 March 2020 .

Penn, M.R., Pauer, J.J. and Mihelcic, J.R., 2003. Biochemical Oxygen Demand. Environmental and Ecological Chemistry, Vol. II, pp. 278 – 297.

Redder, A., Dürr, M., Daeschlein, G., Baeder-Bederski, O., Koch, C., Müller, R., Exner, M. and Borneff-Lipp, M., 2010. Constructed wetlands–Are they safe in reducing protozoan parasites?. International journal of hygiene and environmental health, 213(1), pp.72-77.

Ridderstolpe, P., 2004. Introduction to greywater management. EcoSanRes Programme.

Ritchie H. and Roser M., 2019. Sanitation. OurWorldInData.org, [online] Accessed 12 April 2020 .

Rounds, S.A., Wilde, F.D. and Ritz, G.F., 2013. Dissolved oxygen (ver. 3.0): US Geological Survey techniques of water-resources investigations. Reston, VA: US Geological Survey.

Saliling, W.J.B., Westerman, P.W. and Losordo, T.M., 2007. Wood chips and wheat straw as alternative biofilter media for denitrification reactors treating aquaculture and other wastewaters with high nitrate concentrations. Aquacultural Engineering, 37(3), pp.222-233.

Schaider, L.A., Rodgers, K.M. and Rudel, R.A., 2017. Review of organic wastewater compound concentrations and removal in onsite wastewater treatment systems. Environmental science & technology, 51(13), pp.7304-7317.

Shamyan, A., 2011. Cost-Benefit Analysis of Wetland Alternatives on Vege River, Sweden. TVVR10/5022.

Sklarz, M.Y., Gross, A., Yakirevich, A. and Soares, M.I.M., 2009. A recirculating vertical flow constructed wetland for the treatment of domestic wastewater. Desalination, 246(1-3), pp.617-624.

Stefanakis, A.I., Akratos, C.S., Gikas, G.D. and Tsihrintzis, V.A., 2009. Effluent quality improvement of two pilot-scale, horizontal subsurface flow constructed wetlands using natural zeolite (clinoptilolite). Microporous and Mesoporous Materials, 124(1-3), pp.131-143.

Stefanakis, A.I. and Tsihrintzis, V.A., 2012. Use of zeolite and bauxite as filter media treating the effluent of Vertical Flow Constructed Wetlands. Microporous and Mesoporous Materials, 155,

pp.106-116.

Swedish environmental protection agency, 2019. Total nitrogen. Swedish Pollutant Release and Transfer Register, [online] Accessed 27 March 2020 .

Tanner, C.C., Sukias, J.P., Headley, T.R., Yates, C.R. and Stott, R., 2012. Constructed wetlands and denitrifying bioreactors for on-site and decentralised wastewater treatment: comparison of five alternative configurations. Ecological Engineering, 42, pp.112-123.

U.S. Environmental Protection Agency, 2002. Onsite Wastewater Treatment Systems Manual. Office of Water, Office of Research and Development, EPA/625/R-00/008.

Van Afferden, M., Cardona, J.A., Rahman, K.Z., Daoud, R., Headley, T., Kilani, Z., Subah, A. and Mueller, R.A., 2010. A step towards decentralized wastewater management in the Lower Jordan Rift Valley. Water Science and Technology, 61(12), pp.3117-3128.

Van Afferden, M., Cardona, J.A., Lee, M.Y., Subah, A. and Müller, R.A., 2015. A new approach to implementing decentralized wastewater treatment concepts. Water Science and Technology, 72(11), pp.1923-1930.

Vohla, C., Kõiv, M., Bavor, H.J., Chazarenc, F. and Mander, Ü., 2011. Filter materials for phosphorus removal from wastewater in treatment wetlands—A review. Ecological Engineering, 37(1), pp.70-89.

Vymazal, J., 2010. Constructed wetlands for wastewater treatment. Water, 2(3), pp.530-549.

Wallin, A., Zannakis, M. and Molander, S., 2013. On-site sewage systems from good to bad to…? Swedish experiences with institutional change and technological dependencies 1900 to 2010. Sustainability, 5(11), pp.4706-4727.

Wen, L.I.U., Hua, C.L., Ping, Z.Y. and Xiang, L.Z., 2011. Removal of Total Phosphorus from Septic Tank Effluent by the Hybrid Constructed Wetland System. Procedia Environmental Sciences, 10, pp.2102-2107.

Whitman Elizabeth, 2019. A land without water: the scramble to stop Jordan from running dry. Climate change, a wave of refugees and poor planning are draining water supplies in Jordan. Nature 573, pp. 20-23 , [online] .

Woodard and Curran, Inc., 2006. Waste Characterization. Industrial Waste Treatment Handbook (Second Edition), Butterworth-Heinemann, pp. 83-126, [online] .

Woodford Chris, 2009/2019. Zeolites. Explainthatstuff, [online] Accessed 7 April 2020 .

World Health Organization, 2015. Water sanitation hygiene. Key facts from JMP 2015 report, [online] Accessed 12 April 2020 .

World Population Review, 2019. Developing Countries 2019. [online] Accessed 11th April 2020 .

World Population Review, 2020. Jordan Population 2020 (Live). [online] Accessed 26th May 2020

Wu, S., Carvalho, P.N., Müller, J.A., Manoj, V.R. and Dong, R., 2016. Sanitation in constructed wetlands: a review on the removal of human pathogens and fecal indicators. Science of the Total Environment, 541, pp.8-22.

Xiong, J., Guo, G., Mahmood, Q. and Yue, M., 2011. Nitrogen removal from secondary effluent by using integrated constructed wetland system. Ecological Engineering, 37(4), pp.659-662.

Xu, Y., He, T., Li, Z., Ye, Q., Chen, Y., Xie, E. and Zhang, X., 2017. Nitrogen removal characteristics of Pseudomonas putida Y-9 capable of heterotrophic nitrification and aerobic denitrification at low temperature. BioMed research international, 2017.

Yalin Li, 2019. Wastewater contains nutrients, energy, and precious metals—scientists are learning how to recover them. PHYS.ORG. [online] Accessed 18 April 2020 .

Yates, M.V., 2011. On-Site Wastewater Treatment. Encyclopedia of Environmental Health, pp.256-263.

Ye, F. and Li, Y., 2009. Enhancement of nitrogen removal in towery hybrid constructed wetland to treat domestic wastewater for small rural communities. Ecological Engineering, 35(7), pp.1043-

1050.

12. Appendix – A (Instruments, detailed test procedures and theoretical information regarding Ph; EC, DO, BOD5, COD, Nutrients and bacteria) Instruments The HQ40D Portable multimeter from Hach shown in figure (9) was used to conduct the temperature, pH, DO, and EC measurements in both sampling time and testing time. Its intellectual probe can automatically recognize the testing parameter with storing the calibration history, allowing quick and easy replacement of probes without recalibrating. Besides, a stored method sitting is available to minimize setup time and provide a wide range of measurements for all parameters with minimal errors. Table (8) illustrates the operational characteristics of the HQ40D Portable multimeter.

Figure (9): The HQ40D Portable multimeter

Table (8): Operational characteristics of the HQ40D Portable multimeter. Operation temperature 0 – 60 °C (32-140 oF)

Temperature resolution 0.1 pH measurement range 0 – 14 pH resolution 0.001 / 0.01 / 0.1 (selectable)

Conductivity measurement range 0.01µS/cm – 200.0 mS/cm

Conductivity resolution 0.01µS/cm - 0.1µS/cm upon selected measuring range.

DO measurement range 0.1 – 20.0 mg/L (ppm) 1-200 saturation

DO resolution 0.1

The DR1900 Portable VIS Spectrophotometer from Hach shown in figure (10) was used to - - measure the COD, NO3 , TN, and PO4 values of the samples. The DR1900 Portable VIS Spectrophotometer is certified by CE (Canadian Radio Interference-Causing Equipment Regulation, IECS-003, Class A). The DR1900 Portable VIS Spectrophotometer operates under wavelength ranges 340–800 nm with wavelength accuracy ±2 nm.

Figure (10): The DR1900 Portable VIS Spectrophotometer

Digital Reactor Block 200 (DRB 200) from Hack shown in figure (11) was used for the sample's - digestion to measure (COD, TN, and PO4 ). The device has a programmable temperature range of 37–165 °C with temperature stability ± 2 °C.

Figure (11): The Digital Reactor Block 200 (DRB 200)

BD 600 apparatus from Lovibond shown in figure (12) was used for BOD5 measurements. The device measurement precision applies for the use of the devices in EMC (Electromagnetic compatibility) environments in compliance with the basic requirements following DIN EN 61326- 1:2013. The BD 600 unit consists of the test bottles and BOD sensors as a closed system. Its measuring principle, as explained in the apparatus manual, is a measurement utilizing pressure differential in a closed system (respirometric BOD measurement). By filling the specified sample quantity (diluted or undiluted) in the test bottle and therefore, a defined quantity of air in the gas compartment will be known. During the measurement, the sample's dissolved oxygen will be consumed by living bacteria available in the tested sample. The oxygen in the bottle gas compartment will replace this amount of consumed dissolved oxygen. The combined carbon dioxide produced within the bacterial reaction will be bounded by the potassium hydroxide put in the test bottle's seal cup. Thus, the system pressure drop will be detected by the BOD sensors and recorded as a BOD value in mg/l O2. The system records a measurement hourly on the first day, every two hours on the next day, and once-daily starting on the third day (Lovibond, 2019).

Figure (12): The BD 600 apparatus

Masterclave 528 from Biomerieux shown in figure (13) was used for the wastewater sampling bottles' autoclaving, especially for the microbial test samples. The Masterclave 528 meets Compliance with GLP (Good Laboratory Practice) terms. The Masterclave 528's design is especially suited to small to middle laboratory needs (5L to 28L) within 75 minutes at sterilization temperature 95-125 °C (microprocessor-based regulation with accuracy ± 0.5 °C).

Figure (13): The Masterclave 528

Measurements 1. Temperature, pH, dissolved oxygen (DO) and electrical conductivity (EC) pH value is the measurement of the hydrogen ion (H+) activity in water (Oram B., 2014). It is crucial to measure pH regularly as all the conducted laboratory tests procedure (except TSS) state that the pH value has to be in a specific range to gain the most accurate results. If pH value is out of these ranges, calibration of the test sample's pH value must be considered (as shown in this section later). The value of dissolved oxygen (DO) indicates the amount of oxygen could be available in the water for the living aquatic organisms, and it is usually measured in mg/L O. DO concentrations in ether its seasonal and daily cycles are affected by the temperature. At low water temperature, the water holds more oxygen, and therefore the concentration of DO is high. At the time, the concentration of DO is often lower at higher temperatures (Rounds et al., 2013). The lower DO indicates the anaerobic condition in the constructed wetland body (Stefanakis et al., 2009). Electric conductivity (EC) is one of the most parameters used to evaluate the water quality and is defined as the measure of water ability to pass electricity through it. This capability is due to the

ion's dissolved salts, minerals, and inorganic materials and their concentrations in the water. The

water's EC is usually measured in micro-siemens per centimeter (µS/cm) or millisiemens per centimeter (mS/cm). The water conductivity is directly proportional to the water temperature. When water temperature increases, so will water conductivity. An amount of 2-4% increment in conductivity will be measured with every 1°C increment (Environmental F., 2014).

2. Biochemical oxygen demand (BOD5)

The biochemical oxygen demand (BOD5) in water, is the measured amount of oxygen consumed during the degradation of organic matter through the biochemical processes within five days

(Brake, 1998; Sklarz et al., 2009). The BOD5 provides information related to the organic strength of wastewater. Thus, Measuring the wastewater influents' and effluents' BOD is a standard rule for any treatment facility performance assessment (Penn et al., 2003). According to a USEPA approved for wastewater analyses (Standard Method 5210 B 2011), using respirometric bottles, the BOD5 test was executed according to the following procedure: 1- After rinsing the BD 600 apparatus test bottles with hot/distilled water, a clean magnetic stir bar had to be added to each test bottle.

2- The BOD5 value range of the sample to be expected to determine the volume of the test sample.

Table (9) shows the test sample volumes and nitrification inhibitor dosage (ATH) for each BOD5 range value. 3- Use a volumetric cylinder to measure a required volume of a well-mixed and homogenized test sample and add it to the test bottle.

4- Add the optional dosage of a nitrification inhibitor (ATH), which depends on the BOD5 measurement range and according to the table (9). 5- Fill the dry seal cup with (three/four) drops of Potassium hydroxide solution (KOH). Then place the seal cup in the test bottle. 6- Place the BOD sensors on the test bottles and screw them carefully. Then place the test bottles in the bottle rack. 7- Place the BOD analyzer in the thermostat incubator to be incubated according to the specifications (20 °C, five days) and finally start the test.

Table (9): Test sample volumes and nitrification inhibitor dosage according to BOD5 range value.

BOD range Sample volume Nitrification in mg/l in ml inhibitor ATH dosage

0 – 40 428 10 drops

0 – 80 360 10 drops

0 – 200 244 5 drops

0 – 400 157 5 drops

0 – 800 94 3 drops

0 – 2000 56 3 drops

0 – 4000 21.7 1 drop

For ensuring the most accurate results for this test procedure, some criteria have to become real:

- The pH value has to be between pH 6.5 and pH 7.5. Otherwise, if pH is higher than 7.5 has to be readjusted and neutralized either by a diluted hydrochloric acid (1 molar) or a diluted sulphuric acid (1 molar). If pH is lower than 6.5, it must be readjusted and neutralized by a sodium hydroxide solution (1 molar). - The volume of the test sample has to be filled very precisely to avoid significant measurement errors. - A double or triple test bottle for each sample is preferred, as different results can be expected for the same sample due to particulate matter distribution. - Adding the nitrification inhibitor (ATH) drops for the suppression nitrification, especially in the expected low measurement range (0-40 mg/l) for the final effluent. This step's importance is derived from, as the nitrifying bacteria also consume oxygen, which could occur in the first five days. - To avoid falsified measurement values to be created, the test sample may never come into contact with the potassium hydroxide solution, which was added to the seal cup. - The prepared test samples must be brought to ± 1 °C of the desired temperature before the measurement. (e.g. 20 °C ± 1 °C). 3. Chemical oxygen demand (COD) The estimation of the oxygen amount required by organic matter when undergoing oxidation is known as COD. The COD is a quickly measured variable for water characterizing and essential as a wastewater quality parameter to quantify the biologically active bacteria and quantify the biologically inactive organic matter in water ( Khan and Ali, 2018). The Reactor Digestion Method was used to measure the COD of the tested samples. COD test for the range of 20 to 1500 mg/L is USEPA approved for wastewater analyses (Standard Method 5220 D), Federal Register, April 21, 1980, 45(78), 26811-26812.

The measurement in milligrams of O2 consumed per liter of a sample is defined as the results in mg/L COD. The test's principle is that the tested sample digests for two hours mixed with the vial's solution, which consists of sulfuric acid and a potent oxidizing agent, potassium dichromate. The digestion allows the oxidizable organic compounds to react and reduce the dichromate ion 2– 3+ 3+ (Cr2O7 ) to green chromic ion (Cr ). The produced amount of Cr is measured. The precision of the test is 95% under a wavelength of 620 nm. This precision achieved as the COD reagent vial also contains in its solution the silver and mercury ions. Silver as a catalyst and mercury is used to convoluted chloride interferences (Hach, 2014). The below procedure was followed to execute the COD test: 1- Remove the testing vial cap and hold it in 45 degrees. 2- After getting sure to properly mix the sample, use a clean pipet to add 2.00 mL of homogenized sample to the testing vial and close the vial tightly. 3- Rinse the vial with water and wipe with a clean paper towel. By holding the vial by the cap, invert several times gently to mix. 4- Put the vial to be digested within 150 °C for two hours in the preheated DRB200 reactor and close the DRB200 reactor lid.

5- After digestion finishes, Let the vial cool in the reactor to 120 °C or less.

6- While the vial is still warm, invert the vial several times, then put it in a tube rack to cool to room temperature. 7- Set the proper COD measuring program (according to the range) in the DR1900 Spectrophotometer. 8- Clean the testing vial and Insert it into the DR1900 Spectrophotometer's cell holder and push Read. Results show in mg/L COD. 4. Total suspended solids (TSS) Total suspended solids (TSS) is one of the distinct measurements that assess water quality. Total suspended solids describe particulates like soils, metals, organic materials, and debris held in water, and that can be filtered by a 0.45 µm filter (Woodard & Curran, 2006). The conducted test procedure to measure the TSS follows Standard Methods 2540 D and EPA Method 160.2 (Residue, non-filterable) (EPA, 1983; Standard Methods, 2017). The procedure was as follow: 1- Starting by preparing the evaporating dishes, heat the clean dishes to 103 -105°C in a drying oven for 1 hour. Store and moderate dishes in a desiccator until needed. These dishes to be weighed immediately before use. 2- Using a filtration apparatus, a 0.45 µm filter paper, and a diaphragm vacuum pump, filter a quite well-mixed sample volume that will introduce a residue between 2.5 and 200 mg. 3- Use a pipette to measure 20 ml of well-mixed and filtered samples and put them in pre-weighed dishes. 4- Dry the dishes with the evaporated samples in an oven at 103 to 105°C for at least one hour, get the dishes out from the oven, and put them in a desiccator, leaving them to cool to room temperature. 5- Take and record the weight of the dishes after drying. The difference in weight between the dried and pre-weighted dishes is the amount of total suspended solids in a 20 ml tested sample. For more accurate results, it is possible to repeat the cycle of drying, cooling, desiccating, and weighing until a constant weight is gained, or until the differential in weight is less than 4% compared with the previous weight. While weighing, using a balance with a glass draft shield is obligatory to avoid weight change due to the ambient air effects. 5. Nutrients Wastewater contains organic and inorganic nutrients. The quality of surface water and groundwater will be affected if high nutrients are drained to it. The most significant impacts on water quality due to high nutrients (nutrient quantity exceeds 100 parts per million) are eutrophication, increased turbidity, and toxicity to livestock (Yalin Li, 2019; Hang et al., 2016). Also, the leaching nitrates to sources for drinking water (groundwater) could be a reason for many public health problems such as methemoglobinemia, blue baby syndrome, or effects for pregnant women (USEPA, 2002; Hang et al., 2016). Although nutrients, particularly nitrogen and phosphorus, are essential for plant growth, the intensive growth of plants is potential when waterways become over-enriching with nitrogen and phosphorus. Consequently, it contributes to the growth of algae that may be toxic besides lose the aesthetic value of the waterways. Furthermore, the bacteria consume dissolved oxygen in the water for the dead plants decomposing, by this means affects the rest of the remaining organisms that depend on dissolved

oxygen in the water (Extension, ND; USEPA, 2002).

The source of nitrogen and phosphorus in the wastewater are human waste, household detergents, and other waste. Nitrogen could be found in the wastewater in different forms like ammonia, organic nitrogen, nitrite, and nitrate (Liu W., 2016). The biological nutrient removal operations and within an aerobic condition, transform the ammonia and organic nitrogen to nitrate under the nitrification processes. Then, within an anaerobic condition, minimize the nitrate to produce the nitrogen gas under the denitrification processes (Leverenz et al., 2010). In contrast, phosphorus exists in the wastewater in several phosphate forms (orthophosphate, organic phosphate, and condensed phosphate) (Liu W., 2016).

- phosphorous (PO4 ) Phosphorus could be found in the water in two forms, organic and inorganic, and its mobility is very slow in the environment. Phosphorus is too valuable for the plants as the plants use the inorganic form of it (orthophosphate), which usually scant in the water due to its attachment to the sediments. Adding a low amount of phosphorus to the soil could cause excessive plant growth. However, when these plants die, algal blooms often will be created, which could be toxic sometimes (Extension, ND; USEPA, 2002). Phosphorus removal is significant to lower the high potential impact from wastewater effluent to the other water sources (García-Pérez et al., 2009). The ascorbic acid method following Standard Methods 4500-P (F-H) - 2011 PHOSPHORUS (Standard Methods, 2017) used to measure the total phosphorus (TP) with the range 6 to 60 mg/L – PO4 (UHR) using the DR1900 Portable VIS Spectrophotometer under the wavelength of 714 nm. The principle of measuring phosphates in water as the total phosphorus procedure depends on converting the organic and condense inorganic phosphates to reactive orthophosphate. The hydrolysis of organic and inorganic phosphates will be provided by adding the sample to the acid and persulfate in the test vial with digestion. This reactive orthophosphate then reacts with molybdate and antimony ions in the acidic solution in the vial to form the antimonyl phosphomolybdate complex. Finally, the antimonyl phosphomolybdate complex will be reduced by the ascorbic acid to form phosphomolybdenum blue (Hach, 2016). Following procedure was followed to measure phosphorus: 1- For accurate results, the sample temperature is prepared to be between 15 -25 °C. 2- Start the DRB200 digester and set the temperature to 100 °C. 3- Carefully remove the lid from the test vial cap then remove the cap from the test vial. 4- Add 0.40 mL of a test sample and turn the cap over on the test vial, so the reagent side goes into the test vial. Tighten the cap. 5- Shake the test vial two to three times. Get sure that the reagent in the cap dissolved within the solution. Insert the test vial to the preheated digester. 6- Close the digester lid. Leave the vial in the digester for one hour. 7- After digestion finishes, carefully remove the vial from the digester and let it lose temperature until it reaches room temperature. Shake again the vial two to three times. 8- Using a proper pipet, add 0.50 mL of Solution B and replace the vial cap by DosiCap C, which contains reagent in it (available with the phosphorus reagent set). 9- Tighten the cap on the vial and invert the vial two to three times. 10- Leave the test vial for 10 minutes to complete the reaction. Invert two to three times then

clean the test vial.

11- Set the DR1900 Spectrophotometer program to phosphorus measuring (according to the range - UHR) and Insert the test vial into the DR1900 Spectrophotometer's cell holder and push Read. - Results show in mg/L PO4 .

- Nitrate (NO3 ) - The most common form of inorganic nitrogen found in water bodies is Nitrate (NO3 ) which could percolate readily into aquifers because of its high mobility in soil (Baker, 1998). Plants directly use the nitrate to build proteins (Extension, ND). However, the potential impacts on groundwater due to the discharge of many wastewater treatment systems into the valleys or water bodies made the nitrate to be identified as a constitutive of worry (Leverenz et al., 2010). The dimethylphenol method (Hach 1020675) used to measure the nitrate using the DR1900 Portable VIS Spectrophotometer under 345 nm wavelength. The test method is USEPA approved for water and wastewater analysis, 40 CFR part 136. The principle of measuring method is by adding the tested sample to the test vial, whose solution contains sulfuric and phosphoric acids. The nitrate ions in the sample will react with 2,6- dimethylphenol to form 4-nitro-2,6- dimethylphenol (Hach, 2020).

– – Following procedure was followed to measure NO3 with the range 0.23 to 13.50 mg/L NO3 – N – or 1.00 to 60.00 mg/L NO3 (LR) in the samples: 1- For accurate results, the sample temperature prepared to be between 20 -23 °C 2- Add 1.00 mL of the sample using a proper pipet to the test vial. 3- Add 0.20 mL of solution A using a proper pipet to the test vial. Then tighten the vial cap and invert it until thoroughly mixed. 4- Leave it for 15 minutes to complete the reaction. After that, Clean the test vial. 5- Set the DR1900 Spectrophotometer program to nitrate measuring (according to the range - LR) and Insert the test vial into the cell holder in DR1900 Spectrophotometer and push Read. Results – show in mg/L NO3 –N. – 6- Multiply the read value by 4.4 to get the value in mg/L NO3 .

– – – For measuring NO3 with the range 5 to 35 mg/L NO3 –N or 22 to 155 mg/L NO3 (HR), the following procedure was followed: 1- For accurate results, the sample temperature prepared to be between 20 - 23 °C. 2- Add 0.20 mL of the sample using a proper pipet to the test vial. 3- Add 1.00 mL of solution A using a proper pipet to the test vial. Then tighten the vial cap and invert it until thoroughly mixed. 4- Leave it for 15 minutes to complete the reaction. After that, Clean the test vial. 5- Set the DR1900 Spectrophotometer program to nitrate measuring (according to the range - HR) and Insert the test vial into the cell holder in DR1900 Spectrophotometer and push Read. Results – show in mg/L NO3 –N. – 6- Multiply the read value by 4.4 to get the value in mg/L NO3 . Total nitrogen (TN). +4 ˉ The term TN refers to the calculation of the combination of all forms of nitrogen (NH -N, NO3 -

N, and organic nitrogen compounds) (Swedish environmental protection agency, 2019).

The persulfate digestion method was used to measure the total nitrogen within the range of 20 to 100 mg/L N (UHR) following standard methods (4500-N.C) using the DR1900 Portable VIS Spectrophotometer under the wavelength of 345 nm. The method of total nitrogen measurement employs the digestion of the organic and inorganic nitrogen compounds with peroxydisulfate. The organic and inorganic nitrogen compounds will be oxidized to nitrate. In a sulfuric and phosphoric acid solution, the nitrate ions react with 2,6-dimethylphenol to form a nitrophenol (Hach, 2018). Following procedure was followed to measure the amount of total N: 1- For accurate results, the sample temperature prepared to be between 15 - 25 °C. 2- Start the DRB200 digester and set the temperature to 120 °C. 3- Add 0.20 mL of a test sample, 2.30 mL of solution A and one reagent B tablet to a 20 mm reaction tube and close it immediately. Without inverting the reaction tube, insert it to the preheated digester. 4- Close the digester lid. Leave the reaction tube in the digester for 30 minutes. 5- After digestion finishes, remove the reaction tube from the digester and let the tube lose temperature until it reaches room temperature. Then invert the reaction tube two to three times. 6- Using a proper pipet, add 0.50 mL of the digested solution to the test vial then add 0.20 mL of Solution D to the test vial. 7- Quickly, close the test vial cap and invert it until totally mixed. 8- Leave the test vial for 15 minutes to complete the reaction. Clean the test vial. 9- Set the DR1900 spectrophotometer program to total nitrogen measuring (according to the range - UHR) and Insert the test vial into the cell holder in DR1900 Spectrophotometer and push Read. Results show in mg/L N. 6. Total coliform and E.coli The gram of human fecal usually includes a quantity reaching 1012 of bacteria, and most of this quantity is non-etiological of diseases. However, the World Health Organization estimates that 2.1 million people die every year from diarrheal diseases, and the majority occurs in less industrialized countries. The wastewater's microbiological quality is one of the most critical parameters to consider when evaluating any wastewater treatment system. It could be assessed by measuring the concentration of the bacteria present in the fecal materials in the wastewater known as indicator bacteria. The presence of indicator bacteria in the wastewater could indicate the pathogenic microorganisms' presence in this wastewater. TC and E.coli are the most common groups of indicator bacteria (Yates MV., 2011). In CW, the pathogenic microorganisms may come from human or animal excreta to the wastewater effluent, or available within the wetland community. Thus, quantifying fecal contamination in the wastewater is necessary for evaluating the CW feasibility in pathogen removal performance (Wu et al., 2016). The enzyme-substrate test was used to quantify the total coliforms (TC) and Escherichia coli (E. coli) in the tested samples. The test tray (Multiple tube/multi-well) contains hydrolyzable chromogenic and fluorogenic substrates. The total coliform bacteria generate an enzyme called β- d-galactosidase. The β-d-galactosidase works to disunite the chromogenic substrate in the medium to release chromogen. At the same time, the E. coli strains generate an enzyme called β- glucuronidase. The β-glucuronidase works to disunite the fluorogenic substrate in the medium to release fluorogen (9223 Enzyme substrate coliform test, 2017). Colisure media contain Ortho-Nitrophenyl-β-d-Galactopyranoside (ONPG) and Chlorophenol

Red-β-d-Galactopyranoside (CPRG) as chromogenic substrates to quantify the total coliform. The

β-d-galactosidase enzyme works to hydrolyze the chromogenic substrate and gives a change in the color. The presence of non-coliform bacteria that may generate the enzyme β-d-galactosidase will be excluded from the measurements as the media prevents their growth. Thereby a false changing color will not be given (Ibid). In like manner, Colisure media contain 4-Methyl-Umbelliferyl-β-d-Glucuronide (MUG) as a fluorogenic substrate to quantify the E. coli. When the β-d-glucuronidase enzyme works to hydrolyze, the fluorogenic substrate gives a cerulean luminance when viewed under ultraviolet light with 365 nm wavelength. Some available bacteria in large numbers or stains may generate the same cerulean luminance under the (UV) light. However, they lack the presence of the β-d- galactosidase enzyme, which generates the change in the color. Jointly, changing in color (due to β-d-galactosidase) and the cerulean luminance (due to β-d-glucuronidase) indicate a positive measurement for E. coli (Ibid). Following procedure was followed to quantify the Total coliform and E.coli amounts: 1. If it is necessary, the wastewater sample has to be diluted for more specific quantifying measurements. 2. In a sterilized vessel, add 100 mL of the wastewater sample with the content of one pack of Colisure. 3. Five drops of IDEXX antifoam solution to be added. 4. Fix the vessel cap and shake it carefully, allowing the sample to stand for a minimum one minute and then shake again. Be sure that the media dissolved, and no big media particles are remaining. 5. Pour the vessel content into the Quanti-Tray. The Quanti-Tray to be sealed by butting it in the IDEXX Quanti-Tray Sealer. Put the sealed tray in the incubator 24 hours at 35±0.5°C. 6. To quantify the total coliform, the wells which turned its color to magenta or red counts as positive. count the number of positive wells and read the MPN results according to the Result Interpretation Table (10) in Appendix B provided with the trays. 7. To quantify the E.coli, put the tray under the (UV) light. The wells with cerulean luminance represent the positive reading for E.coli. Count the number of positive wells and read the MPN results according to the Result Interpretation table provided with the trays. 7. Pseudomonas Aeruginosa Pseudomonas aeruginosa is a kind of bacteria that is commonly found in the soil and water environments. The most often type of Pseudomonas aeruginosa that causes infections in humans (blood, lungs, or other parts of the body after surgical treatment) is called Pseudomonas aeruginosa (CDC, 2019). The enzyme-substrate test was used to quantify the Pseudomonas aeruginosa in the tested samples. The used Pseudalert reagent contains amino acids, vitamins, and other nutrients, causing the rapid growth of Pseudomonas aeruginosa cells. Pseudomonas aeruginosa cells generate an enzyme that works to disunite and hydrolyze the substrate in the Pseudalert reagent, giving a cerulean luminance when viewed under ultraviolet light with 365 nm wavelength (Idexx, 2017). Following procedure was followed to quantify the Pseudomonas aeruginosa amount: 1. If it is necessary, the wastewater sample has to be diluted for more specific quantifying

measurements.

2. In a sterilized vessel, add 100 mL of the wastewater sample with the content of one pack of Pseudalert. 3. Fix the vessel cap then shake it carefully. Be sure that the media dissolved, and no big media particles are remaining. 4. After that, add two drops of the IDEXX antifoam solution to the mixture. 5. Pour the vessel content into the Quanti-Tray. Put the Quanti-Tray in the IDEXX Quanti- Tray Sealer to be sealed. Put the sealed tray in the incubator for 24-28 hours at 38±0.5°C. 6. To quantify the Pseudomonas aeruginosa, put the tray under the (UV) light. The wells with cerulean luminance represent the positive reading for Pseudomonas aeruginosa. Count the number of positive wells and read the MPN results according to the Result

Interpretation table provided with the trays.

13. Appendix – B (Calculation tables)

Table (10): The Idexx tables for quantifying bacteria indicators (TC, E. coli, and Pseudomonas)

Table (11): Microbial test calculations' and results' tables on 04/03/2020

Table (12): Microbial test calculations' and results' tables on 08/03/2020

Table (13): Microbial test calculations' and results' tables on 16/03/2020

Table (14): The contractor pricing on the systems' tendering.

14. Appendix – C (Groups discussion) Minutes of the group discussion with local households in Sakib 1 - What is the full name of the landlord? Mohammed Mahmood Aoad Fryhat - Initially and in general, what are your notes about the system that could affect your lifestyle and activities from the time the system starts to work? Honestly, now it is much better than it was with the cesspools. We are seven houses that previously had seven cesspools. The cesspools were overflowing. There was danger from cesspools to our children and the passing animals to fall in. Within approximately ten years of the cesspools' operation, four accidents of passing animal falling happened. These accidents were costing us a lot of effort, time, and money to rent a loader from Sakib city and drive to here to get the animal out from the cesspool. No noise at all is coming from the system. About the odors, we are not suffering from it as before. Now, it is approximately not existing if we clean the system regularly and once weekly. Just a small amount of odor appears during the pump operation. During the old system (Modified septic tank), the soil color changed from red to black. We think this happened due to the failure of the operation of the system. - How much was it cost you monthly to deal with your wastewater before the construction of the system? It cost 60 JRD to rent a truck to draw one cesspool. In addition to the strong odor created in the drawing day. - For how long the cluster using this system? The old system constructed before four years and a half. After that, they update the system by adding a constructed wetland that operated just before one month. - What is the primary use of the effluent from the system? In the beginning, we used the effluent to irrigate 600 grab trees. Then we had been informed by the royal scientific society to stop the irrigation and discharge it to the valley as the lab tests showed that the produced water is not sufficient for irrigation. Now and after the wetland construction, we are planning to store the produced water for irrigation purposes. However, we are waiting for recommendations after testing. - Can you tell me about the disease incidences in the population and about the health in general in your area before and after constructing and operating the system? There is no history of any disease incidences in our area, and the population health is good in general. Before constructing the system, we suffered from the cesspools and their odors. In the summers, we suffered from the mosquitos. Now and after constructing the system, these problems are less. - Did you notice that this system could create a suitable environment for Insects, rodents,

scorpion, snakes, or some kinds of animals like hyenas?

We could not notice this issue yet as the new system is newly constructed. However, during discharging the effluent from the old system (modified septic tank) to the valley or irrigation, we suffered from wild boars, wolves, and black crows. They were coming in large groups to our trees and taking them out and destroy our irrigation pipes. - What is your source of water for domestic use (water network or wells)? A water network from the government provides us with water every 14 days for four hours each time. - How much the amount of water that every house in the cluster uses monthly? Each house in the cluster uses around fifteen to twenty cubic meters monthly. - Tell me about the quality of the water supplied to the houses from the national water network. Is there any color, odor, salinity, turbidity, or taste? Yes. In the first hour of water suppling, we receive water contains a red clay and high turbidity in addition to clay or rust taste. So, we never use this water for drinking. We are buying our filtered drinking water from the market. - What about the economic and educational status of the households in the cluster? All of our children are going to schools and universities. All the parents had educated. At least to the ground school. Regarding the economic situation, it is less than the average. There is poorness in our cluster. We can say that our current economic status meets basic living needs. - How much time and effort does the operating and maintenance of the system take from you as householders? Moreover, what kinds of work are they? Nearly one hour and a half weekly. We remove the floating grease and sludge from the first tank and put it in a pre-dug pit. - To what extent are all beneficiaries from the system cooperating to help each other operate and maintain the system? Currently, my children and I (landlords) are the only people operating and maintaining the system. However, at any time I will need help with that, I am sure that the others will not hesitate to be available and do help. - Are you ready to farm and consume vegetables irrigated by the effluent from the system? No. mentally and psychologically, it is not accepted by our society here. - How much the operating and maintenance of the system cost you as householders? It is just the amount of electricity used by the pump. The pump connected to my house (the landlord). The increment in the monthly electricity invoice is 25 JDR, which is honestly more than my ability. Even after we change our el meter to an agricultural el meter, it is supposed to have lower tariffs, but nothing changed. I hope if the royal scientific society could provide a solar system to operate the system instead of cost me the el bills. - Does the area have a heritage or tourism value? Moreover, how much could this system affect these values? In this area, you can find the deer reserve and cedar reserve areas, making the area a target for

the tourists and visitors in the summer. Besides, there are many summer houses in the area

that belong to people not from the area. We are not sure to what extent the system could affect this tourism value due to the odor, but we do not think so. - (To the landlord) Personally, what do you think, and what is your extent of satisfaction about the system? As I told before, this system saved monthly the cost to draw the cesspool, which is 50 JDR, and the cost to rent a water truck for irrigation purposes 40 JDR. Also, the cost of the fertilizer I used to buy for planting my trees, which was 20 JDR. I am delighted with the current situation. On the other hand, I have a problem to use the produced water from the system in my upper part of the farm beside our houses. I need to pump it up, which cost me to buy a pump and more on electricity bills. - How many people or beneficiaries in each household in the cluster? We are seven households contain 37 persons (8+4+4+6+5+2+8). - Was there any educational program about the system carried out for households? What is your feeling in general about transparency in decisions and management? Was there any role of households in choosing between the systems or sharing on construction? Yes. Everything explained to us with full transparency and clarity. RSS even transported us to the educational program hall by their vehicles. They showed and talked about some other systems and explained to us how the systems are working. Besides, they allow us to choose between several systems. In the construction stage, we involved ourselves in doing some works while building this system. We supported the contractor by providing and transporting some materials and water. Besides, doing some digging work. Furthermore, monitoring the construction. ------

Minutes of the group discussion with local households in Sakib 2 - What is the full name of the landlord? Musa Mahmood Abdelhamid Fryhat - For how long your cluster using this system? Four years and this is the fifth year. - Initially and in general, what are your notes about the system that could affect your lifestyle and activities from the time the system starts to work? No significant effects from the system on our life or activities. No chemicals, noise, or odors. Except a small amount of odor appears when we operate the system to feed the wetland. However, this happens only on windy days and in the summer and only if we did not clean the septic tank or remove the grease, oils, or sludges from the tanks. Otherwise, if the system is cleaned, no odors produce. In the summer, fortnightly, we take care of cleaning and removing the floating grease and

sludge and put it in a big absorption pit in our land.

- What is your source of water for domestic use (water network or wells)? The water source in the area is a water network from the government. They provide us with water every 14 days. We do not have wells in this area as we live in a rocky mountainous area. It is tough for us to dig wells in such areas. - Can you tell me about the disease incidences in the population and about the health in general in your area before and after constructing and operating the system? There is no history of any disease incidences in our area, and the population health is good in general. Before constructing the system, we suffered from the cesspools and their odors. In the summers, we suffered from the mosquitos. After constructing the system, these problems had been eliminated. The biggest problem solved by construction this system was the fall of our livestock in one of the cesspools. At least, every two years, an accident of this kind happens. One accident was costing us a lot of effort, time, and money to rent a loader from Sakib city and drive to here to get the animal out from the cesspool. Also, we lose this livestock as it dies due to the fall. - Did you notice that this system could create a suitable environment for Insects, rodents, scorpion, snakes, or some kinds of animals like hyenas? Hyenas are generally present in the area, but not close to the residential areas. Our answer is yes. The system always collects Insects, rodents, scorpions, and snakes around it. Especially around the distributing pipes on the surface of the wetland. However, it is acting as a trap because it became much easier for us to deal with them. Before constructing the system, beetles, mice, scorpion, and serpents found all around the area and went inside the houses every so often. Now, after the system, this stopped to happen. They are eating each other around the system or being eaten by the cats or the birds. Otherwise, we kill them regularly. On the other hand, the birds began to fly more around as they drink from the produced water out of the system and catch insects, which give a more beautiful view around the houses. - How much was it cost you monthly to deal with your wastewater before the construction of the system? It cost 60 JDr to rent a truck to draw one cesspool. We are four houses, and each house had its cesspool. To be honest, we had not the ability to do it monthly, and that created the problems for us due to the odors and insects. - How much the amount of water that every house in the cluster uses monthly? I (landlord) have the biggest family in the cluster, and I am using around ten cubic meters monthly—the smallest family using around three to five cubic meters. - What about the economic and educational status of the households in the cluster? All of our children are going to schools and universities. All the parents had educated. At least to the ground school. Regarding the economic situation, it is less than the average. We can say that our current economic status meets the basic living needs required, but it does not meet the unexpected circumstances that may occur from time to time. - If we go back to the water supplied to the houses from the national water network, Is there

any color, odor, salinity, turbidity, or taste?

No, nothing of the things you mentioned except it contains the added chlorine for disinfection purposes. As a result, we just use it for our domestic use but never for drinking. We are buying our filtered drinking water from the market. - What is the primary use of the effluent from the system? I (landlord) am the only one using the effluent produced from the system as I am the owner of the land that the system builds on. I am the only one in the cluster who has a small farm. I am using the produced water for irrigating the olive trees. In the summer, I am irrigating the clover that I grow as food for livestock as well. Furthermore, I am planning to create a pergola of grapes that need to be irrigated with water at the start of planting it. - Do you grow vegetables in the area? If yes, how do you irrigate them? No. Not as vegetable farms. However, some of us plant some vegetables around their houses for their personal use. And they depend only on the rainfall for irrigation. - Are you ready to farm and consume vegetables irrigated by the effluent from the system? No. mentally and psychologically, it is not accepted by our society here. - How much time and effort does the operating and maintenance of the system take from you as householders? Moreover, what kinds of work are they? Not too much. Monthly, it takes two to three hours maximum. We re-cover the system pipes with the sheds that could be exposed due to the wind, kill the Insects, rodents, scorpion, or snakes around these pipes and remove the floating grease sludge from the first tank. The last is done only during the summer months. - How much the operating and maintenance of the system cost you as householders? Just the increment in the monthly electricity invoice, which is 5 to 7 JDR. I (landlord) pay this. The royal scientific society promised me that they will set up a small solar system to cover the electricity of the recirculation pump but not done yet. - Does the area have a heritage or tourism value? Moreover, how much could this system affect these values? The area contains many oak trees, making the area a target for tourists and visitors in the summer. Also, there are many summer houses in the area that belongs to people not from the area. As long as this system does not generate noise or odors, it will never affect this tourism value. Even if there are many such systems in the area provided that they must be maintained regularly. - (To the landlord) Personally, what do you think, and what is your extent of satisfaction about the system? In the beginning, I did not accept to construct the system in my land. Later on, the royal scientific society explained to me the system and how we could benefit from it, and they offered to try the system for one year, then I accepted. Currently, I am satisfied, and we regret the time lost during the objection. - To what extent are all beneficiaries from the system cooperating to help each other

operate and maintain the system?

We are very agreed with this. Every week it is on someone of us to perform this simple maintenance, and everyone is committed. - How much this system saves for you to irrigate your trees? The system did not save us any cost as we depended previously on the rainfall to irrigate the trees. However, the system made the tree production better than before as they currently receive more irrigation. - How many people or beneficiaries in each household in the cluster? We are four households contain 24 persons (7+6+5+6) in addition to our livestock. - Was there any educational program about the system carried out for households? What is your feeling in general about transparency in decisions and management? Was there any role of households in choosing between the systems or sharing on construction? Yes. Everything explained to us with full transparency and clarity. RSS even transported us to the educational program hall by their vehicles. They showed and talked about some other systems and explained to us why this system is the most suitable for our area. In the construction stage, they did some constructions more than they already talked about, and it was for our benefit.

15. Appendix – D (Laboratory tests photos)

Figure (14): Sampling for laboratory tests

Figure (15): A side of laboratory output