Attachment_J.18_2_LWP_Assessment_Small_Wastewater_Treatment_Plants.pdf

LEBANON WATER PROJECT

ASSESSMENT OF SMALL WASTEWATER TREATMENT PLANTS

IN LEBANON

SUMMARY

OCTOBER 2017

This publication was produced for review by the United States Agency for International Development. It was prepared by DAI Global L.L.C

III

SWWTP Summary

LEBANON WATER PROJECT

ASSESSMENT OF SMALL WASTEWATER TREATMENT PLANTS

IN LEBANON

SUMMARY

Program Title: Lebanon Water Project

Sponsoring USAID Office: Lebanon

Contract Number: AID-268-N-15-00001

Contractor: DAI Global LLC (DAI)

Date of Publication: October 24, 2017

Author: Lebanon Water Project

DISCLAIMER

The authors’ views expressed in this publication do not necessarily reflect the views of the

United States Agency for International Development or the United States Government.

IV

CONTENTS

CONTENTS ................................................................................................................ IV

ACRONYMS................................................................................................................. V

BACKGROUND

OBJECTIVES

METHODOLOGY

FINDINGS

SWWTPS PROCESS AND TECHNOLOGIES

STATUS OF EQUIPMENT USED IN THE SWWTPS

RESULTS OF ON-SITE PARAMETER AND LABORATORY ANALYSIS

TECHNICAL AND ADMINISTRATIVE LIMITATIONS AND CHALLENGES

ANALYSIS AND LESSONS LEARNED

TECHNICAL LESSONS LEARNED

ADMINISTRATIVE LESSONS LEARNED

V

ACRONYMS

BNR Biological Nutrition Removal

BOD Biochemical Oxygen Demand

BMLWE Beirut and Mount Lebanon Water Establishment

CAPEX Capital Expenditures

COD Chemical Oxygen Demand

DAI DAI Global LLC

ELARD Earth, Link, and Advanced Resources Development

EVL Environmental Limit Values

GoL Government of Lebanon

KPI Key Performance Indicators

LWP Lebanon Water Project

MoE Ministry of Environment

O&M Operation and Maintenance

PH Potential of Hydrogen

RWE Regional Water Establishment

SOP Standard Operating Procedure

SWWTP Small Wastewater Treatment Plant

TKN Total Kjeldhal Nitrogen

TP Total Phosphorus

TSS Total Suspended Solids

USAID United States Agency for International Development

WW Wastewater

WWTP Wastewater Treatment Plant

BACKGROUND

The United States Agency for International Development (USAID)-funded Lebanon Water Project (LWP) is a five-year project that works to increase reliable and sustainable access to potable water for Lebanese citizens, improve water management practices and enhance the efficiency and sustainability of public water utilities, while raising awareness on sustainable water use practices. LWP also targets improving wastewater (WW) management practices through implementing new low cost WW treatment options and enhancing the efficiency of existing small wastewater treatment plants (SWWTPs).

The Government of Lebanon (GoL) has implemented several projects to improve WW collection and treatment. However, very little WW is treated before being discharged into the Mediterranean Sea, rivers, valleys, or dry water wells. While Law 221 dictates that the Regional Water Establishments (RWEs) manage WW collection and treatment, only a few of these facilities are commissioned and operated by the RWEs due to the high costs of operation and maintenance of each facility.

OBJECTIVES

Land that can be used for WW treatment is scarce in urban areas with high population density. Opting for a mechanical wastewater treatment plant (WWTP) that requires a relatively small area is the preferable method of treatment, as is the case for the WWTPs located in Tripoli and Zahleh. In rural areas low in population density, land is generally available for less complex technologies with lower operation and maintenance (O&M) costs. Different wastewater treatment technologies have been implemented in rural areas of Lebanon, such as the Kherbet Qanafar wetland (West Beqaa Caza/district) and the Ablah SWWTP (Zahleh Caza/district) In addition to the difference in technologies the management of these plants differs from one area to another. Some of these plants are currently operated by the RWEs, others run by union of municipalities and some others were left for individual municipalities to take care off.

LWP hired the consulting engineering firm Earth, Link and Advanced Resources Development (ELARD) to assess the status of SWWTPs in various rural areas of Lebanon. The rural areas assessed were located in Chouf, Beqaa, and Jezzine Cazas. The assessments primary objective was to develop a case study that would document lessons learned on the key administrative and technical factors behind establishing sustainable low cost sanitation solutions in rural areas. Based on these lessons LWP will conduct its assessment with the GoL to identify locations under each RWE for low cost sanitation solutions.

A secondary objective of this exercise included a technical assessment to identify additional investment needs to enhance the operation of the selected SWWTPs.

METHODOLOGY

Twelve (12) small wastewater treatment plants were selected for this case study by LWP team. The selection was based on the following criteria:

1. The various treatment technologies used: When selecting the plants, the different treatment technologies being used were identified and then plants using different technologies were selected to give a representative sampling. The two main treatment technologies used in most of the SWWTPs are Extended Aeration and Activated Sludge, and in some cases a combined system. The selected sites include both technologies.

2. The operational status: The selection considered the operational efficiency of the potential plants to be included in the study. Some of the selected plants are operational, others are not at full capacity, and one of the plants selected is not operational. The main purpose is to understand why these plants are operating at different levels and what could have been done to increase operational efficiency.

3. The various entities responsible for the operation of these facilities: An important criterion considered in the selection was the entity responsible for the operation of the facility. In some cases the SWWTP is being operated by the local authority, and in others are operated by the relevant RWE.

4. The geographical spread of the SWWTPs: To make sure the selection has a geographic spread across the different RWEs. The main purpose behind this criterion was to share lessons learned with the respective RWEs about SWWTP operations and to understand if other social, economic, and political factors may influence the successful implementation of sanitation solutions in rural areas.

The outcome of this case study is to provide guidance and strategic insight to LWP on how to approach sanitation solutions as part of its mandate. As LWP will be addressing low cost sanitation solutions, the outcome of this case study will help LWP formulate its strategy in selecting and implementing low cost sanitation solutions for the coming two years. The main challenges and recommendations stated in the following sections are the main pillars on which LWP can build a strong foundation for investing in low cost sustainable solutions in its course of action.

The 12 SWWTPs included in the assessment are listed by location in Figure 1.

Figure 1. List of SWWTPs Included in the Assessment

No. Mouhafaza Caza

1 Mount Lebanon Chouf El Khraibe

2 Mount Lebanon Chouf Jbaa

3 Mount Lebanon Chouf El Moukhtara/Boutme

4 Mount Lebanon Chouf Aammatour

5 Mount Lebanon Chouf Niha/Bater

6 Mount Lebanon Chouf Maaser El Chouf

7 Mount Lebanon Chouf Mrousti

8 Beqaa Zahleh Ablah

9 Beqaa Zahleh El Fourzol

10 Beqaa West Beqaa Aaitanit

11 South Lebanon Jezzine Barti

12 South Lebanon Jezzine Rihane

The work methodology followed to assess these 12 SWWTPs is based on:

1. Site Visits for Data Collection

After reviewing available data (design criteria specifications, treatment process, schematic drawings and actual inflow, O&M budgets and expenditures, status of operation, and challenges), the consultant conducted a site visit to each SWWTP to gather additional information. The following activities occurred during site visits:

Recording of the location coordinates of each facility using a GPS.

Measurement of inflow/outflow of each SWWTP where possible.

Interview of operator staff to collect information on the plant management procedures and difficulties and challenges faced during O&M.

Site inspection to verify possible deficiencies or technical problems.

2. Wastewater Sampling and Analysis

The consultant collected wastewater samples from the operating SWWTPs using standard sampling protocols for collecting and preserving. The samples delivered to the Civil Engineering Service Laboratories at the American University of Beirut were analyzed for all parameters except oil and grease.

Samples delivered to the Industrial Research Institute at the Lebanese University were analyzed for oil and grease. Physicochemical and microbiological parameters were analyzed for the collected WW samples, and the influent and effluent quality criteria were evaluated based on environmental limit values (ELVs) set by the Ministry of Environment (MoE) in Decision No. 8/1/2001.

The inflow and outflow tests performed at each SWWTP included the following:

PH and temperature parameter (recorded on site).

COD, BOD5, TKN (TN), TP, TSS, oil and grease (accredited laboratory analysis).

Total and fecal coliforms (accredited laboratory analysis).

3. Analysis of Data Gathered

As a final step, the consultant:

Technically reviewed and analyzed design documents and drawings of the SWTTPs, where available.

Reviewed performance monitoring and maintenance records provided by plant operators.

Reviewed and interpreted results of influent and effluent laboratory analysis.

Appraised the efficiency of different treatment technologies by comparing concentrations of pollutants at the inlet and outlet of the treatment plant with ELVs.

Analyzed documentation (O&M contracts and financial documents where available) and filled in gaps through operator interviews.

FINDINGS

The SWTTPs examined rely on mechanical technologies to treat WW. Although most of these SWWTPs are operating, they are still not functioning at optimal level nor at full capacity and must be properly managed for improved results. Specifically the assessment findings focused on:

1. Eleven of the SWWTPs evaluated use the Activated Biofiltration process and/or the Trickling Filter (TF) process. The remaining SWWTP, located in Barti in the Jezzine Caza, was visited but not assessed because it is out of service due to existing problems in the sewage network that prevent wastewater from reaching it.

2. The status of the equipment used in the SWWTPs.

3. The results of WW parameters tested on-site (pH and temperature) and laboratory analysis.

4. Technical and administrative limitations/challenges noticed in all SWWTPs assessed.

SWWTPS PROCESS AND TECHNOLOGIES

Two main processes are used in the assessed SWWTPs.

The Activated Biofiltration Process (Treatment Type “A”) is a hybrid combining the trickling filter technology (TF) with an activated sludge (AS) system. It is used in the seven Chouf SWWTPs and in the Rihane SWWTPs in Jezzine. All seven SWWTPs in the Chouf use the TF technology combined with diffused aeration to provide oxygen to treat incoming WW. The Rihane WWTP combines the TF technology with a bioreactor to provide oxygen. The purpose of oxygen aeration is to remove physically certain and odor- producing substances, and to remove chemically metals, gases and other compounds.

The Trickling Filter Process (Treatment Type “B”) is a conventional process by which wastewater is constantly trickled over a filter. As the wastewater goes through the filter pores, organic substances polluting the water are degraded. Metals in the wastewater are not removed through this process. All three SWWTPs of the Beqaa use the TF process/technology exclusively to treat WW.

General information gathered about the current operational status of each of the SWWTPs is summarized in Figure 2 below. Data on actual incoming flow in each plant clearly shows that most of these WWTPs are operating below treatment capacity, which can be increased with through appropriate improvements.

Figure 2-General Plant Information

Caza SWWTP Served Area(s) End of

Construction Year

Year of Start of

Operation

Design Flow

(m3/day)

Actual Flow (m3/day)

% Actual Flow to

Treatment Capacity

El Khraibe 70% of El Khraibe 2008 2008 450 80 18%

Jbaa Jbaa 2007 2008 300 82 28%

El Moukhtara/ Boutme

El Moukhtara & Boutme

2007 2008 450 170 38%

El- Chouf

Aammatour

Aammatour, Haret Jandal, Ain Qani and part of Baadarane

2007 2008 900 170

19%

Niha/Bater Niha and Bater 2007 2009 900 130 15%

Maaser El Chouf

80%of Maaser El Chouf

2004 2006 450 80-100 23%

Caza SWWTP Served Area(s) End of

Construction Year

Year of Start of

Operation

Design Flow

(m3/day)

Actual Flow (m3/day)

% Actual Flow to

Treatment Capacity

Mrousti Mrousti 2007 2008 225 90 40%

Ablah Ablah (80%)-Nabi Ayla (70%)

2012 2012 2,000

700-800 (summer)

1,000-1,500 (winter)

40% (summer)

75% (winter)

Beqaa

El-Fourzol El-Fourzol (80%) 2009 2009 1,500

700-800 (summer)

Overflow (winter)

53%

Aaitanit

Aaitanit, Baaloul, Machghara and Qaraoun

2009 2009 5,000 1,200 24%

Jezzine Barti Barti 2003 2003 195

Treatment plant is out of service

Rihane Rihane 2004 2014 3,000 900 30%

STATUS OF EQUIPMENT USED IN THE SWWTPS.

Equipment used to treat wastewater at the SWWTPs was examined by looking at both the liquid (wastewater/sewage and effluent) and the sludge lines. As wastewater/sewage enters the WWTP through the liquid line, water is separated from waste. Treated water moves down the liquid line while sludge/waste moves down the sludge line. The kind and the condition of equipment used in both lines are crucial as they directly affect the efficiency of treatment. Figure 3 below describes the status of the equipment of these SWWTPs.

Figure 3-Major Treatment Elements and Equipment in All Plants

Major Treatment Elements Chouf/Jezzine Plants Beqaa Plants

L

IQ

U

ID

L

IN

E

L

IQ

U

ID

L

Raw Sewage Pumping Station

Raw sewage is either pumped by one submersible pump with one standby pump or flows by gravity (no pumping used).

Raw sewage is pumped by three submersible pumps (two operational and one stand-by).

Primary Settling Tank

One settling tank in each plant.

There are two primary settling tanks.

Biological Reactor

One trickling filter and two aeration tanks (except in Rihane where there is no trickling filter).

Two trickling filters.

Recirculation Pumps There are no recirculation pumps to the trickling filter.

Trickling filter recirculation pumps are supplied.

Air Pump There is only natural ventilation for the trickling filter.

There are ventilation pumps for the trickling filters.

Major Treatment Elements Chouf/Jezzine Plants Beqaa Plants

Final Clarifier One clarifier (final). Two to three clarifiers.

Contact Tank and Chlorination A chlorine contact. Chlorine gas injection is used.

A chlorine contact basin. The effluent is not disinfected with chlorine.

Filter Pumps and Pressure Filters Filtration system (Sand and Carbon filter pumps).

The effluent is not filtered.

Management of treated effluent The effluent is disposed in nearby watercourses.

The effluent is disposed into Litani river.

S L

U D

G E

L

Sludge Holding Tank There are aerated sludge storage tanks.

Anaerobic digesters are used as sludge holding and thickening tanks.

Sludge Treatment/Stabilization The sludge is stabilized in a sludge-holding tank.

The sludge is treated in anaerobic digesters with recycling/transfer pumps used for mixing.

Sludge Dewatering Unit The sludge is kept in open air-drying lagoons.

The sludge is kept in open air-drying lagoons.

Sludge Disposal The sludge is disposed for agricultural use.

The sludge is not reused.

RESULTS OF ON-SITE PARAMETER AND LABORATORY ANALYSIS

On-site measurements of pH and temperature and laboratory results for WW collected from each of the SWWTPs are summarized in Figures 4 and 5 below. ELVs were provided for reference and comparison.

Figure 4- Table of pH and Temperature - Measured On-Site Parameters Results

Reference Temperature pH

Specific

Conductivity

Salinity

TDS

Inf. Eff. Inf. Eff. Inf. Eff. Inf. Eff. Inf. Eff.

(°C) (µS/cm) mg/L mg/L

Treatment Type "A" 30 (ELV) 5-9 (ELV)

El Khraibe WWTP 13.80 14.60 7.86 7.78 1,227 975 666 530 869 692

Jbaa WWTP 23.70 22.90 7.67 7.74 839 837 458 459 595 595

El Moukhtara/Boutme

WWTP

33.20

27.00

7.86

7.78

1,273

Aammatour WWTP 16.10 12.10 - 13.49 1,447 1,023 833 577 1,030 727

Niha/Bater WWTP 26.60 26.10 7.95 7.58 1,176 943 652 515 833 665

Maasser El Chouf WWTP 14.60 12.50 8.48 8.05 1,166 962 642 508 822 680

Mrousti WWTP 17.30 14.40 7.90 7.81 1,446 1,097 784 586 1,030 778

**Barti WWTP - - - - - - - - - -

Rihane WWTP 23.00 22.20 8.27 7.38 1,415 1,357 792 753 1,000 961

Treatment Type "B"

Ablah WWTP 16.40 15.10 8.19 7.90 1,430 899 788 493 1,010 723

El Fourzol WWTP 28.40 31.60 7.56 7.83 1,832 1,438 1,030 807 1,270 1,020

Aaitanit WWTP 28.50 25.50 8.09 8.58 1,292 1,099 719 605 916 778

Figure 5-Laboratory Analysis Results

Reference

BOD COD BOD/COD TSS TN TP

Total

Coliforms Fecal

Coliforms Oil and Grease

Inf. Eff.

Rem Inf. Eff.

Rem Inf. Eff. Inf. Eff.

Rem.

Inf. Eff.

Rem.

Inf. Eff.

Rem.

Eff. Eff. Inf. Eff

Rem mg/L mg/L mg/L mg/L mg/L CFU/100 mL.

CFU/100

mL.

mg/L

Maximum Allowable Limits for Receiving Water Bodies- Surface Water (MoE Decision 8/1)

Treatment Type "A"

El Khraibe WWTP 225 16 92.90 641 68 89.40 0.35 0.24 92 7.00 92.40 71 6.00 91.50 50.60 1.10 97.80 11,000 9,000 35 18 48.60

Jbaa WWTP 1,700 30 98.30 2,193 55 97.50 0.78 0.55 3,000 18.00 99.40 56 24.00 57.20 60.00 17.70 70.50 TNTC TNTC 178 <5 97.20

El Moukhtara/Boutme

WWTP

203 14 93.10 274 45 83.60 0.74 0.31 181 2.00 98.90 31 16.00 48.40 19.00 8.00 57.90 TNTC 14,000 24 18 25.00

Aammatour WWTP 471 130 72.40 2,700 200 92.60 0.17 0.65 162 22.00 86.40 84 3.00 96.40 36.30 5.70 84.30 TNTC TNTC 14 <5 64.30

Niha/Bater WWTP 178 5 97.20 550 38 93.10 0.32 0.14 120 13.00 89.20 43 8.20 80.90 14.50 0.03 99.80 TNTC 7,000 <5 <5 -

Maasser El Chouf

WWTP

315 15 95.20 538 60 88.80 0.59 0.25 126 0.30 99.80 63 26.20 58.40 54.00 28.80 46.70 63,000 15,000 24 5 79.20

Mrousti WWTP 500 29 94.20 792 96 87.90 0.63 0.30 148 22.40 84.70 3 1.20 60.00 36.70 35.80 2.50 TNTC TNTC 24 33 37.50

**Barti WWTP - - - - - - - - - - - - - - - - - - - - - -

Rihane WWTP 449 35 92.20 1,600 327 79.60 0.28 0.11 98 33.00 66.30 78 20.00 74.40 20.00 7.00 65.00 TNTC TNTC <5 25 -400

Treatment Type "B"

Ablah WWTP 96 10 89.60 349 60 82.80 0.28 0.17 194 12.00 93.8 32 16.90 47.20 17.30 20.00 -15.60 TNTC 69,000 16 6 62.50

El Fourzol WWTP 604 53 91.20 1,740 124 92.90 0.35 0.43 890 42.00 95.30 41 17.00 58.60 6.50 4.70 27.70 TNTC 8,100 30 93 -210

Aaitanit WWTP 314 5 98.40 463 23 95.00 0.68 0.22 132 8.00 94 49 40.00 18.40 8.00 4.0 50.00 TNTC 3,300 270 16 94.00

The increase in the oil and grease level for the Rihane and El Fourzol SWWTPs is due to the oil and grease coming to the WWTP in low quantities where they float on the surface of the clarifier and accumulates. Then they overflow from the clarifier and are directed to the effluent outlet. This was observed during the site visits and the oil and grease were noticed going out of the clarifier by the overflowing process and going directly to the effluent. This will induce the increase of the oil and grease level in the tests done to the effluent.

TECHNICAL AND ADMINISTRATIVE LIMITATIONS AND CHALLENGES

Two operation management systems were identified in the SWWTPs. The seven SWWTP located in the Chouf Caza were operated by the Beirut Mount Lebanon Water Establishment (BMLWE). The operations staff included seven laborers, two technicians, and one engineer. The remaining five SWWTP were operated and maintained by local municipalities or union of municipalities with one technician in each plant.

SWWTPs have not been a priority for RWEs and/or municipalities. This lack of proper management coupled with decreasing resources has resulted in technical, as well as administrative limitations and challenges, which have negatively affected the operation of the plants assessed.

Technical Limitations and Challenges

Designed and constructed under less stringent regulatory standards, these plants are currently under-operated because of mismanagement. They need technical upgrades and improvement in management practices to operate properly at full capacity. In addition, financial resources are so constrained that even when management approves some plant upgrades, operators still experience long delays in the procurement process. Main technical limitations identified during the assessment include:

The SWWTPs did not have automated instrumentation or telemetric systems for operation, which made them highly dependent on operator's skills and availability.

The capacity utilization reports revealed that nine of the 12 SWWTPs operated between 14 and 47 percent of their treatment capacity. Two plants operated at between 51 to 60 percent of their capacity. The majority of plants had plans for sewage collection network expansion to increase wastewater volumes nearer to their design capacity. This lack of initial planning between the construction of SWWTPs and networks must be coordinated in the future.

There was an overflow for excess water during heavy rainfall at the inlet of the WW tank of the SWWTPs. The overflow allowed for excess water to be diverted into a nearby water body/stream to avoid flooding during heavy rainfall.

The influent contained high levels of BOD, COD, and phosphorous. The levels were considerably higher than the design values for some of the SWWTPs. In some cases, industrial wastewater was discharged into the domestic sewage network without pre-treatment as mandated by the MoE Decision 8/1/2001.

Excessive scum: oil, grease, and foam build-ups were visible at the surface of the settling tanks and aeration tanks, in addition to floating activated sludge.

Sludge was held longer than necessary in the system or recirculated in excess of the tank capacity.

Dried sludge was stored in sludge drying ponds for long periods with no analysis of its components to assess the treatment efficiency and the sludge’s potential use as fertilizer.

Necessary operational testing instruments or accessories were not found in the plants.

Preventive maintenance on mechanical and electrical equipment was not routinely performed and long delays often occurred before critical equipment repair.

Administrative Limitations and Challenges

RWEs tariffs imposed and collected were not sufficient to cover the SWWTPs operation and maintenance.

Operators and staff did not have the expertise to differentiate between normal effluent variability and variations in effluent that require response/action.

The number of staff members managing the plant was not sufficient.

The inattentiveness of management and lack of financial resources has resulted in the decline of the morale of operating personnel and the prevalence of poor operating, maintenance, and housekeeping practices.

The majority of the SWWTPs were constructed and put into operation without consideration of proper sludge management.

Operators were not informed about proper sludge handling, treatment, and disposal measures.

Contracts issued to operators were not performance-based, which made it difficult to assess the actual performance of operators, and did not provide any incentive for improved performance.

The relatively small size of these facilities did not create economies of scale for the purchase of chemicals, supplies, or materials. This resulted in an inability for contract operators to recruit and retain qualified operators.

There was no written Emergency Response Plan and no management plan in any of the plants.

Operators did not receive safety training.

No special measures were followed for chemicals handling and storage.

There was no sustainable energy source in any of the plants.

ANALYSIS AND LESSONS

LEARNED

The TF and EA technologies being exclusively used at the assessed SWWTPs, the consultant first carried out a technical comparison between the TF and Extended Aeration (EA) treatment technologies based on a desk review of reference studies. This was done to identify the optimal technology to operate these SWWTPs. In this quantitative and qualitative comparison, the consultant adopted a scoring system/scale from 0-2, with higher scores indicating better performance. Figure 6 below summarizes this technical comparison.

Figure 6-Technical Comparison of Extended Aeration and Trickling Filter Processes/Technologies

Area of Comparison Extended Aeration (Score) Trickling Filter (Score)

Required Area Smaller (2) Larger (5 - 10 %) (1)

Capital Cost Lower (2) Higher (10-25 %) (1)

Operating Cost (Power) Higher (1) Lower (40 - 60 %) (2)

Effluent Quality Better (5 – 15 %) (2) Good (prone to high suspended solids) (1)

Ability to Treat Industrial Wastewater

Prone to failure (largely due to variability) (0)

Good (1)

Fly/Odor Nuisance Limited (1) Can be high (0)

Head Loss Low (0.3 m) (1) High (2 – 5 m) (0)

Mechanical Equipment Requirement

High (aeration system, return & waste sludge pumps) (1)

Low (delivery / recirculation pumps, distributor arm) (2)

Sludge Handling Requirement Higher (1) Lower (20 – 40 % less volume) (2)

Ability to Nitrify/Denitrify Generally, nitrifies only (1) Generally, nitrifies only (1)

Process Control Complex (1) Simple (2)

Required Operators Few staff with high skill levels (1) Few staff with medium skills (2)

Removal Efficiency 95% (2) 80 - 85% (1)

Operation & Maintenance Problems

Continual control of Sludge content and Recirculation (-0)

Less frequent (2)

Climate Effect Problems during dry months (1) Best at high ambient temperatures (2)

Overall Scoring 17 20

Ref.: (Bliss 1983, Ch. 4-5; Metcalf & Eddy 1991; Amenu 2014; Moodie 1979; EPA 2008)

This technical comparison resulted in finding that TF technology is more appropriate than EA for SWWTPs. TF technology is more flexible, less complicated to operate and maintain, and requires lower operational costs.

The consultant then carried out an economic comparison of TF and EA technologies based on reference studies for the cost of WWTP built in Lebanon during the past 8 years following the completion of the technical comparison. Figure 7 below summarizes this economic comparison.

Figure 7-Economic Comparison of Methods of Wastewater Treatment in Rural Areas

Area of Comparison Extended Aeration Trickling Filter

Area Share (m2/m3/d) 2 - 3.5 3 - 6

Construction Cost ($/m3/d) 600 - 750 500 - 750

Power Cost ($/m3/d) 1.4 - 2.8 0.5 - 1.5

Labors Cost ($/m3/d) 3.0 - 6.0 2.0 - 3.0

O&M Cost ($/m3/d) 0.54 - 0.6 0.1 - 0.3

Chemical and Laboratory costs

($/m3/d) 0.5 - 0.7 0.1 - 0.3

The main finding from this economic comparison is the fact that TF technology is less costly than EA technology, and could potentially be adopted for future SWWTPs.

In a third and final step, the consultant reviewed the laboratory analysis results in conjunction with its technical and economic comparison findings. This resulted in the following specific recommendations, technical and administrative, to remedy and mitigate identified limitations and challenges, and ultimately improve the operation of these SWWTPs.

TECHNICAL LESSONS LEARNED

Based on the technical assessment of the technologies and equipment used in the assessed WWTPs, Consultant offered the recommendations listed below to technically enhance the operation of the assessed WWTPs:

Combine TF and EA technology for improved treatment of WW. TF technology is the most cost effective because of its low O&M costs. However, a combination of TF and EA has proven to be the most successful treatment option for these SWWTPS. Even if TF and EA treatment are not, on their own, a biological nutrition removal processes (BNR), enhanced treatment of wastewater was achieved through a combination of both TF and EA in eight of the audited plants. TF treatment minimized operating costs and acted as the main organic treatment unit, while the activated sludge system (with significantly reduced aeration requirements) reduced nitrogen and polished the effluent.

This conclusion is supported by the results from wastewater sampling and analysis, which revealed that all plants except for Fourzol, Aammatour, Mrousti, and Jbaa, meet Lebanese ELVs. These plants even achieved significant levels of di-nitrification and di-phosphatisation, although originally not designed for such purpose.

Mitigate risks related to flies and odors through design criteria and enhance ability for high recirculation. The location of any future SWWTP should be as far as practical from residential areas and be accessible year round. Additional space around the plant should be set aside for future upgrades.

Establish a comprehensive approach for SWWTP O&M. It should include, but not limited to, operating schedules, key performance indicators (KPIs), data collection and monitoring, responses with corrective actions, standard operating procedures (SOP), and work instructions. O&M plans must be incorporated into the design process, and receive appropriate review and approvals along with the SWWTP engineering designs.

Develop a preventive maintenance plan for each SWWTP. The plan must ensure proper use and functioning of equipment in accordance with the manufacturer’s requirements. Maintenance should be carried out by a qualified operator (preferably an engineer) assisted by skilled helpers and qualified technicians (electrician, plumber, mechanic, laboratory technician, etc.).

Include sludge management in the design. Sludge management is a key element of a successful wastewater treatment strategy. Sludge uses should be defined and potential users identified during the design. The selection of the final destination of sludge should also be integrated and planned during this phase and should be approved by the sludge receiving authorities/stakeholders.

Evaluate alternative energy sources as part of every design. Minimizing energy consumption and identifying alternative sources of energy for the plants is needed to increase operating periods in an effort to obtain 24/7, 365 days/year operation.

ADMINISTRATIVE LESSONS LEARNED

For purposes of efficiency and sustainable operation, technical improvements must be combined with administrative improvements in management practices and managerial skills of operators and staff.

Administrative recommendations include:

Establish a Wastewater Management Department in all RWEs to oversee WW operations and improve services. This department will manage contracts with private sector operators and gradually develop in-house capacity for WW O&M.

Stakeholders identification and management should be a primary element of the plant’s design.

Identifying stakeholders that could be affected directly or indirectly by the treatment plant and engaging them in the process from the design stage would significantly decrease risks of conflicts and problems during plant operation.

Cultural and socio-political considerations should form an integral part of the stakeholders’ identification process. It is recommended that both, cultural acceptance and political buy-in, are secured at all levels starting with the identification phase all the way to the commissioning and operation phase. This will secure needed buy-in and acceptance of the projects at the decision making level and will facilitate the smooth operation of the plant in the long run.

It is critical that, during the identification of potential sites for low cost sanitation solutions, enough time is invested in consultations. These consultations should be open and transparent and should include all relevant stakeholders be it at the national government or local administrative level.

Consultations should ensure the buy-in of these stakeholders including the community where the site is being selected and those who will benefit from the service.

For those low cost sanitation solutions operated, or to be operated, by RWEs, it is recommended to consider collaborating with the private sector in operating and maintaining these facilities. The collaboration with the private sector should be governed by performance-based contracts establishing a well-structured public private partnership. It is economically advisable to group or bundle a number of smaller plants under the scope of one operator or a single contract to improve efficiency and minimize operational costs. The same can apply to facilities operated or managed by municipalities or union of municipalities.

At the policy level, implement the legal mandate for RWEs to manage wastewater. This should be backed by an organizational structure that supports such mandate in addition to a tariff structure that includes WWT as a service.

Despite including it under the technical aspects, sludge management also has a social aspect. After drying the sludge, it can be valorized and tested to ensure the quality is suitable for agriculture use as soil conditioner or trucked for landfilling. This is why facilities with considerable sludge production should be accompanied during the design phase with a civic engagement program to include potential sludge users (farmers) or operators of disposal sites so that it is not kept as a burden on the operator affecting the efficiency of the facility.

As RWEs are starting to manage WWT facilities there should be a focus to develop and implement a capacity-building program in each RWE for managing WW treatment plant O&M contracts.

Develop O&M Plans for each SWWTP. The plans must include equipment use and operation, monitoring programs, reports and logbooks, and health and safety plans. The procedures should outline the systematic tasks that employees are required to carry out in order to ensure the long-term sustainability of the WWTP.

For additional detailed recommendations and cost estimates specific to each of the plants, assessed reference should be made to Figure 8 below. The recommendations below have been divided into four categories of priority, with the first category for the most pressing upgrades needed and the fourth category for the least pressing upgrades.

ASSESSMENT SWWTPS 15

Figure 8-Recommendations and Cost Estimates

RECOMMENDATIONS

Kraibeh Jbaa

El Moukhtara/

Boutme Aammatour

Niha/ Bater

Maaser El Chouf

Mrousti Ablah El

Fourzol Aaitanit Barti Rihane

Total

$US

FIRST PRIORITY* 7,500 7,500 7,500 19,000 20,000 7,500 7,500 3,500 3,500 15,000 20,450 31,950 150,900

SECOND PRIORITY* 25,400 25,400 25,400 25,000 25,400 25,400 25,400 4,000 4,000 4,000 22,200 22,200 233,800

THIRD PRIORITY* 14,425 14,825 14,425 14,425 14,825 14,425 14,425 5,500 5,500 5,500 14,625 16,875 149,775

FOURTH PRIORITY* $13,320 10,170 10,170 12,920 10,170 10,570 10,570 0 10,170 16,620 104,680

MISCELLANEOUS* 11,250 11,250 11,250 11,250 11,250 10,500 10,500 1,100 1,100 1,100 19,000 19,000 118,550

71,895 69,145 68,745 82,595 81,645 68,395 68,395 14,100 14,100 25,600 86,445 106,645 757,705

* For detailed information on the priority listing, please refer to the main report