Sanaa WWTP Upgrade (English)

1Upgrade of Sana'a WWTP14.03.2005

Upgrade of the Sana‘aUpgrade of the Sana‘aWastewater Treatment Plant Wastewater Treatment Plant

Presentation of the DesignPresentation of the Design

Implementation of the New Preliminary Implementation of the New Preliminary Wastewater and Sludge Treatment Wastewater and Sludge Treatment

FacilitiesFacilities

14.03.2005 Upgrade of Sana'a WWTP 2

TopicsTopics BackgroundBackground Goals of the ProjectGoals of the Project Design CriteriaDesign Criteria Objectives of the DesignObjectives of the Design The Final DesignThe Final Design Implementation / CostImplementation / Cost


1994: Design of the new Sana‘a WWTP by Howard Humphreys, UK, 1994: Design of the new Sana‘a WWTP by Howard Humphreys, UK, as activated sludge process with simultaneous sludge stabilizationas activated sludge process with simultaneous sludge stabilization

1999: Turn-Key Implementation of the new Sana‘a WWTP (Financing 1999: Turn-Key Implementation of the new Sana‘a WWTP (Financing World Bank); Start of operation through Degremont, France (1 year)World Bank); Start of operation through Degremont, France (1 year)

2000: Takeover and responsible Operation through Sana’a Water 2000: Takeover and responsible Operation through Sana’a Water and Sanitation Local Corporation (SWSLC)and Sanitation Local Corporation (SWSLC)

Operational Problems right from the very beginning of operation:Operational Problems right from the very beginning of operation:

Overloading of WWTP due to high BODOverloading of WWTP due to high BOD55-concentration-concentration

High operation costs due to high energy consumption High operation costs due to high energy consumption Sludge not stabilized causing odor nuisance Sludge not stabilized causing odor nuisance Odorous nuisance along the inlet trunk main sewer Odorous nuisance along the inlet trunk main sewer Utilization of treated wastewater and sludge for irrigation / agriculture Utilization of treated wastewater and sludge for irrigation / agriculture had not been solved had not been solved

1 Background1 Background


Remedying Measure: Execution of a Feasibility Study Remedying Measure: Execution of a Feasibility Study (August 2000(August 2000 until May 2001) until May 2001)

Decision for Implementation of Decision for Implementation of Sana‘a WWTP UpgradeSana‘a WWTP Upgrade (10/2002)(10/2002)

Preparation of Final Design + Tender Documents according to FIDIC Preparation of Final Design + Tender Documents according to FIDIC „Red„Red Book“ Book“ Consultant: CONSULAQUA Hamburg GmbH Consultant: CONSULAQUA Hamburg GmbH

1 Background1 Background


Implementation of technical measures for upgrade ofImplementation of technical measures for upgrade of

Sana’aSana’a WWTP (design flow Q = 65,000 m³/d in 2020) WWTP (design flow Q = 65,000 m³/d in 2020)

Improvement of treatment efficiency + operational stability Improvement of treatment efficiency + operational stability

Reduction of external energy input Reduction of external energy input

Improvement of the quality of dried sludge to allow Improvement of the quality of dried sludge to allow

proper sludge marketing proper sludge marketing

Implementation of technical measures to reduce massive Implementation of technical measures to reduce massive

odor problems to a tolerable levelodor problems to a tolerable level

2 Goals of the Project2 Goals of the Project


3 Design Criteria3 Design Criteria

Effluent RequirementsEffluent Requirements

BOD5 < 30 mg/l (inflow: BOD5 = 1,100 mg/l)

SS < 30 mg/l (inflow: SS = 1,200 mg/l) pathogen removal:

- Coliform Germs < 1,000/100 ml- Worm eggs < 1/Liter Avoidance of infections to those working on irrigated

fields and those consuming vegetables grown on fields

Existing wastewater treatment stage will be fully able to fulfil effluent requirements if sludge problem is solved


Original Design

Existing Situation

Start of Operation

Design Horizon

Design Horizon / Target Year - 1995 2004 2008 2020

INFLOWDaily Wastewater Inflow m³/d 50.000 36.000 50.000 50.000

Peak factor (max flow/average flow) - 3,0 2,0 2,0 2,0 Safety factor - 1,0 1,0 1,0 1,3 Maximum Treatment Capacity m3/d 50.000 36.000 50.000 65.000

BOD5

BOD5-concentration mg/l 500 1.100 1.100 1.100

BOD5-load kg/d 25.000 39.600 55.000 71.500

Specific BOD5-pollution load g/cap*d 55 55 55 55 Pollution load (Population Equivalents) PE 454.545 720.000 1.000.000 1.300.000

SUSPENDED SOLIDS SS-concentration mg/l 750 1.070 1.070 1.070 SS-load kg/d 37.500 38.520 53.500 69.550 Specific SS-pollution load g/cap*d 82,5 53,5 53,5 53,5

Design Criteria UnitBOD-Elim. / Sim. Aerobic Stab. BOD5-Elim. / Anaerobic Digestion

Wastewater Characteristics / Target YearsWastewater Characteristics / Target Years

3 Design Criteria3 Design Criteria


4 Objectives of the Design4 Objectives of the Design

High safety of operation High safety of operation (( redundant systems, hydraulic redundant systems, hydraulic crosswise connections) crosswise connections)

O & M-requirementsO & M-requirements ( ( easy handling & maintenance of easy handling & maintenance of treatment facilities)treatment facilities)

Staff requirements Staff requirements (( number and skills of staff number and skills of staff degree degree and complexity of automation)and complexity of automation)

Local availability of material, equipment and Local availability of material, equipment and consumablesconsumables

Minimization of investment costsMinimization of investment costs Essential savings in operation costsEssential savings in operation costs Minimization of environmental impactsMinimization of environmental impacts (odor, noises) (odor, noises) Future extension possibilitiesFuture extension possibilities ( ( modular structure of modular structure of

plant layout, extension areas)plant layout, extension areas)


5 The Final Design5 The Final Design

Technical Measures to be implemented Technical Measures to be implemented under the Sana’a WWTP Upgrade Projectunder the Sana’a WWTP Upgrade Project New Inlet Pumping Station with pre-applied Coarse New Inlet Pumping Station with pre-applied Coarse

ScreensScreens

Fine ScreensFine Screens

Primary Settling Tanks / New Distribution Chamber Primary Settling Tanks / New Distribution Chamber

Retention BasinRetention Basin

Primary Sludge ThickenersPrimary Sludge Thickeners

Anaerobic Digesters (incl. Auxiliary Building)Anaerobic Digesters (incl. Auxiliary Building)

Stabilized Sludge Thickeners Stabilized Sludge Thickeners

Co-Generation Plant + Co-Generation Plant + Boiler StationBoiler Station

Gasholders with gasflareGasholders with gasflare

Adaptation of Electrical Power Supply and Distribution Adaptation of Electrical Power Supply and Distribution

Additional 44 Sludge Drying Beds Additional 44 Sludge Drying Beds

Odor Control Measures Odor Control Measures

WWTPUpgrade

SludgeTreatment

OdorControl


The new The new plant layout plant layout in complete in complete overviewoverview

Arrangement of New Plant Arrangement of New Plant Layout (newLayout (newstructures in RED color)structures in RED color)++ 4 4 clearlyclearly defined operational areas: defined operational areas: IPS/Mechanical Wastewater IPS/Mechanical Wastewater TreatmentTreatment Biological Wastewater Treatment Biological Wastewater Treatment Sludge Treatment Sludge Treatment Gas Utilization Gas Utilization+ + Connection of new with existing Connection of new with existing facilitiesfacilities is easy is easy continuation of operation continuation of operation duringduring construction construction++ Future Extension of Plant is very easy Future Extension of Plant is very easy++ O & M requirements can be kept at O & M requirements can be kept at acceptable standards acceptable standards


The new The new layout layout in detailin detail

Mechanical Wastewater Mechanical Wastewater TreatmentTreatmentNew: Coarse / Fine Screens, Inlet New: Coarse / Fine Screens, Inlet PS, Aerated Grit Chambers, PS, Aerated Grit Chambers, Primary Settling Tanks and Primary Settling Tanks and Magnetic Flow MeterMagnetic Flow Meter+ Logical and modular arrangement of + Logical and modular arrangement of Screens,Screens, Grit Chambers and Primary Settling Grit Chambers and Primary Settling TanksTanks allowing easy extension in quantity allowing easy extension in quantity

+ + Separate Coarse and Fine Screens resultSeparate Coarse and Fine Screens result in higher efficiency, easier unloading of in higher efficiency, easier unloading of screenings, and better O & M conditions screenings, and better O & M conditions

+ New aerated grit chambers provide high + New aerated grit chambers provide high gritgrit removal efficiency (protection of new removal efficiency (protection of new digesters)digesters)

++ The logical spatial arrangement of the The logical spatial arrangement of the mechanical treatment facilities allows for mechanical treatment facilities allows for improved hydraulic conditions improved hydraulic conditions

+ Construction of the new mechanical + Construction of the new mechanical treatmenttreatment facilities can be carried out in one take facilities can be carried out in one take withoutwithout interfering plant operation interfering plant operation

+ Emergency overflow can be further used+ Emergency overflow can be further used

- - The new arrangement requires The new arrangement requires construction ofconstruction of a new Inlet Pumping Station and a new Inlet Pumping Station and extension ofextension of the main incoming sewer the main incoming sewer



Biological Wastewater Biological Wastewater TreatmentTreatmentConversion of Simultaneous Conversion of Simultaneous Sludge Stabilization to Sludge Stabilization to Activated Sludge Process Activated Sludge Process (Carbon removal only)(Carbon removal only)+ All tanks and connecting pipes can be + All tanks and connecting pipes can be

further used further used+ Existing Inlet Pumping Station can be + Existing Inlet Pumping Station can be usedused as Return Sludge Pumping Station as Return Sludge Pumping Station+ Mixing of pre-treated wastewater and+ Mixing of pre-treated wastewater and return sludge and the following return sludge and the following distributiondistribution on to 8 treatment lines can be on to 8 treatment lines can be facilitated by facilitated by construction of only one additional construction of only one additional structure structure



Sludge Treatment3 new Digesters @ 10.000 m3, Gravity Thickeners for Primary Sludge & Digested Sludge (4 in total), 2 Gas Holders, Co-Generation Plant, Boiler Station+ Implementation of third Digester considerably improves operational and process safety+ Expensive Polymers will not be needed anymore+ Due to new spatial arrangement all sludge thickeners can be fed by gravity+ Short distances between digester and thickeners allow for reduced pumping cost+ Gas Utilization facilities are very close together+ Gas Utilization allows for considerable reduction of specific energy supply from external sources (approx. 65 %)


The new The new Digesters Digesters (Profile)(Profile)



Odor Control3 Biological Filters close to the new Screen Building, Return Sludge Pump Station, and PS Thickeners+ Easy to operate and maintain+ Low running cost+ High Efficiency


5 The Final Design5 The Final Design

Power Supply ConceptPower Supply Concept

Introduction of 4 gas generator sets, each rated @ Introduction of 4 gas generator sets, each rated @ 626 kW626 kW Balance of Total Power Requirement for future Balance of Total Power Requirement for future Sana‘a WWTPSana‘a WWTP

Maximum Power Reduction is 25%Maximum Power Reduction is 25% Considering the extended capacity (increase of treatment Considering the extended capacity (increase of treatment capacitycapacity from 450,000 PE up to 1,000,000 PE,) the specific power from 450,000 PE up to 1,000,000 PE,) the specific power consumptionconsumption of Sana‘a WWTP can be reduced by approx. 67% of Sana‘a WWTP can be reduced by approx. 67%


Implementation (planned)Implementation (planned)

09/2005:09/2005: Award of Contract Award of Contract 10/2007:10/2007: Commencement of Operation under Responsibility of the Commencement of Operation under Responsibility of the Contractor + Start of Staff Training (1 Year) Contractor + Start of Staff Training (1 Year) 10/2008: 10/2008: Takeover through SWSLCTakeover through SWSLC

Investment Cost (estimated)Investment Cost (estimated)

Civil WorksCivil Works:: 18.2 Mil. USD (incl. Sludge Drying 18.2 Mil. USD (incl. Sludge Drying Beds) Beds) Mechanical Works: Mechanical Works: 5.8 Mil. USD 5.8 Mil. USD Electrical Works: Electrical Works: 2.6 Mil. USD2.6 Mil. USD Incontingencies: Incontingencies: 1.6 Mil. USD 1.6 Mil. USD Engineering: Engineering: 1.8 Mil. USD 1.8 Mil. USD GRAND TOTALGRAND TOTAL 30.0 Mil. USD30.0 Mil. USD

6 Implementation & Cost6 Implementation & Cost


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