Issuu on Google+

Group One Project Management Expertise, Technology, Results

Business Case Initiation Phase

Client

Revision

Date

Compiled

Checked

Approved

B

03/03/13

LM/JC/FK

JC

JC

Board of Management AIT C/o Group One Project Management Ltd, Athlone, Co. Westmeath

B.Eng(Hons) Civil Engineering


Group One Project Management

Contents Contents ................................................................................................................................ i Table of Figures ................................................................................................................... iii Table of Tables .................................................................................................................... iii 1

Executive Summery ...................................................................................................... 1 1.1

Current Issues ........................................................................................................ 1

1.2

Anticipated Outcomes ........................................................................................... 1

1.3

Recommendation .................................................................................................. 1

1.4

Justification ............................................................................................................ 2

2

Business Case Analysis Team ....................................................................................... 2

3

Problem Definition ....................................................................................................... 2

4

Project Overview .......................................................................................................... 3 4.1

Project Description ................................................................................................ 3

4.2

Goals and Objectives ............................................................................................. 3

4.3

Project Performance .............................................................................................. 3

4.4

Project Assumptions .............................................................................................. 4

4.5

Project Constraints ................................................................................................ 4

4.6

Major Milestones................................................................................................... 5

5

Strategic Alignment ...................................................................................................... 5

6

Appraisal ....................................................................................................................... 6 6.1

Site Appraisal ......................................................................................................... 6

6.2

Extended-Aeration System .................................................................................... 6

6.2.1

Description ..................................................................................................... 6

6.2.2

Application ..................................................................................................... 6

6.2.3

Monitoring...................................................................................................... 6

i


Group One Project Management 6.2.4

Sludge Treatment ........................................................................................... 7

6.2.5

Maintenance .................................................................................................. 7

6.2.6

Advantages and Disadvantages ..................................................................... 7

6.2.7

Construction and Running Cost Estimate ...................................................... 8

6.2.8

Capital Investment Appraisal ....................................................................... 13

6.3

6.3.1

Description ................................................................................................... 15

6.3.2

Application ................................................................................................... 15

6.3.3

Theory and fundamentals ............................................................................ 16

6.3.4

Outputs......................................................................................................... 17

6.3.5

Advantages and Disadvantages ................................................................... 17

6.3.6

Construction and Running Cost Estimate .................................................... 18

6.3.7

Capital Investment Appraisal ....................................................................... 22

6.4

7

Submerged Aeration Filter System...................................................................... 15

Pumped Flow Biofilm Reactor ............................................................................. 24

6.4.1

Description ................................................................................................... 24

6.4.2

Application ................................................................................................... 24

6.4.3

Monitoring.................................................................................................... 25

6.4.4

Sludge Treatment ......................................................................................... 25

6.4.5

Maintenance ................................................................................................ 25

6.4.6

Advantages ................................................................................................... 26

6.4.7

Costs ............................................................................................................. 26

6.4.8

Capital Investment Appraisal ....................................................................... 30

6.5

Selection Criteria Analysis ................................................................................... 31

6.6

Selection of Treatment System ........................................................................... 32

Approvals.................................................................................................................... 33

ii


Group One Project Management

Table of Figures Figure 4.1 – Initial project milestones .................................................................................. 5 Figure 6.1 – Extended-Aeration System ............................................................................... 7 Figure 6.2 – Preliminary sketch scheme layout ................................................................... 8 Figure 6.3 – Submerged aeration filter system .................................................................. 15 Figure 6.4 – Simplified process flow diagram (Ewert 2013) .............................................. 15 Figure 6.5 – Pumped Flow Biofilm Reactor above ground (MolloyPrecast 2013) ............. 24 Figure 6.6 – Average influent and effluent data (MolloyPrecast 2013) ............................ 25

Table of Tables Table 2.1 – Business case analysis team .............................................................................. 2 Table 4.1 – Performance measures ..................................................................................... 4 Table 6.1 – Civil Works Cost Estimation Table (Extended Aeration) ................................... 9 Table 6.2 – Mechanical and Electrical Works Cost Estimation Table (Extended Aeration) 9 Table 6.3 - Civil Works/Mechanical and Electrical Cost Summary Table (Extended Aeration) ............................................................................................................................................ 12 Table 6.4 – Running Cost Particulars (Extended Aeration) ................................................ 13 Table 6.5 – Net present project expenditure over 20 year lifecycle (Extended Aeration) 14 Table 6.6 - Civil Works Cost Estimation Table (Submerged Aeration Filter) ...................... 19 Table 6.7 - Mechanical and Electrical Works Cost Estimation Table (Submerged Aeration Filter) .................................................................................................................................. 19 Table 6.8 – Running Cost Estimates per Annum ................................................................ 22 Table 6.9 – Net Present Value for SAF System ................................................................... 23 Table 6.10 – Civil Works Cost Estimation Table (PFBR) ..................................................... 27 Table 6.11 – Mechanical and Electrical Works Cost Estimation Table (PFBR) ................... 27 Table 6.12 - Civil Works/Mechanical and Electrical Cost Summary Table (PFBR) ............. 29 Table 6.13 – Running Cost Particulars (PFBR) .................................................................... 30 Table 6.14 – Net present cost of PFBR system .................................................................. 31 iii


Group One Project Management Table 6.15 Selection factors for treatment system ........................................................... 32

iv


Group One Project Management

1 Executive Summery This business case outlines how the proposed waste water treatment plant project will address the current waste water discharge concerns, the benefits of the project, and recommendations and justification of the project. The business case also discusses detailed project goals, performance measures, assumptions, constraints, and alternative options. Three site locations were appraised based on social, economic and environmental factors. As a result of this appraisal a location was chosen for the proposed treatment plant directly to the South of the Engineering building in AIT. To select a suitable wastewater treatment system certain criteria needed to be fulfilled. These included initial costs, operating costs and performance factors. Three systems were appraised under these conditions and the submerged aeration filter system was chosen.

1.1 Current Issues Due to problems associated with the acceptance of untreated waste water to the Athlone Town waste water treatment system, Athlone Institute of Technology is now required to treat the waste water discharged from the Engineering Building on site. The treatment system will need to treat the waste water from 400PE with a long term capacity of 500PE.

1.2 Anticipated Outcomes The construction and operation of this waste water treatment facility will ensure that the discharge water from the facility will meet the Urban Waste Water Treatment Regulations 2010. There will be a BOD loading under the recommended regulation value discharging to the Athlone Town waste water treatment plant. The expected discharge properties will be in line with current Urban Wastewater Treatment Regulations 2010 (S.I No. 48 of 2010)

1.3 Recommendation The main option available to AIT for the discharge of wastewater to the Athlone Town sewer network was to treat the wastewater to the current wastewater regulation standard. The desired resulting output from treating the water will only be achieved by 1


Group One Project Management the implementation of a treatment facility which will meet the required BOD5, suspended solids and COD values.

1.4 Justification The provision of a wastewater treatment facility serving the Engineering building at AIT is a direct result of the constraints imposed by Westmeath Co. Co. as a requirement of planning.

2 Business Case Analysis Team Table 2.1 outline the individuals that were part of the formation of the business case. Table 2.1 – Business case analysis team Role Senior Responsible Owner Technology Support Project Management Design

Description Provide executive support for the project Provides all technology support for the project Manages the business case and project team Provide information on design specifications

Name/Title Mr. Paul Dolan Various WWT consultants, Frank Casey Jason Corbett, Luke Molloy, Frank Kenna Jason Corbett, Luke Molloy, Frank Kenna

The individuals listed above are responsible for the analysis and creation of the AIT Engineering Building wastewater treatment facility project.

3 Problem Definition The new Engineering building at AIT is expected to have 400 users at opening and is predicted to have a capacity of 500 users in the future. This will lead to a significant increase in both the hydraulic loading, and more significantly the biological loading, on the current wastewater treatment facility in Athlone. Due to the current facility in Athlone and the sensitive areas associated with the discharge of treated effluent from this plant, the EPA has enforced a limit on the extra loading to this plant. For this reason any further discharges to the sewerage network must have 2


Group One Project Management effluent values which are deemed satisfactory for discharge into rivers or the groundwater.

4 Project Overview The project overview provides details as how the provision of an onsite wastewater treatment facility will address the problem with discharging raw effluent to the town sewer. The overview consists of a project description, goals and objectives for the wastewater treatment facility project along with project performance criteria, project assumptions, constraints, and major milestones.

4.1 Project Description Several types of wastewater treatment technologies will be reviewed and analysed. This will be done by assessing each option for their advantages and disadvantages coupled with a cost benefit analysis using the Net Present Value technique to assess running, operational and maintenance costs over a 20 year time frame.

4.2 Goals and Objectives The overall goal of the project is to construct a waste water treatment facility in the most economically and environmentally advantageous manner bearing in mind initial outlay and long term asset costs.

4.3 Project Performance The performance of the project as a whole will depend on several key functions being undertaken. Proper communications throughout the project planning and execution will ensure all stakeholders are informed as necessary when needs be. The key resources and performance measures are listed in Table 4.1 below. These performance measures will be quantified and further defined in the detailed project plan.

3


Group One Project Management Table 4.1 – Performance measures Key Resource/Process/Service Reporting

Staff Resources

Performance Measure Online collaboration systems will reduce reporting discrepancies (duplicates and gaps) and require reconciliation every 3 months instead of monthly. Adequate staff resources will be deployed to areas in need as the project manager sees fit.

4.4 Project Assumptions Project assumptions are made on an on-going basis and may need to be added to or adjusted as the project plan develops. The following is a preliminary list of assumptions made: 

The project has executive level support and backing from AIT Board of Management

Funding has been made available for the design and construction of a wastewater treatment facility on the premises

Planning constraints should be relaxed as the demand from Westmeath County Council have stipulated the requirement to discharge only treated water to the sewerage network

Users of the college have been informed of the disruption and that there will be a wastewater treatment facility on site

The project management and design teams have adequate resources and experience to see the project through

4.5 Project Constraints The following constraints apply to the current project. As project planning begins and more constraints are identified, they will be added accordingly. 

The system that is chosen to treat the wastewater from the engineering building must meet the regulations set out in the EPA guidelines

There are limited options for a viable location for the treatment plant 4


Group One Project Management 

Issues such as smell and noise are of greater concern than a traditional wastewater treatment plant due to its close proximity to buildings and large populations

There is a limited schedule

4.6 Major Milestones The major project milestones identified at this time are highlighted in Figure 4.1. As the project planning moves forward and the schedule is developed, the milestones and their target completion dates will be modified, adjusted, and finalized as necessary to establish the baseline schedule. These milestones will be highlighted and monitored weekly on the progress Gantt chart.

Figure 4.1 – Initial project milestones

5 Strategic Alignment This project will support AIT’s strategy and strategic plans in order to add value and maintain executive and organisational support.

5


Group One Project Management

6

Appraisal

6.1 Site Appraisal Considering all the social, economic and environmental factors of each site that was appraised in the AIT Site Selection document, site one, located at the Southern end of the engineering building stands out as the most viable option. Socially the site is located in an area which is seldom used by the college community and could be relatively easy to conceal aesthetically with proper landscaping. Environmentally the site is the easiest of the three to control noise and the dispersal of odours and is located furthest away from the buildings within the campus. On the economic front the site will provide for gravity fed collection and discharge of influents and effluents and will have the least site preparation costs. In addition only minor works will be required for efficient and safe access to the treatment facility, if located at site one.

6.2 Extended-Aeration System 6.2.1 Description This appraisal option provides for the treatment of wastewater from the Engineering building of Athlone Institute of Technology by means of an Extended-Aeration Activated Sludge (EAAS) system. This type of system is characterised by low loading rates and long hydraulic retention times. The Figure 6.1 shows the typical arrangement for the system. Properly designed and operated extended-aeration systems can be expected to produce a wastewater with BOD5 and SS levels less than 30 mg/l, 90 % of the time and less than 20 mg/l, 50% of the time. 6.2.2 Application Extended-aeration systems are widely used and are constructed either of in-situ concrete or assembled on site as a pre-packaged system. Most systems discharge wastewater to surface waters directly, but, have also been used for treatment prior to land application. 6.2.3 Monitoring Monitoring requirements may include system inflow and wastewater flows, suspended solids concentrations and substrate concentrations. Operational monitoring should

6


Group One Project Management include MLSS, aeration tank dissolved oxygen, pH, sludge settleability, alkalinity, return sludge flow, and sludge wastage rate.

Figure 6.1 – Extended-Aeration System

6.2.4 Sludge Treatment No sludge treatment would be allowed for with this system, alternatively sludge storage would be provided with storage capacity up to two months. A nominal fee would be paid to the Local Authority for the removal and treatment of the sludge off site. 6.2.5 Maintenance Operation and maintenance requirements for an extended-aeration facility are high because of the general complexity of the equipment, and the need for skilled and regular operator supervision. 6.2.6 Advantages and Disadvantages Advantages   

Relatively low initial cost Relatively low sludge production High quality wastewater achievable 7


Group One Project Management     

Reliable with sufficient operator attention Relatively minimal land requirements Nitrification can occur Moderate shock loadings can be handled with minimal problems Service of 20 years with proper maintenance

Disadvantages      

High power consumption High operation and maintenance costs Skilled operators necessary Blower noise, aerosols and sludge handling odour/ need for careful sludge management Alarm systems required to indicate malfunction Characteristic tests on the wastewater are required on a daily basis for the proper operation of the system.

6.2.7 Construction and Running Cost Estimate The estimated costs for the construction and running of an extended-aeration system to service a population equivalent of 500 discharging from Athlone Institute of Technology’s Engineering building are based off the preliminary sketch scheme layout below.

Figure 6.2 – Preliminary sketch scheme layout

8


Group One Project Management It is expected that the system would comprise of;    

Inlet works with flow measurement system and grit removal. Influent sump with submersible pump feeding 2.8x5.6m aeration tank. Clarifier, sludge holding tank, air jet pumping station and sludge pumping station. Control building housing Scada control system and wastewater test apparatus.

Table 6.1 – Civil Works Cost Estimation Table (Extended Aeration) Ite m No 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Civil Works DESCRIPTION

Inlet / intermediate pumping stations Preliminary Treatment Plant Biological treatment units Final settlement / Sludge Return Sludge Draw-Off and Transfer Sludge Thickening/Storage Plant Interconnecting pipework and ductwork including site drainage, wash water pipework etc. Outfall pipelines and tidal flaps Site Roads and Paving Site Fencing, Gates and Walls Landscaping Administration & Control Building Site Investigation Collection and discharge sewer works and pavement reinstatement Total for Civil Works

Total Price

37,500 8,600 26,700 36,500 1,400 10,800 70,000 31,500 44,400 36,800 16,900 6,500 9,000 150,000 €486,600

Table 6.2 – Mechanical and Electrical Works Cost Estimation Table (Extended Aeration) Mechanical & Electrical Works Item DESCRIPTION No Interception of Wastewater /Preliminary Treatment 1 Screening Equipment Screening Equipment - list components (i) Mechanical screen/integral compactor (ii) Bypass screen 2 Access covers

Total Price

13,200 1,750 5,000 9


Group One Project Management Total for Interception of Wastewater / Preliminary Treatment

€19,950

Item DESCRIPTION No Main Treatment Plant 1 Pumping Stations Any item required for the inlet/intermediate pumping stations list below (i) Foul pumps (ii) Pipework, valves and fittings 2 Biological Treatment Biological Treatment Units - list components (i) Flow distribution chamber (ii) STM aerators (iii) Pipework, valves and fittings

Total Price

3

4

Final Settlement Final Clarification Units - list components (i) Rotating bridge (ii) Motor (iii) Pipework, valves and fittings Any other items included by tenderer - list below (i) Lifting (ii) Access platforms Total for Main Treatment Plant

Item DESCRIPTION No Sludge Draw-off, Transfer, Storage and Thickening, Odour Control 1 Sludge Return Equipment - list components (i) Sludge pumps (ii) Pipework, valves and fittings 2

3

4

5,400 1,820

21,600 2,190 650

13,800 2,000 1,100

1,500 1,800 €51,860 Total Price

4,900 1,800

Sludge waste equipment - list components (i) Control valves

2,100

Sludge thickening / storage - list components (ii) Pipework, valves and fittings

1,240

Odour Control (i) Sludge tank OCU Total for Sludge Draw-off, Transfer, Storage and Thickening, Odour Control

1,600 €11,640

10


Group One Project Management Item DESCRIPTION No Instrumentation / Miscellaneous Flow Measurement 1 Flow meter - list components (i) Inlet (ii) Full treatment (iv) Overflow (v) Outlet

2

3 4 5 6 7 8 9 10

Level Measurement Level Measurement Process Instrumentation Dissolved oxygen measurement in biological treatment MLSS measurement in biological treatment Influent and effluent samplers Furniture and fittings for buildings Laboratory equipment Workshop equipment Hot and cold water supplies Heating and ventilation equipment Total for Instrumentation / Miscellaneous

Item DESCRIPTION No Electrical Installation / Controls 1 Low / Medium / High Voltage Switchgear, Transformers and Cabling 2 Standby power generation 3 Electrical installation/cabling 4 Domestic Electrics, Lighting / Sockets, Site Lighting 5 Fire, Intruder, Gas Alarm Systems 6 Earthing and Lightning Protection Systems 7 Main control panel / switchboard / switchgear including PFC, VSDs etc. 8 PLC/Control System - list components below (i) PLC/Control System (ii) Telemetry 9 SCADA - List components below (i) HMI (ii) Programming and configuration Total for Electrical Installation / Controls Item DESCRIPTION No Testing / Commissioning and Training 1 Tests at manufacturers works

Total Price

1,800 1,150 1,200 1,800

5,100

1,425 2,650 5,450 1,100 1,500 700 1,200 500 â‚Ź25,575 Total Price 2,100 11,800 19,500 9,600 1,950 900 27,600

7,100 5,800 7,000 3,400 â‚Ź96,750 Total Price 950 11


Group One Project Management 2 3 4

Preparation and Submission of Commissioning Plan Start-up and Commissioning of Works Operation and Maintenance of Works During Notification and Performance Validation Period Performing Testing on Completion of the Design-Build Works in accordance with Section 8 (including costs of sampling to determine compliance with Employer's Requirements). Operation and Maintenance of Works during Reporting and Evaluation Period upon successful completion of Performance Validation Period and prior to issuing of Taking Over Certificate Tests after completion (at end of Operation and Maintenance Period) Spares and consumables required for the testing and commissioning period Total for Testing / Commissioning and Training

5

6

7 8

1,400 2,800 3,000 3,200

2,500

1,500 750 â‚Ź16,100

Table 6.3 - Civil Works/Mechanical and Electrical Cost Summary Table (Extended Aeration) Ite m No 1 2 3 4 5 6 7 8

Civil Works/Mechanical and Electrical Cost Summary DESCRIPTION

Civil Works Total for Civil Works Mechanical and Electrical Total for Interception of Wastewater / Preliminary Treatment Total for Main Treatment Plant Total for Sludge Draw-off, Transfer, Storage and Thickening, Odour Control Total for Instrumentation / Miscellaneous Total for Electrical Installation / Controls Total for Testing / Commissioning and Training Design and Planning Fees Total cost estimate

Total Price

486,600 19,950 51,860 11,640 25,575 96,750 16,100 50,000 â‚Ź708,475

12


Group One Project Management Table 6.4 – Running Cost Particulars (Extended Aeration) Ite m No 1

Running Cost Particulars per annum DESCRIPTION

Aeration pumping based on 12hr usage and 14c per kWhr

Total Price

5,300

2

Influent pumping based on 6hrs/day

800

3

Sludge pumping based 3hrs/day

650

4

Grit removal screen and control systems

5

Operator costs

30,000

6

Sludge disposal

2,000

7

Maintenance per annum

4,000

8

Control building utility bills Total running costs per annum

1,800

2,500 €47,050

6.2.8 Capital Investment Appraisal Assumptions made;  

2% increase in running costs per annum over 20 year lifecycle. Discount factor for future cost cash flows taken as 10%.

13


Group One Project Management Table 6.5 – Net present project expenditure over 20 year lifecycle (Extended Aeration)

Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

31/12/2013 31/12/2014 31/12/2015 31/12/2016 31/12/2017 31/12/2018 31/12/2019 31/12/2020 31/12/2021 31/12/2022 31/12/2023 31/12/2024 31/12/2025 31/12/2026 31/12/2027 31/12/2028 31/12/2029 31/12/2030 31/12/2031 31/12/2032

Extended Aeration System P.V. D.F. N.C.F. € 10% € 42,773 0.9091 47,050 39,662 0.8264 47,991 36,777 0.7513 48,951 34,103 0.6830 49,930 31,623 0.6209 50,928 29,323 0.5645 51,947 27,190 0.5132 52,986 25,213 0.4665 54,046 23,379 0.4241 55,127 21,679 0.3855 56,229 20,102 0.3505 57,354 18,640 0.3186 58,501 17,284 0.2897 59,671 16,027 0.2633 60,864 14,862 0.2394 62,081 13,781 0.2176 63,323 12,779 0.1978 64,590 11,849 0.1799 65,881 10,988 0.1635 67,199 10,188 0.1486 68,543

Total Present Running Cost Plus Initial Cost Net Present Cost

458,222 708,475 1,166,697

14


Group One Project Management

6.3 Submerged Aeration Filter System 6.3.1 Description This is a Biofilm aerated filter system which consists of a primary settlement tank, aerated (forced) submerged biofilm filter and a secondary settlement all incorporated a single unit. Figure 6.3 shows the typical layout of the inner workings of the submerged aeration filter system.

Figure 6.3 – Submerged aeration filter system

6.3.2 Application Readymade design tanks to cater for PE of 100 to 2500 as shown in Figure 6.4.

Figure 6.4 – Simplified process flow diagram (Ewert 2013)

15


Group One Project Management 6.3.3 Theory and fundamentals The SAF treatment process consists of high void space media that is submerged in wastewater and typically aerated from beneath. Rusten1 (1984) states that such treatment has been in use around the world for more than 50 years, with stone, coke, laths and ceramic materials among the media types used. The main developments in the technology have been in the major elements of the process design: media choice, backwash options, applied loading rates, and solids-liquid separation methods. SAFs are a relatively simple treatment process. They incorporate attached growth biological kinetics (through formation of a bio-film on either fluidized or rigid carrier media), and a degree of suspended growth biological kinetics. Pollutants within the wastewater are oxidized biologically by both fixed and suspended biomass and oxygen is typically supplied by diffused (fine or course bubble) aeration. There are various names associated with this type of technology, such as Integrated Fixed Film Activated Sludge (IFAS), and Moving Bed Bio Reactor (MBBR) and others. The process can be used to remove organic carbon, achieve nitrification (the conversion of ammonia to nitrate through aeration), and under specific configurations can provide denitrification (conversion of nitrate to nitrogen gas in the absence of dissolved oxygen) although this is much more limited and much less predictable in terms of process kinetics. A SAF system typically consists of a reactor tank containing submerged media (typically plastic that has high void space and high specific surface area), to which microorganisms attach and create a bio-film. The media is aerated from beneath and oxygen and organic matter in the wastewater are absorbed into the bio-film. As the bio-film thickness increases, due to concentration gradients less organic matter and oxygen can penetrate to the interior of the bio-film resulting in a loss of food and oxygen for the microorganisms clinging to the media surface. These microorganisms eventually can no longer cling to the media surface and are “sloughed� off and a new bio-film begins to grow. The bio-film that detaches from the media (through natural sloughing as well as hydraulic shear and air scour) is suspended in the reactor tank, and is eventually washed out of the SAF reactor by displacement from the incoming wastewater.

16


Group One Project Management Adequate aeration must be provided to ensure sufficient oxygen can be absorbed into the bio-film in order to satisfy the biological oxygen demand. In addition, aeration provides the mixing energy for the system that is essential to ensure contaminant and oxygen transfer to the biomass as well as aiding in the biomass sloughing process. Following the reactor tank is some form of solid-liquid separation device and typically a conventional clarifier or lamella clarifier is used. The solids that are displaced from the SAF reactor are gravity thickened at the clarifier base and withdrawn on a continuous or semicontinuous basis for further processing, while the clarified effluent passes out of the clarifier over a weir arrangement at the top. Clarifier size requirements are typically less than the requirements for an equivalent sized activated sludge plant, due to the low solids flux applied to the clarifier as a result of having the majority of the biology fixed within the reactor tank. Also some form of primary treatment is usually required to reduce otherwise problematic oil and grease concentrations, non-degradable and inert particulate material and gross solids. This reduces the loading on to the SAF reactors and protects the media from organic overloading and fouling with inert or difficult to degrade material (Ewert 2013). 6.3.4 Outputs Average values from treatment:    

BOD5 – 10.1mg/l Suspended solids – 4.3mg/l NH4-N – 8.4mg/l Total Nitrogen – 10.6mg/l

6.3.5 Advantages and Disadvantages Advantages:      

Operate in up flow, down flow and horizontal flow conditions Denitrification, carbonaceous oxidation and nitrification can take place in tanks in series or in a single tank if it is properly designed. The level of operator skill required is less for that of the activated sludge system Adequate for shock loading Low noise levels No fly nuisance 17


Group One Project Management

Disadvantages:        

Periodic backwashing required Need for grease and oil to be removed from influent Requires pumps and compressors Granular media may leave reactor Foaming Sludge disposal and treatment Need for disposal of backwash waters Complex control system

6.3.6 Construction and Running Cost Estimate Items needed to be priced:      

Primary settlement tank and screening device Sludge storage facility Pumps and compressors Actual unit Control system Backwash tank

Associated costs:        

Land and fencing Earthworks Pipework’s and fittings Media Operation and maintenance Monitoring Sludge treatment Backwash water processing

18


Group One Project Management Table 6.6 - Civil Works Cost Estimation Table (Submerged Aeration Filter) Ite m No 1 2 3 4 5 6 7 8 9 10 11 12 13

Civil Works DESCRIPTION

Inlet / intermediate pumping stations Preliminary Treatment Plant SAF Unit Final settlement / Sludge Return Sludge Draw-Off and Transfer Sludge Thickening/Storage Plant Interconnecting pipe work and ductwork including site drainage, wash water pipe work etc. Site Roads and Paving Site Fencing, Gates and Walls Landscaping Administration & Control Building Site Investigation Collection and discharge sewer works and pavement reinstatement Total for Civil Works

Total Price

37,500 10,000 20,000 36,500 1,400 10,800 70,000 44,400 36,800 16,900 6,500 9,000 150,000 â‚Ź409,840

Table 6.7 - Mechanical and Electrical Works Cost Estimation Table (Submerged Aeration Filter) Mechanical & Electrical Works Item DESCRIPTION No Interception of Wastewater /Preliminary Treatment 1 Screening Equipment Screening Equipment - list components (i) Mechanical screen/integral compactor (ii) Bypass screen 2 Access covers Total for Interception of Wastewater / Preliminary Treatment

Item DESCRIPTION No Main Treatment Plant 1 Pumping Stations Any item required for the inlet/intermediate pumping stations list below (i) Foul pumps (ii) Pipe work, valves and fittings 2 SAF Unit Treatment (iii) Pipe work, valves and fittings

Total Price

13,200 1,750 5,000 â‚Ź19,950

Total Price

5,400 1,820 650 19


Group One Project Management

3

4

Final Settlement Final Clarification Units - list components (i) Rotating bridge (ii) Motor (iii) Pipe work, valves and fittings Any other items included by tenderer - list below (i) Lifting (ii) Access platforms Total for Main Treatment Plant

Item DESCRIPTION No Sludge Draw-off, Transfer, Storage and Thickening, Odour Control 1

2

3

4

13,800 2,000 1,100

1,500 1,800 â‚Ź28,070 Total Price

Sludge Return Equipment - list components (i) Sludge pumps (ii) Pipe works, valves and fittings

4,900 1,800

Sludge waste equipment - list components (i) Control valves

2,100

Sludge thickening / storage - list components (ii) Pipe works, valves and fittings

1,240

Odour Control (i) Sludge tank OCU Total for Sludge Draw-off, Transfer, Storage and Thickening, Odour Control

Item DESCRIPTION No Instrumentation / Miscellaneous Flow Measurement 1 Flow meters - list components (i) Inlet (ii) Full treatment (iv) Overflow (v) Outlet

1,600 â‚Ź11,640

Total Price

1,800 1,150 1,200 1,800

2

Level Measurement Level Measurement

5,100

3

Process Instrumentation Dissolved oxygen measurement in effluent treatment

1,425 20


Group One Project Management 4 5 6 7 8 9

Influent and effluent samplers Furniture and fittings for buildings Laboratory equipment Workshop equipment Hot and cold water supplies Heating and ventilation equipment Total for Instrumentation / Miscellaneous

Item DESCRIPTION No Electrical Installation / Controls 1 Low / Medium / High Voltage Switchgear, Transformers and Cabling 2 Standby power generation 3 Electrical installation/cabling 4 Domestic Electrics, Lighting / Sockets, Site Lighting 5 Fire, Intruder, Gas Alarm Systems 6 Earthing and Lightning Protection Systems 7 Main control panel / switchboard / switchgear including PFC, VSDs etc. 8 PLC/Control System - list components below (i) PLC/Control System (ii) Telemetry 9 SCADA/Telemetry - List components below (i) HMI (ii) Programming and configuration Total for Electrical Installation / Controls Item No 1 2 3 4 5

6

7 8

DESCRIPTION Testing / Commissioning and Training Tests at manufacturers works Preparation and Submission of Commissioning Plan Start up and Commissioning of Works Operation and Maintenance of Works During Notification and Performance Validation Period Performance Testing on Completion of the Design-Build Works in accordance with Section 8 (including costs of sampling to determine compliance with Employer's Requirements). Operation and Maintenance of Works during Reporting and Evaluation Period upon successful completion of Performance Validation Period and prior to issuing of Taking Over Certificate Tests after completion (at end of Operation and Maintenance Period) Spares and consumables required for the testing and commissioning period Total for Testing / Commissioning and Training

5,450 1,100 1,500 700 1,200 500.00 €22,925 Total Price 2,100 11,800 19,500 9,600 1,950 900 27,600

7,100 5,800 7,000 3,400 €96,750 Total Price 950 1,400 2,800 3,000 3,200

2,500

1,500 750 €16,100 21


Group One Project Management Table 6.8 – Running Cost Estimates per Annum Ite m No 1

Running Cost Particulars per annum € DESCRIPTION

SAF Unit based on 24hr usage and 14c per kWhr

Total Price

10,600

2

Influent pumping based on 6hrs/day

800

3

Sludge pumping based 1hrs/day

200

4

Grit removal screen and control systems

5

Operator costs

10,000

6

Sludge disposal

1,000

7

Maintenance per annum

6,000

8

Control building utility bills Total running costs per annum

1,800

2,500 €32,900

6.3.7 Capital Investment Appraisal Assumptions:  

2% increase in running cost per annum 10% discount factor taken for present value

22


Group One Project Management Table 6.9 – Net Present Value for SAF System

Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

31/12/2013 31/12/2014 31/12/2015 31/12/2016 31/12/2017 31/12/2018 31/12/2019 31/12/2020 31/12/2021 31/12/2022 31/12/2023 31/12/2024 31/12/2025 31/12/2026 31/12/2027 31/12/2028 31/12/2029 31/12/2030 31/12/2031 31/12/2032

N.C.F. € 32,900 33,558 34,229 34,914 35,612 36,324 37,051 37,792 38,548 39,319 40,105 40,907 41,725 42,560 43,411 44,279 45,165 46,068 46,989 47,929

Total Present Cost Plus Initial Cost Net Present Cost €

SAF System D.F. 10% 0.9091 0.8264 0.7513 0.6830 0.6209 0.5645 0.5132 0.4665 0.4241 0.3855 0.3505 0.3186 0.2897 0.2633 0.2394 0.2176 0.1978 0.1799 0.1635 0.1486

P.V. € 29,909 27,734 25,717 23,847 22,112 20,504 19,013 17,630 16,348 15,159 14,057 13,034 12,086 11,207 10,392 9,636 8,936 8,286 7,683 7,124

320,414 605,275 925,689

23


Group One Project Management

6.4 Pumped Flow Biofilm Reactor 6.4.1 Description In a Pumped Flow Biofilm Reactor (PFBR) aeration is achieved by alternately exposing biofilm attached to plastic media in each of the two reactor tanks to atmospheric air, thereby eliminating the need for forced aeration. Anoxic/anaerobic conditions are achieved by keeping the biofilm media immersed. This is a new technology and has been developed and patented by an NUI Galway Civil Engineering research team and extensively tested at laboratory-scale and field-scale. Figure 6.5 shows a PFBR structure.

Figure 6.5 – Pumped Flow Biofilm Reactor above ground (MolloyPrecast 2013)

6.4.2 Application In a typical treatment cycle settled wastewater is pumped into reactor 1. Simultaneously, treated effluent is pumped from reactor 2. Wastewater is repeatedly transferred between reactor 1 and reactor 2. This process alternatively exposes the biofilm to the atmosphere and bulk fluid and is the main aeration mechanism, thus, no mechanical forced aeration system is required. This process lasts for the duration of the treatment cycle which is 24


Group One Project Management generally between 6 and 8 hours. To achieve anoxic/ aerobic periods, the bulk fluid is simply keeping the biofilm immersed for a period of time. To enhance the energy efficiency when transferring liquid between the reactors an equalisation valve is provided, this allows liquid levels to equalise in each tank by gravity. The remaining liquid is transferred using a pump. The average influent and effluent data for a plant that was designed for 600PE is shown in Figure 6.6.

Figure 6.6 – Average influent and effluent data (MolloyPrecast 2013)

6.4.3 Monitoring Monitoring requirements may include system inflow and wastewater flows, suspended solids concentrations and substrate concentrations. Operational monitoring should include MLSS, aeration tank dissolved oxygen, pH, sludge settleability, alkalinity, return sludge flow, and sludge wastage rate 6.4.4 Sludge Treatment Sludge production would be considerably less for this type of system compared with activated sludge plants. Sludge could be pumped out and held in a holding tank before it is removed. 6.4.5 Maintenance Due to the employment of no moving parts except for those in the hydraulic pumps and motorised valve, maintenance is kept to a minimum. Cleaning is the only maintenance

25


Group One Project Management required to ensure that the readings from the DO, ORP and pH sensors are not influenced by biofilm growth. Pumps are usually maintained on a bi-annual basis or when required. 6.4.6 Advantages Advantages: 

Relatively low initial cost

Relatively low sludge production

High quality wastewater achievable

Ease of operation and maintenance

Relatively minimal land requirements

Few moving parts

Simple Construction

Low operating cost

Disadvantages: 

Relatively new technology

High number of pumps which may need replacement

Control of biofilm thickness is difficult

Little information on long term performance

Deep excavation may be required

6.4.7 Costs Items needed to be priced:  Primary settlement tank and balance tank  Sludge storage facility  Pumps and compressors  Actual unit  Control system Associated costs:     

Land and fencing Earthworks Pipework’s and fittings Media Operation and maintenance 26


Group One Project Management   

Monitoring Sludge treatment Backwash water processing

Table 6.10 – Civil Works Cost Estimation Table (PFBR) Civil Works Item DESCRIPTION No 1 PFBR Unit including Primary Tank, Buffer Tank, Feed Reactor and Discharge Reactor 2 Outfall pipelines and tidal flaps 3 Site Roads and Paving 4 Site Fencing, Gates and Walls 5 Landscaping 6 Site Investigation 7 Collection and discharge sewer works and pavement reinstatement Total for Civil Works

Total Price 106,000 31,500 44,400 36,800 16,900 9,000 150,000 €394,600

Table 6.11 – Mechanical and Electrical Works Cost Estimation Table (PFBR) Mechanical & Electrical Works Item DESCRIPTION No Primary Tank/Buffer Tank 1 Pumps Automatic Sludge Return Pump (x2) = [1,400 x 2] 2 Access covers Total for Interception of Wastewater / Preliminary Treatment

Item DESCRIPTION No Main Treatment Unit 1 In Built Control Room (i) Foul pumps (x3)= [3,000 x 3] (ii) Pipework, valves and fittings 2 Feed Reactor Feed Reactor - list components (i) Biological Media (ii) Pipework, valves and fittings 3

Discharge Reactor Discharge Reactor - list components (i) Biological Media (ii) Pipework, valves and fittings

Total Price

2,800 600 €3,600

Total Price

9,000 1,820

3,000 650

3,000 650 27


Group One Project Management

4

Any other items included by tenderer - list below (i) Lifting (ii) Access platforms Total for Main Treatment Plant

Item DESCRIPTION No Instrumentation / Miscellaneous Flow Measurement 1 Flow meter - list components (i) Inlet (ii) Full treatment (iv) Overflow (v) Outlet

2

3 4 5 6 7 8 9 10

Level Measurement Level Measurement Process Instrumentation Dissolved oxygen measurement in biological treatment MLSS measurement in biological treatment Influent and effluent samplers Furniture and fittings for buildings Laboratory equipment Workshop equipment Hot and cold water supplies Heating and ventilation equipment Total for Instrumentation / Miscellaneous

Item DESCRIPTION No Electrical Installation / Controls 1 Low / Medium / High Voltage Switchgear, Transformers and Cabling 2 Standby power generation 3 Electrical installation/cabling 4 Domestic Electrics, Lighting / Sockets, Site Lighting 5 Fire, Intruder, Gas Alarm Systems 6 Earthing and Lightning Protection Systems 7 Main control panel / switchboard / switchgear including PFC, VSDs etc. 8 PLC/Control System - list components below (i) PLC/Control System (ii) Telemetry 9

SCADA - List components below (i) HMI

1,500 1,800 â‚Ź18,720 Total Price

1,800 1,150 1,200 1,800

5,100

1,425 2,650 5,450 1,100 1,500 700 1,200 500 â‚Ź25,575 Total Price 2,100 11,800 19,500 9,600 1,950 900 27,600

7,100 5,800

7,000 28


Group One Project Management (ii) Programming and configuration Total for Electrical Installation / Controls Item No 1 2 3 4 5

6

7 8

DESCRIPTION Testing / Commissioning and Training Tests at manufacturers works Preparation and Submission of Commissioning Plan Start-up and Commissioning of Works Operation and Maintenance of Works During Notification and Performance Validation Period Performing Testing on Completion of the Design-Build Works in accordance with Section 8 (including costs of sampling to determine compliance with Employer's Requirements). Operation and Maintenance of Works during Reporting and Evaluation Period upon successful completion of Performance Validation Period and prior to issuing of Taking Over Certificate Tests after completion (at end of Operation and Maintenance Period) Spares and consumables required for the testing and commissioning period Total for Testing / Commissioning and Training

3,400 €96,750 Total Price 950 1,400 2,800 3,000 3,200

2,500

1,500 750 €16,100

Table 6.12 - Civil Works/Mechanical and Electrical Cost Summary Table (PFBR) Ite m No 1 2 3 5 6 7 8

Civil Works/Mechanical and Electrical Cost Summary DESCRIPTION

Civil Works Total for Civil Works Mechanical and Electrical Total for Primary Tank/ Buffer Tank Total for Main Treatment Unit Total for Instrumentation / Miscellaneous Total for Electrical Installation / Controls Total for Testing / Commissioning and Training Design and Planning Fees Total cost estimate

Total Price

€394,600 3,600 18,720 25,575 96,750 16,100 50,000 €605,345

29


Group One Project Management Table 6.13 – Running Cost Particulars (PFBR) Running Cost Particulars per annum Item DESCRIPTION No 1 Estimated running costs are 11.5 Kwh per day = 4197.5KWh per year (@ 0.17 cent per KWh) 2 Grit removal screen

Total Price 713 1,800

3

Operator costs

20,000

4

Sludge disposal

2,000

5

Maintenance per annum

4,000

6

Utility bills Total running costs per annum

2,500 €31,013

6.4.8 Capital Investment Appraisal Assumptions made;  

2% increase in running costs per annum over 20 year lifecycle. Discount factor for future cost cash flows taken as 10%.

30


Group One Project Management Table 6.14 – Net present cost of PFBR system

Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

31/12/2013 31/12/2014 31/12/2015 31/12/2016 31/12/2017 31/12/2018 31/12/2019 31/12/2020 31/12/2021 31/12/2022 31/12/2023 31/12/2024 31/12/2025 31/12/2026 31/12/2027 31/12/2028 31/12/2029 31/12/2030 31/12/2031 31/12/2032

Extended Aeration System N.C.F. D.F. P.V. € 10% € 31,013 0.9091 28,194 31,633 0.8264 26,143 32,266 0.7513 24,242 32,911 0.6830 22,479 33,569 0.6209 20,844 34,241 0.5645 19,328 34,926 0.5132 17,922 35,624 0.4665 16,619 36,337 0.4241 15,410 37,063 0.3855 14,290 37,805 0.3505 13,250 38,561 0.3186 12,287 39,332 0.2897 11,393 40,119 0.2633 10,564 40,921 0.2394 9,796 41,739 0.2176 9,084 42,574 0.1978 8,423 43,426 0.1799 7,810 44,294 0.1635 7,242 45,180 0.1486 6,716

Total Present Cost Plus Initial Cost Net Present Cost

302,037 605,345 907,382

6.5 Selection Criteria Analysis To select which treatment system to use for this project, a scoring system has been applied to several factors, which are outlined in the EPA document Treatment Systems for Small Communities, Business, Leisure Centres and Hotels. The scores that each system received for each factor is outlined below.

31


Group One Project Management Table 6.15 Selection factors for treatment system Selection Factors Rating System : 1 = poor 2 = Moderate 3 = Good the ability to treat the expected load to the requirad standard accreditation of the product additional costs prior to commissioning annual running cost capital cost construction requirements prior to delivery of components delivery or construction time design, criteria (including the minimum loading the system can accept) distance to nearest habitation durability ease of inspection ease of operation environmental impact expected operating life of the system experience in use of similar systems final wastewater discharge location fly and odour nuisance guarantees head loss through system health, safety and welfare considerations installation and commissioning agreements maintenance service available/provided means of desludging noise levels recommendations from owners of similar system recommended daily, weekly and annual maintenance requirements regulatory requirements resilience to shock and noxious loadings restart difficulties risk of environmental pollution robustness safety of the installation seasonal factors site requirements sludge production and frequency of desludging sludge storage in system start up time and procedure type of wastewater collection system visual impact

Submerged Pumped Extended-Aeration Aeration Filter Flow Biofilm System System Reactor 3 3 2 1 2 2 1 2 3 3 3 1 3 3 3 3 1 3 3 2 3 3 3 2 3 1 3 3 1 3 3 3 2 2 3 3 2 2 3 95

3 3 2 2 2 3 2 2 3 3 3 2 3 3 3 3 3 3 3 3 3 2 3 2 3 2 3 3 3 3 2 3 3 3 2 2 3 3 3 105

3 1 3 3 3 3 3 2 3 2 3 2 3 3 2 3 3 3 3 3 3 3 3 3 1 3 3 3 1 3 3 3 3 3 3 3 2 3 3 106

6.6 Selection of Treatment System Based on the capital investment appraisal and the results of scoring the selection criteria factors, it is proposed that the Pumped Flow Biofilm REACTOR be used for this project. This system had the lowest net present cost and it was felt that because it scored

32


Group One Project Management significantly higher than the alternative systems in the scoring of the selection criteria, it had the most advantages for this project.

7 Approvals The signatures of the people below indicate an understanding in the purpose and content

of this document by those signing it. By signing this document you indicate that you approve of the proposed project outlined in this business case and that the next steps may be taken to create a formal project in accordance with the details outlined herein Approver Name Title Signature Paul Dolan Senior Responsible Owner Tom Farrell Financial Controller

Date

33


Group One Project Management

Bibliography

Ewert, J. (2013) Submerged Aeration Filters A atreatment Solution for Small Communities. [Online].

Available

at:

http://www.awtwater.com/docs/publications/2008publications/nzwwa/awt_sub mergedaeratedfilters_290908.pdf [Accessed: 20/01/2012]. Molloyprecast (2013) Municipal Wastewater Treatment System. [Online]. Available at: http://molloyprecast.com/sewage-treatment-systems/municipal.html [Accessed: 20/01/2013]. O'reilly, E., Rodgers, M. & E., C. (2013) Water Science & Technology 64:6 (2011) 1218-1225 - E. O'Reilly et al. - Operation of a full-scale pumped flow biofilm reactor (PFBR) under two aeration regimes. Water Science & Technology. [Online] 64, 1218-1225. Available at: http://www.iwaponline.com/wst/06406/wst064061218.htm.

34


Business Case