DELHI JAL BOARD WSP SOUTH ASIA

APPENDIX 1
to PARTICULAR SPECIFICATIONS

Commissioning and Decommissioning of Pipelines, District Isolation Test

Method Statement Preparation Guidelines

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP)

WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS

Method Statement Preparation Guidelines

Page 2 of 13

Scope of Work
Part of the works is represented by the replacement of pipes. It is intended to have those pipes in service at the time of the first night flow test. Suggestion for Method Statement for the commissioning of new pipes and the decommissioning of old, not anymore usable, pipes and for District Metered Area Isolation Test are given hereafter. However, the Contractor is requested to prepare and submit own Method Statement as mentioned in the Particular Specifications. The commissioning, the decommissioning of pipes and the Isolation Test have to satisfy the Engineer, and it has to be made sure that no water is lost, safety regulations are kept and the nuisance to the population is kept to a minimum.

Method Statement for: Commissioning of replacement pipes

General
Installation of pipes, replacing old, obsolete, leaking pipes, will be done in strict compliance with the Specifications, part of the Contract.

2.1

2.2

Completed work
The following works are to be completed before a request to connect new pipes can be made: Pipes are to be laid in appropriate lengths of generally not more than 500 meters. Pipes are to be pressure tested, disinfected and flushed. House connections are to be installed including re-orientation of the water meter, pressure tested, disinfected, flushed, connected to the main and re-tested.

2.3

Connection of pipeline
After coordination with DJB and the Engineer the pipe can be connected into the existing distribution system. The network shall than be used once to feed the house connections through the new piping, on DJBs supply day to the area, to make sure that all plots are served properly.

2.4

Commissioning
Having all works completed, the connections at the pipe and the house connections checked with the consent of DJB, the new system could be commissioned, taken into permanent use.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 3 of 13

Method Statement for: Decommissioning of replaced pipes

General
Disconnection of the old, obsolete network will be carried out in compliance with the contractual obligations and according to the instructions of the Engineer.

3.1

3.2

Coordination
Coordination has to be made with DJB and the Engineer as to the work procedure. Also the date of expected decommissioning and the exact location of the existing, to be decommissioned pipe are to be fixed. Shop drawings are to be ready approved from the Engineer.

3.3 3.3.1

Suggested Decommissioning procedure

General Disconnection shall be carried out only on empty pipe (outside the supply cycle of DJB) in presence of the Engineer.

3.3.2

Details on work to be done The following points will be the normal preparation and procedure for the decommissioning (disconnection) of the replaced pipe: Preparation of skilled labor, tools, fittings, dewatering pump, chlorine water solution (10 ppm), hoses, electric source, grinder, welding machine (where required) etc.. Excavation around the pipe at the pre-determined location of disconnection. It has to be ensured that there is enough working space according to the pipe diameter and the method of disconnection. Marking on the pipe, showing the length of the existing pipe to be cut out. The to be removed piece shall generally be of at least 1.5 meters. Cutting the pipe perpendicular to the pipe centerline, using grinder, metal saw or cutter according to the pipe material. Extreme care is to be taken to avoid any dirt or foreign material entering the existing (and remaining) pipe. Installation of the required fittings to plug the existing (and remaining) pipe. All new parts are completely to be submerged in the chlorine solution (10 ppm) for at least 15 minutes directly before being installed. Installation of thrust block, where required. Repair of any possibly damaged protection layer. Greasing of bolts and washers and installing of the protective coat. After the two weeks period, as described hereafter, all temporary parts are to be removed.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 4 of 13

3.4 3.4.1

Observations on and treatment of decommissioned pipe

General Generally, the replaced pipe (obsolete, rotten) shall remain in the ground. The pipe shall be left open at both ends (not plugged) to ensure that it is not brought back into service. Bringing back into service such pipes, whether intentionally or unintentionally, would be the first step to a second supply net. Such situation has been found many times formerly. Always having in mind the necessities of the Municipality, the excavation shall be left open for about two supply cycles of DJB. During such time the pipe end has to be observed very frequently in order to ensure immediate recognition of a possible flow of water. After the two-week period, with the consent of the Engineer and his approval on the appropriate form, the excavation shall be backfilled and the surface brought back to former condition. If, at certain points or situations, it is not possible to convince the Municipality about the necessity to leave the pipe ends open for the mentioned time other means have to be found to control the appearance of water at the pipe ends. Possible solutions, to be decided on from case to case could be the following: 1. Plug the end where there are restrictions in a temporary form and leave only one end of the decommissioned pipe open. 2. A pipe connection in a side street can be used for observation. 3. A temporary pipe could be laid to the shoulder of the road to bring the possible water flow to the open. 4. Former house-connections could be prepared for observation, after the pipe ends are plugged temporarily.

3.4.2

Unknown connection The possibility is given that any replaced pipe has an unknown connection to another pipe inside the District Metered Area, as well as even outside the District Metered Area. It is completely mandatory that such connections are found and eliminated. Not finding such connections would lead to heavy loss of water and would be the first step to bypass the newly installed supply system. There are principally two different cases: Connection from within the District Metered Area This will be the somewhat easier case. At the time of supply to the District Metered Area the water will appear immediately and will stop somewhat delayed to the closing of the inflow point. Connection from outside the District Metered Area This will be the somewhat more difficult case. The water will appear not during the supply cycle for the zone but most probably at the time of supply to one of the adjacent zones.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 5 of 13

3.4.3

Procedures If water should appear at the unplugged ends of the replaced pipe, the Contractor will contact DJB without delay. DJB will provide information about the latest changes in valve settings and pump operations. With this information the source of the supplied water will be encircled, pointing to a possible unknown connection to the decommissioned pipe. The Contractor will immediately, without any further written instruction, start searching for the unknown pipe. Step one (internal connection) Valves in the immediate vicinity of the decommissioned pipe shall be closed. In case that the water flow stops the connection has to be somewhere close. Opening the different valves and assessing the flow of water will pinpoint search. Such opening of valves should be directed in such form as to avoid supply by the loop system. With the water flow from one single direction it will be easier to locate the connection. If this form does not bring the required result the water might come from outside the district. Step two (external connection) If it becomes evident that the water comes through a connection from outside the district, it will be necessary to examine jointly with DJB what changes in pump- or valve settings has been done recently. With such information it should be decided about the measurements to be undertaken. The task will be to isolate in ever-bigger circles the area where the water appears until the source is found. Because this might be a tedious and sometimes even impossible task another measurement shall be taken. Step three Start digging out the decommissioned pipe from both ends until the unknown connection is found. The found pipe has to be followed until at least the border of the district, in order to isolate the district properly.

Method Statement for: Commissioning of reinforcement pipes

General
Installation of pipes of any DN will be done in strict compliance with the Specifications, part of the Contract.

4.1

4.2

Completed work
The following works are to be completed before a request to connect new pipes can be made: Pipes are to be laid in their full length. Pipes are to be pressure tested, disinfected and flushed.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 6 of 13

4.3

Connection of pipeline
After coordination with DJB and the Engineer the pipe can be connected into the existing distribution system. The valves at both ends will be kept closed.

4.4

Commissioning
Having all works completed, the connections at the pipe checked with the consent of DJB, the new system could be commissioned, taken into permanent use.

Disconnection Arrangements
Fittings for disconnections/connections will be according to contract drawing Standard Details as shown below:

5.1

For DI pipes 80mm

a- Flanged socket. b- Blind flange.

5.2

For Steel pipes DN 80mm

c- Hollow steel flange welded to pipe. d- Steel blind Flange bolted to the welded hollow flanges.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 7 of 13

5.3

For other material DN 80mm

e- Flanged adaptor. f- Blind flange.

5.4

For pipes of DN 75mm

g- GI, Steel pipes 1- Threaded connector with plugs.

h- PE pipes (63) 1- End caps 63mm 2- Or, push fit / threaded adaptors. Threaded connectors with plugs.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 8 of 13

3- For PVC 1- End caps PE DN. 2- Coupling PVC/PE DN.

Note: Existing Pipes left open are cancelled (not in service); Closed pipes are still in operation.

Method Statement for: Commissioning of District Areas

General
The ultimate goal is to to bring the new borders into permanent action. This is not necessarily connected to the completed rehabilitation works. The general approach for verifying the isolation will require the installation of loggers for pressure isolate the district and walk the boundary marking on the drawing which consumer has and does not have water. If the district is against (boundary with) an area that is not under continuous supply then this should be done when the outside area has water.

6.1

6.2

Inflow point
The new system foresees that each District Metered Area has its own inflow point. This inflow point may be a water meter alone or a pressure reducing valve in combination with a water meter.

6.3

Commissioning of new border

After the new inflow point has been installed, the replacement and reinforcement pipes have been connected (commissioned), obsolete pipes have been disconnected (decommissioned) and the first night flow test has been conducted, with the consent of DJB the new border can be taken over. Such take-over (commissioning) would mean that the temporary

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 9 of 13

valves, installed for the purpose of isolation, can be removed and the relevant pipes closed with end-caps. But it will also mean that the designated area will be served by only using the new feeding point. It has to be kept in mind that such action is only possible where there is no temporary supply needed to adjacent areas. Such areas might be other District Metered Areas or single houses not yet included in any District Metered Area. Those pipes shall stay with the temporary valves until the foreseen final solution is executed. 6.4

Commissioning of District Metered Area

After the border of the new area is commissioned, rehabilitation works within the district area can be completed. For rehabilitation the following limits are to be observed, even if they might be contradicting in certain form: The loss of water shall be inferior to 25% The internal rate of return for works executed under the rehabilitation shall be superior to 5%. After this task has been fulfilled the District Metered Area under consideration can be declared completed. Important Note In case house connections are replaced, any exposed part of the old house connection shall be removed and properly disposed of. This will be valid for the part, in flow direction, before the water meter.

6.5 1 2 3 4

Commissioning / Test Reporting

DMA test set up, isolated districts or closed boundary valves etc. Schematic sketch showing reservoir, secondary main and district meters + PRV, PMP, and other important assets related to the test. Flow, available pressure and total pressure data from the test Data analysis: Flow balance of reservoir outlet Flow against the sum of the district flows, Table of total district flows in m day, how do they compare with design ultimate flows; Table of total district flows in m per day per subscriber, is there sensible balance between districts; Discussion + mark up on schematic on pressure loss (total pressure) - ie starting from reservoir and working down the secondary main and thru each district; Discussion / Table on available pressure in each district, how do they compare with the design

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 10 of 13

5 6

Conclusions; Further actions before re-test if required. NOTE: All above reported flow and pressure values shall contain the date and the time of reading (recording) as well as the ID Number of the source device from where the information was born.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 11 of 13

6.6

Handover / Commissioning Steps DMA / District Taking Over and Documentation Steps - Guide

Step 1 Sectional Taking-over Of Network in a not yet Isolated District or DMA Who From N1) Approved As-built drawings showing new, disconnected and still to be disconnected mains and all temporary isolation valves, PMPs, PRVs, Meters - Hard copy (1 copy) ENGINEER N2) Approved As-built drawings showing new, disconnected and still to be disconnected mains and all temporary isolation valves, PMPs, PRVs, Meters - Soft GIS copy on labelled CD with contents list(1 copy) 3) FORM N1 - Sectional Physical Transfer of Network within a not yet isolated District or DMA & associated documents (From DJB To MC) Sectional Taking-over of a Completed / Isolated District or all Districts in a DMA Step 2 and Transfer to MC 1) Approved As-built drawings showing new, disconnected and still to be disconnected mains, PMPs, PRVs, Meters etc -Hard copy (1 copy) 2) Approved As-built drawings showing new, disconnected and still to be disconnected mains, PMPs, PRVs, Meters etc -Soft copy on labelled CD with contents list(1 copy) 3) "Set Up" Description and simple schematic describing how water gets the district, how the meter and PRVs are set up. 4) The District Schematic as per the sample SOP 5) FORM N2 - Sectional Physical Transfer of an Isolated District or all Districts in a DMA & associated documents (From DJB To MC) Step 3 Start of Trial Tests - Test Plan Submittal For The DMA 1) DMA Test Plan -as per ENGINEER proforma, updated between tests to reflect conditions for subsequent tests 2) Reporting after each test with data analysis and recommendations and next test plan update 4) FORM N3 - Notification of Start of DMA Testing & Plan Submittal Step 4 Confirmation that the Engineer Recommends Commissioning of Completed DMA (all work completed except additional Rehabilitation) 1) Verified Draft As-built drawings showing new & disconnected mains all PMPs, PRVs, Meters, boundaries etc -Hard copy (1 copy) 2) Verified Draft DMA SOP/Manual as per the sample already agreed -Hard Copy (1 copy)

ENGINEER

ENGINEER

ENGINEER ENGINEER ENGINEER ENGINEER ENGINEER

ENGINEER ENGINEER ENGINEER

ENGINEER ENGINEER

3) A DMA Pre- Commissioning Report based on the last test showing balance of flow meters, reservoir level, pressures at all PMPs, before and after PRVs, head loss assessment in the secondary main, drop test of individual districts. Comparison of flows and pressures with the design data. Data to be at max 8 hr intervals ENGINEER 4) FORM N4 Confirmation that the Engineer Recommends Commissioning of Completed DMA- Draft Documents Step 5 At the End of Completed DMA Commissioning 1) Report showing that levels of no water complaints are low over 2 rationing periods NGWA to comment on Draft commissioning documents and the pre- commissioning reports - within 14 days of receiving Form N4 and associated documents. Notification of Completed Distribution Zone (when all original CIP works are Step 6 completed in the DMA) 1) Final As-built drawings showing new & disconnected mains all PMPs, PRVs, Meters, boundaries etc -Hard copy (1 copy) ENGINEER

MC MC

ENGINEER

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

Page 12 of 13

2) Final As-built drawings showing new & disconnected mains all PMPs, PRVs, Meters, boundaries etc - Soft copy on labelled CD with contents list (1 copy) 3) Final DMA SOP/Manual as per the sample already agreed -Hard Copy (1 copy) 4) Final DMA SOP/Manual as per the sample already agreed -Soft Copy (1 copy) 5) FORM N5 - Notification of Completed and Tested DMA & associated documents transfer

ENGINEER ENGINEER ENGINEER ENGINEER

Upon Completion of the Additional Rehabilitation works in all Districts in an already Step 7 commissioned DMA 1) Final As-built drawings showing all additional pipes and fittings installed since the issue of the Final As built drawings associated with Form N5 -Hard copy (1 copy) ENGINEER 2) Final As-built drawings showing all additional pipes and fittings installed since the issue of the Final As built drawings associated with Form N5 -Soft Copy (1 copy) ENGINEER 3) FORM N6 - Notification of Completion of the Additional Rehabilitation works in all Districts in an already commissioned DMA Step 8 Taking- Over Certificate For the Whole of The Works Documentation Transfer to MC Relating to the whole works 1) Handover Committee Report for all works (if not already submitted) ENGINEER 2) Taking-over BOQ covering the whole of the works ENGINEER 3) FORM N7 - Taking- Over Certificate For the Whole of The Works Documentation Transfer to MC Step 9 Defects Liability Certificate For the Whole of The Works ENGINEER to develop a Defects Liability Management Procedure ENGINEER

ENGINEER

Note 1: Steps 1, 2, 7 may not occur for all districts, e.g. some contractors will not have sectional handovers or addition rehabilitation Note 2: Above mentioned Forms will be available with the Engineer, or on Contractors suggestion, new ones will be produced in coordination with the Engineer to better suit the specific conditions if considered necessary.

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA

Method Statement Preparation Guidelines

TABLE OF CONTENTS 1 2 Scope of Work.................................................................................................................... 2 Method Statement for: Commissioning of replacement pipes ........................................... 2 2.1 General ....................................................................................................................... 2 2.2 Completed work ......................................................................................................... 2 2.3 Connection of pipeline ............................................................................................... 2 2.4 Commissioning........................................................................................................... 2 Method Statement for: Decommissioning of replaced pipes............................................. 3 3.1 General ....................................................................................................................... 3 3.2 Coordination ............................................................................................................... 3 3.3 Suggested Decommissioning procedure..................................................................... 3 3.3.1 General ............................................................................................................... 3 3.3.2 Details on work to be done ................................................................................. 3 3.4 Observations on and treatment of decommissioned pipe ........................................... 4 3.4.1 General ............................................................................................................... 4 3.4.2 Unknown connection.......................................................................................... 4 3.4.3 Procedures .......................................................................................................... 5 Method Statement for: Commissioning of reinforcement pipes ........................................ 5 4.1 General ....................................................................................................................... 5 4.2 Completed work ......................................................................................................... 5 4.3 Connection of pipeline ............................................................................................... 6 4.4 Commissioning........................................................................................................... 6 Disconnection Arrangements ............................................................................................. 6 5.1 For DI pipes 80mm.................................................................................................. 6 5.2 For Steel pipes DN 80mm ....................................................................................... 6 5.3 For other material DN 80mm .................................................................................. 7 5.4 For pipes of DN 75mm............................................................................................ 7 Method Statement for: Commissioning of District Areas ................................................. 8 6.1 General ....................................................................................................................... 8 6.2 Inflow point ................................................................................................................ 8 6.3 Commissioning of new border ................................................................................... 8 6.4 Commissioning of District Metered Area .................................................................. 9 6.5 Commissioning / Test Reporting................................................................................ 9 6.6 Handover / Commissioning Steps ............................................................................ 11

DELHI WATER SUPPLY AND SEWERAGE PROJECT (DWSSP) WATER DISTRIBUTION AND WASTEWATER COLLECTION IMPROVEMENT

CONTRACTOR CAPITAL WORS DJB / WSP SOUTH ASIA