Federal Electricity & Water Authority Water Directorate ...federalelectricityandwaterauthority.gov.ae/en/OpenData/Documents/16... · B.S. 5481 Unplasticized PVC pipe and fittings

WAM

Client: FEDERAL ELECTRICITY AND WATER AUTHORITY (FEWA) Project: STANDARD SPECIFICATIONS FOR WATER WORKS

Engineer WATER DIRECTORATE - ASSET MANAGEMENT DEPARTMENT

Title: Technical Terms / Chapter-4 / Engineering Specifications / Civil Engineering Works Specification

CS15-DRAINAGE WORKS

Office: DUBAI Order:

Document: MWA_PRO_07/WAM-04-CS15 Rev: OCT/2014 sheet: 1 of: 16

Federal Electricity & Water Authority

Water Directorate

Asset Management Department

STANDARD SPECIFICATIONS

FOR WATER WORKS

TECHNICAL TERMS

Chapter – 4

Engineering Specifications

[C-Civil Engineering Works Specifications]

CS15-Drainage Works

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CS15-DRAINAGE WORKS

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DUBAI Order: Document: MWA_PRO_07/WAM-04-CS15 Rev:

OCT/2014 sheet: 2 of: 15

CS15-Drainage Works

TABLE OF CONTENT

1. GENERAL

2. STANDARDS AND CODES

3. QUALITY AND STANDARDS

4. EXECUTION OF DRAINAGE WORKS

4.1 Setting Out

4.2 Pipes, Conduits and Ducts

4.3 Dimensions

4.4 Pipe Bedding Material

4.5 Inspection and Diversion Manholes

4.6 Washout/ Overflow Chambers

4.7 Continuous Trench Soakaways

4.8 Local Soakaways

4.9 Joints

4.10 Valve Pits

4.11 Accessories

4.11.1 Cast Iron Covers and Frames

4.11.2 Raising and Lifting Bars

4.11.3 Gullies Gratings and Frames

4.11.4 Step Irons

5. FOUL WATER DRAINAGE

5.1 Piping Requirements

5.2 Foul Water Drain Manholes

5.3 Soakaways

5.4 Continuous Trench Soakaways

5.5 Floor Drains

5.6 Clean Outs

5.7 Vent Caps

5.8 Septic Tank

6. SURFACE WATER DRAINAGE

6.1 Areas Contributing Surface Water Drainage

6.2 Surface Water Drain Manhole

6.3 Road Gully

6.4 Road Curb Gully

6.5 Roof Drain Pipe

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7. CONTAMINATED WATER DRAINAGE

7.1 Areas Connected to Contaminated Sump Pits

7.2 Facilities Connected to Contaminated Water System

7.3 Piping Requirements

7.4 Floor Gullies, Drain Trenches and Cut-Off Drain Channels

7.5 Clean Outs

7.6 Tundishes

7.7 Industrial Sinks

8. INSPECTION, TESTING AND COMMISIONING

8.1 Inspection Requirements

8.1.1 Civil Works

8.1.2 Pipes and Pipe Fittings

8.2 Testing

8.2.1 Rejection of Pipes

8.2.2 Testing of Drainage Lines and Manholes

8.2.3 Testing by Air or Smoke

8.2.4 Testing by Water

8.2.5 Testing Manholes

8.3 Commissioning

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CS15-Drainage Works

1. GENERAL

The work to be carried out under this Specification comprises various kinds of drainage channels, pipes and the like, including all accessories such as inspection shafts, etc., if not otherwise specified.This specification covers the requirements for the design, inspection, testing, supply, loading, transportation, unloading and storage at Site, installation and commissioning of the water drainage systems and placing according to drawings and Specifications of all materials and components connected therewith. The pipes and structures of the drainage system shall be placed in safety against buoyancy.The Contractor shall prepare a flow diagram of the drainage system to be executed. The diagram shall show material and sizes of pipes and channels to be used and the proportion of slope, as well as, the invert level at all connection points. The flow diagram is subject to approval.

2. STANDARDS AND CODES

B.S. 65 Specification for vitrified clay pipes and fittings B.S. 497 Specification for manhole covers, road gully gratings, and drainage

purposes. Part 1, cast iron and cast steel. B.S. 1247 Manhole step irons B.S. 2005 Sewerage B.S. 3506 Unplasticized PVC pipes for Industrial purposes. B.S. 4660 Unplasticized PVC underground drain pipes & fittings B.S. 5480 Glass fibre reinforced plastics (GRP) pipes and fittings for use for

water supply or sewerage B.S. 5481 Unplasticized PVC pipe and fittings for gravity sewers

BS 6297 Small Sewage Treatment Work & Cess pools

B.S. 6367 Code of Practice for drainage of roofs and pave areas

B.S. 8301 Building drainage BS EN 124 Gully Tops & Manhole Tops BS EN 752-1 Sewerage BS EN 12056-2 Sanitary Pipework ASTM3517 Specification for Glass Fiber Reinforced thermosetting, resin pressure

pipe Standards shall include all latest amendments and revisions.

3. QUALITY AND STANDARDS Any materials and components, which the Contractor shall supply and install and which will be incorporated in the work or structure, shall be of selected quality which are subject to approval.

All materials and structural parts shall be standardized and shall be adequate for the purpose required. They shall comply with the Specifications and standards listed at the beginning of this section. All materials shall comply with the regulations regarding quality and dimensions and shall be adequate for the required work.

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Materials and structural parts not standardized shall be approved by FEWA/Engineer prior to use. Samples and name of manufacturer of such materials shall be submitted to FEWA/Engineer in good time. Materials and components which are for temporary use during construction and are not to be incorporated in the work may be used or unused at the Contractor's option if not otherwise prescribed in the Specifications.

4. EXECUTION OF DRAINAGE WORKS 4.1 Setting Out Deviations from pipework levels shown on the approved drawings shall not be greater than+20 mm. Gradients shall generally not be steeper than 1 in 75 nor flatter than 1 in 250 generally and with a permissible deviation not greater than 1/20 of the given gradient.Sight rails shall be set in position, using a surveyor's level and properly established bench marks alongside the work. The practice of "transferring" levels by means of a straight edge and spirit level will not be permitted. Where long lengths of sewers are to be constructed in trenches, sight rails shall be fixed across the trench at intervals of at least 20 metres and, at a height equal to the length of the looning rod to be used, above the required invert level of the drain or sewer, at the point where the sight rail is fixed. There shall at no time be less than three sight rails in position on each length of sewer or drain under construction at any one gradient.

4.2 Pipes, Conduits and Ducts Pipes used for drainage shall be generally either uPVC or GRP ounderground pipes to BS 3506, BS 4660 and BS 5481.Pipes, conduits and ducts that are to be encased in concrete, shall be installed by the Contractor before the concrete is placed. The pipe shall be held rigidly so that it will not be displaced during the placing of the concrete.Where pipes are to be laid in pipe trenches the work shall be carried out to meet the requirements set out in Pipelines.

The drains shall be accurately laid in straight lines and to self-cleansing gradients. Pipes shall be laid singly and the level of each pipe shall be tested in a approved manner using sight rails erected at manholes and at intermediate positions as necessary. Pipes shall be laid with the sockets facing upstream.Immediately prior to laying, all pipes and fittings shall be examined carefully to ensure that they are sound. No damaged or defective pipes shall be used.

When pipes pass through walls a flexible joint is to be fitted, situated as close as possible to the outside face and permitting a minimum deflection between adjacent pipes of 3º.Pipes which are laid, or built into walls and manholes, but not immediately connected up, shall be fitted with suitable temporary stoppers or seals, and the position of such pipes shall be clearly defined by means of stakes or training wires properly marked or labelled. Wherever the depth of cover to the pipe laid under a road or driveway is less than 1.20 m, a concrete cover slab spanning the trench width shall be provided.Before the commencement and for the smooth progress of the pipeline work, the Contractor shall coordinate and finalise the routes, ground/invert levels, positions of the manholes etc. with the FEWA/Engineer. 4.3 Dimensions Nominal diameters shall refer to internal diameters of pipes. The nominal length of a pipe shall be the effective length of the installed pipe.

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4.4 Pipe Bedding Material When the as dug material is suitable, the bottom of the trench shall be trimmed and loosened to form the bed otherwise the trench shall be excavated to a depth below the invert level to allow for the thickness of bedding material. When as dug material is not suitable, imported granular material as per the table given below shall be used to provide a 50mm bedding and side fill. Table - Requirements for imported material for bedding and surrounding

Nominal pipe size Material (complying with BS 882: Pt.2).

110 mm 10 mm nominal single sized aggregate

160 mm 10 or 14 mm nominal single sized or 5 to 4 mm graded aggregate.

225 mm and over 10, 14 or 20 mm single sized or 5 to 14or 5 to 20 mm graded aggregate.

If the as dug material contains stones larger than 40 mm the bedding material must be extended 100 mm above the circumference of the pipe. Alternatively the backfill can be graded to eliminate stones exceeding 40 mm and this selected backfill used for the first 300 mm above the circumference of the pipe.

4.5 Inspection and Diversion Manholes Reinforced concrete manholes shall be placed at every change of dimension, direction and/ or slope, and on straight lines at a maximum distance of 50 m, or as shown on the approved working drawings.

Manholes may be of precast ( solid concrete blocks) or in-situ reinforced concrete construction.Manholes shall be designed for the vehicular or other loading to which they will be subjected.Minimum material characteristics for manholes shall be sulphate resistant 30 N/mm² reinforced concrete. Manholes shall be coated externally with a bituminous paint.

The materials entering into the work, and their combination, construction, and/or fabrication, shall conform to the requirements of prevailing standards and these Specifications.Cast-iron frames and gratings shall be free of pouring faults, blow holes, cracks, and other imperfections. The castings shall be sound, true to form and thickness, clean, and neatly finished and shall be coated with coat tar varnish. Gratings, which are to rest on frames shall lie on them evenly.

Foundations to manholes shall be of concrete complying with the relevant Concrete Specification and shall finish flush with the manhole sides unless specifically otherwise required.Concrete block walls shall be bedded and jointed in cement and sand 1:4 mortar and the joints on the internal faces raked out to form a key for rendering. Walls shall be constructed in stretcher bond.The internal surfaces of concrete block walls shall be rendered with cement and sand 1:2 mortar 10mm thick and the rendering shall be finished with a smooth and even surface.

The bottoms of all manholes shall be provided with half round main channels, tapered or curved where necessary and half round and three quarter section branch bends of requisite radii. These shall be bedded and jointed in cement sand 1:1 mortar and shall be benched in concrete vertically from the channels to a height equal to the soffit of the outgoing pipe and thence upwards to the sides of manholes at a slope of 1 in 6 and floated in cement and sand 1:1 mortar to a smooth and even surface.Heavy duty manhole covers shall be used in all paved areas.

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Contractor shall bed and haunch frames in cement and sand 1:2 mortar and seal covers with thick grease. Two sets of keys shall be delivered to the FEWA/Engineer for each pattern of cover supplied. Sections of connection pipe shall be incorporated into the construction and placed at the elevation, direction, and grade required. The inner ends of the pipe shall be flush with the inner faces of the walls unless otherwise specified. Where the depth of invert of manholes exceeds one metre below the finished ground level,aluminum steps as specified in BS 1247 part 3 shall be built in at vertical intervals of 300mm, with alternate steps in line vertically and at 225mm centre to centre horizontally.Entry to deep manhole chambers (> 2500 mm) shall be by means of one or more caged vertical aluminium ladders.

4.6 Washout/ Overflow Chambers Overflow pipes and washout pipes from the storage tanks shall be connected to buried reinforced concrete washout/overflow chambers (surge chamber). These chambers shall be designed to accommodate the anticipated discharges. They shall be fitted with GRP Gratings and shall be located at a minimum distance of 10 m from any tank or structure. These chambers shall be designed to drain the water completely from the tank and if required sump pumps have to be provided.

4.7 Continuous Trench Soakaways Continuous trench soakaways shall be constructed as per design. The filter membrane adopted for the soakaway surround shall be geotextile of appropriate guage. The Contractor shall take every care to avoid damage to the membrane. In the event of damage to the membrane during construction, the Contractor shall make good the damage with a minimum lap of 500 mm all to be carried out at the Contractor's expense.

4.8 Local Soakaways Local soakaways shall be provided at locations determined by the Engineer and to details as approved by him and shall be similar to the soakaway to be provided at the septic tank.

4.9 Joints All joints shall have adequate strength and shall be fully flexible and capable of bearing the same pressure that can be borne by the pipes. Prior to importing any pipes, fittings or jointing rings to the site, the Contractor shall submit a works test certificate from the manufacturer, as to their conformity with the Specification, for the approval of FEWA/Engineer. 4.10 Valve Pits All below ground valve pits and chambers shall have their invert laid to fall towards collection sumps to allow pump out of accumulated rain water etc.

4.11 Accessories 4.11.1 Cast Iron Covers and Frames Cast Iron covers and frames shall be of sound manufacture and free from projections or voids and shall be treated with two heavy coats of an approved coal tar epoxy coating. Thereafter the covers

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shall be fixed on to the previously installed frames after lining from the inside with grease and sand mix.

Cast iron manhole covers shall conform to the Specifications as previously stated and the work shall be carried out in accordance with the working drawings. The work shall include, but not limited to, the supply and installation of cast iron manhole covers of the approved type.Frames shall be square and covers shall be double triangle with seal, according to the dimensions indicated on the drawings but particularly to the Specifications shown on the Drawings.

It is not allowed to cast the frame of a M.H. cover together with the roof slab of M.H. covers and frames shall be fixed in such a way to match adjacent surface levels with tolerances not exceeding 3 mm. Before the maintenance period expires, the Contractor shall check all manhole covers and readjust them if they are in excess of above mentioned tolerances.

4.11.2 Raising and Lifting Bars One raising and lifting bar of approved design shall be supplied by the Contractor with each five manhole covers and frames. No separate payment will be made for these bars and the Contractor must allow for the cost thereof in his rates.

4.11.3 Gullies Gratings and Frames Gratings and frames for horizontal gullies shall be made of cast iron. Gullies shall consist of a concrete pit with cover.Gully gratings and frames shall comply with the requirements of BS EN 124 (Grade A) orequal with straight bars. The Contractor shall bed and haunch frames in cement andsand 1:3 mortar.The finish of steel components shall be given 2 coats of black coal tar epoxy paint with a minimum thickness of 250 microns.

4.11.4 Step Irons Step irons shall be either galvanized steel or corrosion protected cast iron. Steps should be a minimum of 24 cm long and 15 cm away from the wall.

The supply and fixing of galvanized cast iron steps to reinforced concrete manholes using cement and sand mortar (1:3), all as per Specifications.

5. FOUL WATER DRAINAGE The Foul Water Drainage System is required to collect the foul wastewater from the buildings.The toilets, sinks, showers and kitchens are to be connected and routed to a septic tank and local soakaway or connected to the main drainage of the power station. The scope of this work shall include all septic tank/soakaway pits and foul drainage system pipework.The Foul Waste from Toilets, showers, Washrooms and Kitchens shall be collected in the foul drainage manholes & subsequently routed to the septic tank & soakaway pits. The system is to be suitably trapped & externally vented. The Foul Water System is to be laid to fall at a minimum slope of 1:100 generally. Note : Chemical storage & other industrial sinks shall be routed separately.

5.1 Piping Requirements Pipes and Fittings

All pipes & fittings to be used on the project shall comply with the requirements of the latest relevant British/other standards approved by FEWA/Engineer.

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The pipes and fitting for pipe diameter sizes upto 300 mm shall be of uPVC conforming to BS 4660 and BS 5955. The joint sealing rings shall conform to BS 2494. Products to be procured with BSI certification. The dimension & pressure rating of the pipes shall be in accordance with ISO 161/1. The pipes and fittings for pipe sizes equal to or greater than 300 mm shall be GRP pipes.Requirements as per BS 5480 are to be followed for the pipes & pipe fittings.The pressure rating of the pipes shall be a minimum of 10 bar. Jointing Systems The surface preparation to consist of the minimum following steps :

- Surface to be jointed are to be cleared of glass fibre and to be ensured to be free of grease, humidity or dust.

- Surface to be ground, external layer of resin to be taken off and first glass fibre uncovered.

- Surface to be rubbed with an emery cloth and cleaned with a volatile solvent so as to remove all traces of grease, dust & humidity.

(No gluing shall be undertaken during sand storm or rainfall). - The minimum requirements for adhesive are as follows : - Adhesives shall be compatible with the resin and shall not be of a type affected by hydrocarbon or inorganic contaminants that may be present. - Type of adhesive shall be submitted for FEWA/Engineer approval. - Adhesives shall be two component, cold polymerization type. The two components will be maintained within allowable temperature and mixed to form a homogenous mixture just before application to the prepared joint. - The joints shall have adequate strength and this shall be demonstrated by Contractor.

Pipe joints shall be fully flexible and capable of bearing the same pressure that can be borne by the pipes.

For the uPVC piping, the following minimum steps are to be taken while making a joint:

i) Proper alignment of the two pipes to be ensured. ii) The surfaces to be joined are to be thoroughly prepared using sandpaper. iii) Surfaces to be cleaned with solvent. iv) Even layer of cement is to be applied. v) Joint to be made.

It should be ensured the joint is held till the required drying time based on ambient conditions. A minimum of 24 hrs. is required before pressure testing.The joint shall be fully flexible and capable of bearing the same pressure as the pipes. The joint strength shall be demonstrated by the Contractor.

5.2 Foul Water Drain Manholes Manholes shall be provided as on approved Foul Water System Layouts or as required by the detail design of the Contractor. The details of the manholes are to be as per drawings.

5.3 Soakaways Soakaways shall be constructed using precast/cast insitu concrete manhole rings to designated dimensions and depths.The concrete in the rings may be made using moderately sulphate resistant portland cement in accordance with ASTM C 150 designation type II. However Type of

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cement is to be verified as per relevant soil condition.The rings shall be constructed with 75mm diameter holes at 410mm centres in rows spaced 300mm apart. The bottom ring shall be founded on an in situ concrete base, to the approval of FEWA/Engineer.The soakaway shall be surrounded by granular material which shall in fill the whole void between the soakaway and the undisturbed ground around the excavation. The granular material shall be laid and tamped by hand in 300mm layers and shall be clean, crushed rock to the approval of FEWA/Engineer and shall be 20-40mm nominal size with little or no fines.Manhole covers and frames shall be coated cast-iron complying with BS EN 124 or approved equal and shall be designed for the loading category to which they will be subjected.The Contractor shall bed and haunch frames in cement sand 1 : 2 mortar and seal coverswith thick grease. Two sets of keys shall be delivered to FEWA/Engineer for each pattern of cover supplied.

Filter fabric material lining to soakaway excavation shall be Geotextile of approved guage & make. Placing and lapping sheets to be in accordance with Manufacturer/Supplier's recommendations. All pipes and fittings shall be assembled strictly in accordance with the written instructions of the Manufacturer/Supplier and to the satisfaction of the FEWA/Engineer.

5.4 Continuous Trench Soakaways Continuous trench soakaways shall be constructed at the location and to the details as shown on the drawings. The Contractor shall take every care to avoid damage to filter membrane. In the event of damage to the membrane during construction, the Contractor shall make good the damage with a minimum lap of 500 mm all to be carried out at the Contractor's expense. 5.5 Floor Drains All floor drains shall be supplied and installed at the locations and to the details shown on the drawings and as specified herein.Each floor drain shall be of heavy duty uPVC with "S" or "P" trap complete with chrome plated heavy duty, 200 x 200mm, bronze strainer. The strainer shall be screwed to the body of the drain. All floor drains shall have chrome plated removable covers to their strainers or heavy duty aluminium cover. 5.6 Clean Outs All clean outs shall be supplied and installed at the locations and to the details shown on the Drawings and wherever specified herein.Each clean-out shall be of the same material and dimensions as the pipe to be cleaned, and shall be placed in walls, slabs or floors as required for ease of operation.Where cleanouts terminate in floors, a bronze cleanout tile 200 x 200mm, with screwed and sealed cover shall be provided. Tile and cover shall be chrome plated.

5.7 Vent Caps Vent caps shall be supplied and installed on all waste, soil and vent stacks at the locations and to the details shown on the drawings and in accordance with this specification.Each vent cap shall be of uPVC and shall be solvent cemented onto the waste, vent and soil stack.

5.8 Septic Tank General This shall be a rectangular chamber of concrete built underground and to dimension and depth as shown on the drawings.

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Construction The base, walls and roof shall be of reinforced concrete construction. Concrete shall be to grade C40.The base shall be constructed on layer of 100mm blinding. For specification relating to concrete, refer to Specification for Concrete Works.One aluminum ladder shall be provided to access inside each section of the tank for cleaning purposes from time to time. A 600mm x 600mm manhole opening shall be provided on the roof of the septic tank. Adequate manhole cover of minimum size 680mm x 680mm with hand grip shall be provided as described for soakaways. The floor of the tank shall slope 1 in 30 towards one side or centre to facilitate cleaning of sludge and the manhole shall be located directly over this.

Commissioning Initially the septic tank shall be filled with water to its outlet level before sewage is allowed to enter the tank.A small quantity of decaying organic matter should preferably be put into the septic tank to start the initial reaction.

6. SURFACE WATER DRAINAGE

Surface water drainage is required to collect and direct rain water from apron and paving areas and roof run-offs and will also be required to dispose of external washdown.The surface to be drained shall be laid to fall at a minimum slope of 1:250 generally. The collected rainwater, wash water is to be drained by means of surface falls only towards local soakaways at appropriate locations. Roof run-offs to be collected by means of gullies, hoppers & downpipes discharging to grade level local soakaways at appropriate locations.All roads, aprons and paving shall be delineated by kerbs and laid to fall towards soakaways.Parking area to be similarly drained towards soakaways.

6.1 Areas Contributing Surface Water Drainage The following areas contribute to the Surface Water Drainage :

1) Roof of Pump Station 2) Roof of Service Block 3) Paving Around the Building 4) Roads & Aprons within the Plot 5) Parking and Approach Road 6) Roof of Chlorination Building 7) Other areas as applicable

Unpaved areas are to be terraced and gravel (size 20 mm – average) finished to allow insitu soakaway of rain water or washwater.

6.2 Surface Water Drain Manhole Manholes shall be provided as shown on the referred Surface Water System layout or as required by the detail design of the Contractor. 6.3 Road Gully Road gullies are to be provided with silt trap, heavy duty manhole, ductile iron grating non rocking cover with frame and retaining bar as per the drawings. Road gullies shall be provided as indicated on the Surface Water System layouts or as required by the detail design of the Contractor.

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6.4 Road Curb Gully Road curb gullies are to be provided with silt trap, standard ductile iron cover and frame with retaining bar. as per the layouts and Contractor's drawings. Road curb gullies are to be provided as indicated in the Surface Water System layouts or as required by the detail design of the Contractor.

6.5 Roof Drain Pipe Roof drain pipes shall be provided as indicated in the individual building details and the storm water drain system layout or as required by the details of the Contractor. The roof drain pipes shall be provided with an inlet hopper, support brackets, stack and a splay end terminating 150mm above local paving level and directing water away from the building towards local soakaways as per the drawings.

7. CONTAMINATED WATER DRAINAGE The Contaminated Water drainage system is required to collect specific discharges of predominantly contaminated water together with floor spillages within the buildings and other contaminant spillages. Flow rates, salinity, other contaminant levels and temperatures of the contaminated drainage shall be determined.Sources of possible spillage are to be routed via tundishes and hard piped systems aboveground as detailed by the Contractor'S piping/mechanical department, discharging to suitable lined reinforced concrete gullies and trenches from where the contaminated material shall be routed to the main drain sump outwith the building from where it shall be pumped to outfall remote from the plant. 7.1 Areas Connected to Contaminated Sump Pits The following areas are to be served by the contaminated water drainage system :

i) Pump Station ii) Service Block iii) Battery Room iv) Chlorination Building v) Others as applicable

7.2 Facilities Connected to Contaminated Water System The following facilities are connected to the saline contaminated water drainage system :

i) Floor gullies, drain trenches and cut-off drain channels. ii) Safety shower outlets (if applicable). iii) Tundishes & Industrial sinks. iv) Others as applicable

7.3 Piping Requirements For details of all pipes and fittings as refer above in item 5.1.

7.4 Floor Gullies, Drain Trenches and Cut-Off Drain Channels Refer to item 5.5 generally. Note : linings, covers and frames shall be suitably chemically resistant. 7.5 Clean Outs Refer to Section 5.6 generally. Note : linings, covers and frames shall be suitably chemically resistant.

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7.6 Tundishes Tundishes and their hard piping systems shall be provided at locations and to details as determined by Contractor's detailed design and shall be subject to the approval of FEWA/Engineer.

7.7 Industrial Sinks Industrial sinks shall be provided at the locations and to the details shown upon the drawings and shall drain to the contaminated water drainage system.

8 INSPECTION, TESTING AND COMMISIONING

8.1 Inspection Requirements 8.1.1 Civil Works The following items shall be subject to field inspection in respect of setting out, excavation,concrete works including reinforcement, protective membranes and linings, benching and inserts rack filling and finishes, covers and frames, handrailing and access provisions: Manholes, Inspection Chambers, Septic Tank, Soakaway Pits, Drain Sump, Floor Gullies,Drain Trenches, Cut off Drain Channels. 8.1.2 Pipes and Pipe Fittings

(A) GRE/GRP Pipes & Pipe Fittings As a minimum the following acceptance tests shall be performed at site: i) Visual inspection ii) Dimension check iii) Curing iv) Glass content v) Hydrostatic pressure test vi) Impact resistance test

(B) uPVC Pipes & Pipe Fittings

The minimum number and type of acceptance tests at site is to be as per BS 5955 : Part 6 The pressure testing at site is to be carried out in two phases, the preliminary phase is required to allow for the elastic characteristics and the relatively high thermal expansion of the uPVC piping. Care should be taken to evacuate all air from the piping to avoid surge pressures.

8.2 Testing All testing of pipes and fittings shall be done at the cost of the Contractor. The Contractor shall also bear the cost of the sampling and of any certificates, which may be required, as well as the testing procedure. Pipes of different diameters shall be tested according to the requirements of BS 2005.

Material to be tested shall be carried out by a licensed office or institute and shall conform to the accepted Standards or Specification in accordance with the technical data approved by FEWA/Engineer. Selection of samples for testing will be made by FEWA/Engineer.

All drainage lines, joints and fittings must be tested before covering up with sand or approved soil by water and or by smoke.Test at Site shall be carried out in the presence of FEWA/Engineer. All tests shall be recorded and countersigned by FEWA/Engineer if successful.

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8.2.1 Rejection of Pipes All pipes failing to comply with the requirements for dimensions and tolerances shall be rejected. All batches of pipes manufactured with materials, which fail to pass the required tests shall be rejected.

When a pipe fails to pass a particular test, two other pipes shall be selected from the same batch and subjected to the same test. Should either of these two pipes fail to pass the test, the whole batch, which is represented by these samples shall be rejected.

Rejection of pipes due to defective materials shall include all pipes manufactured with the materials represented by the samples of materials which failed to pass the required tests. All rejected pipe shall be stamped "rejected" in a conspicuous location on the pipe. 8.2.2 Testing of Drainage Lines and Manholes The Contractor shall test all drainage pipelines, joints, fittings before carrying out haunching or surrounding of pipes or backfilling trenches.

The tests shall be carried out between each two manholes or less in the presence and with the approval of FEWA.All testing for pipes, which are used under pressure is described elsewhere under potable water supply system.

The following points shall be taken into consideration when conducting the tests.

Drainage pipelines and concrete works shall be clean and dry and the joints not covered with earth.

The underground water level shall be at the lowest possible level.

Air, smoke or water may be used for testing drainage pipelines and FEWA reserves the right to carry out the tests by any of the three methods, and the Contractor shall comply with such opinion without claiming any compensation or addition. All plugs should be fixed prior to the testing operation.

8.2.3 Testing by Air or Smoke Pipes to be tested shall be filled under pressure with air or smoke (after blocking all openings). The pressure shall amount to 10 cm of water to appear on a U-tube gauge fixed at the end of the pipeline for this purpose and the result shall be considered accepted if this pressure is not below 7.5 cm at the end of the first five minutes of stopping and discontinuing the pressure.

8.2.4 Testing by Water Water shall be passed in the pipes to be tested, of whatever diameter, so that air is expelled, and the pipes filled with water so that the highest point in the line shall be subject to the pressure of a 1.5 metre high water head. The line shall be considered acceptable if no leakage is visible from pipes, connections or fittings and if the above water head in a testing pipe of 75 mm diameter is not reduced by more than 15mm per minute for each 30 metre length of pipe. The Contractor shall, after filling the pipes, allow some time before conducting the test in order to allow the pipes their first natural saturation with water. If any damage is noticed in the pipeline, the Contractor shall repair such damage to the satisfaction of FEWA/Engineer.

If in the opinion of FEWA/Engineer any damage had occurred to the pipelines in the process of pouring the concrete or backfilling, he shall have the right to order retesting of the doubtful part by

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any of the aforesaid three methods. If a second testing proves that the pipeline is not serviceable, then the Contractor shall have to locate the damage, make it good and carry out retesting until he secures satisfactory results. The cost of all such works shall be at the Contractor's expense.

If it transpires after installing any of the pipes that the average infiltration to the inside of the pipes is in excess of 0.5 litres per cm diameter per minute per kilometre length of pipes, then the Contractor shall (and at his own expense) locate the parts of infiltration and shall make good and retest such parts to the satisfaction of FEWA/Engineer.

The Contractor shall fix the plugs in ends of pipes to be tested and shall take necessary precautions to prevent plugs or fixing tools from getting inside the pipes as a result of water flushing.

8.2.5 Testing Manholes Contractor maybe instructed to carry out tests to the manholes to establish their watertightness, prior to backfilling around manholes, and any damage revealed by such tests shall be made good. The Contractor shall provide all necessary testing equipment and shall carry out such other tests as may be required by FEWA/Engineer. Ground water shall not be used for the purpose of testing.

After sealing all pipe openings, the manholes shall be filled with water upto the underside of the cover or to a maximum of 9m total head in the system, whichever is applicable, and left for a minimum period of 24 hours. At the end of this period the manhole shall maintain the test water level for a minimum period of 30 minutes without the water level falling more than 10 mm per 3 metres depth.

Before sealing the outgoing pipe, the Contractor shall ensure that the seal may be easily removed upon completion of the test. Complete filling of the outgoing pipe to the next manhole will be permitted provided that the pipeline has been previously tested and approved and that the head does not exceed 10 metres.

8.3 COMMISSIONING All traps and flooded systems shall be charged and periodically refilled until final handover.During commissioning flows shall be confirmed for all major runs.