GUIDELINE

Design Requirements

Part D Materials and Workmanship

Part F Ventilation

Acceptable Construction Details

Acceptable Construction Details Introduction Thermal Bridging and Airtightness

Insulation in Cavity

• Diagram H ACD - 30 Ope split Lintels Ste... • Diagram H ACD - 12 Concrete Intermediate... • Diagram H ACD - 39 Concrete Forward cill... • Diagram H ACD - 38 Concrete backward cil... • Diagram H ACD - 19 Eaves Unventilated At... • Diagram H ACD - 40 Eaves Wall head close... • Diagram H ACD - 29 Flat roof parapet - I... • Diagram H ACD - 9 Insulation below groun... • Diagram H ACD - 33 Prestressed Concrete ... • Diagram H ACD - 22 Eaves Insulation betw... • Diagram H ACD - 15 Timber separating flo... • Diagram H ACD - 17 Masonry Partition Wal... • Diagram H ACD - 18 Stud partition wall -... • Diagram H ACD - 7 Insulation above groun... • Diagram H ACD - 21 Eaves Insulation betw... • Diagram H ACD - 14 Timber Intermediate f... • Diagram H ACD - 27 Gable Insulation betw... • Diagram H ACD - 26 Gable Insulation betw... • Diagram H ACD - 11 Timber suspended grou... • Diagram H ACD - 23 Eaves Insulation betw... • Diagram H ACD - 32 Ope Perforated Steel ... • Diagram H ACD - 20 Eaves Ventilated Atti... • Diagram H ACD - 34 Ope Jamb with closer ... • Diagram H ACD - 29 Flat roof Eaves - Ins... • Diagram H ACD - 8 Insulation above grou... • Diagram H ACD - 13 Concrete Intermediate... • Diagram H ACD - 28 Gable Insulation betw... • Diagram H ACD - 35 Ope Jamb with proprie... • Diagram H ACD - 36 Corner Inverted Corne... • Diagram H ACD - 16 Masonry solid and cav... • Diagram H ACD - 25 Eaves Insulation betw... • Diagram H ACD - 10 Insulation below grou... • Diagram H ACD - 37 Galvanised Top steel ...

Irish Water Requirements for Dwellings

Typical Inspection Reports

No 2. Inspection Foundations Radon Sump Barrier and Blinding No 26 Inspection of Windows on Rainwater System No 11. Inspection of Block work, Brickwork and feature stone band No 2. Inspection Foundations Radon Sump Barrier and Blinding No 12. Inspection of Block work, gable and party walls. No 28. Inspection of timber stairs installation No 3. Inspection Radon Barrier Blinding and Insulation No 22 Inspection Steel Beams and Intumescent paint No 4. Inspection of Radon Barrier and DPC No 25 Inspection of Windows on Front Elevations, DPM and Control Joint No 5. Inspection Radon Barrier Rising Walls Block and Brickwork No 17. Inspection of Stud wall construction No 8. Inspection of Blockwork and elements No 14 Inspection of Structural Beams No 23 Inspection of windows and doors being installed No 21 Inspection of Electrical first fix No 19. Inspection of Roof Construction and breathable membrane No 27 Inspection of Windows on Velux Rooflights No 10. Inspection of Joisting , bridging, Block work, Brickwork and Lintel supports No 16. Inspection of Stud wall construction. No 7. Inspection of Rising walls, Damp proof Course and Blockwork. No 18. Inspection of Roof Construction. No 7. Inspection of Chasing Block work, Brickwork and feature stone band No 6. Inspection Rising Walls Block and Brickwork No 8. Inspection of Radon Barrier and Damp proof Course. No 30 Inspection of timber stairs handrail installation No 15. Inspection of Stud wall and floor joist construction No 29. Inspection of timber stairs and handrail during construction stages No 3. Inspection Radon Barrier Blinding and Insulation No 31. Inspection of Timber stairs handrail. No 32. Inspection of Roof Access Hatch No 24 Inspection of Windows on Front and Rear Elevations No 20. Inspection of chasing in block party walls for electrical first fix No 13. Inspection Brickwork and Firestopping No 9. Inspection of Brick and Block work from 1st to 2nd floor

Design Requirements

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Introduction

The Customer shall carry out or procure the design of the Works in accordance with the Code of Practice as issued by Irish Water.

The design should incorporate a design risk assessment to ensure that risks to both the local community and operators of the Works are minimised.

You or your designer shall certify that the design complies with the Code of Practice and Standard Details and you will be required to accept liability for compliance with appropriate professional indemnity insurance, which shall be kept in place for a period of 6 years after the completion of the Works.

The design of the Works shall be such that:

  • a minimum design life is achieved of 60 years for pipework and structures,

  • 25 years for mechanical and electrical plant and

  • 15 years for information, communication and telemetry (ICT) plant.

Please Note: If these requirements, Standard Details and Codes of Practice are not followed, Irish Water is under no obligation to provide a connection to its Network or to take in charge the Works.

Design Submissions

In order to submit an application to allow Irish Water to assess the Customers Works proposal, a design submission is required to be submitted to Irish Water using [email protected]

The design submission shall comprise the following:

  • The applicant’s details, including name, address (Customer’s or Agent’s details are also required if different from the applicant);

  • Location of the Premises with grid reference to the Irish National Grid;

  • Type of development proposed that requires the connection, along with details of domestic and non-domestic properties;

  • Servicing details, including the required demand, demand profile;

  • Drawings outlining details of the development as outlined in Section 2.4 below,

  • Design calculations as outlined in the Code of Practice;

  • Site Investigation Report;

  • Contaminated Ground Report (if relevant);

  • Mechanical and Electrical plant information (if relevant);

  • Surge analysis report and proposals for surge protection plant, if required;

  • An Environmental Impact Assessment (EIS) or Appropriate Assessment (AA) Report (if relevant);

  • An integrated utility layout plan showing the layout of all utility pipes, ducts, etc. and indicating the relative separation distances between the various utilities infrastructure;

  • Details of the Planning Permission and other statutory requirements relating to the development;

  • A document outlining impact risks of the new infrastructure to existing Irish Water’s wastewater collection and water supply infrastructure to ensure that risks to both the local community and operators of the Works are minimised;

  • The identity of the MDPE/HDPE/HPPE pipeline manufacturer, if PE material is proposed;

  • Where booster pumping stations are proposed, drawings and specifications of the pump station should be provided;

  • A report on specialist advice on separation distances between landscape works the Works as obtained from a competent landscaping architects and/or arboriculturists;

  • The specific location for any scour valve chamber on pressure mains requiring the approval of Irish Water and the relevant Local Authority;

  • A design stage hydraulic model of the Works (if relevant);

  • Construction Method Statements

  • If applicable, a written statement from the Roads Authority in whose functional area the development is located allowing the use of alternative Backfill material to that required by Irish Water’s for the use of Clause 804/808 granular material.

On review of the proposal Irish Water will issue a Statement of No Objection if the design of the Works is deemed satisfactory. A Connection Agreement will not be issued unless the Customer’s design proposal is acceptable to Irish Water. Any variations need to be agreed and submitted for approval.

Drawings, Calculations and Design Information

You will need to supply Drawings and calculations for the Works, including elements that are not to be taken in charge by Irish Water, i.e. Pipes that are not within the Attendant Grounds of the development.

Layout plans will be required to have standard legends and symbols as required by Irish Water’s Drawing Standard and at least with water services industry norms.

The drawings you submit should show the precise layout as dictated by the local topography and all necessary detailed information required for guidance. The drawings should show the site boundary, existing utility apparatus, North point, Ordnance Grid reference for the centre of the site, Ordnance Grid reference for the proposed connection point, etc.

Location and layout plans, longitudinal sections and details should show the water supply system and development in full.

Drawings should be prepared using an electronic system and submitted in standard “Autodesk AutoCAD (dwg/dxf)” compatible file format. Details to larger scales should be provided where necessary. The drawings submitted should also show the following:

  • The location of the site on an Ordnance Survey Map with the site outlined in red;

  • Layout of roads and properties including plot numbers, phasing of development (if relevant);

  • Line and layouts of Water Mains, hydrants, valve Chambers, meter boxes, scour Main systems, air valves, details of all associated features and external property details;

  • Detailed information on the proposed Water Mains including Main size, pipe material, class of pipe, pressure rating, etc., including details of existing services in the case of infill or brownfield sites;

  • Locations of service pipes, showing size of service pipe if above 25mm diameter. Locations of Boundary Boxes, manifold boxes and meter Chambers;

  • Details of type of Service Connections and meter arrangements for apartment and multi occupancy units to allow water supply metering of individual properties;

  • Any fire flow storage capacity arising from Fire Authority requirements as well as associated fire network and accessories;

  • Clear demarcation showing the water infrastructure to be installed by the Customer as opposed to that to be constructed by Irish Water;

  • Details of over ground and underground structures within the Attendant Grounds that are to be taken in charge in Irish Water, including appropriate vehicular access to these structures;

  • Contours of existing ground levels, proposed ground levels and property floor levels relative to Ordnance Datum (Malin Head);

  • Longitudinal sections, to an exaggerated vertical scale, showing proposed levels, existing ground levels, invert levels, pipe sizes, bedding, haunch and surround details, backfill details, together with Chamber locations, chainages, gradients, pipe sizes, pipe materials, etc. All Chambers should be given unique sequential numbers/letters for identification;

  • Locations of all natural features, such as trees, streams, rivers, springs, etc., which are in the vicinity of the proposed water supply network system;

  • Location of manmade features, such as existing structures, buildings, roads, bridges, etc., which are in close proximity to the proposed water network system;

  • An integrated utility layout plan showing the layout of all utility infrastructure (ESB Networks, Gas Networks Ireland’s Networks, telecommunication provider ducting, etc.) and indicating the relative separation distances between the various utility infrastructure;

  • Layout taking into account possible future developments;

  • Location of Ordnance Survey (OS) Benchmarks and their value to Malin Head Datum;

  • Information and details of water management infrastructure within the development as required under the Code of Practice

The submission should include a soil investigation report including details of soil analysis, results of the soil analysis in tabular format, plans showing the locations where site investigations were carried out and the location of samples taken, details of known contaminants, details of possible contamination, mitigation proposals/measures to address soil contamination, details of standing water tables, etc.

Hydraulic Modelling

Irish Water may require you to provide a hydraulic model of the proposed Works within the new development to confirm that it is capable of delivering the required diurnal demand and that it provides optimum pressures at each Boundary Box.

General Minimum Requirements

The following general minimum requirements shall apply to the Works in new developments:

  • Every unit, whether domestic or business, shall have a separate Water Service connection.

  • A connection shall not be taken from an existing Service Connection.

  • All domestic connections shall have individually valve controlled metered services.

  • A bulk meter and associated telemetry system shall be provided to measure the demand of developments with a daily demand exceeding 200 m ^3^ per day (equivalent to approximately 400 housing units). The meter and the telemetry system will be chosen and supplied by Irish Water to its requirements based on the range of flow anticipated and the Customer shall provide the infrastructure to accommodate the meter and the telemetry facilities

  • Where the demand of a development or estate is between 20 m 3 per day (equivalent to 40 domestic houses) and 200 m3 per day, a bulk meter with a SMS/GPRS telemetry datalogger, with capability to record flow and pressure at regular intervals, located in an adjoining kiosk shall be provided. The meter and the telemetry system will be chosen and supplied by Irish

  • Water to its requirements based on the range of flow anticipated and the Customer shall provide the infrastructure to accommodate the meter and the telemetry facilities.

  • Where the flows to developments or estate are less than 20 m3 per day, there is no requirement to install a flow meter to measure water demand of the development

  • Metered connections shall consist of a sluice valve, a straight length of pipework at least 10 times the meter diameter upstream of the meter, approved water meter, a straight length of pipework at least 5 times the pipe diameter downstream of the meter and a sluice valve.

  • In the case of multi-occupancy units, all new/refurbished premises must be designed and have plumbing of each unit installed in such a way so that each unit can be separately metered, with meters and shut-off valves in accessible locations and subject to prior agreement with Irish Water.

  • Temporary water supplies for construction purposes shall have a meter and logger (chosen and supplied by Irish Water) installed to measure flow, complete with a logger to measure flows throughout the duration of the construction works.

  • All units shall have facilities for a minimum water storage capacity of 24- hour water demand.

  • Break tanks and booster pumps will be required in high rise buildings.

  • Where electric showers and dishwasher, washing machine, heating systems, etc. are provided in buildings, they shall not be connected directly to Irish Water’s water supply system. They must be fed from the storage tank located within the building. Direct feeds from Irish Water’s water supply system shall only be to a potable water supply tap and the water storage tank. 2

  • The installation of the connection pipework between the development’s water supply network and the existing Irish Water supply network system shall be carried out only by Irish Water or its agents.

  • The water supply pipework for developments shall not be located on private land. If this is unavoidable, Irish Water shall be nominated as the beneficiary of a wayleave across such land to allow maintenance and repair of and access to the infrastructure. 2.6.16 Valves, meters, hydrants, air valves, etc. shall be located in Chambers as indicated within this document.

Water Main Requirements

The size of the Water Mains within new developments is to be governed by the requirement that:

  • They have adequate hydraulic capacity to deliver customer demands at all times.

  • They reserve the wholesome water quality.

  • They avoid excessive retention or travel times.

  • They ensure adequate turnover of water and to prevent stagnation in the system.

Water Main layout should provide efficient and flexible operation of the Works with minimum control points and surface assets to mitigate future maintenance and operation costs.

Pipes should be free from defects or other features that might give rise to blockage, airlocks or otherwise impede the water flow.

The range of flow velocity within the water supply Mains should lie between 0.3 m/sec and 1.5m/sec, and preferably in the middle of this range.

The pipework should be selected to ensure that the head loss in the pipework does not exceed 3m/km.

Design Requirements

All works are to comply with IW’s Code of Practice and shall also comply with:

  • The Standards listed in Appendix B of the Code of Practice;

  • The Civil Engineering Specification for the Water Industry, 7th 3.1.2 Edition (CESWI), published by the Water Research Centre (WRc plc). This document is subject to amendments set out by Irish Water appropriate to Ireland’s Water Services sector and this Code of Practice takes account of these amendments;

  • IS EN 805, Water Supply – Requirements for Systems and Components Outside Buildings;

Within your curtilage wll works are to comply with:

  • IS EN 806 – Water Supply – Requirements for Systems Inside Buildings, and to

  • BS 8558 which provides complimentary guidance

Water Main Works

The layout of the Works should:

  • be as simple as possible;

  • ensure infrastructure is located so that if there is a structural failure, an excavation may be carried out to repair the failure without impairing the integrity of adjacent buildings or other infrastructure;

  • ensure infrastructure is located in public pavements, roads, in public open spaces, in an area to be taken in charge or in a dedicated service strip to permit access to the infrastructure for maintenance and to enable later connections to be made, if required;

  • ensure infrastructure is designed and constructed in order to provide access for any reasonably foreseeable maintenance activities

  • ensure infrastructure is located so that it is accessible and apparent to Irish Water or their Agents;

  • ensure infrastructure is laid on the side of the street/road where the housing density is greatest so that the number of service pipes road crossings are minimised;

  • ensure a single as opposed to dual Pipe system layouts;

Under no circumstances will Irish Water accept Water Main installations under structures, existing or proposed, or in close proximity to existing structures or features that will inhibit access for post installation maintenance and access.

Water Mains shall be provided in areas to be designated as public areas (roads, footpaths, public green areas, etc.). The provision of Service Connections supplying multiple premises and located ultimately in private areas, referred to normally as common backyard services, are not allowed.

The following general requirements apply to the locations of Water Mains in new developments:

  • Water Mains shall preferably be laid under footpaths or gras margins if possible, otherwise they may be laid on the roadway, subject to locating them a safe distance away from the footpath/grass margin kerb;

  • No new Water Main up to and including 150mm in diameter shall be laid within 3m of an existing or proposed building structure without the express approval of Irish Water;

  • No new Water Main between 200mm and 600mm in diameter shall be laid within 5m of an existing or proposed building structure without the express approval of Irish Water;

  • No new Water Main in excess of 600mm in diameter shall be laid within 8m of an existing or proposed building structure without the express approval of Irish Water;

  • In addition to the foregoing, no new Water Main up to and including 150mm in diameter shall be located within 1m of the boundaries of premises;

  • Water Mains shall not be located under walls, in areas designated for trees, shrubs or flowers. Trees should not be planted in the immediate vicinity of the Water Main unless tree root intrusion protection is provided. The separation distances between the Water Main and the trees/shrubs will be dependent on the species type and on the level of tree root intrusion protection that is provided.

Water Main pipe size and layout

Water Main pipe size and layout shall be in accordance with the requirements of Irish Water’s minimum criteria as outlined below, but subject to any particular requirements associated with individual sites:

  • Water Main layouts shall be arranged in loops or rings so as to avoid "dead ends" or terminal points. All Mains shall terminate in a loop or ring to accommodate one-directional flushing of the network. Loops shall have a minimum of four connected houses and one hydrant;

  • The minimum pipe size shall be 100mm internal diameter in housing developments of 40 houses and up to 100 houses. Developments of 100 houses and above shall have minimum pipe sizes of 150mm internal diameter spine Main with 100mm branch Mains. Nominal internal diameters of 80mm and less may be allowed in smaller developments but not where hydrants are located and only after prior written agreement has been received from Irish Water (See Section 3.7 below);

  • The minimum pipe size shall be 150mm in industrial or commercial developments

  • Every property, whether domestic or business, shall have a separate Service Connection. A connections shall not be taken from and existing service connection. The use of common service pipes is not allowed. Service Connections shall be as short as reasonably possible. Long Service Connections (in excess of 15m) will not be allowed. Service Connections shall be a minimum pipe size of 25mm outside diameter, 20mm internal diameter;

  • Service Connections shall not be taken across roads where the width of the road is greater than 15m, except with the prior agreement of Irish Water. In certain circumstances, a rider Main, located entirely on public property, may be provided to serve small numbers of houses at the streetside remote from the Water Main. This rider Main shall be looped back to the Water Main. Individual house Service Connections shall be provided off the rider Main;

  • Water Mains should be laid to provide the optimum circulation in the local water network. Water Mains may terminate in a dead end only with Irish Water approval, in which case a duck-foot washout hydrant, located within a Chamber or kiosk, shall be provided at the dead end

  • Valves shall be arranged at junctions and spine Water Mains in such a manner so as to ensure that water shut-down will affect no more than 40 properties at any one time;

  • Water Mains greater than 300mm in diameter laid under heavily trafficked roads shall be ductile iron;

  • Looped Water Mains shall return to the spur Main downstream of a sluice valve.

  • The location of hydrants should be such that they can be accessed in an emergency. Hydrants should not be located in roads or parking areas;

  • Where possible, a hydrant should be located within 20m of each junction

  • No domestic property within a development shall be more than 46m from a hydrant. Hydrant details and locations shall be subject to the approval of the relevant Fire Authority. This requirement may take account of deadend or wash-out hydrants. A hydrant shall not be closer than 6m to a property;

  • Fire hydrants should not be supplied from Water Mains of less than 100mm internal diameter;

  • The location of branch valves, hydrants or other apparatus shall be to the agreement of Irish Water.

  • Where a Water Main is located in an area of restricted access such as under motorways, canals, railways, rivers etc., a duplicate Water Main (or a sleeve for a replacement Main) shall be installed to maintain water supply in the event of a problem with the live Main until access is available to carry out repairs. The second Main shall be the same as the first Main in regards to material, diameter and flow capacity. Isolation valves shall be provided on both sides of the inaccessible area to allow the water supply to be redirected between either Main;

  • Where a Water Main is to be located within a structure such as a bridge or culvert, the Customer shall consult with Irish Water to establish if the Water Main is be duplicated. In most instances Irish Water may require that the Mains are placed within sleeves to facilitate easy replacement of the pipe. In general, however, Irish Water discourages the construction of Water Mains within bridge or culvert structures and the installation of the Mains across the watercourse adjacent to the bridge/culvert structure is preferred;

  • Surface water attenuation tanks shall not be constructed over Water Mains.

  • Irish Water will require the Customer to provide bulk metering of the water supply connection to developments with a water demand exceeding 20 m3 per day, with the bulk meter linked to an Irish Water telemetry data collection system in cases where the water demand exceeds 200 m3 per day. Developments with water demands less than 20 m3 per day will not require a flow meter. Irish Water will choose and supply the bulk meter and associate equipment based on the range of flow at the development.

  • Where there is the possibility of connecting into or extending the Works into adjoining land that is not developed, the Water Mains shall be extended to the boundary if required by Irish Water and easements for these extensions provided and executed to include Irish Water as the named beneficiary (Refer to Section 1.23 above);

  • Pressure control shall be provided at the take-off point of the new connection if required to control high pressures by way of a pressure reducing valve (PRV). Where possible their need shall be determined in advance but in some cases Irish Water may require these to be installed after the Main is made live. The cost of this work shall be borne by the Customer. The need for PRVs shall be agreed with Irish Water. Pressure sustaining valves (PSV) may be required in specific exceptional circumstances and only by agreement with Irish Water. The PRVs and PSVs will be chosen and supplied by Irish Water for installation in Customer supplied Chambers;

  • Individual Service Connections shall generally not be taken across roads and their length shall be kept to a minimum. The provisions outlined above may be used to limit long Service Connections;

  • Water Mains shall be laid in common areas and not through individual private gardens or driveways etc.;

  • Any redundant water services shall be traced back to the Irish Water Network by the Customer and shall be blanked off by Irish Water at the Customer’s expense;

  • Any existing lead services pipes to the site shall be replaced/made redundant at no cost to Irish Water. This work shall be carried out to the satisfaction of Irish Water;

  • Water Main bends and road crossings should be kept to an absolute minimum;

  • A three-way sluice valve arrangement shall be provided at all Water Main junctions;

  • The Water Main pipework to new developments should be located at the right hand side of the entrance to the new development (from a view facing into the development) if possible, and where the properties served are equally or reasonably distributed at both sides of the estate roadway

  • Branch pipes off spine Mains should have isolation valves installed to separately control all of the flows downstream of the pipe junction.

  • Three valves to a junction are required to allow the flow of water to be directed in both directions.

  • The need for additional ‘inline’ valves is dependent on the housing density and operational requirements such as step testing relating to active leakage control.

  • Sluice valves should be situated to ensure that water flow can be shut off affecting no more than 40 properties at any one time

  • Mains should extend no more than 1.2m beyond the final Service Connection.

  • Fire hydrants should only be located on paths or open spaces or approved areas. Where a Water Main is located in a road, the hydrant should be legged off-line in to the nearest suitable path or open space and connected to the Water Main with an 80mm spur Main.

  • In some Local authority areas, such legged off hydrants may require the inclusion of a separate valve on the tee piece of the Main where the Main is 200mm or greater in diameter. The provision of such valves shall only be incorporated subject to the approval and knowledge of the Fire Authority.

  • Irish Water will require a bulk meter to be installed at each new connection point to its water supply network for developments with a water demand in excess of 20 m^3^ per day.

Separation Distances

A storm water sewer or a wastewater sewer should generally not be installed to cross over a Water Main.

Where crossing over a water main is unavoidable, joints in the Water Main shall not be located directly above surface water or Wastewater Sewer crossings.

This requirement also applies to power and telecommunication utilities oil filled cable systems.

No other utility service should be laid longitudinally directly above the line of the Water Main. Pipe/ducts, cabinets, poles, junction boxes or Chambers shall not be constructed on top of a Water Main.

Crossings should be located midway between the Water Main joints with a minimum vertical clear distance of at least 300mm and up to 500mm in some instances between the pipe and the Water Main.

There should be a minimum clear horizontal distance of at least 300mm between the Water Main and other utilities running parallel to it, as well as to cabinets, poles, junction boxes or Chambers. The following minimum horizontal clearances to other services running parallel to the Water Main shall apply:

  • 300mm to Water Mains of less than 300mm diameter;

  • 500mm to trunk Mains between 300mm and 450mm diameter;

  • 3.0m to arterial Water Mains of greater than 450mm diameter;

There shall be a minimum vertical distance of 300mm between the Water Main and other utilities laid parallel to it, subject to the specific spatial distance requirement of the utility provider. There shall be a
minimum vertical clearance between the Water Main and any other service crossing over it as follows:

  • 300mm to Water Mains of less than 300mm diameter;

  • 500mm to trunk/arterial Water Mains of 300mm diameter or greater; Over and above the foregoing, all crossings shall be positioned such that they are at least 500mm away from any Water Main fitting or joint.

The location of the water Mains relative to other services, structures and obstructions for a particular development shall be shown on plan and cross section as part of the design submission pack, with clearance dimensions clearly identified. Drawings showing any revisions, during the tendering and construction phase of the development should be submitted to Irish Water for approval. No infrastructure installation shall be advanced without the prior written clearance of Irish Water.

The separation distances outlined above are minimum requirements. Specific separation clearance distances in excess of these minima shall be provided for services such as gas, electricity, fibre-optic or oil filled cables as the case may be. The particular utility providers shall be consulted to determine these minimum separation distances and evidence of this consultation, with the specified separation distances, shall be provided to Irish Water at design submission stage.

For example, the minimum separation distances for Gas Networks Ireland infrastructure shall be in accordance with IS329 ‘Gas Distribution Mains’ and IS328 ‘Code of Practice for Gas Transmission Mains’ as amended/updated. In the case of installations to be constructed in close proximity to existing Water Mains, specific approval of Irish Water shall be obtained.

In the case of existing network pipework, alternative minimum horizontal distances shall be Maintained between pipes/ducts, cabinets, poles, manholes, junction boxes, Chambers, etc., as outlined in Section 3.25 below.

Sizing of Water Mains

This is dealt with in Section 3.2 of the Code of Practice by Irish Water.

The minimum size of Water Main shall be 100mm nominal internal diameter but pipes with a nominal internal diameter of 80mm may be allowed in certain circumstances and only after the prior written permission of Irish Water has been obtained

In exceptional circumstances where a small number of dwellings are to be supplied. In these instances, a 25mm minimum pipe size may be allowed where a single house supply is required. If two dwellings are supplied, the Main size of 32mm internal diameter may be allowed.

A pipe of minimum 50mm internal diameter may be allowed for a supply to house groups of between three and five houses.

The table below gives guidance on the pipe:

Table HIW1 - Typical main size for multiple properties - Extract from Irish Water
Table HIW1 - Typical main size for multiple properties - Extract from Irish Water

Water Demand Calculations

Average domestic daily demand in a development can be established based on daily per-capita consumption, house occupancy, number of properties, etc.

For design purposes the average daily domestic demand shall be based on a per-capita consumption of 150 l/person/day and an average occupancy ratio of 2.7 persons per dwelling.

The average day/peak week demand should be taken as 1.25 times the average daily domestic demand.

The peak demand for sizing of the pipe network will normally be 5.0 times the average day/ peak week demand for customer use only.

Allowance should be provided on a case by case basis for operational water use within the supply network. Adequate headroom should also be provided for exceptional factors.

Irish Water will assess the hydraulic design of the proposed pipe network and may require the use of alternative design parameters on a case by case basis.

This may also include alternative peaking factors appropriate to the size of the proposed development, in particular for large developments where the demand is in excess of 230 m^3^ per day (approximately equivalent to a demand for a 450 unit housing development).

Works will be sized to accommodate the existing and future planned connections based on pressure and flow profiles to achieve the minimum standard of flow and pressure at the highest located premises.

Service Connections to Individual Premises – Sizing and General Requirements

The size of Service Connection to an individual premise is governed by the requirement that there should be adequate supply to meet customer demand at all times whilst ensuring that water quality is not compromised through the use of oversized pipes.

Service Connection pipes should be a minimum of 25mm outside diameter, 20mm inside diameter, and should be provided with appropriately sized fittings.

However, service pipes of greater diameter may be required in certain circumstances where a higher than standard demand is required. Irish Water’s approval of the diameter of the service pipe shall be obtained in advance of the commencement of the proposed development.

The distribution system within premises, along with the internal water supply pipework, including the overflow pipe from the building’s storage tank, shall be suitably sized to accommodate a flow from a 20mm inside diameter service connection.

Each Service Connection shall be fitted with a Boundary Box, located at the public side of the property Curtilage, as close as possible to the property boundary, but separated by at least 225mm from the face of the boundary. Irish Water will supply the meter and install it within this Boundary Box.

The Service Connection between the Boundary Box and the Water Main shall be laid in a public area or an area to be taken in charge.

Service Connection pipes should be laid in a straight line from the connection point to the Boundary Box meter location.

The service pipe shall be laid without mechanical joints between the Water Main Service Connection tapping point and the Boundary Box. The Distribution System pipe from the Boundary Box to the stop valve within the premises shall also be a continuous pipe length without mechanical connections.

Where possible, Service Connections should be installed to enter the right hand side of the premises entrance when viewed looking towards the front elevation of the property, provided that this does not result in the meter box being exposed to repeated traffic movements.

Following Vesting of the Works, Irish Water will be responsible for the Service Connection between the connection/tapping at the Irish Water Network as far as a point 225mm from the boundary of the Curtilage of the premises, including the boundary meter box.

Materials Selection: Mains and Service Connections

Water Mains suitable for Works and approved by Irish Water shall be either ductile iron (DI) or polyethylene (PE), with PE80 or PE100 rating (MDPE, HDPE or HPPE).

All plastic water pipes shall be blue in colour.

U-PVC pipes shall not be used on water supply networks, unless a compelling reason is provided for its use.

For ease of maintenance, the preferred Water Main materials are indicated below.

Table HIW2 - Pipe material based on internal diameter - Extract from Irish Water
Table HIW2 - Pipe material based on internal diameter - Extract from Irish Water

What are the materials and standards the pipes have to meet? These are detailed below:

  • Ductile Iron (DI) pipes shall conform to IS EN 545 and shall have a minimum C40 pressure rating. Ductile Iron fittings shall have 16 bar rating at least. All ductile iron pipework shall be coated internally with a blast furnace cement lining which complies with the requirements of BS 6920. External protection shall include an alloy of zinc and aluminium, with a minimum 15% aluminium, with or without other materials, having a mass of 400 g/m2 complete with a finishing layer of blue fusion bonded epoxy in accordance with IS EN 14901.

  • MDPE and HDPE pipes shall be of a type PE-80 and have an SDR-11 or SDR-17 rating. They shall conform to IS EN 12201: Part 1 and Part 2 (Plastic Systems for Water Supply, Drainage and Sewerage Under Pressure – Part 1, General, and Part 2, Pipes) and I.S. EN 12201-3 (Plastic Systems for Water Supply, Drainage and Sewerage Under Pressure – Part 3: Fittings).

  • HPPE pipes shall be of a type PE-100 and have an SDR-11 or SDR-17 rating. They shall conform to IS EN 12201: Part 1 and Part 2 (Plastic Systems for Water Supply, Drainage and Sewerage Under Pressure – Part 1, General, and Part 2, Pipes) and I.S. EN 12201-3 (Plastic Systems for Water Supply, Drainage and Sewerage Under Pressure – Part 3: Fittings). Polyethylene pipes shall also conform to the following UK Water Industry Specifications (WIS):

Polyethylene pipes shall also conform to the following UK Water Industry Specifications (WIS):

  • 4-32-08 – Specification for the fusion jointing of polyethylene pressure pipeline systems using PE80 and PE100 materials,

  • 4-32-16 – Specification for Butt Fusion Jointing Machines,

  • 4-32-19 – Specification for polyethylene pressure pipeline systems with an aluminium barrier layer for potable water supply in contaminated land,

  • IGN 4-01-03 – Pressure Testing of Pressure Pipes and Fittings for use by Public Water Supplies

Service Connection pipes suitable for Works shall be of MDPE or HDPE (PE-80) material with SDR-11 or SDR-17 rating.

All plastic water Service Connection pipes shall be blue in colour.

Pipe Joints

Pipe joints shall be in accordance with the manufacturer’s instructions for the pipe material. Pipe joints will generally be one of the following:

  • Push in rubber ring joint;

  • Bolted flanged joint;

  • Flexible mechanical coupling with protective coating;

  • Fusion welded joints, site fusion jointing shall be strictly in accordance with UK WIS 4-32-08 (Specification for Fusion Jointing of Polyethylene Pressure Pipeline Systems Using PE80 and PE10 Materials). Equipment used for butt fusion welding shall be in accordance with UK WIS 4-32-16 (Butt Fusion Joining Machines).

Bolted flanged joint shall have raised face flanges complete with nuts and bolts to IS EN ISO 898 and metal washers to BS 4320. Nuts, bolts and washers to be protected against corrosion in accordance with WIS 4-52-03. Flange assemblies, including nuts, bolts, washers and gaskets to be designed to meet a working and test pressure of 16 bar and 25 bar respectively.

Butt fusion welding and electro fusion jointing of pipes shall only be carried out by trained operatives in possession of a current relevant Training Certificate, using fully automatic approved jointing machine/rigs in accordance with the manufacturer’s instructions. In relation to electro fusion jointing, the jointing machine shall incorporate a remote inspection/monitoring system, which allows for real time inspection of the weld integrity.

The identity of the MDPE/HDPE/HPPE pipeline manufacturer shall be made known to Irish Water prior to commencement of the installation. Certification and testing (including independent third party certification) shall be provided to confirm quality assurance compliance.

Each joint shall be clearly marked with the joint logged automatically on the jointing machine.

A printout of the joint details, with a GPS location of each joint, shall be provided and retained for quality assurance purposes.

Auditing and testing of welded joints in polyethylene pipelines shall be carried out as follows:

  • Each installation team and welder will be audited by the Irish Water Field Engineer on a regular basis. The audit will use a standard checklist to ensure that all the correct equipment and working practices are being utilised.

  • All butt fusion joints shall be de-beaded and the bead referenced and kept for inspection. Beads shall be examined upon removal for signs of defects or splitting along the length of the bead joint.

  • Butt fusion welds and electro-fusion welds shall be cut out from the works completed and subjected to a destructive test, as indicated by the Irish water Field Engineer. All sample welds shall be clearly labelled and referenced. One butt-fusion weld per butt-fusion crew per week and one electrofusion weld per electrofusion crew per weeks hall be cut out and taken for testing by the Developer’s contractor. This minimum frequency of destructive testing shall be increased as specified by the Field Engineer if significant failure rates occur.

  • For butt welding, completed welds shall be de-beaded and the weld bead shall be inspected on site by the welding crew. Beads shall be labelled, bagged and stored by the Developer’s contractor and access shall be provided to the Field Engineer to inspect the weld beads when requested.

Weekly equipment checks and supervision of the pressure tests shall be carried out by the Developer and these will be inspected by the Field Engineer.

However the destructive weld testing and analysis shall be carried out by a specialist and accredited testing organisation.

The Developer’s contractor shall provide details of his proposed testing organisation to the Field Engineer for review and approval prior to any testing being undertaken.

The Contractor shall arrange for the selected samples to be tested in accordance with WIS 4-32-08 Appendix B, C and D by an accredited laboratory (by the Irish national Accreditation Board or equivalent) and a test report in accordance with WIS 4-32-08 provided to the Employers Representative within 1 week of the sample joint being taken. The report should indicate the failure mode (above or below 75% and ductile or not), K value MNm, Classification (pass, non-critical failure, failure etc), recommended action. Where welds exhibit <K

Where welds exhibit <75% Ductility and 1.2<K<1.7, the Contractor shall excavate, cut out, and provide the welds carried out immediately before and immediately after failed sample for testing.

The provision of the sample and all costs associated with their provision including restoring the watermain to service and reinstatement will be borne by the Contractor. Untested sample welds shall be properly catalogued and stored by the Contractor until the end of the Defect Period. Welds shall remain the property of the Employer and be made available to the Employer’s Representative at any for testing should he so direct.

Depth of Cover

The desirable minimum depth of cover from the finished ground level to the external crown of a single premise Service Connection pipe shall be 750mm with an absolute minimum of 600mm for short distances (subject to Irish Water agreement). The desirable depth of cover at the Boundary Box should be 600mm +\- 25mm, with a maximum depth of 750mm.

The minimum depth of cover from the finished ground level to the external crown of a Water Main shall be 900mm where the pipe is to be located in housing estate roads. A greater depth of cover and/or greater strength pipe and/or a higher class of bedding may be required where higher traffic loading is anticipated. Depths may be altered to avoid obstructions, including separation distances between other utility services.

The cover for a water main should be 1,200mm, where practicable and should not exceed 3.0m.

The desirable maximum cover for service connection pipe should be 1,200mm, where practicable.

Boundary Boxes

All Service Connections shall include the installation of an approved Boundary Box (meter box) with integral stopcock (the use of traditional stopcock has been discontinued) and suitable for the reception of a water meter.

The provision of the Boundary Box and meter shall be in line with Irish Water guidelines.

The Boundary Box shall be a telescopic type, self-contained Chamber system with Class B or Class C covers in accordance with BS 5834.

You need to consult with Irish Water in relation to the approved types of Boundary Boxes.

A specification for Boundary Boxes suitable for use in assets to be taken in charge by Irish Water is outlined in Appendix A herewith.

The Boundary Box shall be located as near as possible to the Curtilage boundary but set back at least 225mm from the face of the boundary in accordance with the Connection Agreement, on a footway or service strip, off the public road/street and, if possible, sited to avoid vehicle crossing points, drives and parking areas to ensure future maintenance requirements are achievable.

Where Boundary Boxes are to be installed close to each other, there should be adequate space (500mm) around them to allow adequate compaction between and around them as well as subsequent reinstatement and possible future repair and replacement. A concrete surround plinth shall be provided to the Boundary Box cover at ground level where the finished surface is to be either unbound (grass verge), brick paving or macadam. The surround shall be constructed of C20/25 concrete to IS EN 206 complete with bull-nose finish to its perimeter and shall be provided with a mild steel reinforcement link. Alternatively a pre-cast concrete plinth may be provided.

Manifolds

Where a manifold chamber is used to provide a communal Boundary Box, each dwelling should have its own supply pipe and meter and stop valve. All pipes should be suitably identified.

All supply pipes associated with any one manifold should be ready for connection to the Distribution System pipe in one visit. All meters in the manifold shall be tagged to indicate which property is supplied and any unused outlets are to be blanked off.

Meters

Meters to measure water use shall be installed in Boundary Boxes or Chambers on each Service Connection supplying commercial premise. Domestic connections shall be made “meter ready” by the provision of a Boundary Box on the service connection.

In addition, bulk flow meters, measuring the total development water use, shall be provided at the connection point of the Works to the Irish Water’s Network in cases where the daily demand of the development exceeds 20 m3 per day.

These bulk meters shall be capable of measuring minimum night flow demand either directly or by the provision of an associated night flow meter. In developments with a daily demand less than 20 m^3^ per day, there is no requirement to install a flow meter to measure water demand of the development.

All meters used to measure water flow along with associated accessories and technology will remain the property of Irish Water irrespective of who installs the meters or whether they are located on public or private property.

You are l not permitted to add any other technology either directly or indirectly to collect meter readings or other data without the written permission of Irish Water.

Domestic Meters

Domestic connections shall be made “meter ready” by the Developer by the provision of a Boundary Box on the service connection. Domestic meters will be installed by Irish Water’s agents in accordance with Irish Water’s metering policy.

Domestic meters, where required, will be installed for individual Premises in Boundary Boxes by Irish Water or its agents and will be to Irish Water’s requirements and compatible with the automatic meter reading (AMR) system in use.

Meters for apartments and similar properties will be installed internally within the Premises in accordance with the Building Control Authority’s requirements and subject to review by Irish Water.

Sluice Valves

Sluice valves shall be double flanged with ductile iron resilient seal gate valves, suitable for use in Water Mains.

They shall comply with the requirements of BS 5163, Part 1 and 2 and IS EN 1074, Part 1 and Part 2, and they shall have a CE marking in accordance with the EU Construction Products Regulations (No. 305/2011 –CPR) and any other relevant Directives.

All flanges shall be drilled to PN 16 in accordance with BS EN 1092 -2 and shall be suitable to accommodate a maximum differential pressure during operation of 16 bar. Telescopic spindles and shall be fitted with a cast iron square false cap (complete with grub screw).

The depth of the sluice valve cap shall be within 350mm of the finished ground level and no valve spindle shall be greater than 600mm below ground level.

All sluice valves shall be ANTI-CLOCKWISE CLOSING.

The direction of closing shall be imprinted on the valve casing. The number of turns (n) to open/close the valve shall be: n = 2N+1 where N is diameter in inches.

The operating torque must not exceed the max allowed in BS 5163 Part 1 Type B. Valves in deep Chambers shall be provided with extended spindles, adequately fixed/braced within the Chamber.

The sluice valve surface shall be blue and it shall be protected from corrosion by a coating in accordance with WIS 4-52-01 or IS EN 14901.

Butterfly Valves

All valves of 400mm diameter or over are to be butterfly valves.

All butterfly valves have to be capable of being operated remotely with valve actuators, if required. Such valves and actuators shall be located in specially designed valve Chambers with an automatic sump pump to prevent water accumulation.

Actuators shall be electrically operated and shall be capable of being activated automatically via a telemetry link.

Valves shall be hydraulically tested with the body tested to minimum of 17 bar but higher test requirements may be required for specific areas.

Generally, Water Mains of 400mm and greater will not be required in housing developments.

Scour Valves

Scour valves shall be double flanged with ductile iron resilient seal gate valves.

Scour valves shall have the following minimum diameters:

Table HIW3 - Minimum diameters of scour vavles - Extract from Irish Water
Table HIW3 - Minimum diameters of scour vavles - Extract from Irish Water

Scour valves and outlet pipes for large diameter Mains shall be sized for both rapid emptying time and on the assimilative capacity of the downstream receiving waterway. Where scour pipes discharge to a surface water system, it is essential that the surface water pipe has adequate capacity to receive the scour. Each specific scour valve location will require the approval of Irish Water and the relevant Local Authority.

The Scour valve should be located off line from the Water Main in a separate valve Chamber. The scour take-off from the Water Main shall be provided by a flanged tee piece fitting with a level invert outlet of appropriate size. The connection pipe between tee piece at the take-off point on the Water Main and the scour valve, as well as between the scour valve and the scour Chamber, shall be of ductile iron material.

A scour Chamber shall be provided downstream of the scour valve between the take-off point and the discharge point to balance the scour discharge and to allow collection and pumping out of scour debris.

The scour Chamber, as described below, is to be provided with a non-return valve to prevent backflow to the water supply network system. If required by Irish Water, the scour valves shall be provided to allow adaption of automatic scouring of the water supply system.

Hydrants

Hydrants shall be double flanged drilled to PN 16. They shall comply with the requirements of :

  • IS EN 14339,

  • IS EN 1074: Part 6 and

  • BS 750.

Fire hydrants shall be Type 2 and shall have an 80mm diameter flange,n PN16 rated. The hydrant shall incorporate a screw-down gate valve, underground, “guide to head” type, with screw connection outlet and false spindle cap and iron chain.

The surface of the hydrant shall be blue and it shall be protected from corrosion by a coating in accordance with WIS 4-52-01 or IS EN 14901. For coatings in accordance with WIS 4-52-01, the internal water-wetted surface shall be coated to Class A standard while all other surfaces shall be coated to Class B standard. The depth of the hydrant cap shall be located at most 350mm from the finished ground level. All hydrants shall be ANTI-CLOCKWISE OPENING. Hydrants can be provided either on line or off line depending on the site requirements. The hydrant shall have a minimum flow coefficient (Kv) value of 92m3 per hour.

Air Valves

Air valves shall be of double air valve type with isolating valve in accordance with the requirements of IS EN 1074: Part 4. Air valves shall be of ductile iron to IS EN 1563, with a minimum tensile strength 420 N/mm2 and shall have flanged inlets, PN16 rated.

Each valve shall have a large and a small air escape orifice with an isolating valve. The isolating valve shall be either a resilient seated gate valve to BS 5163 Part 1 Type B and IS EN 1074, Part 2 and shall be of a boltless bonnet design, or a butterfly valve to IS EN 1074 Part 2.

The air valve shall be capable of automatically releasing accumulated air/gas from the pipe system while the system is under pressure, release large quantities of air/gas from the pipe system during filling and prevent negative pressure occurring in the pipe system during draining. Air valves can be provided either on line or off line depending on the site requirements.

The inlet diameter shall be in accordance with the following table:

Table HIW4 - Inlet diameter for air valves - Extract from Irish Water
Table HIW4 - Inlet diameter for air valves - Extract from Irish Water

The location of the air valve shall be the subject of particular agreement with Irish Water to ensure that the risk of contamination through the valve is eliminated. The valve shall be generally located at the high points of the water Main comprising pipework of 100mm diameter or more. Service Connections shall not be provided within 2m of the air valve location.

Pressure reducing valves

Pressure reducing valves (PRV), where required, will be selected, supplied and fitted by Irish Water in Chambers constructed by the Customer. The PRV will incorporate appropriate strainers, valve gauges, pilot displays and damper. They shall be capable of variable “day” and “night” pressure adjustment and shall incorporate upstream and downstream pressure assessment capability.

PRV control systems shall also be provided by Irish Water. The valve will be capable of being adjusted locally or remotely and will be supplied with a digital valve controller which can be integrated into an automatic control system.

The control of the valve shall be governed by pre-determined set points. The PRV and its control system will be provided and fitted at the expense of the Customer. The body of the valve shall be ductile iron, 16 bar rated, flanged and drilled to BS EN 1092, PN 16. All external tubing shall be in copper and all external fittings shall be brass. The valve shall be supplied with all necessary solenoid valves to enable automatic operation.

Pressure sustaining valves

Pressure sustaining valves (PSV) will be selected, provided and fitted to a standard approved by Irish Water in Chambers constructed by the Customer.

The PSV and its control system will be provided and fitted at the expense of the Customer. Control equipment, pressure gauges, etc. associated with pressure reducing and pressure sustaining valves shall be located in a kiosk adjacent to the valve location. Appropriate ducting shall be provided between the valve Chamber and the kiosk

Chambers for Hydrant, Air Valves, Sluice Valve and Scour Valves

Hydrants, air valves, sluice valves, scour valves and washout hydrants shall be installed in Chambers suitably sized to accommodate the fitting and allow access for inspection and normal maintenance.

Chambers shall have a minimum plan area of 600mm by 600mm. Alternative dimensions for sluice valves Chambers of 450mm by 600mm or 450mm by 450mm may be allowed, subject to the approval of Irish Water.

Chambers can be constructed of pre-cast concrete or of high density blockwork. Alternatively, proprietary prefabricated Chamber units may also be used, but only subject to the approval of Irish Water.

The walls of blockwork Chambers shall be constructed with 215mm 20N/mm² solid concrete block, laid on flat, bedded in mortar and flush pointed, complying with the requirements of IS EN 771. The walls of Chambers can alternatively be formed with reinforced pre-cast concrete units formed with C28/35 concrete, 20mm aggregate size, with steel reinforcement.

The units shall be square, composite units, with a minimum wall thickness of 100mm, thickened at each corner. Single height precast units will be acceptable. If modular units are proposed, the pre-cast concrete units shall be bedded in mortar and flush pointed.

The Chamber floors shall be formed with C25/30 concrete, 20mm aggregate size, with a minimum thickness of 100mm, complete with mild steel reinforcement. Alternatively, pre-cast concrete bearing slabs of similar depth may be allowed, subject to Irish Water approval. The floor slab shall be founded on the granular pipe surround material or on trench granular backfill material. Off-line hydrant and air valve Chambers floor slabs shall be founded on natural material. The floor slab of on-line Chambers shall not be cast against the sluice valve body or the riser pipe to the hydrant and air valves.

A drain hole shall be allowed in the base slab to allow free drainage of liquid from the Chamber to the granular material below. In the case of off-line hydrants and air valves, the duckfoot bend supporting the hydrant or air valve shall be seated on the floor slab of the offline Chambers. Chambers shall be surrounded in Clause 808 material in accordance with the National Roads Authority’s Specification for Road Works, compacted in 150mm layers, to the underside of the road/footpath structure.

The Chamber of sluice valves, scour valves and hydrants shall be complete with a reinforced concrete roof formed with C30/37 concrete, 20mm aggregate size, of minimum thickness of 150mm, reinforced with high tensile reinforcement to BS 4449.

The roof slab shall be designed to carry road traffic.

Air valve Chambers will not require a roof slab due to the size of the air valve Chamber cover and frame.

Sluice valve chambers shall be covered with approved heavy duty cast iron surface box covers and frames, 445mm by 280mm plan area, to IS 261 or BS 5834, subject to the minimum mass of the cover per m2 for Grade A being 250kg/m2 and Grade B being 200kg/m2 .

The covers and frames shall be suitable for road and traffic conditions. Third Party Certification shall be provided for all cast iron surface box covers and frames. Air valve Chambers shall be covered with approved heavy duty iron covers and frames, 600mm by 600mm, to IS EN 124, rating D400, with a minimum frame depth of either 100mm or 150mm.

The sluice valve, hydrant and air valve cover frames shall be supported on Class B engineering brick to IS EN 771. The brickwork shall be bedded in C50/60 mortar. The covers shall be set on the brick in accordance with the manufacturer’s instructions to finish in alignment with the road or footway surface. The finish of the road surface around the Chamber cover and frame shall be to the requirements of the relevant Roads Authority for the area.

Air valve and hydrants covers, where located in grass areas, shall be surrounded by a concrete plinth, 200mm all round and 100mm deep formed with C20/25 concrete, 20mm aggregate size, bedded in Clause 804 material. The plinth shall incorporate mild steel reinforcement links and shall have a bull-nose finish around its external perimeter.

The metal covers shall have appropriate identification marks on the cover. Covers for surface boxes on Water Mains shall have either the word “WATER” or the letter “WM” cast on the top surface in 75mm letters. Covers for other applications shall have “FH” (fire hydrant), “ScV” (scour valve), “SV” (sluice valve), “AV” (air valve) and PRV/PSV (pressure reducing or pressure sustaining valve) as appropriate.

Covers shall be level with the finished ground level after permanent restoration.

Environmental Considerations

The design, procurement and supervision of the landscaping works next to and over the Works shall be undertaken by the Customer using a fully qualified and competent landscape architect, working in collaboration with a fully qualified and competent arboriculturist, both in consultation with Irish Water.

Any part of Works which does not have special tree root protection measures shall be positioned with adequate separation from new trees/shrubs to ensure that their root systems will not cause damage to the infrastructure.

These separation distances will vary from (tree and shrub) species to species and specialist advice shall be obtained by the Customer from his/her landscape architect and arboricultural advisers in this regard, as outlined above, and provided in the Design Submission.

Special tree root protection measures may be provided to reduce the separation distances between the Works and the new planting.

The design of the tree planting and species selection will need to be decided in relation to the depth of the pipe and the distance from the Works. Where tree planting is proposed within the distances where tree roots could directly damage the Works, as referenced in Table A1 of BS 5837, special protection measures shall be provided.

These measures might be achieved in the pipe system by the provision of high performance joints or the use of polyethylene pipes with welded joints. Alternatively, proprietary protection systems, such as vertical barriers, geotextile pipe wrap, tree planting pits, etc. may be used to prevent the tree roots systems from reaching the Works.

Tree planting will not normally be allowed directly over the Works or within the distances referred to in Table A1 of BS 5837, but this may be increased depending on the species type or relaxed where it can be shown that appropriate species selection and protection measures can be provided to prevent root ingress damage to the satisfaction of Irish Water.

Such protection measures may include root barriers, root directors and by avoiding planting next to joints, valves or other sensitive parts of the pipe system.

Where new pipe installation works are to be carried out near existing tree vegetation, these shall be in accordance with the provisions of BS 5837 (Trees in Relation to Design, Demolition and Construction – Recommendations) and the National Joint Utilities Group (NJUG), Guidelines for Planting, Installation and Maintenance of Utility Apparatus in Proximity to Trees, Volume 4, which outline the following zones:

  • Prohibited Zone (1m from tree trunk): Excavation of any kind shall not be undertaken within this zone unless, after full consultation with an arboriculturist or landscape consultant, it is deemed acceptable. No material, plant and spoil shall be stored within this area.

  • Precaution Zone (defined as a radius of four times the circumference of the tree at 1.5m above ground level): Where excavation is carried out within this zone, the use of mechanical excavation plant shall be prohibited. All such excavation works shall be carried out manually or with the aid of an air-spade or vacuum and precautions shall be undertaken to protect any exposed roots from damage. All such excavation works shall be supervised by a qualified arborist. No material, plant and spoil shall be stored within this area.

  • Permitted Zone (outside the Precaution Zone): Excavation works may be undertaken within this zone, but caution must be applied and the use of mechanical plant limited. Any exposed roots should be protected.

Separation distances from Water Mains and Sewers and required notifications

In the case of installations in close proximity to existing Water Mains and Sewers, the following minimum horizontal distances shall be maintained between pipes/ducts, cabinets, poles, manholes, junction boxes, Chambers, etc.:

  • 500mm at either side of Mains up to and including 200mm diameter;

  • 1m at either side of Mains of 225mm to 250mm diameter;

  • 2m at either side of Mains of 300mm and 375mm diameter;

  • 5m at either side of Mains of 400mm and 450mm diameter;

  • Specific Irish Water advised distances for Mains in excess of 450mm;

  • 500mm at either side of gravity sewer up to and including 225mm diameter;

  • 1m at either side of gravity sewer up to and including 450 mm diameter;

  • 1.5m at either side of gravity sewers of 600mm diameter and greater;

Specific written permission will be required from Irish Water for installing infrastructure closer to the Irish Water asset than the limits outlined above. For strategic fibre optic or oil filled cables, Irish Water may require increased clearance separation distances in excess of the specific utility providers requirements.

Where pipes or ducts are to be laid close to an existing Water Main or sewer in the sole control of Irish Water, notification in writing shall be provided a minimum of 10 working days ahead of the advancement of the work. This requirement shall also apply to the carrying out of trial holes or slit trenches to locate the Main or to gather ground investigation data. In the case of large diameter (350mm or greater) distribution and trunk Water Mains, Irish Water must be notified at least one month before the work is advanced.

This notification is in addition to any formal procedures detailed elsewhere in this document. The notifications shall apply where work is proposed within the following proximities of Irish Water infrastructure:

  • 1m at either side of an existing Main less than 200mm diameter;

  • 2m at either side of an existing Main of 200mm to 350mm diameter;

  • 5m at either side of an existing Main of 350mm or greater;

*Water Storage Requirements for Houses

Only indirect plumbing systems shall be permitted by Irish Water i.e. all appliances shall be plumbed from a cold-water storage tank and supplied by gravity.

The plumbing and water storage requirements for private domestic premises should be in accordance with the current version of the Building Regulations and/or with the requirements of the relevant Local Authority’s Plumbing Regulations and Bye-Laws, if such exist.

In many instances, the Local Authority will require arrangements to be made to have internal plumbing inspected and approved by a Local Authority representative.

All developments over two storeys in height or requiring a supply pressure greater than 15m head at the Curtilage of the property must comply with the requirements of Irish Water.

Specific agreement will be required from Irish Water and the relevant Local Authority as necessary. As a general rule, storage of 24-hour maximum daily consumption should be provided.

General guidelines for domestic premises are shown below in the following Table:

Table HIW5 - General requirements for domestic premises - Extract from Irish Water
Table HIW5 - General requirements for domestic premises - Extract from Irish Water

Rainwater Harvesting and Cross contamination

Rainwater harvesting systems, where proposed in their developments, shall be installed with specific focus on preventing water quality cross contamination. The Customer shall provide full details of the water management proposals to Irish Water and the Local Authority in which the development is being undertaken along with the design proposals for the infrastructure. This may be in the form of a Water Management and Conservation Plan (WMCP). The WMCP will include details of the Customer’s proposals in relation to Water Mains and all internal plumbing, fittings and Distribution Systems as well as proposals for the limitation of use of water.

Such water management proposals may include rainwater harvesting systems. Rainwater harvesting systems usually require the option of top up with water from the water supply network during periods of dry weather when rainfall is not sufficient to meet the demands of the system.

Any connection to a rainwater harvesting system must be provided via a secure connection where it is not possible for cross contamination and/or backflow to the public or private drinking water supply. An acceptable back up supply to the rainwater harvesting system can be provided using a connection to the high level rainwater storage tank via an unrestricted air-gap device (Type AA device, IS EN 1717).

All pipework connected to or from rainwater harvesting systems shall be labelled to avoid misconnection or accidental consumption of non-potable water. The label must carry the marking “RECLAIMED WATER” in black text 5mm high on a green background and must be at least 100mm long. The size of the lettering and labels should be increased as the pipe diameter increases. It should be noted that harvested rainwater will not be of potable standard unless it is treated. Treatment requirements will vary dependent on what is the intended use for the water. All infrastructure storing and carrying reclaimed water must not be utilised for human consumption without adequate disinfection and treatment.

Rainwater Harvesting and Cross contamination

Rainwater harvesting systems, where proposed in their developments, shall be installed with specific focus on preventing water quality cross contamination. The Customer shall provide full details of the water management proposals to Irish Water and the Local Authority in which the development is being undertaken along with the design proposals for the infrastructure. This may be in the form of a Water Management and Conservation Plan (WMCP). The WMCP will include details of the Customer’s proposals in relation to Water Mains and all internal plumbing, fittings and Distribution Systems as well as proposals for the limitation of use of water.

Such water management proposals may include rainwater harvesting systems. Rainwater harvesting systems usually require the option of top up with water from the water supply network during periods of dry weather when rainfall is not sufficient to meet the demands of the system.

Any connection to a rainwater harvesting system must be provided via a secure connection where it is not possible for cross contamination and/or backflow to the public or private drinking water supply. An acceptable back up supply to the rainwater harvesting system can be provided using a connection to the high level rainwater storage tank via an unrestricted air-gap device (Type AA device, IS EN 1717).

All pipework connected to or from rainwater harvesting systems shall be labelled to avoid misconnection or accidental consumption of non-potable water. The label must carry the marking “RECLAIMED WATER” in black text 5mm high on a green background and must be at least 100mm long. The size of the lettering and labels should be increased as the pipe diameter increases. It should be noted that harvested rainwater will not be of potable standard unless it is treated. Treatment requirements will vary dependent on what is the intended use for the water. All infrastructure storing and carrying reclaimed water must not be utilised for human consumption without adequate disinfection and treatment.

*Trench Widths

The trench shall be kept as narrow as possible but the width must allow adequate room for pipe jointing as well as placing and compacting pipe bedding, haunch, surround and backfill material.

Trench widths at the level of the top of the pipe should allow adequate room as safe working conditions will allow, with a desirable minimum width of 300mm plus the external diameter of the pipe barrel, or a minimum trench width of 500mm. The trench width should not exceed the pipe diameter by more than 500mm.

A guideline for trench widths is shown below in the following Table:

Table HIW6 - Trench widths - Extract from Irish Water
Table HIW6 - Trench widths - Extract from Irish Water

In the event that pipe diameters of 350mm, 400mm and 450mm are installed, the trench width will be 900mm.

Trench widths for pipe sizes less than 80mm may be less than 500mm, subject to consideration being given to the trench depth, health and safety consideration, ground conditions and construction difficulties.

In ground that contains ashes, chemicals or material that could accelerate corrosion or deterioration of the pipe, contact shall be made with the Environmental Protection Agency in relation to contaminated soil disposal requirements.

Edges of trenches in bituminous or concrete roads, footpaths and hard surfaces shall be cut using a concrete saw or other equivalent mechanical means in advance of breaking through the paved surface above the trench position. This shall be carried out in all instances to reduce damage to the remaining hard surface and to restrict over-break of the trench along proposed roadways and footpaths in the development.

If the backfill material is within 500mm of a concrete pipe of structure, Clause 808 material shall be used instead of Clause 804 material.

The use of Clause 804/808 Backfill material shall also apply where the trench is in green areas running near roadways and footways.

The Backfill material shall be placed in layers not exceeding 200mm, each layer being compacted to the requirements of the Specification for Road Works.

The first layer of backfill above the granular surround should be compacted in 150mm layers.

Mechanical compaction equipment should not be used until there is a minimum of 450mm of compacted material above the crown of the pipe

Cleaning Pipes

Before installation, all pipes for inclusion in the Works shall be examined internally for dirt, stones or any foreign matter and shall be thoroughly cleaned before installation in the final position. To prevent foreign matter or vermin from entering the Works, all open ends of laid pipes shall be plugged, if work is suspended, until the next pipe is ready for jointing. If proprietary pipe stops/plugs are supplied, they shall be left in place until just before jointing.

Backfill

Backfill material shall be placed above the granular surround material described up as far as the underside of the road construction. The Backfill material shall comprise Clause 804 granular material, in accordance the TII “Specification for Road Works”, and it shall be used where the Water Main is installed along proposed roadways and footpaths in the development.

If the backfill material is within 500mm of a concrete pipe of structure, Clause 808 material shall be used instead of Clause 804 material. The use of Clause 804/808 Backfill material shall also apply where the trench is in green areas running near roadways and footways.

The Backfill material shall be placed in layers not exceeding 200mm, each layer being compacted to the requirements of the Specification for road Works.

The first layer of backfill above the granular surround should be compacted in 150mm layers.

Mechanical compaction equipment should not be used until there is a minimum of 450mm of compacted material above the crown of the pipe.

Alternative Backfill material to that described above (Clause 804 or Clause 808) of the pipe trench will only be allowed by Irish Water where the Roads Authority in whose functional area the development is located provides written approval to the Developer to the use such alternative material. Evidence of this written approval to use alternative Backfill material shall be provided to Irish Water in advance of the issue of the Connection Agreement.

The relevant Roads Authority should specify this alternative Backfill material and this should require compliance with the definition of “acceptable material” as outlined in Clause 601 of the TII “Specification for Roadworks, Series 600 – Earthworks”.

Backfill to the pipe trench above the pipe granular surround material and beneath the road surface in Public Roads shall be to the requirements of “Guidelines for the Opening,

Backfilling and Reinstatement of Trenches in Public Road”, Second Edition, or subsequent amendments published by Department of the Transport, Tourism and Sport, unless otherwise specified and to the requirements of the relevant Road’s Authority’s Road Opening Licence.

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