Self Lay Policy Addendum

8/16/2019 Self Lay Policy Addendum

http://slidepdf.com/reader/full/self-lay-policy-addendum 1/34

Self Lay Policy and

Company Specific Addendum

21 December 2015



3Self Lay Policy & Addendum

Introduction

This document defines Severn Trent Water’s (STW) self lay policy and company specific addendum

to the WRc publication Self-Laying of Water Mains and Services – A Code of Practice for

England and Wales (2nd Edition) (Code of Practice). The policy and addendum should be read

and followed by self lay organisations (SLOs) constructing new mains schemes and undertakingwater connections in the STW operating area.

If this is a printed copy, you are advised to check that this is a current version. Please visit our website at

stwater.co.uk/developers/self-lay/self-lay

Part 1 of this document explains how STW manages self lay activities and how it interacts with SLOs.

Part 2 of this document specifies where STW have variations from the Code of Practice.

This document should also be read in conjunction with the following publications and internal documents

available to all accredited SLOs:

The WRc publication Self-Laying of Water Mains and Services – A Code of Practice for England and

Wales (2nd Edition) – this can be found here selflay.wrcplc.co.uk/

All relevant legislation including but not limited to the Water Industry Act 1991, the Highways Act

1980, the New Roads and Street Works Act 1991 all as may be amended from time to time

STW’s Design Manual

Civil Engineering Specification for Water Industry (7th edition) – this can be found at

sfa.wrcplc.co.uk/ceswi-7th-edition.aspx

STW values working alongside our SLOs and adheres to Ofwat’s expectation of fair competition and therefore:

1. We will not insist on laying all new water mains

2. We will charge reasonable costs for any work that we do

3. Our costs will be transparent

4. Our communications with SLOs will be accurate and clear and easy to find

5. We will not impose unreasonable conditions or working practices on SLOs

Contacting STWThe initial point of contact for any enquiry about self-lay should be sent to:

Developer Services

Severn Trent Water Limited

PO Box 5311

Coventry

CV3 9FL

Telephone: 0800 707 6600

Email: [email protected]

http://www.stwater.co.uk/developers/self-lay/self-lay

http://selflay.wrcplc.co.uk/



http://sfa.wrcplc.co.uk/ceswi-7th-edition.aspx


mailto:[email protected]






http://www.stwater.co.uk/developers/self-lay/self-lay




Part 1: Self Lay Policy

Introduction In accordance with section 51A of the Water Industry Act 1991, Severn Trent Water (STW) will agree

to adopt a new water main that has been laid by a third party, subject to the following

requirements:

1. The work has been done in accordance with section 51A of the Water Industry Act 1991

2. The work has been done in accordance with the current UK Water Industry Research (UKWIR) Self-

Laying of Water Mains and Services - A Code of Practice for England and Wales 2nd Edition (the

Code of Practice) as amended by Severn Trent Water’s Self Lay Policy and Company Specific

Addendum (the Addendum) to the Code of Practice. The Code of Practice can be found at

http://selflay.wrcplc.co.uk.

3. In addition to compliance with the Code of Practice and the STW Addendum, all work undertaken by

Self Lay Organisations (SLOs) must be compliant with STW’s Design Manual.

AccreditationDevelopers can appoint a SLO to construct a new water main and /or lay a new service supply pipe, but all

work must be carried out by an accredited SLO. To ensure the quality and safety of the work undertaken by

SLOs, STW recognise the accreditation scheme operated by Lloyd’s Register and a list of accredited SLOs can

be found at http://www.lr.org/en/energy/utilities-and-building-assurance-schemes/water-industry-

registration-scheme/

Designers and installers need to meet the accreditation criteria set out in Water Industry Registration Scheme

(WIRS) Requirements Document – see here http://www.lr.org/en/energy/utilities-and-building-assurance-

schemes/water-industry-registration-scheme/wirs-accreditation-for-self-lay-organisations.aspx before we

agree to the construction of mains and service supply pipes.

Non Contestable WorkDue to the need to safeguard the water supply to our existing customers, there are restrictions to the work

that an SLO can do. Some work must remain STW’s responsibility so that we meet our obligation to maintain a

wholesome and safe water supply to our customers. STW therefore reserves the right to carry out all work

defined as non contestable. However, in some circumstances STW may be willing to allow some of these

activities to be carried out by the SLO by prior agreement.

This non-contestable work includes:

• Designing ‘off -site’ water systems, which involves improving our existing network to cope with the additionaldemand

• Sizing water pipes

• Approving on-site water main designs

• Off -site work to provide additional capacity to the existing water distribution network

• Determining the timing of service pipe connections to a new main

• Determining the timing of routine in line mains connections

• Connecting a new main to our existing water distribution network

• Connecting a new main to an existing main, when this involves risks to existing customers

• Connecting a service pipe directly to an existing main, when there is a risk to existing customers

• Water sampling and quality testing

• Decommissioning redundant mains following a diversion



http://www.lr.org/en/energy/utilities-and-building-assurance-schemes/water-industry-registration-scheme/




http://www.lr.org/en/energy/utilities-and-building-assurance-schemes/water-industry-registration-scheme/wirs-accreditation-for-self-lay-organisations.aspx











In accordance with the Water Industry Act 1991 (the “Act”), some of STW’s costs in carrying out non

contestable work will be payable by the Developer or SLO.

Contestable WorkThis is the work that can be carried out by SLOs and includes:

• Designing on-site water systems in line with STW specifications

• Installing on-site mains

• Making routine in-line mains connections, subject to relevant safeguards and accreditation schemes being in

place

• Installing off -site mains in third party land and highways where SLOs have obtained the necessary easements

and highway authority approvals, and satisfied any other legal requirements

• Installing new mains for development sites, where SLOs have the necessary permissions and no existing

customers will be affected and/or there are no engineering reasons why this work should be non-contestable

• Installing service pipes to our specifications

• Connecting service pipes to new mains (after STW have commissioned them), provided the appropriate

standards are met and there are no risks to existing customers

• Connecting service pipes for new development sites to water mains installed by STW or other SLOs

• Connecting service pipes directly to existing off -site mains, subject to appropriate accreditation, approvals

and controls

• Swabbing, pressure testing and disinfecting new mains under supervision

• Fitting water meters to our specifications and subject to our approval

• Providing ‘as constructed’ drawings to our specifications

Initial EnquiryIf the development site has not yet reached the planning approval stage, or a SLO just wants to know if the

proposed development site can be supplied with water, a SLO can send STW a development enquiry beforemaking a full application. It will also confirm if the development will affect existing STW assets.

Any party involved in a self lay development can make an application for a development enquiry by completing

a developer enquiry application form and sending it to us along with the following supporting documents:

A location plan

A copy of a site layout plan

Full details of the proposed development including flows/storage details

The current application fee which can be found in our Developer Charges booklet on our website -

https://www.stwater.co.uk/developers/application-forms-and-guidance-notes/

The application form for a development enquiry can be found on our website here:


Once complete, the application form and application fee payment can be posted to us at:

Developer Services

Severn Trent Centre

PO Box 5311

Coventry

CV3 9FL










Or you can email the application form to us at [email protected] attaching all supporting

documentation. If the application form is sent to us by email, we’ll assume that the applicant wants to pay the

application fee payment by credit or debit card and we’ll call to take the payment.

The current application fee can be found in our Developer Charges booklet on our website -


Once we’ve received the application form we’ll confirm receipt and provide a reference number. The

application will then be assigned to a member of our team who will be the point of contact during this stage.

The application fee covers the work we need to do to respond to an enquiry. If the flow requirements are such

that more extensive modelling/evaluation is needed an additional payment may be required for the

completion of a Network Impact Assessment. We’ll tell you if we need an additional payment in our enquiry

response.

The more information that can be given about the development type and the water usage, the more detailed

and tailored our response can be. Our standard response for water enquires will include:

A copy of our water records for the area

Confirmation of any apparatus we have that will be affected by the proposals

Information about our ability to provide water for the development and how it should be supplied

Where appropriate details of any offsite works needed to reinforce our network to supply the

development

Estimated costs associated for the water mains or service connections proposed to serve the site

Making an Application for a New Water Main

Any party involved in a self lay development can make an application for a new water main.

The application form for a new water main can be found on our website here:


Once complete, the application form and application fee payment can be posted to us at:

Developer Services

Severn Trent Centre

PO Box 5311

Coventry

CV3 9FL

Or email the application form to us at [email protected] attaching all supporting

documentation. If you send the application to us by email, we’ll assume that you want to pay the application

fee payment by credit or debit card and we’ll call to take the payment.

The current application fee can be found in our Developer Charges booklet on our website here:

stwater.co.uk/developers/application-forms-and-guidance-notes/

The application needs to tell us about all relevant parties to the Self Lay Agreement, such as the Developer, the

SLO and any third party land owners.





















Once we’ve received the application we’ll confirm receipt and give you a reference number. The application

will then be assigned to a member of our design team who will be your point of contact during the design

stage.

A WIRS accredited designer can prepare and send STW a design for a new water mains scheme along with the

application form, which we will either approve or highlight aspects of the design that don’t meet ourspecifications, as set out in our Design Manual and Addendum. The designer must consult with the local Fire

and Rescue Service (FRS) when designing a scheme.

DesignIf a STW requisitioned design has previously been prepared, this may be used by a WIRS accredited designer.

We reserve the right to charge for the conversion of an approved design. The current charge can be found in

our Developer Charges booklet on our website here: stwater.co.uk/developers/application-forms-and-

guidance-notes/

If an accredited designer needs to vary a design once construction has started he should contact the design

team in writing at [email protected] who will assess the impact of the

changes needed. We reserve the right to recover reasonable costs in relation to any changes.

Once a design has been reworked by a designer it can be sent back to STW for approval and once approved

we’ll either be able to provide costings for the scheme in our Offer Letter, or confirm that the design is

acceptable.

Offer LetterThe Offer Letter is designed to allow the developer to make a choice about who he wants to lay the new water

main and/or service connections. It can be laid by either STW, which is known as a requisition or a SLO, which

is known as self lay.

STW will show the costings for both requisition and self lay and they are valid for 6 months. This means that a

Developer has 6 months in which to make a decision about the option he wants to use. If the Developer comes

back to STW after 6 months he will incur another charge to provide new cost options.

The letter will show the work needed for the new water mains scheme, including what the site specific

contestable activity is, and the assumptions that the costings have been based on.

Developer ResponseWithin the Offer Letter there is an Acceptance of Proposal document which the developer can use to tell STW

whether the work is to be completed by STW as a requisition, or whether he has appointed a SLO. If self lay,

the developer will also need to tell STW who the point of contact will be for the site, i.e. the developer or their

appointed SLO, and who the Asset Value Payment will be paid to. STW don’t expect any payment at this time.

Self Lay AgreementA Self Lay Agreement (Agreement) must be signed by all relevant parties before work can start on a

development site and it’s the developer’s responsibility to ensure they have the correct signed Agreement in

place before any work on site begins.

Relevant parties include:

Self Lay Organisation

Developer














Severn Trent Water

Landowners

Pre start MeetingA pre start meeting must take place before any work can start on a development site and STW expect the

following parties to attend:

The developer

The SLO

STW’s third party contractor

STW’s Customer Experience Manager

Any other interested party

The purpose of the pre-start meeting is to agree such things as the build programme, to review drawings, to

agree the location of off site/spur main and possible delivery date, to review traffic management, to discuss

good and bad practice on site and find solutions to key issues. Where possible, the Notification to startconstructing a new water main (Form 2) should be completed.

The minutes of the meeting will be documented by the STW Customer Experience Manager and sent to all

attendees and will be held by STW against the records for the mains scheme.

The Role of the STW Customer Experience ManagerThe Customer Experience Manager (CEM) is the STW representative on site. Their role is to oversee the

construction on site from inception to completion.

The CEM is expected to attend the pre-start meeting, visit the development site at least once a month and is

the point of contact for any issues on site.

Risk and Contingency PlanIn order to protect the integrity of the STW network and maintain a quality water supply to our existing

customers, STW will complete a risk assessment on the connection being made and may insist that a Risk and

Contingency Plan (R&C Plan) is in place before any connection is made to our existing network.

The risk assessment will be completed by STW and a R&C Plan will be documented by STW after the design has

been approved and the pre-start meeting has taken place.

ConstructionBefore any work can start on a development site, STW insist on the following:

A pre-start meeting with all parties must have taken place and be minuted

STW have approved the design of the mains scheme

A signed Self Lay Agreement is in place

A Risk & Contingency Plan is in place, where necessary

STW have received a complete materials and fittings list

Failure to have these in place before work starts on site will be deemed a failure of process and the SLO will be

reported to Lloyd’s Register.




If any installation of the new water main scheme is carried out without prior authority from STW, the SLO will

need to demonstrate that the work has been carried out to the requirements and specifications of STW. If any

work is done without approval, STW may refuse to vest and connect the main.

A SLO must tell STW when they are about to start construction on site by sending us a completed Notification

to start constructing a new water main (Form 2) 15 days before any work starts.

STW expect the minimum information on a Form 2:

1. The STW reference number(s)

2. The date the SLO intends to start work on site

3. A description of the works

4. The name/organisation who is going to carry out the testing and chlorination and their telephone number

5. The date of the pre-start meeting

6. The expected date of the final connection

7. Who is going to do the final connection

STW expects the SLO to send a copy of the Form 2 to Lloyd’s Register and to the STW Customer Experience

Manager.

An incomplete Form 2 will be returned to the SLO and this may delay the start of main laying.

Sub ContractingWhere a SLO intends to subcontract any part of the self-lay works they must notify STW. The SLO named on

the Agreement remains responsible for ensuring any work is completed in accordance with the Agreement and

this document. Any subcontractor must be WIRS accredited.

CommissioningA SLO must tell STW when they want to connect the new water main by sending us a completed Water mains

sampling and commissioning notification (Form 3) 10 days before the connection is needed.

STW expect this minimum information on a Form 3:


2. Confirmation who is going to make the final connection. If this is the SLO, then we also need a Routine

Inline Mains Connection Notification

3. Confirmation that this is the final Form 3, if applicable

STW also expect the following documentation to be submitted with the Form3:

1. The Pressure Test and Chlorination Certificate

2. The Fire Hydrant Adoption Certificate issued to the local Fire & Rescue Service (FRS)

3. Copy of the Swabbing Record

4. 3 copies of the As-Laid Drawing(s) clearly marked with sampling and connection points along with SLO and

Developer’s name, STW reference number, scheme number, scheme name, scheme type, stage number, date

of completion of the scheme or phase and the date of submission. Where SLO and Severn Trent Water

software is compatible, drawings should be submitted electronically

5. The Asset Data update form

6. The site sign off sheet

STW expects the SLO to send a copy of the Form 3 to Lloyd’s Register and the STW Customer ExperienceManager.




An incomplete Form 3 will be returned to the SLO and this may delay the connection.

Under no circumstances should a connection be made without confirmation of a passed water quality sample

from STW. Any connection done without this approval will be reported to Lloyd’s Register. Works will have to

stop while STW assess the impact on the water quality in the area and will seek to recover any additional costsfrom the SLO involved in this work.

STW will permit the connection of the self laid main when it has been laid in compliance with the provisions of

the Agreement. Until that point the self laid main remains the responsibility of the Developer or SLO.

Audit and ComplianceThroughout construction, STW will conduct routine site visits and complete an audit of works to ensure that

the mains are being laid to specifications and the correct fixtures are used. It is expected that any works that

are found to be defective will be corrected by the SLO at no cost to STW.

During construction, STW expect the Gang Whereabouts in the STW area to be sent to both the STW CEM and

STW’s design team at [email protected] each week.

Adoption of the mainsOnce the main is laid and successfully commissioned, it becomes STW’s responsibility and we will issue a

Vesting Certificate confirming adoption of the main.

Although the main is adopted by STW there is a defects liability period of 12 months, during which time the

SLO is responsible for the repair of any defects. This 12 month period starts from the issuing of a Vesting

Certificate.

Asset Value PaymentsWhen STW adopts the self laid main, or any part thereof, we will pay the Developer or the SLO an Asset Value

Payment (AVP) as detailed in the Offer Letter. STW will retain 10% of the final AVP until the final site sign off

has been completed and there is no corrective work needed on the adopted self-laid mains.

Service ConnectionsService connections can also be laid by a SLO, as long as the installer carries the appropriate Water Industry

Registration Scheme (WIRS) accreditation.

Service connections can be taken from the on-site mains when the service supply pipes comply with TheWater Supply (Water Fittings) Regulations 1999 (the Regulations) and have either passed an STW inspection

process or have been laid by a STW Watermark, or equivalent scheme, accredited plumber. Details of the

Regulations can be found here: legislation.gov.uk/uksi/1999/1148/contents/made.

Details of STW’s Watermark scheme can be found on our website here: stwater.co.uk/businesses/watermark-

plumbers/what-is-the-watermark-scheme/ . Although a plumber may be accredited under our Watermark, or

equivalent, scheme we reserve the right to audit 10% of service supply pipes.

Service connections to existing mains which are adjacent to the development site can be made subject to

STW’s conditions and approval. However, to safeguard the water supply to our existing customers and meet

our obligation to maintain a wholesome and safe water supply STW will put in place a Risk & Contingency Plan.




http://www.legislation.gov.uk/uksi/1999/1148/contents/made



https://www.stwater.co.uk/businesses/watermark-plumbers/what-is-the-watermark-scheme/











A SLO must request a quote for any infrastructure charge and/or meter charges applicable before submitting a

Form 4. Please allow 28 days for the quote.

A SLO must tell STW information about each property it intends to make a service connection to by sending us

a completed Notification to start connecting service pipes (Form 4). This must be sent to STW 10 days before

starting to make any connections, or 5 working days if a STW Watermark, or equivalent scheme, approvedplumber, has completed the work. STW expect that each quote has been paid for before the SLO sends us the

Form 4.

If a STW Watermark approved plumber, or equivalent Water Industry Scheme (WIAPS), hasn’t laid the service

pipes then STW will need to inspect them before the connection to the mains is completed. An STW inspector

will visit the site and inspect the service pipes against a standard set of criteria. The inspector will then let the

SLO know if the laid service pipes have passed this inspection, or if the inspection fails he’ll tell the SLO what

he needs to do to correct any defects. When there is a failed inspection the SLO will need to request a re-

inspection.

STW expect the minimum information for each plot to be completed on a Form 4:


2. The plot numbers which are ready for inspection/connection

3. The postal address of each plot

4. The date the plots will be ready for inspection/connection

5. The name/organisation who is going to install the meters

6. Confirmation that service connections have been paid for

7. Confirmation of pipe size

8. Confirmation of meter size to be fitted

9. Confirmation of connection to an on-site or off-site main

STW expects the SLO to send a copy of the Form 4 to the STW Customer Experience Manager.

An incomplete Form 4 will be returned to the SLO and this may delay the delivery of the meter and service

connections.

Service connections cannot be made without our prior approval. Failure to comply with this requirement may

mean that the right to connect subsequent service supply pipes will be refused. Under no circumstances

should new service supply pipes be connected to a main that has not been made live and where written

confirmation of the Depress Sample from STW has not been received. Written confirmation is often sent to

the SLO by email.

MeteringAll new properties must be fitted with a water meter by the SLO within 5 days of the service connection to our

network.

All water meters will be supplied and delivered by STW to an agreed location and will be paid for by either the

developer or SLO.

SLOs are expected to fit and commission the water meters at the location agreed on the approved design. If an

SLO fails to install a water meter following a service connection then STW will fit one and recharge the cost to

the SLO.




A SLO must tell STW which meters have been installed at each property by sending us a completed

Notification of competed service pipe connections (Form 5) within 5 days of making a service connection.

STW expect the minimum information for each plot to be completed on a Form 5:

1. The STW reference number

2. The plot numbers that have been connected3. The date of connection

4. The postal address

5. The occupier’s details, if known

If the SLO has also installed the meter we also expect:

6. The date the meter was installed

7. The meter location

8. The meter size

9. The meter serial number

10. The meter reading

STW expects the SLO to send a copy of the Form 5 to the STW Customer Experience Manager.

An incomplete Form 5 will be returned to the SLO and repeated failure of process will be reported to Lloyd’s

Register.

If we attend site and find that a meter has not been fitted in the stated timescales we will charge for our visit

and subsequent visit to fit the meter.

Site Sign-off

To ensure that all agreed apparatus such as fire hydrants, boundary boxes, meters, values and standpipes havebeen laid as designed, a STW Customer Experience Manager will walk the site with the site representative

and/or SLO and complete an Apparatus Sign Off form. STW may invite a representative from the local FRS to

a site sign off.

STW suggest completing the Apparatus Sign Off form before the final surface (e.g. tarmac or blocking paving)

has been laid on site, to make it easier to rectify any problems. This can be a phased approach or a one-off

final site walk at the end of the development.

Self Lay Policy and Process ComplianceWe aim to ensure that our processes are efficient and effective for both STW and SLOs, so would encourage

feedback to help us to continually improve and build on our collaborative approach to offering an excellent

service to our developers.

However, where we experience repeated non-compliance of our SLO Policy that has, or could not be resolved

through mutual agreement, we will report these to Lloyd’s Register.

Levels of ServiceWater UK has produced a set of standards that developers and others can expect from water companies in

relation to the provision of infrastructure for new developments.




These standards form part of the government’s initiative to publish levels of service for all utility providers.

They cover the performance of water companies in dealing with a broad range of activities which are essential

for housing development and are shown here:

Target days Definition

Pre Development Enquiry 21 A pre-development report will be sent to the developerwithin a period of 21 days commencing either (i) on the

day after receipt of a full application, or (ii) if an

incomplete application and/or no payment has been

received with the application, on the day after all the

required information and payment have been received.

An application is full when all the required information

and any required payment have been received.

A pre-development report includes any necessary

network modelling.

Self Lay Acknowledgment 5 An acknowledgement of the application will be sent

within a period of 5 days commencing on the day after

receipt of the application confirming either that the

application is complete or, if not, requesting the missing

information.

Self Lay Service Connection 28 A quotation will be sent within a period of 28 days

commencing on the day after receipt of a full

application.


has been received.

Self Lay Design <500 plots 28 A quotation will be sent within a period of 28 days


application.



A quotation includes the design or design approval, the

amount of the asset payment and any amount to be

paid by the SLO or developer. A draft self lay agreement

is sent with the quotation.

Self Lay Design Over 500 Plots

or off Site Reinforcements /

Engineering Difficulties /

Approved List

42 A quotation will be sent within a period of 42 days


application.



A quotation includes the design or design approval, the

details of any required network reinforcement or

associated infrastructure, and the amount of the asset

payment and any amount to be paid by the SLO or

developer.




Mains Construction 90 The construction and connection of the water main will

be completed either (i) within a period of 90 days

commencing on the relevant day, or (ii) no later than on

the date agreed with the developer.

The construction and connection of the new water main

is completed when the new water main is under

pressure from the network.

The relevant day is when an undertaking under S42 of

the Water Industry Act 1991 has been signed by the

developer and a valid security has been received.

This service level is applied separately in respect of each

individual phase on a development site.

Service Pipe Connection 21 The service pipe connection will be completed within a

period of 21 days commencing on the relevant day.

The relevant day is the day after all the required

conditions are satisfied (typically all the conditions are

satisfied when the trench & service pipe inspection has

passed.)

Timescales can be extended by agreement with the

customer due to third party need (Schedule 13 WIA /

TMA / Third Party Land)

Water companies are publishing these standards quarterly to demonstrate their commitment to providing

transparency about their performance and to help drive improvements in their levels of service. To see how

STW are performing against these standards see here Water Companies.

DisputesIf there is an issue that is unable to be resolved satisfactorily by the STW Customer Experience Manager then

please escalate to the appropriate escalation point which can be found on our current contact list

In line with Ofwat’s expectations we aim to be fair, clear, transparent and accurate with our dealings with

SLOs. Any queries about our self lay policy or self lay activities can be raised with our Developer Services Team

on 0800 707 6600.

http://www.water.org.uk/developer-services







Part 2: Severn Trent Water’s Addendum to the Self -Laying of Water Mains

and Services - A Code of Practice for England and Wales (2nd Edition)

Amendments to the Code of Practice

This Addendum show the changes that STW have made to the Self-Laying of Water Mains and Services - ACode of Practice for England and Wales (2nd Edition) (Code of Practice) and apply to the construction of new

water mains by self lay organisations (SLO).

Supplementary clausesThe structure and numbering of the clauses follow those in the Code of Practice.

Part 1 – General

1.1 APPLICATION

Insert clause 12

Where an application is made on behalf of the Developer by the SLO, the Developer must give STW written

notification that the SLO is acting as an agent on their behalf. The Developer will need to enter into a Self Lay

Agreement on STW’s standard terms and conditions, together with the SLO and any relevant landowner(s). If

the Developer wants the Asset Value Payment to be paid to the SLO, they must confirm this in writing in the

Acceptance of Proposal.

1.5 COMPETENCE OF SELF LAY ORGANISATIONS

Insert clause 6In order to demonstrate competence, a SLO must be a member of the Lloyd’s Register Water Industry

Registration Scheme (WIRS) and hold a current approval certificate granting at least partial accreditation

before they can design and/or construct a new water main and service connections within STW’s operational

area.

1.11 FINANCES

Insert clause 8

The following financial terms will apply to a Self Lay Agreement:

a) When the self laid main has been constructed, or part thereof, in accordance with the Self Lay Agreement

and STW then adopts it, STW will pay the developer an Asset Value Payment calculated in accordance with

sections 51A to 51E of the Water Industry Act 1991 (the Act). This Asset Value Payment is the lesser of:

i. the estimated annual income that STW would receive over a 12 year period from the water charges

from the occupied premises that will be connected to the new water main. This will depend on the

rate at which the development and occupation of the site takes place and

ii. the annual borrowing costs of a loan, over a 12 year period, of the amount which STW would have

needed to lay the main itself

b) In accordance with the Act, any payment for non contestable works must be paid before STW countersign

and issue the Self Lay Agreement and before construction. This payment is the lesser of the statutory

commuted sum and the cost for STW to provide non contestable works




c) The Asset Value Payment is paid to the nominated party indicated in the Acceptance of Proposal in the Offer

Letter

d) STW’s charges for the self laying of mains and services can be found in our current Developer Charges

booklet which can be found on our website at stwater.co.uk/developers

http://www.stwater.co.uk/newconnections







Part 2 – Self Lay Procedures

2.2 INITIAL ENQUIRY

Replace clause 1

1. The initial enquiry process is shown in Figure 4




Insert clause 7

Before any design work can be started by STW, we’ll need to do a technical appraisal of our network to find

the point of supply and see if any off site work is needed. The point of supply can be determined through a

development enquiry application which is available on our website: stwater.co.uk/developers/application-

forms-and-guidance-notes/

Insert clause 8

Any costs that are provided at this stage are purely indicative and should not be relied upon as an accurate

reflection of the Asset Value Payment that the Developer or SLO may receive.

Insert clause 9

For developments greater than 500 properties, or those likely to use significant water, STW will confirm within

10 days of receiving the application an alternative date for providing the information.










Insert clause 8

The design shall be in accordance with STW Design Manual and can be requested by emailing

[email protected]

Insert clause9

When the Developer or SLO returns the signed Self Lay Agreement to STW they should provide a material andfittings list to confirm that all materials and fittings meet both industry and STW requirements

Insert clause 10

Fire Authorities are responsible for the cost of any additional hydrants not shown on the original design that

they specifically request to be incorporated into the design

Insert clause 11

Developers can design a new water mains scheme but they or their designers must be WIRS accredited for

design. STW must approve the design before a Self Lay Agreement can be issued and before any construction

starts. During the design process we’ll need to do a technical appraisal of our network to find the point of

supply and see if any off site work is needed. If not already known, the point of supply can be determined

through a development enquiry application - see 2.2.

Insert clause 12

An accredited designer of a new mains scheme must consult with the Fire Authorities to ensure compliance

with the requirements of the Water Industry Act 1991 and the Fire and Rescue Services Act 2004. The designer

is responsible for liaison with the Fire & Rescue Service (FRS) and for agreeing the provision of water for fire

fighting.







Replace clause 2.3.2 Design by Severn Trent Water

Replace clause 1

1. The design process is shown in Figure 6




2.4 CONSTRUCTION STAGE

2.4.1 Notification of Start

Replace clause 11. The construction process is shown in Figure 7




Insert clause 7

From the date of vesting of the new main in STW, there is a maintenance period of 12 months, during which

time STW can require the SLO to repair any defects. In the event of a default of any of the SLO’s obligations

under the Self Lay Agreement, the Developer will become jointly and severally liable for those obligations.

2.4.2 Water Main Installation

Insert clause 8

Before the final connection is made, the SLO must provide STW with a Fire Hydrant Adoption Certificate which

proves that the requirements of the Fire & Rescue Service have been met.

Insert clause 9

Before the final connection is made, STW will need to confirm that the works have been completed as per

design and as-laid drawings.

Insert clause 10

During construction the SLO should display both normal and emergency contact details.

2.4.3 Final Connection

Insert clause 2

SLOs that have met the Lloyd’s Register WIRS requirements are permitted to complete routine in-line mains

connections. The criteria for a routine in-line mains connection is:

To a newly laid main, either laid by STW as a spur off an existing main or by any SLO at the end of a

previous phase of main laying To mains which are controlled by a valve, or mains that can be squeezed off without affecting existing

customers, so there is no interruption to supply to existing customers

Insert clause 3

The Developer/SLO should use STW’s Water mains sampling and commissioning notification (Form 3) to tell

us that a final connection is needed.

Insert clause 4

The Developer/SLO should provide the notification of chlorination within 24 hours of it being taken to reduce

the likelihood of failure.

Insert clause 5

The Developer/SLO needs to be aware that it may take up to up to 5 working days from the date any sample is

taken for the pre and post connection sample results to become available.




2.4.4 Service Pipe Installation

Replace clause 1

1. The process for the installation and connection of service supply pipes is shown in Figure 8




Insert clause 9

Whilst STW gives installers the flexibility to programme service connections to suit their own construction

programme, this programme must be agreed with STW to allow us inspect the work when necessary.

Insert clause 10

The construction programme for service connections must be given to STW at least five working days before aconnection is needed and STW must be made aware of any changes to the programme within 48 hours of the

planned connection date.

Insert clause 11

Where STW arrange to inspect the work and find that the activity is not proceeding in accordance with the

agreed programme, our abortive inspection charges will be recharged and the work will be subject to

verification before being accepted.

Insert clause 12

Self lay service connections should meet the installation requirements specified in Table 1 and Section 2.4.4. of

the Code. Contestable activities in the design and construction of water mains and services of the Code are

generally restricted to connections up to and including 63mm nominal bore.

Insert clause 13

During construction, the SLO should ensure adequate courtesy signs are available displaying normal and

emergency contact details for the SLO

Insert clause 14

The Developer/SLO should use STW’s Notification to start connecting service pipes (Form 4) to tell us of that

you’re about to start making service connections. This must be sent to us 10 days before starting to make any

connections, or 5 working days if a water regulations certified plumber has completed the work.

Insert clause 15

The Developer/SLO should use STW’s Notification of completed service pipe connections (Form 5) to tell us

about completed service pipe connections and meter installations. This must be sent to us within 5 days of

making each connection.




Part 3 – Design and Construction Guidance

3.1 GENERAL DESIGN PRINCIPLES

Insert clause 8

When undertaking design the Developer/SLO must ensure that the design of mains and services meets the

requirements of:

The Code of Practice

STW’s Addendum to the Code of Practice

The Self Lay Agreement

The STW Design Manual

3.2 DESIGN REQUIREMENTS

Insert clause 3

Polyethylene should be the default material for all diameters up to 180mm nominal bore. However, when

ground conditions are not suitable for PE80/PE100 the following products are approved for use within STW’s

operating area:

Size of Pipe Pipe Material

Mains and services up to 110mm diameter Puriton, Protectaline

Mains 180mm diameter Protectaline

Mains 100mm to 300mm diameter Ductile Iron

Standard sizes acceptable are 63mm, 90mm, 125mm, 180mm PE. All other pipe sizes must have approval

from STW.

3.4 DESIGN GUIDANCE – GENERAL

Replace clause 6

The design should take into account the impact of the works on the environment and the impact of the

environment on pipe installation.

STW’s recommendations for tree and surface planting are:

Poplar and willow trees should not be planted within 10m of the water main The following trees should not be planted within 6m of any pipe – ash, beech, birch, most conifers,

elm, horse chestnut, lime, oak, sycamore, apple and pear

No shrubs or bushes should be planted within 1m of the centre line of any pipe

The following shallow rooted shrubs/bushes are suitable for screening purposes in close proximity to

water mains – blackthorn, broom, cotoneaster, elder, hazel, laurel, privet, quickthorn, snowberry and

most ornamental flowering shrubs




Traditional valve positions Valve arrangement for safer

operation

Footway Footway

Carriageway Carriageway

3.5 DESIGN GUIDANCE MAINS

3.5.1 Mains Design

Insert clause 4

As a general guide, it should be possible to limit the loss of supply to about 50 properties when isolation valvesare closed due to operational or emergency situations.

Insert clause 5

The diagram below shows the preferred locations for the location of values at road junctions, where valves are

required to be installed at road junctions.

Safer Operation of Valves at Junctions




Insert clause 7

Fire hydrants – Full Bore Hydrants are the STW standard and must be used in all new installations. There are

exceptions to the application of this standard where Type 2 Loose Jumper Hydrants should be installed in areas

considered to be at risk of back siphonage resulting in water quality issues. Requirements are detailed in the

STW Design Manual. In built up areas, marker posts will only be provided where requested by the fire service.

Insert clause 8

Pressures within the distribution system are maintained as low as possible but should provide a minimum

pressure of 20m head at the outlet of the stop tap on the boundary for all services.

Insert clause 9

Maximum flow velocity should be 1m/sec. Minimum velocity should be 0.2m/sec achieved at least twice per

24 hour period, not withstanding pipe sizes.

Insert clause 10

Connections should be designed so that once installed there is no need to disrupt the live system again in

order to make the final piece through. Piece up lengths should be kept to less than 5m in length.

Insert clause 11

As a principle, service connections are preferred over rider mains and the design should take account of this

requirement.

3.5.2 Depth of Cover

Replace clause 1

All water mains are to be laid to a minimum cover of 900mm to finished ground surface. The maximum covershould not be greater than 1200mm.

In addition:

Consideration should be given if mains will be subject to wheel and point loads, especially from

construction traffic

In fields which are likely to be ploughed the depth of cover should be 1200mm

Mains may be laid outside the above specified depths in exceptional circumstances, e.g. geological

conditions or crossing of existing utilities, with the prior agreement, in writing, from STW.

3.6 DESIGN GUIDANCE – SERVICES

3.6.1 Service Design

Insert clause 8

Under normal conditions blue MDPE pipework to BS 6572 must be used. Where the ground is contaminated,

then metal sheathed MDPE must be used. This is standard MDPE pipe factory sheathed with an aluminium

barrier coating protected with an outer layer of blue MDPE incorporating 4 brown identification stripes.

Various sizes are available between 25mm – 110mm nominal bore inclusive.

If copper tube is used as the alternative, it must be to BS 2871 Table Y for underground use and be factory

coated with blue PE. The pipe must bear a BS Certification Mark which states that it has been effectivelycleaned internally.




3.6.3 Sizing of Service Pipes

Replace clause 1

The head loss due to friction should not exceed 1m per 10m head at average flow. The minimum size for

service pipes is 20mm nominal bore.

3.6.4 Multiple Service Connections

Replace clause 4

Where multiple connections, 4 and above, are required, manifolds should be installed.

3.6.5 Meter Boxes

Replace clause 1

All service connections to new properties require a boundary box to be fitted, normally on the edge of the

property boundary to control flows and enable a meter to be fitted. For apartments or flats where a single

incoming service is provided into the building, internal meters shall be fitted to each property in accordance

with STW metering specification.

Replace clause 2

Boundary boxes/stop taps should be situated no more than 300mm from the customer’s boundary. Boundary

boxes to comply with WIS 4-37-01 and shall be rigid Type R. The box shall provide continuously variable height

adjustment up to 150mm. Boxes for installation in normal ground conditions shall be Class 2 and in

contaminated ground shall be Class 1 sealed units with metal union connectors. Screw down covers should

not be installed on the Boundary Box and plastic covers are only acceptable when installed in the footway.

3.7 CONSTRUCTION

Insert clause 8

Joints in PE pipes – The layout of the pipe system should be designed to minimise the number of joints. Butt

fusion joints are the preferred method and electrofusion joints shall only be designed when site specific

circumstances dictate that welding cannot be carried out outside the excavation. The design should allow for

sufficient room to complete the process. If using electrofusion joints, and as per manufacturer’s guidelines, the

mechanical scraping of joints is the preferred option. Hand scraping joints are only acceptable under

exceptional circumstances and must be approved before use by STW.

Insert clause 9

Joints in PE barrier pipes, such as Puriton and Protectaline, can either be mechanical or electrofusion in

accordance with the manufacturer’s recommendation. The appropriate fittings should be used to ensure the

integrity of the pipework.

Insert clause 10

When installing ductile iron fittings to PE mains, joints should be by stub flange thereby maintaining a fully end

loaded system.




3.7.4 Service Connections to the Water Distribution System

Replace clause 1

The service pipe should be laid at right angles to the main and ferrules.

Replace clause 2The minimum spacing between tappings, for any material, should be 500mm apart.

Replace clause 3

Service connections to Puriton or Protectaline mains shall only be made using the pipe manufacturer’s self

tapping ferrules designed specifically for use with their own barrier pipe system.

Insert clause 8

In order to protect the integrity of the STW network and maintain a quality water supply to our existing

customers, STW will complete a risk assessment on the connection being made and may insist that a Risk and

Contingency Plan (R&C Plan) is in place before any connection is made to our existing network.

3.7.5 Data Capture/‘As-Laid’ Drawings

Replace clause 12

Prior to being sampled or connected the SLO must provide 3 copies of ‘as laid’ drawings and a fully completed

STW Asset Data form, clearly marked with sampling and connection points along with SLO and Developer’s

name, STW reference number, scheme number, scheme name, scheme type, stage number, date of

completion of the scheme or phase and the date of submission. Where SLO and Severn Trent Water software

is compatible, drawings should be submitted electronically.



Version control

Version number Date Signed off by

Draft v1.0 6 November 2015 Vicky McGrory Business Change

Manager (STW)Version 1.0 21 December 2015 Vicky McGrory Business Change

Manager (STW)

Version 1.1 6 January 2016 Vicky McGrory Business Change

Manager (STW)

Self Lay Policy Addendum

Documents

Transcript of Self Lay Policy Addendum