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Department for Environment, Food & Rural Affairs

The Provision of New Drains and Sewers in England and Wales

Responses

The consultation described below has now closed, and an analysis of the responses received has now been published via the following link.

1. INTRODUCTION

1.1 The different ways in which new drains and sewers are provided and the different standards of construction for private and public sewers cause various problems. They result in many householders not being aware of their responsibilities and some householders facing significant costs in repairing and maintaining private sewers.

1.2 This paper concentrates on the provisions for new foul water drains and sewers to help prevent the proliferation of the problems. It examines the current legislation, procedures, standards and controls in England and Wales, identifies the issues and explores solutions.

1.3 Views are invited on the proposals and issues arising from them as summarised in section 7.

Responses should be sent to:

Anne Brunskill
Department of the Environment, Transport and the Regions
Zone 3/H23
Ashdown House
123 Victoria Street
London SW1E 6DE
Tel: 020 7944 5401
Fax: 020 7944 5408
E-mail: anne.brunskill@defra.gsi.gov.uk

Consultees from Wales are asked to copy their responses to:

Joanne Corfield
Environment Division
National Assembly for Wales
Cathays Park
Cardiff
CF10 3NQ

A Welsh translation of the consultation paper is available on request from the above address.

The deadline for responses is 19 May 2000.

1.4 The Government may wish to publish responses to the consultation and deposit them in the Department’s and National Assembly’s libraries. Respondents who wish their comments to be treated as confidential should state this clearly. The Department and the National Assembly will assume that all other responses can be published. In any event, all responses will be included in any statistical summary of the comments received and the views expressed. A list of those consulted will be placed in the libraries of the Houses of Parliament and the National Assembly for Wales.

2. CURRENT ARRANGEMENTS

2.1 There are two sets of standards to which new drainage systems can be constructed:

(a) drains and private sewers built to comply with the Town and Country Planning Act 1990 and the Building Act 1984;

(b) public sewers and sewerage systems built to comply with the Water Industry Act 1991 (WIA).

A note on definitions is at Appendix A.

2.2 Drains and private sewers are built by owners, by developers and to a lesser degree by local authorities. They constitute engineering operations in or over land, and are therefore developments controlled under the Town and Country Planning Act 1990. So express planning permission from the local planning authority is required.

2.3 Planning Policy Guidance 23 (PPG 23 – Planning and Pollution Control), issued in July 1994 by the then Department of the Environment, advises that the adequacy of the sewerage infrastructure can be a material consideration in planning applications and appeals. This advice is reinforced in the DETR Planning Circular 3/99 (WO Circular 10/99) Planning requirements in respect of the use of non-mains sewerage incorporating septic tanks in new development, issued on 1 April 1999 by the Department and the Welsh Office.

2.4 The construction standard of private drains and sewers is controlled by local authorities to ensure compliance with the functional requirements set out in Part H of Schedule 1 of the Building Regulations 1991, made under the Building Act 1984. Technical guidance is provided in the Approved Document to Part H issued in 1992 by the Department and the Welsh Office. It primarily aims to protect public health and safety. It offers guidance to prospective developers on ways of meeting the requirements of the Building Regulations. It does not give detailed design and specifications of drainage systems but suggests a range of acceptable solutions by reference, where appropriate, to British Standards or British Board of Agrément Certification.

2.5 Under the 1984 Building Act the local authority may, where that is practical and economic, require two or more buildings to drain ‘in combination’ by a single private sewer. In such circumstances the authority sets the proportions in which the expenses of constructing, maintaining and repairing the private sewer are to be borne by the owners concerned. This practice, has over the years, created small private sewerage systems. Developers may also choose to have a group of buildings share interconnecting drains, effectively creating private sewers. There is no legal obstacle as long as they have the necessary right of way and consent of the landowners. Where the developers own the relevant sites, the question of consent does not arise. This practice of building private sewers also appears to have grown.

2.6 Public sewers and sewerage systems (incorporating pumping stations) are built to meet the drainage duties and levels of service required of the appointed sewerage undertaker under the Water Industry Act 1991 (WIA). These are generally more complex and usually serve wider areas than those required of private sewers. To ensure compliance and consistency throughout the country, all the sewerage undertakers in the UK have collectively produced, published and adopted standard specifications set out in Civil Engineering Specification for the Water Industry and Water Industry Mechanical and Electrical Specification. Based on these specifications, the Water Industry has published Sewers for Adoption. This gives guidance to developers and builders on design and construction of sewers which enable sewers to be vested in the sewerage undertaker on completion.

2.7 There are six different regimes under which new public sewerage can be provided, described in more detail in Appendix B:

(a) built by a sewerage undertaker under Section 94 of the WIA to ensure that its area continues to be drained effectually;

(b) built by a sewerage undertaker under Section 98 of the WIA in response to any ‘requisitioner’ seeking sewerage in the undertaker’s area;

(c) adopted by a sewerage undertaker as a new sewerage system built by others by an agreement under Section 104 of the WIA;

(d) built by a sewerage undertaker under Section 101A of the WIA to overcome environmental or amenity problems;

(e) built by a sewerage undertaker exercising its pipe-laying powers outside its own area of appointment in order to facilitate the operation of an ‘inset appointment’;

(f) built by anybody and made to comply with a sewerage undertaker’s enhanced requirements as permitted under Section 112 of the WIA.

2.8 The current arrangements described at 2.1 to 2.7 above result in different standards of construction which can give rise to a range of problems. These can result in a good deal of confusion over responsibilities and ignorance amongst householders about ownership and upkeep of the private systems. The issues and possible solutions are explored in the next three sections:

Section 3: Rationalising standards and controls for the construction of sewers.

Section 4: Clarifying the provisions in the Water Industry Act 1991 for new public sewers.

Section 5: Improving awareness of ownership of and responsibilities for maintaining drains and sewers.

Section 6 considers the possible cost implications. Section 7 summarises the proposals and issues which arise from them, on which views are invited.

3. RATIONALISING STANDARDS AND CONTROLS FOR THE CONSTRUCTION OF SEWERS

3.1 Under current arrangements, the standard used for new public sewers is higher and more robust than that used for new private sewers. The main features are set out in Appendix C. Essentially there are two differences:

(a) a public sewer generally drains larger and more complex areas than a private sewer; and

(b) under the WIA, there is a well defined responsibility for maintenance and repair of all public sewers, whereas there are generally no such arrangements to ensure long term care of private sewers.

3.2 Most large developers follow the Sewers for Adoption procedure for their new developments. They also generally ‘requisition’ from the sewerage undertaker any off-site sewer required to link their new development to the undertaker’s existing system. However, some developers, primarily to save costs, tend to follow the practice of providing drains in combination or private sewers, joining several properties to a single carrier drain which generally links up to a public sewer. As this practice has grown, particularly among small developers, it appears to have resulted in more extensive private sewers being constructed to serve larger developments. While this may save initial construction costs, it can lead to inadequate drainage and result in higher maintenance costs in the long run. It also offers an opportunity for less diligent builders not to adopt the most appropriate standard for constructing drainage systems.

3.3 If a drain or private sewer is constructed to serve a single building or a small group of buildings within a single curtilage, and that drain or sewer is subsequently linked up to serve future development in the area, the private sewer can effectively act as a public sewer without having met robust construction standards - and, sometimes, without arrangements for its long term upkeep and repair. The present arrangements do not provide close enough scrutiny at design and planning stage nor high enough standards to allow for possible future change of the status of a drain to a public sewer.

3.4 Initial control over drainage of any proposed development is exercised by the local planning authority through planning permission. Detailed drainage plans are checked by building control bodies, which may be a local authority or an approved inspector, to ensure that they meet the requirements of the Building Regulations. Local authorities are also required under Section 21 of the Building Act 1984 to ensure that the drainage system provided for a building is adequate. Local authorities are obliged to consult statutory consultees as laid down in the Town and Country Planning Regulations and General Development Order. Input from the sewerage undertaker could help to avoid drainage problems - such as providing private sewers where public sewers would be a more appropriate solution, or overloading the existing sewerage system. But sewerage undertakers are not a designated statutory consultee.

3.5 The issues arising from the use of two different standards, could be addressed by introducing a single well-defined standard. The specification for building public sewers set out in the Civil Engineering Specification for the Water Industry which is also incorporated in the industry’s publication, Sewers for Adoption, has served well. It would therefore be logical to see this tried and tested specification as the model for a single standard for constructing all sewers. Sewerage undertakers as the adopting bodies would retain the responsibility to draw up, publish and refine the standard in consultation with all interested parties, as they have been doing for the last decade or so.

3.6 To give effect to this single standard, it would be necessary to direct those wishing to provide any sewers (defined as drainage pipework serving buildings in more than one curtilage) to construct them to the adoptable standard, as specified in Sewers for Adoption. This, in turn, would call for a clear definition of a single curtilage. Whilst, at a development stage, a site for a housing estate with several dwellings may well be a single ownership, the curtilage for this purpose should be the boundary of the individual dwelling.

3.7 The minimum pipe diameter of 150 mm is one of the main requirements of Sewers for Adoption. Taking into account the carrying capacity and flow characteristics, it should, in theory, be possible to drain more than two dwellings by a smaller pipe. However, the gradual build-up of scale and fat could lead to deterioration in flow characteristics and to an effective reduction in diameter. Not only would the use of a smaller pipe be more prone to blockages; it would also deprive the householders concerned of the right to have their sewers adopted. This would effectively lead to a new generation of private sewers.

3.8 It would also be necessary to cover the situation where a proposed drain may in the future be linked up to the drainage of any new or existing developments in the vicinity. Such a drain should be built to an adoptable standard and, if necessary, to an enhanced design to meet the sewerage undertaker’s requirements under Section 112 of the WIA. The undertaker would be responsible for any additional costs associated with the enhancement work.

3.9 Whether sewers built to the adoptable standard were actually vested in the sewerage undertaker would depend on individual circumstances. The presumption should be that most sewers would be vested in the sewerage undertaker. In particular, any new sewer intended to be linked by means of a direct connection to a public sewer, ought to be adopted. However, any sewer built with the intention of being provided, operated and maintained by an authorised service provider, say through competition rules, whilst being built to the ‘adoptable standard’ might be exempt from being adopted by the incumbent sewerage undertaker. These could include remote and isolated developments such as Forestry Commission properties and other self contained units. The suggested philosophy is that:

3.10 To promote the introduction of the single adoptable standard, developers would need to be made aware, at an early stage, that they should plan for this standard of construction. Developers’ initial contact with regulatory authorities is generally with the local planning authority when applying for planning permission – often preceded by informal discussion. PPG 23 (Planning and Pollution Control) advises on the need to consider the availability of sewerage infrastructure when formulating development plan proposals and to be satisfied about its adequacy when determining planning applications. DETR Circular 3/99 (WO Circular 10/99) additionally advises on the need to consult the sewerage undertaker for development proposals incorporating non-mains sewerage and on the factors which are likely to render such arrangements inadequate. PPG 23 is being revised and it could be strengthened by the inclusion of similar advice on consultation with the sewerage undertaker and requiring sewerage to be built to adoptable standard.

3.11 Part H of the Building Regulations, which deals with drainage and waste disposal, is currently under review. As the actual control of the standard of construction is exercised through building control mechanisms in accordance with the Buildings Regulations, the Review of Part H of the Regulations will need to consider the amendments necessary to put into place the practice of a single adoptable standard for the construction of all sewers. Proposals for amendments to be made to Part H of the Building Regulations will be the subject of a separate consultation, to be issued later this year.

Views are invited on:

4. CLARIFIYING THE PROVISIONS IN THE WATER INDUSTRY ACT 1991 FOR NEW PUBLIC SEWERS

4.1 It has been suggested that the provision of public sewers has been discouraged by a lack of understanding of the various statutory provisions and by some established practices. This section outlines actual or potential problems that have been identified, and the information which might solve or ameliorate them.

4.2 Section 94 of the Water Industry Act 1991 (WIA) sets out the general duty of every sewerage undertaker to provide sewerage systems and operate and maintain them. Section 94(1)(a) of the WIA requires an undertaker to ‘‘provide and extend such a system of public sewers as to ensure that the area is, and continues to be, effectually drained’’. Section 94 (4) of the WIA specifies that the obligations and duties set out in Section 94 (and Section 95) shall be absolute and not qualified by any of the obligations set out in Part IV (Sewerage Services), which include ‘requisitioning’ and ‘adoption’ of sewers. By contrast, the previous legislation (Section 16(14) of the Water Act 1973) specified that the sewerage duties (described under Sections 14 and 15 of that Act) of ensuring effectual drainage etc were subject to finances being made available through requisition under Section 16.

4.3 But there is some indication that the duty in the WIA has, in practice, been interpreted as conditional. Sewerage undertakers frequently stipulate that it can be triggered only when linked with requisitioning and other means of providing sewerage services under the Act. Undertakers who are not prepared to construct new sewers unless they are requisitioned, appear to be following that previous legislation.

4.4 This ambiguity could be resolved by a guidance note clarifying the extent to which the sewerage undertaker has an absolute duty to provide new sewers to ensure effectual drainage under Section 94 of the WIA. It might be helpful in this guidance to define various roles of the undertaker. The undertaker is clearly responsible for improvement (enlargement, diversions, rationalisation, refurbishment etc) of existing infrastructure. It is suggested that the undertaker might also be responsible for the provision of new strategic sewerage – that is, a sewerage system, or an extension of the existing network of sewers, required to serve an area incorporating more than one existing built up area and/or new development.

4.5 The practices of adoption and requisitioning to provide new sewerage are well established. These, by and large, work satisfactorily. But there can be ambiguity in the scope of work upon which the sewerage undertakers base their charges. For example, where a new development or an area currently unsewered is situated at a considerable distance from the existing sewerage system, the cost of providing long off-site trunk sewers or pumping mains could be significantly higher than building a local sewage treatment works. If, in such circumstances, sewerage undertakers insist on the higher cost option, the requisitioners are then unreasonably penalised, providing a disincentive to developers to build sewers to adoptable standard.

4.6 Furthermore, there could be circumstances in which the reasonableness of a sewerage undertaker charging a developer for off-site work might be questioned, given the undertaker’s statutory duty to extend its system of public sewers. There is an argument that all offsite sewers beyond, say 30 metres, be treated as strategic sewers, as defined above. This would be in step with section 21 of the Building Act 1984 whereby local authorities can make any property to connect to a sewer that is within 100 feet (30 metres) of its boundary.

4.7 The issues of cost-effectiveness and equitable apportionment of the charges imposed on developers by sewerage undertakers could be established through guidance issued by OFWAT on the regime for requisitioning a sewer from a sewerage undertaker. This could include guidance on the costs which can reasonably be taken into account in the calculation of ‘Relevant Deficit’. The object would be to apply the principle of cost effectiveness and to ensure that only those costs directly attributable to the drainage of requisitioners’ properties are used (e.g. excluding costs of strategic sewerage and allowing an appropriate discount which can be apportioned to the spare capacity in the undertaker’s ‘‘off-site’’ sewerage).

4.8 Section 101A of the WIA requires sewerage undertakers to install new public sewerage systems to overcome actual or potential amenity or environmental problems. This should trigger automatically when conditions in the Department’s guidance are met. This provision came into force from 1 April 1996 through legislation which placed a duty on sewerage undertakers to build new public sewers to overcome sewage related amenity or environmental problems. Sewerage undertakers are expected to draw up programmes for discharge of this duty. They should also respond to any approach for a public sewer made to them by local authorities, householders or others. There is recourse to appeal to the Environment Agency if a householder is not content with the undertaker’s decision. There are some indications that these provisions, which are relatively new, are not fully acknowledged or understood. This may call for better promulgation of the guidance, including the message that undertakers have both pro-active and reactive roles in providing new sewerage.

4.9 There seems to be limited awareness amongst developers and builders about the provisions of Section 112 of the WIA whereby anybody proposing to build a drain or a sewer may be asked by the sewerage undertaker to upgrade the design of that drain or sewer so as to form part of the undertaker’s general system. The undertaker is responsible for any additional costs involved in such cases. Developers need to be reassured that sewerage undertakers cannot place undue burden on them. Better dissemination of this provision should encourage developers to be more ready to consult sewerage undertakers when considering building new drains and sewers.

4.10 At present the Information Note 11 First Time Rural Sewerage, issued by OFWAT, plays a key role in publicising various means by which public sewers can be provided. A revised and extended version of this document could be a useful vehicle for a clear dissemination of the provisions, addressing some or all of the concerns above, and helping underpin the proposal to change to a single adoptable standard for all new sewers.

Views are invited on:

5. IMPROVING AWARENESS OF OWNERSHIP OF AND RESPONSIBILITIES FOR MAINTAINING DRAINS AND SEWERS

5.1 There is a well-defined responsibility for sewerage undertakers to operate and maintain sewers adopted on completion. But there is no statutory requirement for new private sewers to be placed under effective management. This, and the various issues outlined in this paper, lead to a range of problems. One is that many property owners are simply unaware of responsibilities they have taken on.

5.2 Leasehold properties generally have maintenance provisions and obligations written into the lease documents, which encourages workable provisions for dealing with drains and private sewers. But it is generally left to the owners of freehold properties collectively to carry out maintenance, repair and future upkeep of their ‘drains in combination’ and private sewers. In practice this does not work satisfactorily, particularly in the long term. Changes in ownership often mean that new incumbents fail either to recognise or to accept their responsibility. This can result in local authority Environmental Health Departments intervening with enforcement orders under Section 59 of the Building Act 1984 to remedy the problems. The local authority then recovers its costs from the owners, placing a financial burden on owners for which they are unprepared – and which may seem unreasonable.

5.3 There would be benefits in recording at the Land Registry the locations of drains and sewers and the extent of responsibility of the owner to maintain them. HM Land Registry have indicated their willingness to look at this suggestion. They have explained that where developers submit this information when filing new transfers at the Land Registry, showing drains and sewers on the transfer plans, it is usual for the transfer to be referred to on the register and a copy attached to the land certificate. Although a land certificate is not issued whilst there is a mortgage on the register, owners will generally hold, or can easily obtain, an office copy of the transfer carrying information on sewers and drains.

5.4 The Government has announced proposals to reform the home buying and selling process, including a requirement that before putting a home on the market the seller, or the seller’s agent, should put together a pack of standard information for prospective buyers. This information pack should include a report on the general condition of the home and this could help draw attention to any suspected problems with drainage and other services. Increasing home buyers’ awareness of the status of drainage services might also be possible through other means, for example:

(a) seeking through pre-contract enquiry any information known to the seller about the ownership of drainage systems, any financial or other liabilities which attach to the owner, and any problems encountered with the drainage system;

(b) including relevant questions in standard local land search enquiries.

5.5 A particular issue is the responsibility for repair and maintenance of drains from individual property boundaries to the public sewers. These are referred to as ‘laterals’. Under present arrangements, property owners usually own these drains and therefore have responsibility for their upkeep and repair. Individual property owners are generally not aware of this responsibility. This has generated a steady flow of complaints to the Department particularly where owners have found themselves having to be involved in work to the public footpath and roads outside their properties in order to carry out repairs.

5.6 It is questionable whether the property owner should own that part of the drain situated outside the curtilage. Transferring the ownership of existing laterals could be complex and place financial burden on the sewerage undertaker. But there should be little financial implication for sewerage undertakers to adopt new laterals built to a prescribed standard. This would bring sewerage in line with water supply, as statutory water undertakers are generally responsible for communication pipes connected to their mains that are outside the curtilage of customers’ properties. If new laterals were to be vested in the sewerage undertaker, it would be necessary to prescribe standards of construction of those laterals. This could logically be achieved by including standards in the new edition of Sewers for Adoption.

5.7 While this proposal seems a sensible way of preventing the proliferation of problems, it is doubtful whether the provisions for adoption of sewers and drains under Section 104 of the WIA can be applied here. Under subsection (6), a ‘drain’ has to become a ‘sewer’ for the adoption to be effective. If this is so, a change in primary legislation could be required to establish undertakers’ ownership and responsibility for future maintenance and repair for those new laterals built and connected to public sewers after a prescribed date. It is also questionable whether existing powers to enter third party land to construct and maintain sewers would apply to lateral drains. It might therefore be necessary to amend the legislation to cover the situation where a lateral may have to pass through third party land or public highway in order to connect up to a public sewer.

5.8 For this proposition to work in practice, it would be necessary to provide a definitive demarcation at which responsibility switched from a property owner to an undertaker. An inspection chamber located at or close to the boundary would be the most appropriate solution. Apart from defining the demarcation and allowing each party to attend to its problems (such as blockages) without interfering with the drain belonging to the other party, a chamber has other practical benefits - such as providing access for testing, checking infiltration, baiting for rodent control and simplifying construction by allowing the normal practice of change of pipe material at this junction. Such an inspection chamber is desirable in its own right, whether or not the ownership of laterals was changed, and is generally accepted as good practice.

Views are invited on:

6. COST IMPLICATIONS:

6.1 The change to a single adoptable standard for all sewers would have an implication on the cost of providing new housing. There are several variables such as project size, site conditions etc which would influence the costing and it would therefore be misleading to give a single figure. In new developments, by designing the layout cost effectively and not incurring separate trench reinstatement costs in an unfinished site, the additional cost of up-grading the sewer to an adoptable standard could range from £100 to £150 per property. In denser developments, for example those involving terraced houses and blocks of flats, the cost increase per unit would be even lower. In contrast, to serve existing unsewered areas comprising 100 to 400 properties in rural locations where properties are generally scattered, an additional cost in the range of £200 to £500 per property could be expected when providing sewers to the higher adoptable standard.

6.2 This price would be offset by the life-time benefit of proper operation, maintenance and repair of the sewerage system by the undertaker. Getting it right first time is important. Once a drain or sewer is built, the cost of repair or modification can be prohibitive.

6.3 Because there is currently little public awareness of the potential difficulties of private sewers, a developer can at present cut construction costs without any reduction in sale price by providing private sewers. So providing better information on ownership and responsibilities is likely to reduce slightly the price of new dwellings built with private sewers. While a higher standard of construction would increase costs somewhat, it could also bolster sales and possibly the selling price.

6.4 There should be no significant cost implications for local authorities in dealing with the changes proposed in this paper as they would have rationalised and better defined requirements against which to check the planning applications and undertake building control functions. In the long term, the proposed changes should lead to cost savings in their enforcement functions arising from unsatisfactory private sewers. Similarly, social housing providers can expect to see, in the long term, savings in the management, repair and maintenance costs if their sewerage systems are, in the first instance, built to robust adoptable standard.

6.5 There should be no negative cost implications for sewerage undertakers. The positive financial implication for the undertaker is that the new standard for sewers and ownership of laterals will increase their capital asset base by having more new sewers and laterals vested in them with a potential of proportional increases in their income.

Views are invited on the likely costs and benefits for:

7. SUMMARY OF PROPOSALS AND ISSUES

The proposals explored in Sections 3–6 of this paper and the issues which arise from them are summarised below.

Section 3: Rationalising standards and controls for the construction of sewers:

Section 4: Clarifying the provisions in the Water Industry Act 1991 for new public sewers:

Section 5: Improving awareness of ownership of and responsibilities for maintaining drains and sewers:

Section 6: Cost implications:

The likely costs and benefits of the proposals, for:

Appendix A: Definitions of Drains, Sewers and Sewerage Systems

A ‘drain’ and a ‘sewer’ are defined in Section 219(1) of the Water Industry Act 1991.

In practice, it is now generally accepted that a drain represents a pipeline and associated works (inspection chambers etc) which carry foul water from sanitary and other appliances in a single building, or group of buildings within a single curtilage, to a disposal point such as a septic tank, cesspool or a sewer. A sewer, on the other hand, is a system of pipework including manholes which serves buildings situated in more than one curtilage.

There are basically two types of sewers:

A private sewer is, in general, collectively owned and maintained by the owners of the buildings it serves.

A public sewer is vested in the appointed sewerage undertaker of the area and they have full responsibility to maintain it.

An overall sewerage system serving a locality comprises a network of pipelines and manholes and may, if the topography of a locality requires, incorporate pumping stations and pumping mains to enable low-lying properties to be drained. In essence therefore this paper covers:

(a) new foul drains

(b) new foul private sewers

(c) new foul public sewers

Appendix B: Regimes for the Provision of New Public Sewers

Public sewerage can be built under the following regimes:

1. Under Section 94 of WIA:

1.1 Sewerage built by a sewerage undertaker, at its own cost as a part of its general duty under Section 94 of the Water Industry Act 1991 (WIA) to provide, improve and extend such a system of public sewers to ensure that the area is effectually drained.

1.2 The performance of sewerage undertakers is assessed by the Director General of Water Services (OFWAT) against regular returns on levels of service which they submit to OFWAT. The scale of the undertakers’ efforts can also be verified by reference to the levels of investment each makes towards sewerage.

2. Under Section 98 of WIA:

2.1 Sewerage built by a sewerage undertaker in response to a ‘‘requisition’’ notice served under Section 98 of the WIA on the undertaker by any one of the bodies listed in subsection 1(c), which include the owner/occupier of premises and the local authority in whose area the locality is situated. This places the duty upon the sewerage undertaker to design and build a public sewer to be used for the drainage for domestic purposes of existing buildings or buildings to be erected in a locality within the undertaker’s area.

2.2 In these circumstances the requisitioner is liable to pay the undertaker an amount equal to the ‘‘Relevant Deficit’’ which is the difference between (i) the total capital cost including interest of the new sewerage scheme repayable over twelve years and (ii) the income derived by the undertaker through the sewerage charges for new connections provided under the scheme. Upon making the connection, each owner/occupier is also required to pay the undertaker a single infrastructure charge set centrally by OFWAT.

2.3 The duty to provide the sewer as requisitioned is absolute and the undertaker is deemed to be in breach of its duty if it fails to do so within six months, or any extension of this period agreed mutually between the requisitioner and the undertaker. It is open to any requisitioner to claim for recovery of any loss or damage sustained through any breach on the part of the undertaker to provide the sewer requisitioned. There are also provisions for dealing with disputes arising from this process for determination by OFWAT and/or an arbitrator appointed by the President of the Institution of Civil Engineers.

3. Under Section 104 of WIA:

3.1 Sewerage built by any person, generally a developer, constructing or proposing to construct any sewer under an agreement, provided for under Section 104 of the WIA, with a view to the sewerage undertaker adopting that sewer on completion, thus taking over full responsibility for its future operation, maintenance and repair. The agreement can also be applied to sewage disposal works which, although not covered by this review, can have a bearing on the cost implications of a scheme involving both new sewerage and sewage disposal works. There is a right of appeal to the Director General of Water Services (OFWAT) against dispute arising from entering into the agreement or its terms. The adoptable sewers are built in accordance with the design and construction guide published and issued by the Water Industry and referred to as Sewers for Adoption. The guide incorporates the standards stipulated in the Civil Engineering Specification for the Water Industry. The underlying philosophy is that developers should only be expected to work to standards no higher than those set up by a sewerage undertaker for its own works and operations.

3.2 The House Builders Federation has endorsed the current (fourth edition) of Sewers for Adoption by commending it to its members. The Guide recommends that sewers should only be laid in public land such as highways etc. However, if for practical reasons, the locating of sewers in public land is not feasible, they can be laid on private land with a Deed of Grant of Easement to allow the sewerage undertaker access for the purposes of operation, maintenance and repair of the sewers, and to restrict land owners from carrying out any activity which may adversely affect those sewers.

4. Under Section 101A of WIA:

4.1 Sewerage built by a sewerage undertaker, at its own cost, under Section 101A of the WIA. The duty to provide a new public sewer arises where there are environmental or amenity problems arising or likely to arise from the existing non-mains arrangements for dealing with sewage, and provision of a new sewer is the appropriate solution. This applies to those premises existing or substantially completed by the 20 June 1995. The Department and the Welsh Office (National Assembly) have jointly issued guidance to sewerage undertakers to enable them to determine in each case whether the duty to provide a public sewer has arisen. There is a provision of appeal to the Environment Agency if anyone seeking a public sewer under this legislation is not satisfied with the decision by a sewerage undertaker.

5. Under competition rules:

5.1 Sewerage built by a contractor acting on behalf of a community or by a sewerage undertaker exercising its pipe-laying powers outside its own area in order to provide, operate and maintain any existing local sewerage system or to serve a greenfield site under ‘inset appointment’ arrangements.

6. Under Section 112 of WIA:

6.1 Sewerage built by any person who proposes to construct a drain or sewer which a sewerage undertaker may wish to form part of its general sewerage system. The undertaker may seek under Section 112 of the WIA for that drain or sewer to be constructed to a higher standard as regards design, workmanship, and materials to suit its ultimate duty. For example, instead of the 150mm diameter sewer originally proposed, the undertaker seeks a 600mm diameter sewer to act as a relief to its existing overloaded system. The undertaker is responsible for any additional costs associated to meet its enhanced requirements. This provision also serves as a useful check to ensure that an undertaker cannot ask for a sewer to be built to standard higher than the minimum required standard without paying for the additional cost involved.

Appendix C: Comparison of Private Sewers to Public Sewerage

Private SewersPublic Sewers
1 Built to comply with the ‘Approved Document H’ issued jointly by the Department of the Environment Transport and Regions and the Welsh Office as a practical guidance on how to meet the drainage and waste disposal requirements of Part H of Schedule 1 of the Building Regulations 1991.Built to accord with the requirements of ‘Sewers for Adoption’ issued, on behalf of the ten sewerage undertakers in England and Wales, by Water Services Association as a guidance to developers on the design and construction of sewers to ensure compliance with Section 104 of the Water Industry Act 1991.
2 Belong to property owner(s).Vested in the sewerage undertaker.
3 Mostly situated in privately owned roads, gardens and land. (Maybe partially in public highways where they link up to a public sewers).Mostly situated in public highways. But can also be routed through private land with permanent wayleave for the undertaker for maintenance and restriction on the landowners not to prejudice the integrity of the sewer.
4 Mostly deal with the drainage of a small group of buildings or an ‘estate’ type development. Generally all gravity sewers and very rarely incorporate pumping.Mostly deal with drainage of large and complex areas. May also incorporate one or more pumping stations.
5 Construction details
(a) Minimum pipe size 100 mm diameter
(b) Normally shallow to deal with relatively simple and smaller drainage areas
(c) Pipes can run closer to and sometimes under buildings
(d) Change of direction can be by long radius bends
(e) Communication with another pipe can be by a pipe junction
(f) Allowed to be laid to slight curve on plan
(g) Chambers generally in brickwork and with lightweight covers (e.g: u.PVC, steel)
Construction details
(a) Minimum pipe size 150mm diameter
(b) Deeper to suit the complexity of topography of large drainage areas and to withstand vehicular loads in public highways
(c) Pipes run further from buildings and not under them
(d) Change of direction at manholes
(e) Except for lateral connections by pipe junction, communication with other sewer runs by manholes only
(f) Laid in straight lines
(g) Manholes in concrete and with medium/heavy duty covers (ductile iron)


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Published 14 March 2000 / Updated 28 March 2002
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