Technical guidance for developer services February 2018

Transcription

1 Technical guidance for developer services February 2018 wessexwater.co.uk

2 Document revisions Major version number Details Lead contact Date 1 Draft issued for comment RSL September Final version 1 February

3 Executive summary This document is designed to accompany our Charging Arrangements which sets out, in a single document, all charges relating to developer services. This is available on our website but we will also provide our customers with a copy of this document on request. To request a copy of this document, please either: developer.services@wessexwater.co.uk Telephone: or Write to: Developer Services Wessex Water Claverton Down Bath BA2 7WW 2

4 Contents Executive summary New water supply connections Water supply (service connections and mains) Typical domestic fire sprinkler installation Water regulations Whole site back-flow protection Contaminated land New mains connections Accreditation of self-lay providers Diversion of water pipes Can I build over a water main? How close can I build to a water main? What information do I need to provide? Asset enquiries First time sewerage New connections to our existing public sewers What is a public sewer? Are there different types of public sewer? Are there any public sewers in the vicinity of my site? What can be discharged to each system? Do I need to make a capacity enquiry? Connections by means of a Y junction or saddle Your ground worker will be responsible for: New or existing manhole connection Your contractor will also be responsible for: What if I need to make a pumped connection? Can I make a connection to a private drain? Will my new pipework be adopted by Wessex Water? Sewer requisitions Sewerage for non-domestic use What is a sewer requisition? Who can requisition a sewer? Can I requisition a sewer for commercial properties? Can I requisition a lateral drain? What are Wessex Water s land entry powers? How long does a requisition take? What is a 1 contract? What information do I need to provide? What is included in the estimate? Building over or close to a public sewer Can I build over or near to a public sewer? Can I build over a manhole chamber? Can I connect rainwater to the sewer? When can t I build over or near to a sewer? You must contact us for additional guidance (prior to making an application) in complex cases, such as where: Are there any sewer protection/foundation requirements?

5 10.7 Technical guidance Who can carry out my drainage works? What happens if I don t obtain approval? Making your application What information do I need to provide? Are any works exempt from this process? Diversion of existing sewers What are the diversions options? What do I need to provide? What happens after the sewer has been diverted? Adoption of new sewers What is a sewer adoption? Are there any structures that Wessex Water does not adopt? I m not sure about a specific design or construction detail When can I apply? What information do I need to provide? What extra information is needed for a pumping station? Does Wessex Water have standard details? How many sets of drawings do I need to send? What do site inspections involve? What happens if the design changes during construction? Do I need to pay any other charges? Adoption of existing sewers What is a public sewer? Can Wessex Water adopt a private system? What information do I need to provide? How much will it cost? Do I need to pay any other charges? Who can carry out the CCTV survey? Who will carry out the manhole inspection What details are reviewed? What happens if the sewer is in poor condition? What can I do if I disagree with the decision? Adoption of existing sewage treatment works What is a public sewer or sewage treatment works? Can Wessex Water adopt a private sewage treatment works? What information do I need to provide? How much will it cost? What is vesting? What happens if the pipework and plant is in poor condition? What can I do if I disagree with the decision? Adequacy of existing infrastructure CCTV camera survey Why do I need to arrange a CCTV camera survey? What should the survey include? How is a survey carried out? What happens if the sewer is full or flowing? What happens if the recording is poor quality? How much will it cost me? Who can carry out a survey? Contractors currently employed by Wessex Water for CCTV camera surveys

6 Can I use a different company? Pumping station septicity control What is septicity? How does Wessex Water predict septicity? When does a septicity form need to be submitted? What information do I need to provide? What happens if septicity is identified? What is chemical dosing? How much will it cost? How long does the review take? Working in confined spaces What is a confined space? What information do I need to provide? Your company Your employee How much will it cost? What happens next? Will my permit card be reviewed? How to contact us

7 1. New water supply connections To ensure your new development has access to potable water, you will need to make a new water supply connection between your new development and our water network. Most new developments require a new service connection, as shown in the diagram below. Figure 1-1 New service connection This section sets out the information you need to know if you require a new service connection. You may also need a new water mains. Information on new water mains can be found in section Water supply (service connections) Where our main lies within a street, your pipe will need to be brought to the edge of that street for connection to your service at the stop tap and meter box. You will need to arrange access to enter any private land and pay for and install any additional length of private service pipe needed between your property and the point of connection. This pipe will need to be inspected by Wessex Water or an approved contractor. 6

8 Figure 1-2 Figure 1-3 Your pipe should be blue medium density polyethylene (mdpe), or protective pipe if the land is contaminated, and laid in a trench at a depth of at least 750mm and no more than 1,350mm. The pipe should be laid on and protected from stones by sand or fine material, or installed in a suitable duct. The private service pipe should be at least 25mm diameter. Larger pipes may be needed for very long pipe runs. Developers will be required to provide a chlorination certificate for pipes of 50mm outside diameter and above before the connection can be carried out. Where pipes enter the building they must be passed through a continuous duct and sized accordingly so that the service pipe can be readily removed and replaced. Pipes shall be insulated where necessary with a minimum of 19mm rubberised foam. 7

9 Figure 1-4 The pipe must be terminated at a suitable stop valve, which should be located inside the dwelling above floor level and near to entry point of building. Stop valves in underground chambers or communal hallways will be an extra requirement on separately occupied/ owned premises (ie, flats) above ground floor level. Service pipes and ducts should be laid in straight runs and should not cross neighbouring building plots. When laying multiple service pipes together, the tails of the pipes must be labelled to indicate plot numbers. Where multiple service pipes are laid in the same trench, we will require internal stop taps to have been fitted inside the new properties before fitting the meters. This will help to prevent misconnections and avoid future water metering issues with our customers. If the tails are not labelled, the connections will not be carried out. For the safety of our staff we require ducts in the highway and on sites to be blue. We will not lay services in ducts of other colours or designation and will not share ducts with other utilities. Where multiple occupations occur within a single curtilage, provision should be made to locate the meters at the boundary of the property or in a communal area with 24 hour access for reading and maintenance. All new properties will require a water meter to be fitted, normally at the boundary of the property in the public highway. We will consider internal metering for multi-occupancy buildings provided the meters are installed in a communal area. Where these meters are accessible, standard meters will be fitted but where access is limited, remote read meters (AMR) will be required. For the safety of our staff we will not make connections or carry out work underneath or in the vicinity of scaffolding. Please ensure that all scaffolding is removed before requesting connection. 8

10 1-2 Typical domestic fire sprinkler installation Figure 1-5 9

11 2. Water regulations The water fittings regulations are national requirements for the design, installation and maintenance of plumbing systems, water fittings and water using appliances. Their purpose is to prevent inefficient use of water, waste, misuse, undue consumption or erroneous measurement of it and, most importantly, to prevent contamination of drinking water. In England and Wales they replace the former water supply bylaws. We have a legal duty to enforce the water regulations. Owners and occupiers of premises, and anyone who installs plumbing systems or water fittings, have the legal duty to ensure that the systems comply with the regulations. If you do not use a member of one of the schemes listed below, plans will be required for all new domestic premises as well as industrial, commercial and agricultural purposes: the Water Industry approved Plumbers Scheme (WIAPS) Association of Plumbing and Heating Contractors (AHPC) Chartered Institute of Plumbing and Heating Engineering (CIPHE) Scottish and Northern Ireland Plumbing Employers Federation (SNIPEF) Anglian Water s A Plus Severn Trent s Watermark Thames Water s TAPS If you use a member of one of the above schemes, plans will not be required for new domestic premises, although they will be required for industrial, commercial and agricultural proposals. For further information on approved plumber schemes, please visit Please allow at least 10 working days for approval to be granted. For the erection of any new building or structure, advance notification must be given to the water company before work starts on any proposed installation. We will provide water regulations type approval for large housing developments with properties of a similar design and plumbing arrangements. An example of the type of information required is given below. Figure

12 2.1 Whole site backflow protection To prevent pollution of the public water supply system, the use of whole site backflow protection in addition to point of use protection will be required for high water users or where a development is categorised as high risk. The decision regarding whether a development is high risk will be assessed on information provided with the water regulations notification. The installation and maintenance of the back-flow device will be the responsibility of the customer. It is essential that routine maintenance is carried out on the device to prevent pollution to the public water supply. It shall be located as close to the site boundary as possible and be Water Regulations Advisory Scheme (WRAS) approved. Although a schematic drawing is not required for a standpipe, trough or compound supply, these installations must comply with water regulations. Please see following typical installations. Figure 2-2 Figure

13 2.2 Contaminated land We have an obligation under the Water Supply (Water Fittings) Regulations to safeguard against contamination of water supplied through its pipes. Accordingly, all service pipes must provide adequate protection from organic or inorganic contaminants and toxic substances that may be present within the soil. Such contaminants can pose a serious human health hazard as they can permeate through pipe materials and pollute the water supply. They can also accelerate the deterioration of pipe materials resulting in premature failures, leakage and loss of water quality. Please note that where oil central heating systems are installed, barrier pipe must be used. In order to determine the likelihood for contaminants to be present within site soils or groundwater, an assessment and/ or site investigation needs to be undertaken. The Water Regulations Advisory Scheme (WRAS) Information and Guidance Note Laying Pipes in Contaminated Land has been withdrawn and developers seeking new connections must submit a site assessment report (SAR) meeting the specifications of Guidance for the Selection of Water Supply Pipes to be used in Brownfield Sites (UKWIR ref.10/wm/03/21). This information must be sufficient to allow us to confirm the appropriate pipe or mitigation method. Failure by a developer to supply an adequate SAR will result in the requirement for pipes to be laid with protection to avoid future contamination of the water supply. Please note that further information on the installation of water supply pipes in contaminated land can be found on the United Kingdom Water Industry Research (UKWIR) website under Report Ref. No. 10/WM/03/21 Guidance for the Selection of Water Supply Pipes to be used in Brownfield Sites ( 12

14 3. New mains connections To ensure your new development has access to potable water, you will need to make a new water supply connection between your new development and our water network. While most developments require only a new service connection (covered in section 3 above), some will also require a new water main. Figure 3-1 new mains connection We will lay new water mains in accordance with the National Joint Utilities Group (NJUG) guidelines on the positioning and colour coding of utilities apparatus and expect developers to ensure that other utilities also lay their apparatus in accordance with the NJUG guidelines (see Fig 3-2). This is to safeguard the health and safety of our staff and to ensure that our apparatus remains accessible for future maintenance. If our apparatus is obstructed by other utility apparatus laid subsequent to our own main laying operations or by other obstacles, ie, scaffolding etc, we reserve the right to suspend individual property tappings or other related work, until the correct access is provided. As an alternative to us laying the main, the developer can provide a main under self-lay arrangements. The developer or its self-lay organisation (SLO) must either be accredited or satisfy us in advance as to their financial standing, technical competence and experience of mainlaying to safeguard public health and the integrity of our supply network. Figure

15 4. Accreditation of self-lay providers SLOs and their subcontractors shall as a minimum have achieved partial accreditation with the Lloyd s Register (LR) Water Industry Registration Scheme (WIRS) before any self-lay works may be undertaken, see Where prospective SLOs are not accredited, we will consider their applications to self lay taking into account the following criteria: track record technical competence sound knowledge and experience of designing and installing water distribution systems including method statements for all activities to be undertaken health and safety record and demonstration of safety management procedures. Environmental record compliance with hygiene code financial security. Self lay providers must comply with the latest edition of the Industry Code of Practice. SLPs performance will be fed back to LR. Failure to perform to the required standards and to follow correct procedure may result in accreditation being cancelled by LR. 14

16 5. Diversion of water pipes We are responsible for maintaining approximately 11,800 kilometres of public water mains, most of which are under public highway. Some, however, are under private land. We require access to water mains at all times in case we have to dig down in an emergency. Water mains are pressurised and if they burst the force of the water can cause subsidence and large holes in the ground. Consequently we require any new development to be located a safe distance from the main, either by siting the development away from the main or by diverting it. Mains diversions are normally carried out by us at the customer s expense. Alternatively we can consider permitting a developer to carry out the works using a suitably qualified and accredited third party contractor (self-lay provider). Figure Can I build over a water main? Building over a water supply main is not allowed under any circumstances. It is vital that you discuss proposals with us at an early stage and failure to do so may result in expensive changes to your layout, or construction being stopped while a solution is agreed. 5.2 How close can I build to a water main? Figure 5-2 shows our normal stand-off distances required between any new structure and our water main. The easement strip is the minimum width necessary to repair, maintain or renew our asset. It varies with the size, depth and pressure of the water main, and we also consider pipe material and ground conditions. We reserve the right to change the requirements for specific sites or strategic mains if you are in any doubt please ask. Please note that some strategic water mains can be small diameter. No structure or other obstruction is allowed over or within the stand-off distance. This includes sheds, greenhouses and trees. Building foundations must be taken down to a lower depth or be designed in such a way that they do not place additional loading on to a water main. Piling proposals are reviewed on a case by case basis auger bored is preferred rather than driven methods. 15

17 Figure 5-2 Measurements are given for a pipeline depth of between 900-2,000mm. The stand-off distance may increase for a strategic water main due to material, size, depth and pressure. 5.3 What information do I need to provide? The exact location of the water main should be established (using ground penetration surveys or trial holes). We will advise you if this needs to be done under our supervision. You are liable for all costs if you damage our asset. If a water main needs to be diverted, you need to provide the following information: application form (can be downloaded from the Wessex Water website) appropriate payment location plan layout plan, showing position of building work relative to the existing water main (autocad format) third party details (if affected) ground investigation report confirming soil conditions or contamination any other relevant information. When we are happy with your proposals to divert, an offer letter will be sent to you detailing the terms and conditions. You will be asked to deposit the full estimated cost of the works. When the final costs are known you will be invoiced or reimbursed accordingly. We can lay a main for you, or you can arrange for an accredited self lay contractor to do the contestable part of the works. However, to protect our customers, some work can only be undertaken by us. This work is described as non-contestable work and further details can be found within our separate Charging Arrangements document. 16

18 6. Asset enquiries We hold extensive information about our water mains and sewers and plans showing the location of our water mains and sewers can be obtained from our asset enquiries team within developer services. Our electronic records are captured to be viewed in context with Ordnance Survey background maps to show the approximate location of our pipelines and assets. You can request a copy of these plans showing our services near to your house or development site. Alternatively, plans showing the location of our sewers only can be viewed at local authority offices. Figure 6-1 Reproduced from Ordnance Survey Map with the permission of the Controller of Her Majesty s Stationery Office. Crown copyright reserved, Licence No

19 7. First time sewerage There is provision under S101a of the Water Industry Act 1991 for a water company to provide first time sewerage to unsewered areas, ie, areas not served by mains drainage. This only applies for two or more properties. An application for first time sewerage can be made by an individual or a group of individuals, often with the support of the parish or local council. The sticking point is normally cost in nearly every case it is not cost effective to provide first time sewerage when the cost of a scheme is compared to the number of properties that would benefit. If you think your property is eligible for first time sewerage you first need to look at the problems that you have with the current drainage system and consider whether it is possible to solve this by repairing structural damage or replacing the existing system. Improved maintenance of the system, eg, regular emptying or desludging the contents of the unit, could be a solution. If you are satisfied that the drainage problem could not be solved in this way and you wish us to look at ways of improving the situation, we suggest you seek the support of other property owners because new public sewers are only practicable where several properties are involved. The best way of doing this is to seek co-operation from your parish or district council. Application forms and guidance notes can be found on the Wessex Water website but it is recommended that an initial enquiry is made to the development engineer for the area. We can normally advise informally and quickly whether or not there is any possibility of a first time sewerage scheme being economically viable. 18

20 8. New connections to our existing public sewers 8.1 What is a public sewer? Wessex Water owns and has a duty to maintain more than 30,000 kilometres of sewerage pipes known as public sewers. These sewers often run down the side or rear of domestic properties. Most sewers shared by more than one property or lateral drains (pipes outside of property boundary but only serving one unit) are public. The diagram below illustrates some typical drainage arrangements. There are exceptions, for example sewers: located in a village that is not connected to a public system, so the sewerage system is entirely private that are owned, operated and maintained by another sewerage company (inset or management company) that were laid on or after 1 July 2011 and have not been offered for adoption under a s104/ s102 agreement Figure 8-1 Typical drainage arrangements Are there different types of public sewer? We own and maintain a network of foul, stormwater and combined public sewers. These range from small diameter, shallow domestic pipes, to large diameter deep trunk mains that can accept waste from thousands of properties. We also own and maintain pumped systems and effluent disposal mains however these cannot be connected into and alternative means would need to be considered. 19

21 Figure Are there public sewers in the vicinity of my site? Our asset records may be viewed to help establish whether a public sewerage system is available. However, it is important to note that not all public sewers, particularly those within private land, will be shown and for those that are, the position indicated on the plan will be approximate only. In all cases, it is important to make further investigations, potentially including a full survey of the site, to determine the actual drainage arrangements. There are some tell-tale signs that there is pipework within your property boundary. For example, there may be an inspection chamber or manhole cover in your garden (see below). Figure 8-3 manhole covers However, even if there are no physical signs of drains or sewers that does not mean that there is not something under the ground. Your architect or builder may be able to help you find out if there is a public sewer or drain within your property boundary. Details of drainage arrangements may be included within the legal documentation related to your property. 20

22 Please also be aware that there are known non sewered areas within our region. These are mostly found in rural locations and you can contact us to confirm if your site is located within one of these areas What can be discharged to each system? Foul waste must only be connected to gravity based foul or combined public sewers. Foul waste will typically include discharge from toilets, bathrooms, kitchens and domestic appliances, etc. On many projects you will need to adequately dispose of rainwater but this can lead to sewer flooding within our network. Alternative means of disposal (eg, SUDS, natural watercourse, highway drains) must be properly investigated before any connection could be considered. In cases where there is no other option, only rainwater from impermeable surfaces could be considered and then only into a dedicated public surface water sewer. Details relating to flow rates and storage would also need to be submitted. Such connections must not be made to our foul or combined systems. If there is no discharge (either directly or indirectly) of rainwater from your site to the sewerage system, you will be entitled to a reduction in your sewerage bill. More information is available on our website Do I need to make a capacity enquiry? For large developments our planning liaison team must be contacted to establish whether the public system has adequate capacity to accommodate the proposed flows from your development. For smaller sites, a foul connection can normally be applied for without the need for detailed consultation. However, rainwater connections have the potential to cause flooding issues within our sewers and therefore we will need to carefully consider the available capacity of our public system for development proposals of all sizes. 8.2 Connections by means of a Y junction or saddle To connect to a public sewer you will EITHER require a junction/saddle connection OR you will make your connection via an existing or newly built manhole. A junction/saddle involves installing a simple connection piece on to the public sewer, and should be used for developments consisting of up to a maximum of three dwellings or the commercial/industrial equivalent. You will need to contact us to schedule the works and the final connection to the public sewer will be completed by us. Figure

23 8.2.1 Your ground worker will be responsible for: laying your new private drain up to the public sewer fully exposing the public sewer (even if encased in concrete) by at least 500mm around the circumference of the pipe, with a minimum exposed pipe length of 1.5 metres obtaining prior approval of any landowner(s) to cross third party land ensuring that the excavation is free of groundwater, the trench is safe and fully stabilised (trench support) ensuring that safety precautions are observed at all times, ie, no naked lights, keeping the excavation free of groundwater and safe to work in carrying out all licensed work in the public highway to the satisfaction of the highways authority. In such cases you must obtain a section 50 licence from them before starting work maintaining the flow in our sewer, and keeping it free from any cement, bricks, soil or other debris. If we consider a trench unsafe to work in, we will not carry out the connection. Connections to public sewers can only be made during normal working hours, Monday to Thursday 8am to 4pm and Friday 8am to 3.30pm. Once we have installed the connection piece, your ground worker will connect your private and backfill the trench. You will need to provide us with at least 10 working days notice when arranging for the connection to be made. 8.3 New or existing manhole connection For developments involving more than three properties or the commercial/industrial equivalent, connection via a manhole is mandatory. For smaller developments connections can still be made to existing manholes, but where none exist we would normally expect a junction/saddle to be used in preference to constructing a brand new chamber. Figure 8-5 You are required to hire a suitable contractor to complete the manhole connection. The contractor will need to hold a Wessex Water permit card and a list of suitable contractors who already hold these cards can be sent to you on request. The inclusion of a contractor on this list does not guarantee that the work will be up to standard but you may find it a helpful guide to enable you to obtain quotes. 22

24 If your contractor does not currently hold a permit card, then they may contact us with a view to obtaining one. However, they will need to meet a number of key requirements and we can provide further details upon request Your contractor will also be responsible for: laying your new private drain up to the public sewer and backfilling the trench as necessary obtaining prior approval of any landowner(s) to cross third party land carrying out all licensed work in the public highway to the satisfaction of the highways authority. In such cases you must obtain a section 50 licence from them before starting work maintaining the flow in our sewer, and keeping it free from any cement, bricks, soil or other debris. We will inspect the manhole works as required. You need to ensure your contractor contacts our inspector to arrange a visit, giving 10 working days notice prior to the start of works. Before arranging a visit for inspection of new works, we require that: all work that you have requested to be inspected or tested is/will be complete that before the visit, all manhole cover lifting eyes have been cleared out and covers have been freed up and eased. The inspection fee covers two visits for new manholes and one for existing manholes. All works must be carried out in accordance with the current edition of Sewers for Adoption. 8.4 What if I need to make a pumped connection? Pumped systems are more complex than gravity systems and can pose a risk to the public sewerage system, particularly with regards to septic waste. We will require detailed information at the design stage to support any pumped sewer connection application. You will also need to complete a septicity control form more information is available on our website. Where a private rising main will discharge into a public sewer, a break manhole must be constructed at the end of the rising main, to allow the flow to gravitate to the public sewer. 8.5 Can I make a connection to a private drain? Indirect connections may be made to suitable existing private drains, with permission being obtained from the owner of that drain. Technical approval and the inspection of indirect connections will be carried out by Building Control, not by Wessex Water. They may only wish to attend or formally approve the work if it forms part of a new build or significant extension. You can employ any ground worker to complete the work with the agreement of Building Control or your private inspector. Please be aware that any foul waste/rainwater that you connect will ultimately discharge to a public sewer. In certain cases, particularly with larger developments or where a rainwater connection is being proposed, you need to obtain our informal approval for the resultant flows. 8.6 Will my new pipework be adopted by Wessex Water? Your new private drainage between your development and the public sewer, or any existing private drainage that you have connected onto, will remain private and will not be adopted as 23

25 public. However, pending a change in national sewerage law (date to be confirmed), applicable lengths may be adopted by Wessex Water in the future. New pipes that only serve a single property, and are entirely within that property s boundary, will never be adopted and will remain the responsibility of the property owner. Adoption of new sewerage systems under an S104 Agreement is a separate process to a connection application. New manhole chambers built on an existing public sewer will automatically become part of the public system on completion. You will remain responsible for any works or liability in respect of road opening permit conditions and for any remedial works required to the chamber for a minimum period of 12 months. We will recover all costs from the applicant if we are required to undertake these works in an emergency or in default by the applicant. 24

26 9. Sewer requisitions If you have a development with no access to our sewers due to intervening third party land outside your control, we can, at your expense, lay a sewer or lateral drain to serve the site if it is for domestic purposes or in some cases, commercial developments with a domestic sewage discharge. We can negotiate land entry, easements and compensation for crossing the land. Our involvement in undertaking this work can be high, particularly when the proposed works or entry to private land is opposed. We can only provide a new stormwater outfall arrangement with the consent of the relevant land drainage authority and the written agreement of the landowner. Overall scheme costs may be several times the actual construction works costs, particularly for short lengths of sewers. In the cases of sewers, requisitioned for domestic purposes, we will contribute 15% towards the cost of the works we will require an initial deposit to prepare and make a formal offer. 9.1 Sewerage for non-domestic use Should you wish to connect non-domestic flows to our sewerage system, you may need a trade effluent discharge consent. You will need to submit a trade effluent notice, providing full details of the proposed discharge. We may impose conditions on any approval to safeguard our sewers and any operation of our sewage treatment works. Where there is insufficient capacity in our system to accommodate your discharge, we may require you to pay for any necessary improvements. It is important to contact us at a very early stage as major works with long lead-in times may be required to accommodate your development. These guidance notes are provided to help you fill in a sewer requisition application form. The notes should be read in conjunction with the Water Industry Act Relevant sections are: Section 98 duty to comply with sewer requisition. Section 99 financial conditions of compliance. Section 100 calculation of relevant deficit. Section 101 determination of completion date and route. On-site Section 104 adoption agreements or Section 185 diversions are separate arrangements to a requisition. 9.2 What is a sewer requisition? Sometimes an agreement cannot be reached between a developer and a private landowner to lay a new sewer to connect to the public system. Under Section 98 of the Water Industry Act you can formally request a new public sewer to cross the land to serve the development. Sewers are normally only requisitioned for domestic purposes, either to serve new development or as a first time service to existing properties. The requisitioned sewer will be constructed by us. It is termed as a public sewer if it serves two or more properties or an adopted lateral if it serves only one property. Costs incurred in transferring or acquiring the freehold of land required for pumping stations or other sewerage assets will be included in the cost of the requisition. 25

27 Figure Who can requisition a sewer? Public sewers and lateral drains can be requisitioned by the owner or occupier of a property, or the relevant local authority. You must have been granted full planning permission for a proposed development before sewer construction can start. If outline planning has been agreed, then appraisal can start while full planning is finalised. To requisition a surface water sewer, you should have agreed formal discharge consent from the riparian owner of the watercourse where the outfall is to be located riparian ownership is the property alongside the watercourse. If agreement cannot be reached with the riparian owner, we can acquire this by negotiation or compulsory purchase order. Without a discharge consent agreement in place, the sewer cannot be connected. 9.4 Can I requisition a sewer for commercial properties? Although legislation refers to requisitioning off-site sewers for domestic purposes, any commercial development containing an element of domestic flow will be considered. Nondomestic flows may need trade effluent consent. 9.5 Can I requisition a lateral drain? A lateral drain is a pipe that runs from the property boundary to connect to the public sewerage system. It is generally laid in third party land where land entry notice may need to be served, or in the highway. If necessary, we can serve notice on third party landowners to allow a connection to be made. You can requisition a lateral drain from us to serve a domestic property. 9.6 What are Wessex Water s land entry powers? We have power under the Water Industry Act 1991 to lay pipelines in private land. We can serve land entry notices and negotiate easements for crossing third party land to serve your site. We are unable to serve notice on the Crown, MOD or other statutory undertakers such as EA, British Waterways or Network Rail. The cost of negotiating easements through such land is included in the budget estimate. 26

28 9.7 How long does a requisition take? We will provide an offer letter within six to eight weeks from receiving the application and initial payment, subject to modelling, operational considerations and waste water concerns. From receiving the returned signed agreement sheet, we will liaise with you and agree a construction programme. We aim to start on site within six months, but this is dependent on factors such as land entry, confirmation of planning permission, tying in with the development s on-site construction programme, operational logistics, environmental issues and any other constraints. 9.8 What is a 1 contract? In some cases we may be prepared to enter into a 1 contract. Example reasons may include a complicated demolition and construction programme on site, timescale or resources. The use of a 1 contract is entirely at our discretion. In these cases we agree to the requisitioner designing and constructing the sewer on our behalf we will pay the requisitioner 1 as a nominal contract sum. We will serve statutory land entry notice but all scheme costs including compensation will be payable by the requisitioner. During 1 contracts, the requisitioner takes on the role as principle contractor. Construction must be carried out by an approved sub-contractor and your health and safety plan must comply with our requirements we will inspect and test the works. On completion, you will arrange a CCTV survey and production of as-constructed plans and levels. 9.9 What information do I need to provide? In order for us to produce a high level budget estimate, you need to provide the following information: site plan third party land ownership details and any information relating to previous dealings with third parties proposed site layout, levels, details of on-site drainage arrangements, and flow data. site investigation information (if known). This includes soils reports, and any contamination records number of domestic dwellings, or anticipated water consumption for non-domestic developments valid planning consent confirmation of discharge consent with the riparian owner if a surface water sewer discharges to a watercourse, if available What is included in the estimate? Based on the information you provide, our estimated costs will include: legal fees survey detailed design environmental checks land entry 27

29 construction including plant, materials, associated works and welfare facilities health and safety plan NRSWA and utility information operational or temporary measures reinstatement site inspection and testing approximate compensation to third parties any other constraints or factors identified. 28

30 10. Building over or close to a public sewer We are responsible for maintaining more than 30,000 kilometres of public sewers and public lateral drains, some of which have been laid within the boundaries of properties. You must obtain our agreement to carry out any building work over or within three metres of most public sewers to ensure no damage is caused or restrictions made to the way we use and maintain the sewer. For large or deep sewers a greater clearance is normally required and in some cases it is not possible to give approval, as the proposed works would impair our ability to maintain the sewer. Lack of formal approval from your local water company may jeopardise the future sale of your property or lead to complications later. It is recommended that you submit an application before seeking planning or building regulations approval and well in advance of starting work on site Can I build over or near to a public sewer? Our preference is that you amend your proposal to avoid the sewer. If your planned development will not be within 3m (measured horizontally) of a typical public sewer, or 6m of a strategic sewer, then you do not need to formally apply to us. Instead, please send us confirmation in writing and a simple sketch for our records. We will then issue you with a response of no objection, which you can add to your property deeds for future reference. If you are unable to avoid the public sewer then please submit an application to us for further consideration. We will consider a number of variables, including the size, depth and catchment of the public sewer, as well as the location and nature of the project. Please be aware that on some occasions we may either refuse a submission or request that you seek approval via an alternative process. This could involve diverting the sewer away from the proposed building or leaving the pipe in-situ but entering into a formal legal buildover agreement with the company. This is more complex than the standard buildover consent that we use for most projects. Additional fees will apply and we will provide further details and guidance Can I build over a manhole chamber? No. Where a manhole/inspection chamber would fall within your proposal, please be advised that these would need to be re-located as appropriate at your expense. This is necessary to ensure that we have continued access to our public systems for operational and maintenance purposes. Internal chambers can also pose an increased risk of sewage flooding and odour issues Can I connect rainwater to the sewer? Not normally. On many projects there will be a need to adequately dispose of rainwater but this can lead to or exacerbate sewer flooding within our network. All other means (eg, soakaways) must be properly investigated before a connection could be considered. A separate application is necessary for all new proposed connections (both foul and rainwater) that will be made direct to an existing sewer. 29

31 10.4 When can t I build over or near to a sewer? Under no circumstances could you build over or close to a pressurised pumping main (rising main). We do not allow any public manholes or inspection chambers to be located within a building, as this would increase the risk of internal sewer flooding and odour issues. However, we will consider proposals that involve the removal and relocation of a chamber, where technically viable. Where entirely new dwellings or commercial premises are proposed (eg, as opposed to a simple extension of an existing structure) on land that has not been previously developed (eg, a greenfield site) You must contact us for additional guidance (prior to making an application) in complex cases Where: strategic public sewers will be affected (eg, your proposed development is within 6m). As a general rule we will not permit such works. However, we are most likely to give further consideration to your proposal in cases where you are redeveloping a previously developed piece of land (a brownfield site), or if the sewer is exceptionally deep or oversized for its catchment new dwellings or commercial premises are proposed on land that has been previously developed Are there any sewer protection/foundation requirements? We normally expect strip foundations to be used wherever possible. However, in certain circumstances alternative foundation designs may be considered with our prior agreement. These may include pads/piling, cantilever or raft designs. However, these are non-preferred and should you wish to use such a design then this will need to be fully justified and approved. Foundations will normally need to be taken down to a specified depth to avoid any loading on the sewer pipe and provide a stable environment for any future excavations. Where you are building over a sewer, your load-bearing walls will extend over the sewer pipe. In most circumstances you will need to bridge over the sewer using pre-stressed concrete lintels in accordance with our standard detail. Our requirements may vary on a site to site basis and we will advise you of these as part of the application process. 30

32 Figure Technical guidance Below are a number of common build over or near examples. Sewers must be designed and built according to the current edition of Sewers for Adoption, which is available from the Water Research Council. Foundations and walls should be designed and built so they do not put any loading on the sewer. 31

33 Figure

34 10.8 Who can carry out my drainage works? This will depend on the type of works on your site. For remedial works on public sewer pipes we will undertake the required works (historical defects only should your works cause a new defect to the sewer then this must be made good at your cost). Please note if trench excavations are required, you need to complete these before we attend to fix the pipe. If you need to move or re-build an existing public manhole chamber, or construct a new one for your works, this can be completed by your ground worker (at your cost). If the sewer is deeper than 500mm, you must use one of our approved contractors who hold Wessex Water permits. A list is available upon request. If your ground worker is not on our list they would need to prove to us that they have the required skills and experience to complete the works to the correct standard. Moving or re-building a public non-man entry inspection chamber can be completed by your ground worker (at your cost) and they will not normally require these permits. For works involving private drainage (pipes serving only your property), you can employ any ground worker to complete the work (at your cost) with the agreement of Building Control or your private inspector What happens if I don t obtain approval? If you carry out building works near or over our sewer without written approval, you may encounter problems at a later date. We have a duty to operate and maintain our sewerage apparatus. If temporary or permanent structures are constructed in such a way that they obstruct us carrying out this duty, we can take action to remove the obstruction. When you sell your property, you need the correct paperwork to prove the sewer build over or build near was agreed by Wessex Water. Solicitor searches will reveal whether an agreement is in place on our records. You may encounter difficulties selling your property if our approval has not been obtained Making your application Once you have located the public sewer and established that none of the above factors apply to your development, then you are ready to make your application for one of our standard buildover agreements What information do I need to provide? You need to send the following information when you apply: application form the fee design drawings. These should include a plan and section showing the position of your proposed works and foundations relative to our sewer. 1:50 or 1:100 scales are preferred. Drawings submitted for Building Regulations are normally sufficient, as long as the sewer is clearly marked. Do not scale directly from our asset records as these are approximate only. 33

35 Are any works exempt from this process? Yes. Minor works associated with landscaping (retaining walls, decking, patios, fencing etc) and small wooden structures (eg, sheds) that do not require Building Regulations do not generally require formal consent via this process. However, this does not mean that such works pose no risk to the public sewerage system. So we request that you send us an informal notification of your works together with a simple sketch which outlines the proposal together with the position of the public sewer. In most cases we will have no objection to the proposal. However, we may request that certain protective measures are implemented or send one of our inspectors to visit you for a site meeting, particularly where a manhole or inspection chamber will be affected or our future access to it is obstructed. Please note that although some extensions and conservatories are exempt from Building Regulations, you must apply to us if you are considering building such a structure. 34

36 11. Diversion of existing sewers If there are sewers crossing a new development site and the layout cannot be designed to avoid them, they must be diverted if technically possible What are the diversion options? Major diversion of critical sewer where the work is carried out by us. We will provide an estimated offer that includes appraisal, design and construction. Major diversion which, depending on the importance of the sewer may be carried out using a suitable contractor. We will charge a technical assessment, inspection and legal fee. Minor diversion where the sewer is relatively shallow, is less than 150mm in diameter and serving fewer than 25 properties. In these circumstances we would normally allow the works to be carried out by a suitable contractor. You will be required to pay an application fee and a refundable deposit What do I need to provide? Location plan. Layout plan showing diverted sewer(s). Cover and invert levels, pipe material and gradients. CCTV survey identifying any existing connections along the diverted length. Third party land ownership details. Any other relevant information What happens after the sewer has been diverted? The diverted sewer is added to our records and maintained in future as public. The abandoned sewer needs to be either broken out or grouted up to prevent collapse, water or rodent ingress. 35

37 12. Adoption of new sewers These guidance notes are provided to assist you in completing a sewer adoption application form they should be read in conjunction with the Water Industry Act The relevant section is Section 104 agreement to adopt sewers, drain or sewage disposal works at a future date. We can adopt existing private sewerage systems under Section 102 arrangements. You must provide details to prove that the sewer(s) has been designed and constructed to an adoptable standard. You must pay all inspection fees and the cost of any remedial works required to ensure the sewerage system is to an acceptable standard before the sewers are adopted What is a sewer adoption? An adopted sewer is operated and maintained as a public asset by a water company. A private sewer is owned and maintained by the private owner at their expense. Sewers constructed as part of a new development may be offered for adoption so that the water company is responsible for them in the future. Sewers and pumping stations should be designed and built according to the current edition of Sewers for Adoption, which is available from the Water Research Council. You first submit your design to us for technical review and, when approved, you will enter into an adoption agreement. You will then construct the sewerage system and test it to prove it is built to the correct standard. We will inspect the site and indicate whether there any defects that need rectification. When it is completed to our satisfaction, we will adopt the system and maintain it as part of our public network Are there any structures that Wessex Water does not adopt? We do not normally adopt balancing ponds, culverted watercourses or rhynes, only the headwall/s into them we will need details of who will be responsible for their future maintenance. We do not adopt soakaways or land drainage and we are currently not adopting underground cellular storage I m not sure about a specific design or construction detail We are keen to offer you advice and help throughout the adoption process from start to finish. We d rather you phone us to discuss a detail at an early stage than it escalate to a costly or awkward problem on site When can I apply? You can send us draft drainage proposals at an early stage in your design process this often helps identify any problems, and we can agree a design in principle. But to enter an agreement you must have full planning permission What information do I need to provide? In order for us to assess the scheme you need to provide the following information: 36

38 location plan layout plan, which must be coloured as follows: o any adoptable foul lengths highlighted red o any adoptable surface water lengths highlighted blue o the site boundary that you own outlined in green o all background detail and existing sewers shown in black or grey. this includes any references to any other works such as sewer diversions or requisitions layout plan showing any off-site adoptable lengths, coloured either foul/red or surface water/blue as above long sections manhole and pipeline schedules. A downloadable spreadsheet is on our website agreed discharge rates confirmation of discharge consent with the riparian owner if a surface water sewer disharges to a watercourse details of any soakaways, attenuation tanks and flow control devices a copy of your soils report if the site has contaminated ground conditions pumping station layout. We will ask for detailed information when you confirm which manufacturer you use third party details if a sewer is proposed to be laid or connected off site any other relevant information What extra information is needed for a pumping station? We have published an addendum that must be read in conjunction with Sewers for Adoption and can be found on the Water Research Council s website. You will need to provide the additional information in your application: detailed layout and section drawings showing civils details, kiosk design and pump apparatus M&E electrical plans including the control panel septicity control form O&M manuals, electrical certification and other relevant documentation when commissioning is complete Does Wessex Water have standard details? Each water company has their own particular preferences to be used in conjunction with Sewers for Adoption. We have standard drawings available showing structures such as headwalls, flow control chambers, bollards, pumping station layout and kiosk, vents and pipework protection. Ask for copies How many sets of drawings do I need to send? For an initial review, your application needs to include one set of drawings, which must include layout, long sections and relevant details such as flow control chambers, outfall structures. You need to show the indicative pumping station position if applicable. We can review small drawings as PDF files via , but large layouts or complicated systems need to be printed on A1 or A0 for us to clearly interpret your submission. If we need extra copies we will ask. After technical approval is given, you will need to send us: seven sets of the coloured-up layout drawing 37

39 two sets of other relevant drawings such as long sections, details or pumping station design What do site inspections involve? Once a sewer has been constructed, it needs testing to prove it meets the standard required. On large phased sites, the system is often split into sections. You are responsible for air testing each sewer length, which our site inspector must witness on site. You will also need to carry out a CCTV survey of all pipelines. Our site inspector will check all manholes and any adoptable structures when they are complete. For pumping stations, our site inspector will check civils and kiosk construction, along with connecting pipework and our M&E engineers will check and commission the electrics and pumps. We will issue you with a list of defects and rectifications which we require you to carry out before the sewers can be signed off as ready for adoption What happens if the design changes during construction? If your design changes during construction, you need to send us a layout revision so our site inspector is kept up to date with alterations and additions to routes and manhole references Do I need to pay any other charges? If new properties are being built, infrastructure charges are payable in addition to sums in respect of the adoptable works. Details are in our charges information. 38

40 13. Adoption of existing sewers These guidance notes are provided to help you fill in an application form to adopt an existing sewer. This is for private sewers that have been in use for a number of years, not newly constructed systems. The notes should be read in conjunction with the Water Industry Act The relevant section is Section 102 adoption of existing sewers What is a public sewer? Most sewers shared by more than one property or lateral drains (pipe outside the property boundary but only serving one unit) are public and will be owned and maintained by Wessex Water. There are some exceptions. The only sewers that remain private are those that: serve only a single property within that property boundary are maintained privately as part of a documented property management scheme. do not connect directly to the public system, eg, some surface water systems that flow directly to a culvert, watercourse or soakaway. Developer Services 13.2 Can Wessex Water adopt a private system? Yes, we can consider adopting a privately owned system so that it becomes part of the public network. The Act requires that we have regard to all the circumstances of the case and consider the method of construction and state of repair of the sewer or works. When a sewer is adopted, we are responsible for future maintenance, improvements and agreeing any connections to it. For instance, it may be beneficial for a developer to ask us to consider adopting an existing private sewer or highways drain so they can apply for a connection. Figure 13-1 The adoption process first involves you carrying out a structural survey of the sewers you want us to adopt. We will inspect the system and advise whether any repairs are required. When we agree it is an acceptable standard we will serve a formal notice on the current owners and interested parties. After two months, if no objections have been raised, we will vest the sewers and confirm the system has been adopted as public. 39