Developer Services. Building over or near a sewer. DEV 005G Guidance notes and procedure. What is a public sewer?

Transcription

1 Developer Services DEV 005G Guidance notes and procedure Building over or near a sewer If you are thinking of building a structure (for example, a new building, extension, conservatory, garage etc.) you must check that you are not building over or near to a public sewer. You will need to apply to Wessex Water if works are proposed within three metres of any public sewer. Please note that this is extended to six metres for strategic sewers. What is a public sewer? Wessex Water owns and has a duty to maintain more than 30,000 kilometres of sewerage pipes. These are known as public sewers. These sewers often run down the side or rear of domestic properties. Most sewers that are 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 Flats/apartments Terraced Semi-detached Detached Footpath Public highway Key Private drain, responsibility of homeowner Responsibility of Wessex Water How do I know if a public sewer runs through my site? Our asset records may be viewed to help establish whether a public sewer will likely be affected by your proposal. They will also indicate whether the sewer is classified as strategic. However it is important to note that not all public sewers will be shown, and for those that are, the position indicated on the plan will be approximate only. Please do not rely on our asset records as these should be used for guidance purposes only. In all cases it is important to undertake further investigations, potentially including a full survey of the site, to determine the actual drainage arrangements. Further information: 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 examples on the right). However, even if there are no physical signs of drains or sewers, that doesn t 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 DEV 005G September of 5

2 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 utilise for most projects. Additional fees will apply and we will provide further details and guidance. Please see below for additional details. 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, such as 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 (brownfield). 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. How much will it cost? We have a set charge of 325 for all applications to build over or near to a public sewer. This covers: Administering and evaluating your proposal Engineering consultation and/or site inspection if necessary Liaison with Building Control or your Private Inspector Formal approval If you are building over a public sewer, we will survey the pipe and complete any necessary remedial works before you proceed. If an application is rejected, your application fee will be refunded. 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. Therefore we would 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 impacted 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 DEV 005G September of 5

3 What is the normal process? Step 1 Application & Payment Please complete the application form and return it with a single set of design drawings plus the application fee of 325 to our Sewer Protection team. Payment can be by cheque made payable to Wessex Water Services Ltd, or we can invoice so you can pay by BACS. You can also pay by credit card. Step 2 CCTV survey (for building over or piling works only) We will arrange to carry out a CCTV camera survey to check the structural condition of our sewer. We will then advise if any remedial works are necessary. For piling works, a post works CCTV survey will also be required. Step 3 Decision If your proposal is acceptable we will approve your works. If no drainage works are required then you may proceed to step 6 and begin your project. However, if drainage works are necessary (eg, sewer remedial works, moving a manhole chamber etc.), then our approval will be conditioned as appropriate pending completion of these works. Step 4 Drainage works (if applicable) If any drainage works on the public sewer are required then these will need to be completed and inspected. If trench excavations are required then you need to complete these before Wessex Water attends to fix the pipe. Step 5 Completion (if applicable) Once the required drainage work has been carried out to our satisfaction, we will send you a completion letter which confirms this to be the case. Step 6 Construction Your works can commence and any further inspections will be undertaken by the Council s Building Control department or your Private Inspector as part of their normal regime. 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 utilise 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. Please see guidance overleaf for further information and illustrations DEV 005G September of 5

4 Technical Guidance Please find below 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 DEV 005G September of 5

5 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; however 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. Further information is available via our website. 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 Wessex Water 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 groundworker (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 if an agreement is in place on our records. You may encounter difficulties selling your property if our approval has not been obtained. Is Wessex Water still responsible for the sewer? If we give permission for you to build over or near our sewer, we still have a statutory right of access to the sewer now and in the future. If we need to repair, unblock or maintain it, we will do so at our own expense. Send your application to: Sewer Protection Developer Services, Wessex Water, Claverton Down, Bath BA2 7WW Tel: sewer.protection@wessexwater.co.uk Developer Services Building over or near to a public sewer DEV 005A Application form (please refer to the guidance notes before completing this form) Buildover ref: A Applicant's details Company/Name Contact name Company Reg. no. Signature Address Postcode Phone number B Agent s details (if different from A) Agent s name (company name where appropriate) Address Postcode Phone number C Site details Site address Postcode Site contact name Site agent's name and number D Development details Type of development Side extension Rear extension Other Please specify Local authority area Have you applied for building regulations approval? Yes No If yes, please state the local authority/approved inspector reference number Local authority/approved inspector contact name Date of application/notice E Other details Please confirm the type of public sewer to be built over/near: Foul Surface Combined Unknown Please confirm the size of sewer (if known) 100mm 150mm 225mm 300mm Depth of any manholes indicated on the site plan: (metres) Do you need to make a new connection to the public sewer? Yes No (If yes, a separate application will be necessary which can be downloaded from our website at or can be sent to you on request). F Fees We have a set charge of 325 for all applications to build over or near to a public sewer. This covers: Administering and evaluating the proposal. Engineering consultation and/or site inspection if necessary. Liaison with Building Control or your Private Inspector. Formal approval. If you are building over a public sewer, we will survey the pipe and complete any necessary remedial works before you proceed. Cheques should be made payable to Wessex Water with the reference number (if known) written on the back. If you wish to pay by credit card please tick here Contact name and tel. no: G Checklist and declaration (please ensure that you have included the following): Drawings Appropriate fees Has the sewer(s) been accurately located on site Yes No Has the precise route of the sewer(s) been plotted on the submitted drawings Yes No PLEASE NOTE Failure to include any of the above may be deemed as an incomplete application and result in the application being delayed/returned. By signing this application, you are not automatically granted approval. No works should start until full payment has been received and formal written approval has been granted. I confirm to the best of my knowledge the above information to be complete and correct. Signed Date: Print Name 3548 DEV 005A October DEV 005A October DEV 005G September of 5