Useful definitions for Inspection Chambers and Manholes

When it comes to manholes and inspection chambers, there are a number of definitions and acronyms that you may need to know. 

Here’s a helpful list of definitions:

• Access Point – provision to access a sewer or drain for testing, inspection, maintenance and removal of debris, and includes any manhole or inspection chamber.
• Adoptable – in general, terms the process whereby assets are vested in the water company or another body and subsequently maintained by that body at its expense.
  
• BS EN 1401-1:2009 – British and European Standard for plastic piping systems for non-pressure underground drainage and sewerage – Unplasticized polyvinyl chloride (uPVC).
• BS EN 13598-2 – Plastics piping systems for non-pressure underground drainage and sewerage – Unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) – Part 2: Specifications for manholes and inspection chambers in traffic areas and deep underground installations.
• Combined Drainage System – where both foul and surface water run through one set of pipes. Please note: on all new developments foul and surface water should always be kept apart in completely separate drainage systems.
• Foul Drainage –  is the system of pipework that carries wastewater away from a property i.e. bathrooms, kitchens etc. For all properties connected to mains drainage, foul sewers will eventually transfer the contents of the drainage system to a local sewage treatment plant.
• Granular Backfill – is the type of material used to backfill the chambers, once they have been connected. 
• Inspection Chamber – means a chamber in a drain or sewer with working space at ground level only. Access is required to drain and sewer systems for testing, inspection, maintenance and removal of debris. In line with the Confined Spaces Regulations 1997, operations should be carried out, where practicable, without entering the confined space. SfA7 and The National Annex to BS EN 752: 20171 a strong preference for working at ground level i.e. non-man-entry wherever possible, inspection chambers provide a means of access compatible with this aim.
• Catchpit – as above, only there is a sump/catchpit under the main pipework that traps dirt and solids.
• Manhole – means a chamber with working space at drain/sewer level used for entry of personnel and equipment.
• Non-Adoptable – in general, any drainage that the water company has seen fit not to adopt and maintain and the maintenance is the responsibility of the developer.
• Non-Man Entry – same as inspection chambers. 
• Restriction Cap – used on top of all chambers above a depth of 1200mm, to restrict man access. This is a requirement of SfA7.
• SfA7 – an abbreviation of Sewers for Adoption 7th edition, 2012 (SfA7).
• Surface Water Systems – is the system of pipework used to carry away rainwater from surface areas i.e. roofs, patios, driveways, roads and sports fields. The rainwater, which is not contaminated and hence is not harmful will be delivered via a pipework system to a suitable watercourse ie. culvert, pond, stream, river or outfall.
• SfA7 Type 3 Inspection Chamber – an inspection chamber of less than 3000mm depth and accommodating the lateral drains from more than 3 properties.
• SfA7 Type 4 Inspection Chamber –  an inspection chamber of less than 2000mm depth.

At Cotterill Civils, we supply a wide range of inspection chambers and manholes should you need to replace them, please call us on 0121 351 3230.