What is the cost of connecting to a main sewer?

Road works

New sewer connection costs can be complicated; a lot depends on the specifics of the site. It’s because of this that we often hesitate when we’re asked to give a ballpark figure for works, ‘just as a guide’. We believe that when it comes to mains drainage connection costs, it’s far better to have a detailed quotation, rather than use some kind of ready reckoner – and it doesn’t have to cost you anything to get this important information.

We always advise it’s far better to get a proper quote from the off, because this means you have dependable drainage cost figures to work with. This is why we offer a free quotation service. We believe you shouldn’t have to spend money in order to plan your build budget properly.

New sewer connection costs are complex

So why is it complicated to estimate mains drainage connection costs? Well, there are a lot of variables. Every site is different, and every development is different. Boiled down to the absolute basics, the factors involved in calculating the cost of a new sewer connection include 1) the length, depth and diameter of the public sewer, and 2) the logistics of getting the actual work done. 

Pipework: The length of the pipework is dictated by the location of the nearest mains sewer, while the diameter is determined by the size of the development (and therefore the volume of waste that the sewerage pipes will need to accommodate). The depth of the pipework will depend on how the required falls are going to be achieved. 

Logistics: The ‘logistics’ includes any aspect which impacts on the process – whether that’s restrictions on machinery-use owing to tight site dimensions in urban areas, the need to implement traffic control measures, or any onsite drainage that’s required during the build. 

There are also a variety of other factors that could affect the cost of connecting to a main sewer, including which water company you’re working with. You’ll find there are differences in their procedures and charging structures, which can impact on your eventual bill, including whether you need to build the boundary manhole.

Are there any fixed costs for a new sewer connection?

Much more predictable are the costs associated with making the necessary applications to the water company; this being the Section 106 (consent to connect) and Section 104 (sewer adoption). These do vary according to the water company in question. We work across an area of the country served by Thames Water, Anglian Water and Southern Water, and these three do have differences in the way they calculate these charges.

To summarise briefly…

Thames Water currently charges:

  • £330 for consent to connect directly to a public sewer, and £110 for an indirect connection, under Section 106
  • £1,000 to cover the application fee for sewer adoption (Section 104), plus:
  • 1.4% of the estimate of the construction cost using their indicative rates.
  • A £850 legal fee for the adoption agreement
  • A £750 easement fee (to formalise access rights)
  • A security deposit of either £5,000 or 10% of the construction cost estimate (released on expiry of the 12-month maintenance period)

Anglian Water currently charges: 

  • Legal agreements – £377. This fee applies to: Section 104, Section 185 (Off-site diversion) and Section 30.
  • Solicitor enquiries – £43
  • Deed of Grant of Easements and transfer of pumping stations standard charge – £785. This fee applies to: Transfer of pumping stations; Deed of Grant of Easement for discharge to a watercourse; Deed of Grant of Easement for discharge to a balancing lagoon.
  • Discretionary rate for combined deeds – £1,046
  • Additional charges: in the case of complex issues, the following standard additional charges shall apply: additional title £52 per title, complex title(s)/additional documents requiring review £105 for first title or document, £52 for each additional title of document.
  • Complex amendments: charged based on time spent reviewing at a rate of £125 per hour.
  • Unforeseen disbursements: at cost.

Southern Water currently charges:

  • £230.83 for a Section 106 application
  • Section 104 costs include:
    • An application fee of £515
    • An inspection fee of 2.5% of the construction value
    • A £400 legal fee
    • A bond of 10% of the construction value

NB. The figures above are intended as guide only. Please check with the relevant water authorities directly about current charges.

Achieving best value with new sewer connection costs
If you’ve looked at the links above to each water company’s charging structure details (you can download the PDFs, too), you’ll notice that all three companies – Thames Water, Anglian Water and Southern Water – also give ready-reckoner costs for doing the new sewer connection works. Our view is that it’s better value to deal with a contractor directly, and get a detailed quotation for the works required, than it is to use a water company’s sub-contractor. We often find that our quotes are very competitive indeed, in comparison to the charges indicated by water companies.

Here are some real-life examples of new sewer connection costs for projects we have completed recently, to give you some kind of benchmark:

Asset owner: Anglian Water (foul water)
Location: Woodbridge, SuffolkDepth: 1.50M
Existing sewer Ø: 150mmNew lateral connection Ø: 100mm
Connection method: existing manhole
Project value: £10,700

Asset owner: Thames Water (foul water)
Locations: Stratford, East London  
Depth: 4m
Existing sewer Ø: 300mm
New lateral connection Ø: 150mm
Connection method: new pre-cast concrete manhole
Project value: £19,400

Asset owner: Thames Water (foul and surface water)
Locations: Brent, North-west London
Depth: 4m and 3.5m
Existing sewer Ø: 225mm and 300mm
New lateral connection Ø: 225mm and 150mm
Connection method: 2x existing manholes
Project value: £43,700

Note: prices accurate at the time of writing (May 2020)

To get a free quotation for a new sewer connection on your project – which will enable you to plan your build costs with proper certainty – call us on 01268 950050 or send an email to [email protected]

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