If your planning to connect to an existing drain - even your own - you need to get approval from the Sewerage Undertaker for the area. This may or may not be the same as your water company (for example, in Bristol the water undertaker is Bristol Water, but the Sewerage Undertaker is Wessex Water). Here's a
map
on Ofwat's website showing who your Sewerage undertaker is.
While they all operate under the same laws and regulations, the application process and costs differ between each company. We can help you get the approval you need with the minimum of fuss - please contact us for a quote.
We can also recommend skilled contractors to complete the works if required.