Few variables in this situation, firstly, method depends on size of chamber. Shouldn't be any weight put on the pipe, if a deep chamber then brickwork needs to be suitable supported above the pipe entry. Foul drainage will need to discharge into the channel, into direction of flow to avoid fouling of the benching opposite. As Muggles has said, Building Control will need to be informed.
Whether the Water Co. need to be informed as well as B.C. depends on what goes through the said chamber. If it is just your property using it, then the drain is private and of no concern to the Water Co. However, if one or more other properties drainage runs through this chamber, then it is actually under the ownership of the Water Co. now, and they will need to give permission and guidance for any work carried out on or in their asset.