We paid a certified contractor to place a sewer connection to our boundary but they claim to have met with other services that meant raising the pipe by 200mm to overcome them. This left the connection at exactly the same height as the waste outlet under the main slab of the house some 8m away (so not enough fall to make an effective waste connection).
I'm being told that there's nothing for it but to put in a 2nd pumping station (we already have one for the basement - but it wasn't designed for the whole house!)? This is extremely frustrating and concerning as the design was not meant to rely on electricity or maintenance, and if the issue had been highlighted earlier, we could have changed the specification of the basement pumping station.
Q1: How common is it that the main house (in a street - it's an infill plot) is unable to connect to the main sewer? It seems our foundations are deeper than the neighbour's 1930's properties and that there are obstructing services at an unusually low depth under the pavement.
Q2: What remedy could you suggest is the best option in my circumstances? It's a 5 bed detached house and we move in in 2 weeks time!!
I’m sorry to hear about your situation, but it just goes to show that you can never really accurately plan or budget for below ground work until you start digging, something that every building contractor will be aware of. To answer your first question, it’s not uncommon for houses to be unable to connect to a nearby sewer due to levels, obstructions or lack of capacity. It’s situations like this that reinforce the need to hold a contingency in the budget.
As for a solution, I think you have two options, both of which will add to your costs. You can either go for an off-mains solution, such as a septic or treatment plant, but I would suggest this would introduce unacceptable additional cost when you are so close to the main sewer. The other option is the pumping station you have been advised to install. From what you have told me, this sounds like the best solution and the one I would recommend. You mention that you already have a pumping station in the basement, however I think you are referring to a macerating pump such as a Saniflo system which is quite a small affair. What is being suggested here is a mains system which will be much larger, installed in the main sewer line and capable of handling waste from the whole house.
The good news is that you will barely know it’s there because it will look just like any other inspection pit once installed - all you will see is the manhole cover. I would recommend speaking to a company like Kingspan Environmental to discuss which of their pumping station options will fit the bill.
Mike Hardwick (Build It Expert)