The Big Dig - Water Main Replacement

Today, just 3 days before Christmas, and with snow on the ground, Sutton Water Company are busy replacing the water main to my property plus that of my 3 neighbours.

The houses were built in 1905, and at that time it was standard practice to share a water connection between houses - especially if they were pairs of semi-detached properties. So it came to pass that four properties were all connected to the one section of lead pipe - and after 105 years in the ground, that lead pipe was leaking like a seive.

Back in July, during leakage testing, an excessive flow was detected on our shared main, and since the old lead main is no longer accessible as it passes under driveways, patios and modern extensions, the only effective measure is to replace the shared main with a separate modern plastic main and meter for each property.

The crew from the water company turned up at 8am on Tuesday and started to dig a couple of trenches, one near the pavement and one close to where the main would enter the property. Using a pneumatic mole, a duct was bored through the soft clay soil to connect the two trenches - a distance of some 15 metres. However because of very cold conditions yesterday, the Mole froze up in the bore, and had to be retrieved by digging a third hole, just 2m short of the pavement excavation. With one bore in place the blue water pipe was threaded through and the Mole set up again to put a second bore through for my neighbour's pipe.

Today the gang have got extra help from another 3 crews, judging by the 4 large vans in the street. The main runs down the road on the opposite side of the street, and so 4 separate access pits will have to be dug on each side of the street, and individual plastic connections tee'd into the original main. A lot of digging in temperatures that are barely above freezing.


Thursday morning, and Day 3 of the Big Dig. Two gangs from Clancy Docwra accompanied by another private contractor who's turned up with another compressor. About 11:15am, the water company arrived to assist with the pipe connections. It should not go unmentioned that replacing the water mains to 4 adjacent properties is no small undertaking, and made particularly gruelling in such bitterly cold weather. Whilst to the homeowner, the pipe from the pavement to their kitchen might at first appear a major task, this is actually only one small part of the job, and the connections to the water main on the opposite side of the street each with two access trenches is by far the bulk of the work.

Inside the house, in the kitchen extension, the dishwasher was removed to gain access, and a 32mm hole drilled downwards and outwards through the kitchen wall, such that the drill emerged in the small connection pit outside the kitchen window. This is a busy area in the kitchen with heating pipes, hot and cold water pipes and cables all laid in a ductspace that runs around the external wall of the kitchen. It's now a case of connecting up to the incoming main to ensure that the kitchen, bathroom and toilet, and the rising main to the tank in the loft are all connected to the new supply. The plumbing in this house dates back in various phases back to 1905, and much of it is no longer accessible, having been laid under the concrete floor of the kitchen and the 1950's bathroom extension. Once everything is working properly from the new main and no leaks detected, the old lead and copper connection can be isolated and left in the ground as a bit of ancient history.

I must say I am very impressed with the teams that have worked outside in miserable conditions, and temperatures barely above freezing. Sutton and East Surrey Water who did the work within the boundary of the properties and Clancy Docwra who undertook the excavations and connections to the main in the street. Whilst £900 is quite a large sum to find just before Christmas for replacing a main, when you look at the effort involved with up to 6 people on site for 3 days, it is clear that it is justified when you see the effort and comittment involved.