Category: Sewer Connections

The public sewer that we needed to connect to, was at the bottom of a very narrow, single-track lane, and there was no way to carry out the works, without closing the road. As usual, we took care of all the permits for our customer, including the application to connect to the public sewer (the Section 106 application), the application to work in the highway (Section 50) and also a TTRO application – which is the application for a full road closure.

Highways agreed to our need to close the road, and a diversion route was agreed. In the days leading up to the start of the road closure, a local pub owner was particularly worried about any loss of trade, as his pub was at one end of the closure. We agreed with Highways and with our third-party traffic management company, that extra signage would be put out at either end of the diversion, advising people that the pub was still open for business.

Despite a large section of the road being closed for the duration of the works, we still had to give vehicular access to a handful of residents whilst the works were being carried out. To enable this to happen, we carried out the work in ‘sections’, and residents were able to access their properties from one direction and then from another direction, after trenches were backfilled and reinstated.

The sewers in the road that we had to connect to, were not particularly deep, the foul sewer being 3m deep and in the centre of the road, and the surface water being 2m deep, and on the far side of the road. The original Section 106 Approval that our customer had already arranged, had detailed new manholes to be built on both the surface water and foul sewers in the road. This would have meant a road closure lasting in excess of 2 weeks. Highways were unlikely to allow a road closure and diversion on a A-road, and for this length of time. We therefore approached Thames Water and requested the method of connection be changed to Junction Insertions, with the pipework being laid to two demarcation chambers built just inside the private shared driveway of the properties.

Thames Water agreed, and this would have shortened the work in the Highway to around 8 or 9 days, and might have allowed the works to be done under 2-way traffic lights instead. We had a meeting with Highways, but based on the width of the road, the location of both of the sewers to be connected onto, and also the depth of the excavations, it was still looking like it needed to be a road closure. But Highways weren’t keen on a road closure for this length of time, at such a busy location in London. Transport For London were also reluctant.

Highways suggested a shaft on one side of the road, and for it to be tunnelled to the other side of the road. However, existing services on the side of the road nearest the site, made a shaft in the road near-on impossible. Our only option left was to sink a shaft for tunnelling, in private property. But this meant denying the residents vehicular access for the duration of the works, which would take well in excess of one month. Our customer spoke to the neighbour, and a boundary fence was taken down between the new shared driveway and next door, enabling the residents of the new properties access via the neighbour’s driveway.

Our customer already had a treatment plant in his garden, which was serving his relatively new property. However the effluent was struggling to soak away in whatever drainage system had been installed for the treatment plant. Also, under new regulations that came into effect in 2020, you are no longer permitted to install a replacement treatment plant in the event that a public sewer exists in close proximity, and there was indeed a foul sewer in the carriageway outside the property.

If you need a sewer connection doing, please contact us as early as possible, there are many reasons why the lead-time for a sewer connection can be up to a year or more. For more information click here.

Our customer already had a connection into a neighbouring property, but required two connections to be made into the public sewers in the Highway instead. This included both the foul and surface water sewers. The surface water sewer was in the centre of the road, at a couple of metres deep. The foul was closer to the pavement, but was in excess of 3m deep.

We facilitated to Section 106 to Thames Water, which included us putting together a basic drainage drawing, which detailed where the pipework was within the property, and also how we planned to connect to the two sewers and by which method. For the surface water we were able to fit a saddle connection and for the foul we had to fit a junction insertion.

If you need a sewer connection doing, please contact us as early as possible, there are many reasons why the lead-time for a sewer connection can be up to a year or more. For more information click here.

Our customer already had a connection into a neighbouring property, but required two connections to be made into the public sewers in the Highway instead. This included both the foul and surface water sewers. The surface water sewer was in the centre of the road, at a couple of metres deep. The foul was closer to the pavement, but was in excess of 3m deep.

We facilitated to Section 106 to Thames Water, which included us putting together a basic drainage drawing, which detailed where the pipework was within the property, and also how we planned to connect to the two sewers and by which method. For the surface water we were able to fit a saddle connection and for the foul we had to fit a junction insertion.

If you need a sewer connection doing, please contact us as early as possible, there are many reasons why the lead-time for a sewer connection can be up to a year or more. For more information click here.

On this occasion our customer already had the Section 106 approval from Thames Water which was really handy, and enabled us to go straight to Highways and apply for the Section 50 application, which we always take care of on behalf of our customer. (You cannot apply for a Section 50 before you have the Section 106)

This required us filling out the Section 50 Application Forms, supplying our accreditations, insurance documents, a traffic management plan, utilities drawings for all other services (Highways have a duty of care to ensure we know where all other utilities are before we start excavating) and various other documents. For the traffic management, we opted for 2-way traffic lights, as this was quite a busy main road.

Our S50 application was rejected initially, as the road was a HS2 diversion route at the time, and traffic lights and road closures are prohibited on HS2 diversion routes. This created a huge problem for our customer as the house was pretty much finished, and waiting for HS2 to complete in the area would have meant a delay of over a year, before he could finish the project and sell the property.

If you need a sewer connection doing, please contact us as early as possible, there are many reasons why the lead-time for a sewer connection can be up to a year or more. For more information click here.

We appealed to Highways and they eventually agreed on ‘give & take’ traffic management for this job, if we were able to keep our excavation far enough over, that we could leave 7m of road remaining outside of the works, for two lanes of traffic to be maintained. We took measurements on site, and this was indeed possible.

Despite these works being quite challenging in many different ways, traffic management was quite simple on this one. The two connections to the sewer were made at the back of the site, onto a quieter road, and we were therefore able to use ‘give & take’ traffic management.

However, the road was riddled with services including multiple high voltage electric ducts, large water mains, two gas mains (one of them Medium Pressure) and also two very large decommissioned steel mains, likely to have been gas & water. We also had to contend with lower voltage electric cables & BT ducts.

The surface water connection was done first, this required us to excavate in the pavement and a metre into the carriageway, where connection was made into an existing surface water manhole. The depth of this connection was 2 metres. The excavation was sheeted and a third party core-driller was brought in to core-drill the manhole. The pipework was installed, the excavation backfilled, and the manhole was ‘made good’ inside. 

The foul connection required excavation in the footpath also, and then 4 linear metres into the carriageway in the direction of the existing foul manhole. This manhole was 4.3m deep, and United Utilities (owner of the apparatus) required a soffit-to-soffit connection, as is usual for foul connections in particular. The excavation in the carriageway was extensive and required a large pit excavating 4m wide and across half of the carriageway. Within this excavation was an existing Medium Pressure Gas Main, amongst many other services. The presence of the MP Gas Main required us to consult with the owner of the apparatus, Cadent. We put proposals to Cadent which excluded use of the excavator within 1 metre of the Gas Main. Adjacent to the MP main, we had to hand dig, and then the bulk of the excavating was done with a Vacuum Excavator (Vac-Ex), which is basically a big vacuum the size of a very large lorry, see pictures below.

As the MP Gas Main would be passing through our excavation, and the supporting ground dug out from underneath it, the gas main would need to be supported from above. We put proposals to Cadent which included a 5m long steel beam, 150mm x 100mm, placed directly above the gas main. From the steel beam, we strapped the gas main at 500mm centres. Cadent approved all of our proposals and visited site to inspect our method of working, which was all satisfactory to them. 

The excavation at its deepest was 4.3m, which had to be excavated with the Vac-Ex in stages, with us inserting trench sheets, heavy timbers, and acrows as the excavation got deeper. Ordinarily a ‘trench box’ would be lowered into the ground, but with all the services we had to contend with, the excavation had to be sheeted out around and underneath the services. The deepest part of the excavation was directly under the gas main. 

With all of the trench sheeting complete, a third party core-driller was brought in and the manhole core-drilled. The pipework was installed for the foul from the site to the manhole. The manhole was very small inside, for its depth, such as they used to be, this is likely a Victorian-era manhole. As with any manhole entry though, an operative has to be lowered down on a winch, with gas tests done prior and during entry into the manhole. Should anything happen to the operative whilst down the manhole, he would be winched out as opposed to somebody going down there to rescue him. All of our operatives have confined-space training for this reason, which has to be updated and renewed regularly. We cannot undertake new sewer connections without these accreditations, and of course it’s what is needed to keep everybody safe. 

The deep excavation was filled with primary aggregate, with all excavated material having been removed from site. The excavations for both the surface water and foul sewer connection were reinstated at the same time, and the site cleared of all signage and plant & machinery etc.

This was a challenging sewer connection due to the depth of the foul in particular, and also as a result of the Medium Pressure Gas Main, exactly where we didn’t want it. But as always there is a safe method of carrying out these types of works, no matter what the depth and the difficulties involved.

It was a pleasure to have carried out this work for Fox Construction and JW Clark continue to work with Fox Construction on sites across the UK.