Celebrations were the order of the day as Glanville Environmental scooped yet another prestigious award from South West Water.
This followed an announcement that an innovative solution they deployed to overcome a site access problem had been awarded a prestigious ‘Pure Award.’
The Menagwins sewerage catchment was experiencing chronic issues with winter ground water infiltration, causing prolonged spills from a Combined Sewer Overflow.
A number of areas in the catchment were identified as requiring rehabilitation, all of which were successfully addressed.
One particular area, however, was not without its challenges.
The Sawles Road sewer near St Austell was experiencing severe infiltration problems.
But because of the location and the confined spaces involved, access to the manhole where the liner was to be inserted, (in the conventional manner), was not possible.
This scheme required an innovative solution, one that challenged convention and defied gravity!
The project team looked at the options and the decision was made to run the liner in the opposite direction going upstream!
Although this method has been used within the industry, this was a company first for Glanville’s.
Over pumping controlled the waste water flow, but the challenge was controlling the infiltration entering the sewer pipe being lined.
This barrier was overcome by erecting a scaffold tower and draping the liner from the top.
The liner was then placed into the mouth of the manhole and water pumped into the trunk to create a ‘head of pressure.’
This exercise also involved working out how high the scaffold needed to be to ensure the pressure was sufficient to push the infiltration flow back, as the liner slowly progressed upstream.
In effect, creating a moving dam.
It was critical to maintain the correct head of pressure throughout the lining process until it was completed.
Once the ‘tail end’ of the liner reached the upstream manhole the curing process then started.
The liner was then successfully cured.
Adam Kelly, Site Agent, at Glanville Environmental, said, “The company is delighted to receive this award. It is a testament to the skills and professionalism of the team involved and another great example of how our company embraces innovation to find solutions that provide positive outcomes for our clients and their customers.”
The team’s expertise and efforts paid off, the project was a complete success.
The team’s actions significantly reduced the infiltration flow into the mains by approximately 25%. This course of action mitigated the chances of any future spills and possible pollution issues.”
Pictured: Left, James Blake – Civils Delivery Manager, Right, Adam Kelly – Site Agent.