Improvement of the Maer Lane STW Inlet Works

HUBER Technology recently completed and commissioned a large project for South West Water to improve the inlet works facility to treat the sewage from the town of Exmouth in Devon.

Project Profile

HUBER Technology were approached by Tecker towards the end of 2015 to look at improving the existing inlet works on site. The site features a balance tank which was prone to a large build up of rag and screening which were overloading the existing inlet works. Cleaning of this rag build up proved difficult and dangerous so the project was split into two sections, supply of a coarse screen to protect the balance and storm tanks and supply of new fine inlet screens and screenings handling equipment.

HUBER Technology Supplied:

• 1 x HUBER Multi-Rake Bar Screen RakeMax® 4160/990/40, throughput 1027 l/s peak flow per screen
   
• 2 x HUBER Belt Screen EscaMax®  5000/1352/6, throughput 363 l/sec peak flow per screen
   
• 2 x HUBER Screenings Wash Press WAP® WAP/L BG4-V, throughput 4.5m³/hr

Objective

The challenge on site was to maintain adequate screening on site whilst the new screens were installed.

Previously the flow into the balance tank was via four pumped rising mains, flow to the inlet screens was controlled by penstocks in the balance tank. We worked with the contractors – Tecker to develop a solution to minimise downtime. This solution was to install the coarse screen into a off-site fabricated site channel which could be mounted on top of the existing balance tank structure.

This was installed on site and the rising main connections made, the coarse screen was then installed into it with the screening discharging directly to a skip.

Following agreement on the installation sequences with Tecker we ensured the hydraulic constraints of the structure were taken into account to ensure the screen performed correctly and adequate bypass weirs were provided.

The fine screens and handling plant were installed in a phased manner to allow the screening at the inlet works to be maintained.

Richard Willis, Area Manager for HUBER Technology said “This difficult project was delivered in conjunction with Tecker and already significant improvements can be seen on site, particularly the coarse screen which is protecting the balance tank and fine screens from the large volume of screenings received into the works”.