Challenge

South East Water operates the Mike Keleher Water Treatment Works, formerly known as Bray Water Treatment Works. 2H Water Technologies was called in to discuss an improvement scheme on the existing water intake settlement system.

Two square settlement tanks received the incoming raw water. The tanks, with the original lamella system installed, were achieving a throughput of 33mld per day.

South East Water required a significant increase in throughput.

Solution

2H's TUBEdek lamella system was proposed as the best solution.

In total, South East Water installed 256 cubic metres of 900mm-depth TUBEdek FS41.50PP, which is DWI-approved for use in potable water applications. The installation was co-ordinated by primary contractor, Bam Nuttall.

The DWI Reg 31 approval confirms a product's suitability for use in potable water installations.

2H's TUBEdek FS41.50 system comprises interlocking polypropylene profiles, connected with a tongue and groove system to form tubular channels. They are assembled into modules for easy installation into the tank. Once assembled, the chevron pattern of the inclined tubes allows excellent laminar flow of the water up through the system, while collecting the solids that slide down the tube to the base of the tank for collection via a scraper system.

Due to the efficiency of this system, the higher flows were achieved while maintaining efficient separation of the solids.

Outcome

Following installation of the TUBEdek system the flows were increased to the required throughput of 45mld.

The refurbishment of the two tanks with TUBEdek achieved the improvement without the need to build an extra tank thus saving significant time and cost.

South East Water achieved its target of increasing the overall capacity of the water treatment works.

Testimonial

Brian Steventon, Project Manager at South East Water, said: “We chose TUBEdek because it was the best match for our requirements; price, performance – notably hazen velocity - and DWI accreditation,” he explained. “Replacing the existing horizontal lamella clarification system wouldn’t provide the required improvements in production capacity. We also rejected a stainless steel alternative which was effective but expensive.”

Brian concluded: “TUBEdek has met all our objectives, most notably in removing the bottleneck that restricted output in the previous horizontal lamella clarification system. Since the upgrade we’ve seen an improvement in process control and increased the throughput of the clarifiers from 25ML/d to 40ML/d.”