Installation of Sewage Treatment Pump Station
All sewage in the Road Town area is directed to a central collection point in the middle of Road Town. Using three large pumps, this sewage is pumped through an 18”, high-density polyurethane pipe for a distance of one mile to the new tertiary treatment plant at Burt Point.
Meridian was contracted by Biwater International to construct the pump station and install the pumps. This work was technically difficult as the pump station, located at a depth of 25’, is situated on reclaimed land and below the water table. Additionally the subsurface is running, waterlogged sand. This meant that no ordinary excavation could be conducted and required Meridian to devise a method to construct and install these 15-ft diameter, reinforced concrete tanks.
The new pump station is made up of ten concrete segments, 15’ in diameter and 3’ in depth and each weighing 10-tons specially manufactured by Meridian at their Pockwood Pond precasting yard. These sections were delivered at night due to their size and weight. Through use of their 60-ton crawler crane, the tank segments were aligned on top of each other and coupled using a pre-formed, tongue-and-groove connection and securely sealed with a non-soluble bonding agent.
Once all segments were aligned, the tank, weighing 100-tons, was sunk to a depth of 25’. The installation of the tank walls took a total 3 days to sink to the correct level guided by steel sheetpiles. A 4’ concrete plug with a drain and valve was then set into the base and topped with reinforced concrete once the chamber had been emptied of water and sludge.
With the completed installation of the sewage treatment tank and the 18” sewage pipes, Meridian was responsible for successfully disconnecting the pipes from the old sewage pump and making home connections to the sewage treatment tank.
Meridian was also engaged to undertake the piling at Burt Point for the tertiary treatment plant and to install the new, 25,000-gallon sewage treatment tank which replaced the old 5,000-gallon tank.
From February 2016, for the first time in 35 years, there was no more raw sewage being pumped out to sea in the Slaney area, which had also affected the Sea Cows Bay and Nanny Cay bays. There has also been an immediate impact in Road Town Inner Harbour where the water is now clearer with a noticeable increase in marine life.
“Tertiary Treatment of sewage water includes processes like filtration, lagooning, nutrient removal, and disinfection and is the last step of the entire sewage water treatment process, after this the waste water becomes comparatively safer and can be discharged into the environment.” – Thewatertreatmentplants.com