The state-of-the-art waste water treatment plant on the Bellanaboy Bridge gas terminal has been handed over by the Construction team to the Operations team that will run the plant when gas comes on stream.
As the Corrib facility is located in an environmentally sensitive area, it is necessary to treat any waste water for eventual discharge to both onshore and the immediate environment offshore, to a set of very strict parameters, as set by the Environment Protection Agency. To meet these extremely stringent levels, a bespoke suite of equipment was put together.
There are two separate waste water streams treated in the plant. The Surface Water Plant treats run-off from the paved areas and has a capacity of up to 30m3 per hour, while the Produced Water Plant treats water which comes from processing the gas and has a capacity of up to 6m3 per hour.
To ensure that EPA levels are complied with, a number of innovative and top-of-the-range solutions have been introduced, both for the surface water run-off from the paved areas and for the treatment of the condensate from the process gas. These include tilted plate separators, multi-media filters, ultra-filtration membrane packages for oil removal, and nano-filtration membranes together with carbon filters and ion exchange resin for the removal of metals from the condensed and formation water.
Combined Sludge Treatment
The rejected process waste together with any cleaning and regeneration waste products are treated via a precipitation and fl occulation process before being passed through a fi lter press unit, with the filter cake being removed for disposal and the fi ltrate returned to the start of the process. According to Michael Flannery, Project Delivery Engineer, the combination of technologies used in the Produced Water Treatment Plant is “very advanced and purposely designed for the Corrib project”.