Carrigrennan wastewater treatment plant

Carrigrennan wastewater treatment plant

Carrigrennan wastewater treatment plant

P.J Hegarty worked alongside our partner VINCI Construction on the design, build and operation of the Cork wastewater treatment and mud-recycling plant at Carrigrennan, on the Little Island peninsula at the mouth of the Lee River. The plant was the final component in the city’s water-sanitation network and was an important capacity upgrade required to meet the needs of a population of 250,000.

Client : Cork City Council
Service : Civils
Architect : N/A
Structural Engineer : N/A
Value : €40 million

The project comprised construction of 16 hydraulic storage tanks, 10 reinforced-concrete transfer chambers and seven facility buildings, with more than 23,00om3 of concrete and 3,800 tonnes of steel used and approximately 1,500 metres laid of ductile Iron pipe work of various diameters. Primary treatment is carried out in two reinforced-concrete basins that are 35 metres in diameter. Four reinforced-concrete basins, also 35 metres in diameter, can store excess water in the event of storms. Secondary treatment consists of eight circular reinforced-concrete basins measuring 45 x 35 metres, while an 800-metre-long polyethylene pipe discharges treated water into the bay.

Construction of the plant, which is located in a residential zone and a natural wildlife and aquatic vegetation reserve, required us to work with various environmental organisations and local associations to monitor floral and wetland ecosystems, dust emissions, and to mitigate noise pollution caused by worksite machinery.