Assessment of the embodied energy for manufacturing and laying a submarine outfall pipeline

The Life Cycle Assessment (LCA) methodology was applied to a submarine outfall pipeline intended for the disposal of treated MWW in the South Tyrrhenian Sea, on Western Coast of Sicily. The pipe serves 115 thousands inhabitants; it is 3,1 km long with an outer diameter of 800 mm and is allocated in a submarine trench down to 18 m bsl. The pipe ends with a multiport diffuser with outer diameter 500 mm. The whole pipeline is made in HDPE and is statically stabilized by cast iron rings and concrete anchor blocks. From the detailed constructive project of the pipeline the most relevant items involved were drawn and the most important ones were selected, both as materials employed and as laying works. Each item was then characterized by the amount of the so-called “embodied energy”.