During the 1990s and 2000s there was an extensive upgrade of wastewater management, all over Greece, having a clear environment-friendly orientation. This included both the modernization and extension of sewage waste networks and the construction of Wastewater Treatment Plants (WWTP) along with sewage disposal pipelines that ended up to specified “recipients” (sea, rivers etc.).

Sewage waste disposal pipelines consist of onshore and offshore sections. The successful construction and operation of the latter faces several wave sea conditions, other operational risks associated with the activities of fishing and navigation and the risk of "blocked” nozzle due to possible sediment deposition.

CNWAY has considerable experience in submarine pipelines protection studies which consists of off-shore pipe laying, armoring and overall design of the layout based on the hydrodynamic and coastal engineering conditions of the area.