HDD to clean up North Sea holms

摘要

The holms, or tidal mudflats, off the North Sea coast of Germany, act as breakwaters for the mainland. They calm the sea, stabilise sand banks, and are an important habitat for wildlife. Among the 10 holms in the North Sea is Oland, with 37 inhabitants, and Grade, with just 18 inhabitants. Classed as nature preserves, any building work on the holms is strictly controlled: "The construction of a foul water pipeline and sewage plant on both holms is no exception, despite being designed to assist nature preservation," commented Martin Woltering from the engineering firm IVERS GmbH.