Experiences of the Federal Republic of Germany With Dumping of Sewage Sludge

Abstract

From 1961 to 1980 annually 350 000 m ³ of sewage sludge of the City of Hamburg were dumped into an area located in the outer stretches of the Weser and Elbe estuary in the inner German Bight of the Southern North Sea.

Long term investigations on macrobenthos revealed a steady downward trend of the species diversity mass development of single species at certain periods of the year and a recurrent collaps of the macrofauna during summer. Low dissolved oxygen in the water column and the sediments were considered to be prime causes.

Impairment of trawling was one further nuisance. Increased prevalences of diseases of cod and dab in the vicinity of the area were further biological effects ascribed to the pollution in the estuary. The dumping was shifted to a location further offshore in the German Bight from there into an area in the Atlantic and it was finally terminated at April 15, 1983. Investigations were continued in the area, slight changes of sediments were demonstrated, an indication for recovering benthic communities was present but a collaps of macrofaunal elements in the summer of years 1983 and 1984 occurred, which were interpreted as indication for the general degraded water quality within the estuary.

After cessation of dumping the wastes were stored in land fills and it is presently attempted to develop alternative uses for the sewage sludge material, which is mainly objected because of its high contamination with organochlorines and heavy metals.