sentences:  In 1959, the first sewerage was laid in Dunzweiler, and in 1961 the work was finished with the opening of a new sewage treatment plant.That same year, planning began for building a new schoolhouse, for the old one, which had been built in 1840, was simply too antiquated.The school was finally dedicated on 11 December 1964, and the old one was torn down three years later.