Since 1966, a snow-melting system for roads in Sapporo, Japan, has been in operation using water from the Jozankei Spa. As of December, 1978, the system covers 1,328 m (10,400 m2 ), and provides snow-- and ice-free conditions. The initial construction of 240 m (1,440 m2 ) for the Mikaerizaka Hill was undertaken in December, 1966, and consisted of four 50- to 75-mm diameter pipes embedded 30-cm deep at 140-cm spacing. External corrosion, not caused by the internal geothermal fluid, required gradual replacement of the steel pipe with 25-mm diameter polybutene pipes after September, 1973. In February, 1976, the extension of the system by the Sapporo municipal authorities, changed the hot spring source from a , private one belonging to several hotels, to a municipal one