Teesside the four independent unitary authority boroughs of Hartlepool, Stockton, Middlesbrough and Redcar and Cleveland (a renamed Langbaurgh). At this time they were returned to the counties of North Yorkshire and County Durham for ceremonial purposes, with Stockton-on-Tees becoming the only district in England split between two ceremonial counties. In 1998 the neighbouring Borough of Darlington also became an independent unitary authority and this along with the four former Cleveland boroughs form the sub-region of the Tees Valley which is used for statistical purposes and governmental organisation. The name Tees Valley is increasingly promoted for economic and cultural connections, though Teesside,
Teesside Refinery a year. Today the Teesside Refinery is a crude oil reception, storage and trans-shipment installation. Operations consist of both processing and tanker loading facilities and cover a site. Stabilised oil is stored in a tank farm at Greatham. A corridor containing pipelines, communications and utility services links the two sites, operated jointly by 270 employees. In its 35 years of operations, the terminal has processed over five billion barrels of oil, seen 15,000 ships visit their jetties and had a first-class safety record. The plant has also been run with a downtime of less than 24 hours in 30 years.