Big Chemical works in the area were Hugh Lee Patterson and Allhusen. There were others.

Points to ponder upon.
Recent British Geological Survey

It may be a coincidence but here are some facts I have come across which may have caused of the dock collapse at Hebburn where I am sure Allhusen and other chemical companies may have dumped their waste. Of particular interest is the conclusion of the report shown here in the last paragraph.

I have inclued notes taken from a British Geological Survey of Gateshead and district groundrisk fact finding, I am uncertain of the date of the report but feel it was just prior to the suspension of house building taking place near what was the Elephant on the Tyne Hotel. Work was suspended around 2010ish until waste material from the chemical industries had been removed from the site surface.

In the 19th century, soda ash was a crucial industrial chemical, primarily used for making glass, soap, and textiles. Before the mid-century, Soda ash was produced using the LeBlanc process with a waste product called Galligu. It is estimated that TWO TONS OF WASTE GALLIGU (Calsium Sulphate) were produced for every ONE TON OF SODA ASH.
The industry developed where the essential raw materials of rock salt, coal and limestone were in plentiful supply, including the riverside area between Saltmeadows and the Bill Quay area on Tyneside. Galligu was disposed of in mounds or spread over much of the land in the Saltmeadows, Felling Riverside and Bill Quay areas. The waste was also commonly used as fill for railway embankments in that area. ( the “mounds” referred to were of colossal proportions. Heights of fifty feet and covering areas the size of football pitches. They streched from just north of Sunderland Road down to the River. They were squared off with cliff faces and used by the MOD during WW2 as part of the defence wall which ran from the top of Fox Ftreet down to the river at Friars Goose)

If Galligu is left in the ground during site redevelopment, it can become unstable and cause ground subsidence that will affect any buildings or infrastructure overlying the material .As well as the pollution risks posed, Galligu's uncontrolled disposal in areas surrounding the factories has resulted in significant ground stability problems.