Apparently the 'red diesel' has "spread upstream along the SE1 riverside and beyond, with patches spotted as far away as Wandsworth."
According to the Port of London Authority one of the pontoon's tanks did not leak while "a lot of oil from the other was safely pumped away". And of the 50 tonnes of fuel on the barge, less than 10 leaked out.
Incidentally, the PLA is holding a public meeting tonight "to discuss current and future aspects of the tidal Thames" (that includes 'safety on the river').
As you can imagine, Wandsworth council are not best pleased at this idea.