Prompt action by units from the Llandeilo and Ammanford fire service averted an explosion when a 7,000 gallon oil tank caught fire in the Llandeilo depot yard of Carmarthenshire county council on Friday.
The tank at the Rhosmaen Street depot contained about 3,000 gallons of tar-oil mixture. It had been filled only a few minutes earlier from a transport tanker.
Some of the mixture overflowed and immediately burst into flames.
Thick clouds of black smoke rose hundreds of feet and could be seen from Ammanford and Carmarthen.
The blazing mixture at one stage threatened to engulf a 400 gallon diesel oil storage container which blew its cover off because of the intense heat.
Tyres and other equipment in the yard were damaged.