Three of the four oil companies at the Pickett Road tank farm in Fairfax City have agreed to construct an automatic, foam fire-fighting system on their loading docks to reduce danger in the event of a major fire, Fairfax City officials announced last week.

Officials said the action by Amoco, Gulf and Cities Services Oil companies is the result of a 1975 study recommending improvements at the tank farm.

A fire at the Amoco loading dock last June claimed the life of one driver and caused $1 million in damages.

The foam fire-fighting system will permit foam to be injected into a flaming fuel tank which will reduce the danger to fire fighters and equipment. Each company will pay more than $300,000 for the new system.

Texaco is the only company that has not agreed to install an automatic foam fire-fighting system. Officials said Texaco is waiting an engineering analysis of the recommended improvements before making any commitments to the city.

City officials have been negotiating with the four companies for several months on the recommemded improvements, which include construction of access roads to all tanks on the 29 tank faciltiy.

Officials have requested that the four companies share in the purchase of a minicipal fire-fighting system with foam dispensing capabilities. Cities Services and Amoco have agreed to share the expenses of the new equipment, which would be operated and maintained by fairfax City.