The U.S. Department of Energy launched an investigation yesterday of reports that multimillion-gallon gasoline storage tanks in the Washington area are so full that new shipments are being turned away.

The Washington Post reported yesterday that the bulk storage tanks of several major oil companies here contain more gasoline than normal and that, while motorists here wait in line for gasoline, some new shipments by pipeline are being turned down because tanks here already are full.

W.L. Nicoll, manager of community relations for Colonial Pipeline Co., the largest of two pipelines that bring petroleum products here from the Gulf Coast, confirmed yesterday that deliveries by pipeline to the Fairfax City bulk terminal increased by 10-to-14 percent during the first five months this year over deliveries during the same period last year.

Nicoll confirmed that deliveries to the terminal increased 17 percent this May over last May - a period when representatives of service station operators in the Washington area said they were having their supplies cut by the oil companies 22-to-25 percent.

The increased deliveries to the Fairfax City terminal are significant for the entire Washington area because it is one of just two such terminals or bulk storage "tank farms" here that hold petroleum products until fleets of trucks deliver them to service stations.

The other terminal is in Newington, also in Fairfax County. Exxon, Shell, Crown, Gulf, Texaco, Cities Service and Amoco all have huge storage tanks at these locations.

Washington area members of Congress said yesterday that they had little faith that the energy department auditors will get to the bottom of the question.

"The oil industry has apparently trained DOE to stay out of their business," said Rep. Herbert E. Harris (D-Va.), who has led congressional efforts to find out why the Washington metropolitan area appears to have less gasoline available than some other areas of the country.

Harris said he talked with DOE officials yesterday and was "distressed" by their "lack of urgency" in looking into the reasons for long gas lines in the Washington area.

While DOE officials have repeatedly asserted that this area is getting its fair share of the nation's limited gasoline supplies, Harris said that. "There isn't any doubt about it, that the Washington area is being shorted."

Harris and other Washington area members of Congress said they plan to meet early next week with Energy Secretary Jafes Schlesinger.

"I want to ask him where the supplies are for this area, what's being done and why we're being shorted," said Harris. "I want to know why [Schlesinger and DOE] have not seen that this gas moved from storage on tank farms into service stations."

DOE spokesman Dianne Novick said that the audit begun yesterday "will not be a one or two-day thing . . . They want to look at the tank farm volumes, the arrival schedules, the record of delivery rejection . . . who holds title to which amounts of the products."

Novick said it may be learned that some of the tanks are full with gasoline that cannot be distributed until next month under the complex U.S. allocation rules.The rules are designed in theory to insure that stations and customers all over the nation receive a fair share of scarce fuel during shortage times.

"If it's July Product, if it were distributed now we might have a severe problem next month," said Novick.

Rep. Gladys Spellman (D-Md.), said yesterday she thinks there is collusion among the oil companies to deny gasoline supplies to the Washington area in order "to soften up the Congress to do whatever the oil companies want to have done."

Rep. Joseph L. Fisher (D-Va.) took another view. He said that "it doesn't make sense" for the oil companies to conspire to bring pressure on the Washington area because this "would encourage Congress to plow ahead into some really tough control and rationing system."

Instead, Fisher said, he has a "hunch that there's something in the allocation system . . . that has led to the diverting of gas out of the pipeline here but that should have been corrected quickly [and wasn't]. I'm still puzzled."

Harris said that if the DOE audit fails to satisfy him he may call on the General Accounting Office, the investigative arm of Congress, to investigate DOE itself "to make them more responsive to consumer needs instead of industry demands."

An Exxon spokesman said yesterday that even if the Washington area bulk storage tanks were brimming with gasoline, it would not be possible under the federal allocation rules to give any of this to the Washington area.

"Regardless of how much more product [gasoline] that terminal has you cannot under law deliver one single gallon more to these [Washington area] dealers," said Exxon spokesman Pat O'Connor." . . . The only way to give more to D.C. is a special DOE allocation or to change the rules."

While Washington area bulk storage tanks appear to contain more gasoline than normal, gasoline stocks nationwide now are at a "minimum level," according to Ed Murphy, chief statistician of the American Petroleum Institute, and industry organization. At the same time, Murphy said, the oil companies' stock of crude oil are growing as imports of crude grows.

Schlesinger last Thursday charged that the oil companies are "unduly" building crude stocks without running the crude through their refineries faster to make more gasoline CAPTION: Picture, Cab drivers, seeking higher fares, in a protest motorcade at L'Enfant Plaza. By James M. Thresher - The Washington Post