When Douglas M. Costle was Connecticut's environmental protection commissioner he found a new way to deal with the persistent problem of industry foot-dragging. Plants that delayed installing pollution control equipment were charged a fee equal to the amount they saved by delaying. Thus, the incentive to procrastinate was remove.

Now, the Connecticut plan, widely acclaimed in the environmental community, may be applied on a national basis. For Costle, a 37-year-old attorney, is Jimmy Carter's new administrator at the Environmental Protection Agency and he wants to make some changes.

High on the agenda, Costle said in an interview last week, is "a major regulatory reform effort" stressing economic incentives for industry to clean up pollution. Besides the Connecticut plan, he is looking at performance bonds, under which industry would put up cash to guarantee cleanup.

He plans to cut EPA's paperwork requirements, but "with a surgical knife rather than meat axe," and force industry, not just to install pollution equipment, but to maintain and operate it efficiently.

"Industry needs a clear signal," Costle said. "There should be no mistake. We intend to get the job done.In terms of enforcement, we will be tough. We will be aggressive. But people will not be able to say that we are unfair, arbitrary or haven't done our homework."

Costle sees no conflict between a tough stance on pollution and Carter's push to boost the economy and use more domestic energy supplies, especially coal.

To those who say the nation must choose between energy and environment, Costle replies, "The truth is, we can have both. People want to make sure that when you go to coal, you protect the public health. So you use the best available (pollution) control technology."

"You're going to see some forcing of technology," Costle predicted, with new methods of pollution control including "second and third generation scrubbers" on smokestacks.

"It's going to be tough on industry in the short term. A plant burning high-sulfur coal in Ohio might want to meet clean air requirements by going to low-sulfur coal instead of scrubbers. But that would be unfair to a lot of miners (who dig high-sulfur coal). I'm not sure utilities should have a choice."

Also, Costle said, "there may be parts of the country where, because of extreme effects on public health, you can't burn coal at all."

A critical test in the environment-energy debate will be Carter's position on the Clean Air Act, now a focus of controversy in Congress. Costle, who is charged with drafting the stance, brushed aside suggestions of a struggle with James Schlesinger's energy staff.

"There has been an intensive collegial dialogue," he said. "But you start with the notion that you need both (energy and environmental protection). That changes the nature of the dialogue. The areas of agreement are dominant.

"We are past the social debate over whether it is a good thing to protect the environment. The debate now is how to do it. We're at the difficult stage of practical problem-solving. You can't have growth without effective pollution control."

Costle, a Harvard-educated Californian, has come full circle in six years. Although an active Democrat, he helped create EPA in 1970 as a member of Nixon's advisory council on executive organization. From there he moved to Connecticut's Department of Environmental Protection where he served until 1975. After a year and a half at the Congressional Budget Office in charge of natural resources and commerce, he joined Carter's transition staff.

Observing EPA from the outside convinced Costle the agency has "a problem with credibility." He recalls that , when EPA was set up, "I told Bill Ruckelshaus (its first administrator) it had a very thin intellectual bank account to draw upon."

Little was known about the effect of population on human health when Congress passed strict air and water pollution laws. "Tight statutory deadlines forced the agency to act before it had the information," Costle said.

"The agency would learn by putting out regulations and seeing who shot at them and what they hd to say. It was, 'Cast they bread on the water and see how soggy it gets,'" he said.

EPA soon became one of the most controversial agencies in government. The pressure from industry, Congress, and the public at large is unceasing because, Costle said, "what we do affects people so directly - whether it's the cars they drive or the industries that employ them. I doubt whether any other regulatory agency has a greater impact on economic development issues than EPA."

In his glass-walled office overlooking the Potomac, Costle greeted a reporter with a chart of 52 congressional subcommittees at which EPA officials testified last year. In the next three weeks, Costle himself will testify before 14 of them.

This kind of scrutiny, Costle believes, requires a new emphasis at EPA on management. The agency's agenda has been largely determined by the laws on air, water, pesticides, toxic substances and solid waste.

Although the air and water laws are now undergoing controversial revisions in Congress, Costle said, "We have been through the legislative era; now we have to consolidate our authority. We need to find better ways of getting things done - for example, economic incentives within the regulatory process. We need to improve the scientific basis of our regulation."

In the months since he took charge, Costle has acquired a reputation for low-keyed charm and careful management. "He's very much a technician," said Marlin Fitzwater, EPA's information director. "He looks at details. On the Clean Air Act, for instance, he demanded to go back to raw data - IBM runs, car tests, volumes of emissions data - information that the staff had already analyzed."

Costle's late appointment has meant EPA is behind, not only in presenting Congress with legislative positions, but also in naming new officers. In place so far are deputy administor Barbara Blum, a former environmental activist who served on the Carter campaign and transition staffs, and William Drayton Jr., soon to be named assistant administrator for planning and management. Drayton, director of a public regulation and management center at Harvard, was a consultant to Costle in Connecticut and worked on Carter's transition.

In line to be assistant administrator for water and hazardous materials is Thomas C. Jorling, director of the Williams College Center for Environmental Studies. Jorling was the Senate Public Works Committee's minority counsel from 1969 to 1972 when the water act was passed.

Blum, whose first contact with EPA was to protest a sewer planttt in Atlanta, said she will encourage citizenn participation - for example on EPA's 16 advisory boards. She is also examining national policy standards for EPA's powerful regional administrators. "Enforcement has varied from region to region," she said, citing, for example, differences in implementing transportation controls. "There needs to be more firm directions."

Costle echoes Carter's contention that "Washington is out of touch. Ninety per cent of problems come on pieces of paper," he said. He plans to run town meetings out in nthe country "so I can learn what is on people's minds."

Costle and Blum said the hostile relationship between EPA and the Office of Management and Budget which thwarted the agency under Nixon and Ford has ended.. However, EPA could lose some of the outspoken independence it had before. "Costle feels very much part of the team," Fitzwater said. "The time for public argument is over."