The Environmental Protection Agency, in the face of growing criticism that it is diluting efforts to control hazardous waste, has retreated from plans to soften or scuttle four Carter administration regulations.

"In the next 60 days you're going to find that this administration is not going to suspend any of those regulations and in fact they will all go into effect rather shortly," Gary N. Dietrich, director of the office of solid waste, said in an interview this week.

These new reversals come on the heels of another turnaround at EPA--its decision March 17 to hastily reimpose a ban on liquids in landfills that was suspended, supposedly for 90 days, on Feb. 25.

All five original actions generated protests from environmental groups as well as some congressmen and state officials. They charged the agency with undoing minimal progress made during the Carter administration.

Dietrich, who was deputy director of EPA's office of solid waste during the Carter years, denied that the agency is retreating on hazardous waste and called such charges "misleading rhetoric."

"The new administration came in with an agenda which they, I presume, supposed was part of a mandate from the electorate, and they did raise some honestly genuine issues," Dietrich said. So EPA decided to open the subjects to public debate and proceed with new standards only when evidence showed they were merited.

The agency received many negative comments on its proposals to suspend or revise the hazardous-waste regulations, and those comments influenced the decision to retain the regulations, according to Dietrich.

"At this point in time I see this administration keeping in place what it inherited," he said.

The Carter-era hazardous-waste regulations that will now take or remain in effect will:

Require that facility operators carry liability insurance to cover claims for personal and property damage resulting from the accidental release of hazardous materials. This was to have gone into effect in July, 1981, but the effective date was deferred until October and then until April, 1982, while EPA reconsidered the requirement.

* Require that facilities have the financial resources to safely maintain a site after it has been closed.

* Require existing incinerators to meet EPA operating standards. Operators claimed retrofitting and energy costs would force half the incinerators to shut down. EPA said in October that it wanted to study the issue before deciding whether to keep the operating regulations, revise them or permanently suspend them.

* Maintain EPA standards for surface impoundments--the pits, ponds and lagoons used for temporary storage. Operators had complained that retrofitting would be costly and time consuming.

Dietrich also discussed the liquids-in-landfills issue. The EPA's reversal, he said, was the result of "bad press" and two petitions. "We felt obliged to respond to those petitions and we also felt a responsibility to address the considerable concern that was expressed by the public. After the public hearing, we determined there was genuine merit and support for a reversal of the suspension and for slightly relaxing the absolute nature of the prohibition," he said.

Dietrich said he was surprised by the public outrage, and placed much of the blame for EPA's awkward handling of the issue on the lengthy regulatory-review process and on bureaucratic delays.

On Nov. 6--13 days before the ban on liquids in landfills was to take effect--the agency decided to temporarily defer the ban while it revised the rule, which industry claimed was unreasonably inflexible. "We took about a week or so to write that up" and it then went through internal agency and Office of Management and Budget review, Dietrich said. By mid-December it was available for EPA Administrator Anne M. Gorsuch to sign, but "because of the press of other affairs" it did not get signed until February, he said.

"I suppose if we had managed to get it out back then in November , it would have looked different. It certainly would not have been suspending a prohibition that had already gone into place," he said. "And I suppose, when it finally was signed, I made a mistake and the attorneys made a mistake in not reassessing whether it made sense to suspend a prohibition that was already in place. It just didn't occur to us. We had so many other issues we were dealing with. We didn't recognize that lifting a suspension after that many days would receive that much attention."