The Environmental Protection Agency has suspended annual reporting requirements for producers and disposers of hazardous waste and has proposed replacing the annual reports with a survey of only about 10 percent of the firms.

The agency will continue to operate the manifest system, by which it tracks hazardous wastes from "cradle to grave." But because the manifest system only monitors waste disposed at a location other than where it was produced, it only covers about 20 percent of the hazardous waste generated. Annual reports apply to all wastes generated and include additional information about hazardous waste operations.

The agency's proposal is part of "a continuing effort to reduce the information collection burdens that [the hazardous waste law] imposes upon the regulated community," according to an EPA memorandum on the annual reporting change. EPA estimated that the 308,000 hours it says it takes companies to fill out the forms each year would be cut by 90 percent under its proposal.

Environmentalists said the action indicated that EPA is backing off on its efforts to curb the dangerous disposal of hazardous waste. But Eileen Claussen, director of EPA's Solid Waste information and analysis office, said the survey would give the agency a more accurate picture of the hazardous waste situation across the country. The proposal is part of "continuing effort to reduce the information collection burdens" on producers and disposers of hazardous wastes.

The agency has been under fire in recent weeks for several actions it has taken or proposed in regard to hazardous waste. EPA and environmental sources said the agency will reverse one of the most controversial--its move on Feb. 26 to lift for 90 days the ban on disposing liquids in landfills--sometime this week. EPA is expected to ban any barrel containing more than a small amount of liquid from landfills.

The Resource Conservation and Recovery Act of 1976 directed EPA to establish an annual reporting system for the nation's 44,000 hazardous waste generators and 15,000 disposal facilities. In 1980, EPA issued regulations that required annual reports for the previous year to be submitted by each March 1.

When the Reagan administration took office, EPA officials immediately suspended the reporting requirements for one year, declaring the agency would not be prepared to evaluate the reports by March 1. A few weeks ago, EPA said it would delay the deadline for the 1981 reports until August while it goes through the rule-making process to substitute the survey system.

Claussen said the agency plans to propose revisions next month and hopes to have a final rule adopted by August.

Noting that the annual report system would have generated "about 65,000 pieces of paper," Claussen said, "there's a question about whether we could use anything we would have gotten." She said past experience has shown that "you don't get good data unless you do an awfully lot of follow-up," and EPA lacks the capability to check the accuracy of all the annual reports.

Under the survey system that EPA wants to adopt, a random sample of 10 percent of the firms that generate or dispose of wastes would be sent questionnaires. Follow-up calls would be made to try to verify information. EPA officials say that this, coupled with routine inspection visits, will improve the system.

However, environmentalists say the annual reports are important tools for private citizens wanting to find out about the activities of specific facilities. They also argue that the survey method will leave gaps in information.

Meanwhile, EPA plans to conduct an initial survey of generator and disposal facilities this spring as part of a regulatory impact analysis it is doing on several components of RCRA. The agency said it hopes to work out any kinks in its survey procedures when it performs that combined survey.