An internal study by the Environmental Protection Agency says the agency's 10 regional offices are now drastically short of the work force needed to enforce federal anti-pollution laws.

The agency lacks the resources to inspect certain public water systems known to contain unsafe levels of contamination and to enforce portions of the Clean Water Act and the Clean Air Act, the study says.

Regarding water pollution programs, the study says, "Actual resources available to the regions . . . are far less than necessary even to meet the major needs of the program."

The study, obtained by Sen. Patrick J. Leahy (D-Vt.), was compiled by officials from the EPA's 10 regions and its headquarters, and is likely to become a focal point of the debate over how to rebuild the troubled agency.

Thirteen political appointees, including former EPA administrator Anne M. Burford, resigned or were fired earlier this year amid charges that their enforcement efforts were influenced by ties to industry and by Republican politics.

Six congressional subcommittees and the Justice Department are still investigating charges of mismanagement, conflicts of interest and political favoritism within the agency.

Another focus of the controversy was the administration's policy of deep budget cuts throughout the agency, reducing spending power by more than 40 percent since 1971, according to congressional analysts. Many members of Congress and environmental groups have long argued that this left the agency without the resources needed to protect the environment, but the recent study is apparently the first from within the agency to say so.

The "workload analysis," as it is called, computes the work force needed to carry out the agency's mandate under each environmental law. This year, it says, the EPA's regional offices need 3,509 employes, compared with the present 1,059. The report obtained by Leahy does not deal with the rest of the agency, which has a total of 9,200 employes.

An EPA spokesman said the numbers are probably inflated because they are based on a "perfect world" with no budget constraints.

"It's almost an agency-wide wish list," said spokesman Rusty Brashear. "It's basically a management tool for setting priorities. It always ends up showing you're short-handed and you don't have enough resources to do your job."

Also yesterday, EPA officials told the Senate Environment and Public Works Committee that the $1.6 billion "Superfund" created by Congress for cleaning up the nation's most dangerous hazardous waste dumps contains too little money to clean up more than half the 419 worst sites in the country.

Superfund director William Hedeman also testified that, under Burford, "I have the personal view there was an implicit policy to slow down the Superfund cleanup. The progress of programs I have been identified with may have been impeded for that purpose."