The California state government yesterday announced details of a far-reaching new program to ban the land disposal of a variety of highly toxic chemical wastes identified as serious hazards to human health.

The program, which would require that toxic wastes be treated at new handling facilities, would be the most stringent in the nation when its first portions take effect, as expected, early next year.

Gov. Edmund G. (Jerry) Brown Jr., who unveiled the program at a San Francisco press conference, said the program, an outgrowth of his executive order last year banning toxic waste land dumps, "will help prevent intolerable human suffering . . . and help end enormous cleanup costs that neither industry nor the taxpayer can afford."

Although the proposed regulations apply only to California, Brown's action yesterday carried a decidedly national slant.

Public concern over toxic waste disposal has been heightened by the Love Canal, N.Y., tragedy, involving sickness and land contamination, and disclosures that hundreds of unregulated toxic dumps may threaten public health across the country.

Brown, the Democratic candidate for the U.S. Senate from California, is a frequent critic of Reagan administration environmental enforcement and a gubernatorial aide conceded yesterday that the state action is intended to spur the federal Environmental Protection Agency to take a more militant enforcement stand.

Brown was joined at his press conference by Sen. Gary Hart (D-Colo.), who has proposed amendments to the federal Resource Conservation and Recovery Act (RCRA), now awaiting congressional reauthorization, that parallel California's program.

The Hart proposals are pending before the Senate Environment and Public Works Committee. The House is expected to debate its own version of a RCRA extension, with amendments similar to Hart's offered by Reps. James J. Florio (D-N.J.), John J. LaFalce (D-N.Y.) and Norman F. Lent (R-N.Y.).

Brown said yesterday that he was "fully supportive" of the Hart proposals.

California officials estimate that their new regulations, although subject to final public comment and review before they take effect next March, would affect at least half a million tons of highly toxic chemical wastes now dumped in landfills.

Wastes that would be banned from landfill-dumping include cyanides, toxic metals, strong acids, PCBs, halogenated organic compounds such as the pesticides DDT, DBCP and Kepone, and all other wastes currently classified by the state as "extremely hazardous."

The proposed regulations carry a maximum fine of $25,000 per day for each violation of the land-dumping ban.

Compliance and enforcement, according to Kent Stoddard of the governor's Office of Appropriate Technology, will be keyed to a two-year timetable for construction of treatment facilities, beginning next March 31.

The facilities will be built by private enterprise, with low-interest state pollution-control loans available. The Brown program also calls for expedited state processing of applications for construction permits.

"We have identified the treatment and recycling technologies that could be used," Stoddard said, "and we know there are clear alternatives to land disposal of these wastes. We have worked closely with the chemical, petroleum and electronics industries in laying out these treatment timetables."

California's plan to phase out landfills as dumps for highly toxic wastes began last October when Brown issued an executive order banning such activity and increasing state monitoring and enforcement at all hazardous waste disposal sites.

State officials estimate that California, with perhaps the nation's fourth largest volume of toxic wastes, has at least 70 major dumping sites that need cleaning up, including some in the state's most populous counties.