Washington — If he wants to continue aiding El Salvador, President Reagan is required by law to submit reports to the United States Congress every 180 days certifying that the Salvadorean government:
* Is making a concerted effort to comply with internationally recognized standards of human rights.
* Is achieving substantial control over all elements of its own armed forces, so as to bring to an end the indiscriminate torture and murder of Salvadorean citizens.
* Is committed to holding free elections at an early date, and to that end has demonstrated its good-faith efforts to begin discussions with all major factions in El Salvador that have declared their willingness to find and implement an equitable solution to the conflict.
* Is making continued progress in implementing essential economic and political reforms, including the land reform program.
There is also an understanding with Congress that the administration will certify that progress is being made toward investigating the murders and bringing to trial the killers of four American churchwomen and two American land-reform advisers who were assassinated in incidents in December 1980 and January 1981, respectively.
The next date by which certification must take place is Jan. 24.