Maryland and three other northeastern states asked Congress yesterday to approve a regional compact aimed at averting a crisis in the disposal of low-level radioactive waste.

The bill, introduced by Rep. Sam Gejdenson (D-Conn.), would ratify the compact that has been approved by the legislatures of Maryland, Connecticut, New Jersey and Delaware.

Congress has given states responsibility for disposal of low-level nuclear waste, such as medical supplies and other materials contaminated with radioactivity. The federal government has the responsibility for disposal of high-level waste, such as spent nuclear fuels.

Currently, the only low-level radioactive disposal sites are in South Carolina, Washington state and Nevada, and officials of those states have complained that the three sites have become national dumping grounds.

The governors of South Carolina and Washington, where 99 percent of the low-level waste is sent, have threatened to quit taking out-of-state wastes at the end of this year if no new sites are found.

Gejdenson said low-level waste would begin to pile up if the two sites were cut off, creating a serious health hazard. Some hospitals and other facilities have only several weeks worth of storage capacity, he said.

Some environmentalists and congressmen question whether the governors can legally cut off access to the sites, and believe the threat is a bluff. But other congressmen have expressed concern, noting that in 1979 when officials at the sites sought to draw attention to the situation, Washington and Nevada closed their sites for several weeks and South Carolina only accepted half as much waste.

Six other regional compacts already have been introduced in Congress, including a Southeast interstate compact, which includes Virginia. The House Interior Committee has approved those compacts, as well as a bill that would set a timetable for establishing regional disposal sites.

The House Energy and Commerce Committee must also approve the bills before they go to the floor. The energy committee expects to consider the bills in early October.

The package of bills would guarantee that the three existing facilities would remain open to all states until Dec. 31, 1992, as long as the states are taking concrete steps toward the creation of regional or state disposal facilities. States that fall behind the timetable would be hit with stiff surcharges and could be banned from using the sites. After 1992, access to the existing three sites would be cut off.

Under the Northeast compact, a commission composed of one member from each state would decide which state would house the Northeast regional facility. The host state would be allowed to select the disposal site. A District spokesman said the District had applied to join the compact, but has yet not been accepted.

The largest generator of low-level nuclear waste in the Northeast compact is New Jersey, which generated 3,633 cubic meters in 1983, according to the Department of Energy. In comparison, Connecticut generated 1,890 cubic meters, Maryland 1,342 cubic meters and Delaware 30 cubic meters.

Virginia generated 4,718 cubic meters in 1983, and the District of Columbia 98 cubic meters.