Migrant children who wait in makeshift camps along the U.S.-Mexico border for the Border Patrol to process them are in the agency’s custody and are subject to a long-standing court-supervised agreement that set standards for their treatment, a judge ruled.

The issue of when the children are officially in Border Patrol custody is particularly important because of the 1997 court settlement on how migrant children in U.S. government custody must be treated. Those standards include a time limit on how long the children can be held and services such as toilets, sinks and temperature controls.

Wednesday’s ruling means the Department of Homeland Security must quickly process the children and place them in facilities that are “safe and sanitary.”