Since June 2004, New Jersey's beleaguered child welfare agency has moved most of the children placed inappropriately in detention centers, found about 1,400 new families willing to be foster families and hired hundreds of caseworkers. But a court-appointed panel overseeing the Division of Youth and Family Services' reform efforts said Tuesday in a blistering letter to the agency that change is still coming too slowly. The New Jersey Child Welfare Panel threatened to find the state had made ``significantly inadequate progress,'' which would open the door for further court action on the way DYFS operates. The letter comes as a blow though not an entirely unexpected one to an agency that for years been at the center of controversy. Kathi Way, the state's deputy human services commissioner for children's services, said she expects DYFS will be able to address quickly the eight specific concerns raised in the letter. The main problem cited in the letter has long been a top concern for DYFS and its critics: That each social worker has too many cases to follow. According to the agency's reform plan, 95 percent of the caseworkers in Essex, Camden, Passaic and Mercer counties were supposed to have fewer than 15 cases by this time. But only half had met that goal, according to the letter. One reason caseloads are not dropping faster, said Way, is that the number of cases referred to the agency keeps rising. In addition, new caseworkers are trained for six months, then have smaller caseloads for the next six months, so even massive hiring sprees don't mean workers get more time with each family. The letter also said the agency has confusing guidelines for deciding when reports on children should prompt abuse and neglect investigations. That issue received renewed attention last week when Alana Duff, a 2-year-old Ocean County girl, drowned in her family's swimming pool nine days after DYFS received an anonymous tip that her mother was neglecting her.