I don't know what state you live in, but I would suggest taking a look at the statues for termination of parental rights - you can get a snapshot summary from
http://www.ncsl.org/statefed/cf/asfasearch.htm. In most states termination of parental rights can be sought if the child has been in care for 15 of the most recent 22 months - but there are exceptions to this. You can get more details from searching the Adoption and Safe Families Act or you can search The Administration for Children and Families (
www.acf.hhs.gov).
Hope this helps - Research - you can never do enough!